which includes the more than #bej original illustrations4 ,see #ejhdf-;h4htm or #ejhdf-;h4zip3 7https3_/_/www4gutenberg4org_/cache_/epu b_/#ejhdf_/pg#ejhdf-;images4html7 or 7https3_/_/www4gutenberg4org_/files_/#ej hdf_/ejhdf-;h4zip7 ,images of the original pages are available through ,internet ,archive4 ,see https3_/_/archive4org_/details_/mechanic sofhouse#jjkeen ,transcriber's note3 ,text enclosed by underscores is in italics 7italics74 ,text enclosed by equal signs is in bold face 7bold74 ,,mechanics ,,of ,,the ,,household 99 99 99 99 99 99 ,mc,graw-,hill ,book ,co41 ,inc4 ,,publishers ,,of ,,books ,,for ,coal ,age ,electric ,railway ,journal ,electrical ,world ,engineering ,news-,record ,american ,machinist ,the ,contractor ,engineering ,mining ,journal ,power ,metallurgical ,chemical ,engineering ,electrical ,merchandising 99 99 99 99 99 99 ,,mechanics ,,of ,,the ,,household ,a ,course of ,study ,devoted to ,domestic ,machinery and ,household ,mechanical ,appliances ,e4 ,s4 ,,keene ,dean of ,mechanic ,arts ,north ,dakota ,agricultural ,college ,,first ,,edition ,mcgraw-,hill ,book ,company1 ,inc4 #bci ,west #cith ,street4 ,new ,york ,london3 ,hill ,publishing ,co41 ,ltd4 #f #h ,bouverie ,st41 ,e4 ,c4 #aiah ,copyright1 #aiah1 by the ,mcgraw-,hill ,book ,company1 ,inc4 ,,introduction ,this book is intended to be a presentation of the physical principles and mechanism employed in the equipment that has been developed for domestic convenience4 ,its aim is to provide information relative to the general practice of domestic engineering4 ,the scope of the work is such as to present3 first1 the use of household mechanical appliances2 second1 the principles involved and the mechanism employed4 ,it is not exhaustive1 neither does it touch many of the secondary topics that might be discussed in connection with the various subjects4 ,it does1 however1 describe at least one representative piece of each type of household apparatus that is used in good practice4 ,the mechanism used in the equipment of a modern dwelling is worthy of greater attention1 as a course of study1 than it has been heretofore accorded4 ,the fact that any house1 rural or urban1 may be provided with all domestic conveniences included in3 furnace heating1 mechanical temperature regulation1 lighting facilities1 water supply1 sewage disposal and other appliances1 indicates the general use of domestic machinery in great variety4 ,to comprehend the application and adaptability of this mechanism requires a knowledge of its general plan of construction and principles of operation4 ,heating systems in great variety utilize steam1 hot water1 or hot air as the vehicle of transfer of heat from the furnace1 throughout the house4 ,each of these is made in the form of special heating plants that may be adapted1 in some special advantage to the various conditions of use4 ,a knowledge of their working principles and general mechanical arrangement furnishes a fund of information that is of every day application4 ,the systems available for household water distribution take advantage of natural laws1 which aided by suitable mechanical devices and conveniently arranged systems of pipes1 provide water-supply plants to satisfy any condition of service4 ,they may be of simple form1 to suit a cottage1 or elaborated to the requirements of large residences and made entirely automatic in action4 ,in each1 the apparatus consists of parts that perform definite functions4 ,the parts may be obtained from different makers and assembled as a working unit or the plant may be purchased complete as some special system of water supply4 ,an acquaintance with domestic water supply apparatus may be of service in every condition of life4 ,the type of illumination for a house or a group of buildings1 may be selected from a variety of lighting systems4 ,in rural homes1 choice may be made between oil gas1 gasolene1 acetylene and electricity1 each of which is used in a number of successful plants that differ only in the mechanism employed4 ,any building arranged with toilet1 kitchen and laundry conveniences must be provided with some form of sewage disposal4 ,private disposal plants are made to meet many conditions of service4 ,the mechanical construction and principles of operation are not difficult to comprehend and their adaptation to a given service is only an intelligent conception of the possible conditions of disposal1 dependent on the natural surroundings4 ,there are few communities where household equipment cannot be found to illustrate each of the subjects discussed4 ,most modern school houses are equipped for automatic control of temperature1 ventilation and humidity4 ,they are further provided with systems of gas1 water and electric distribution and arrangements for sewage disposal4 ,these facilities furnish demonstration apparatus that are also examples of their application4 ,additional examples of the various forms of plumbing and pipe fittings1 valves1 traps and water fixtures may be found in the shop of dealers in plumbers and steam-fitters supplies4 ,attention is called to the value of observing houses in process of construction and the means employed for the placement of the pipes for the sewer1 gas1 water1 electric conduits1 etc4 ,these are generally located by direction of the specifications provided by the architect but observation of their installation is necessary for a comprehension of actual working conditions4 ,it is suggested that the work be made that of1 first1 acquiring an idea of established practice1 and second1 that of investigating the examples of its application4 ,,contents ,,preface v ,,chapter ,i ,,page ,,the ,,steam ,,heating ,,plant #a ,heat of ,vaporization--,steam ,temperature--,gage ,pressure--,absolute ,pressure--,two-pipe ,system--,separate-return ,system--,overhead or ,drop ,system--,water-filled ,radiators--,air ,vents--,automatic ,air ,vents--,steam ,radiator ,valves--,the ,house-heating ,steam ,boiler--,boiler ,trimmings--,the ,water ,column--,the ,steam ,gage--,the ,safety ,valve--,the ,draft ,regulator--,rule for ,proportioning ,radiators--,proportioning the ,size of ,mains--,forms of ,radiators--,radiator ,finishings--,pipe ,coverings--,vapor-system ,heating4 ,,chapter ,,ii ,,the ,,hot-,,water ,,heating ,,plant #cg ,the ,low-pressure ,hot-water ,system--,the ,high-pressure ,hot-water ,system--,heating-plant ,design--,overhead ,system of ,hot-water ,heating--,expansion ,tanks--,radiator ,connection--,hot-water ,radiators--,hot-water ,radiator ,valves--,air ,vents--,automatic ,hot-water ,air ,vents4 ,,chapter ,,iii ,,the ,,hot-,,air ,,furnace #ea ,construction--,furnace-gas ,leaks--,location of the ,furnace--,flues--,combination ,hot-air and ,hot-water ,heater4 ,,chapter ,,iv ,,temperature ,,regulation #ei ,hand ,regulation--,damper ,regulator for ,steam ,boiler--,damper ,regulators for ,hot-water ,furnaces--,the ,thermostat ,motor--,combined ,thermostat and ,damper ,regulator--,thermostat-motor ,connections4 ,,chapter ,v ,,management ,,of ,,heating ,,plants #gj ,general ,advice--,the ,economy of ,good ,draft--,general ,firing ,rules--,weather and ,time of ,day--,night ,firing--,first-day ,firing--,other ,day ,firing--,economy and ,fuels--,for ,burning ,soft ,coal--,for ,burning ,coke--,other ,rules for ,water ,boilers--,air-vent ,valves on ,radiators--,the ,air ,valves--,end of the ,season--,the ,right ,chimney ,flue--8,smokey0 ,chimneys4 ,,chapter ,,vi ,,plumbing #hb ,water ,supply--,water ,cocks--,bibb-cocks--,self-closing ,bibbs--,lever-handle ,bibbs--,fuller ,cocks--,wash-tray ,bibbs--,basin ,cocks--,pantry ,cocks--,sill ,cocks--,valves--,kitchen and ,laundry ,fixtures--,the ,bathroom--,bath ,tubs--,wash ,stands and ,lavatories--,traps--,back-venting--,soi l ,pipe--,water ,closets--,washout ,closets--,washdown ,closets--,siphon-jet ,closet--,flush ,tanks--,low-down ,flush ,tank--,opening ,stopped ,pipes--,sewer ,gas--,range ,boilers--,the ,water-back--,excessive ,pressure--,blow-off ,cock--,location of ,range ,boiler--,double ,heater ,connections--,horizontal ,range ,boilers--,tank ,heaters--,overheater ,water--,furnace ,hot-water ,heaters--,instantaneous ,heaters4 ,,chapter ,,vii ,,water ,,supply #abe ,water ,analysis--,pokegama ,water--,river ,water--,artesian ,water--,medical ,water--,organic ,matter--,ammonia--,hardness in ,water--,iron in ,water--,water ,softening ,with ,hydrated ,silicates--,chlorine--,polluted ,water--,pollution of ,wells--,safe ,distance in the ,location of ,wells--,surface ,pollution of ,wells--,water ,table--,the ,divining ,rod--,selection of a ,type of ,well--,flowing ,wells--,construction of ,wells--,dug ,wells--,open ,wells--,the ,ideal ,well--,coverings of ,concrete--,artesian ,wells--,driven ,wells--,bored ,wells--,cleaning ,wells--,gases in ,wells--,peculiarities of ,wells--,breathing ,well--,freezing ,wells--,pumps--,the ,lift ,pump--,the ,force ,pump--,tank ,pump--,well ,pumps--,wooden ,pump--,pumps for ,driven ,wells--,deep-well ,pumps--,tubular ,well ,cylinders--,chain ,pumps--,rain ,water ,cisterns--,filters--,the ,hydraulic ,ram--,single-acting ,hydraulic ,ram--,the ,double-acting ,hydraulic ,ram--,domestic ,water-supply ,plants--,gravity ,water ,supply--,pressure-tank ,system of ,water ,supply--,the ,pressure ,tank--,power ,water-supply ,plants--,electric ,power ,water ,supply--,the ,water ,lift4 ,,chapter ,,viii ,,sewage ,,disposal #afh ,the ,septic ,tank--,the ,septic ,tank ,with a ,sand-bed ,filter--,the ,septic ,tank and ,anaerobic ,filter--,limit of ,efficiency4 ,,chapter ,,ix ,,coal #ahb ,oxidation of ,hydrocarbons--,graphitic ,anthracite--,cannel ,coal--,lignite--,peat--,wood--,charcoal --,coke--,gas-coke--,briquettes --,comparative ,value of ,coal to ,other ,fuels--,price of ,coal4 ,,chapter ,x ,,atmospheric ,,humidity #aif ,humidity of the ,air--,relative ,humidity--,the ,hygrometer--,the ,hygrodeik--,dial ,hygrometers--,the ,swiss ,cottage 8,barometer0--,dew-point--,to ,determine the ,dew-point--,frost ,prediction--,prevention of ,frost--,humidifying ,apparatus4 ,,chapter ,,xi ,,ventilation #bai ,quantity of ,air ,discharged by a ,flue--,cost of ,ventilation--,the ,wolpert ,air ,tester--,pneumatic ,temperature ,regulation--,mechanical ,ventilation--,the ,plenum ,method--,ventilation ,apparatus--,air ,conditioning--,humidifying ,plants--,vaporization as a ,cooling ,agent--,air-cooling ,plants--,humidity ,control4 ,,chapter ,,xii ,,gaseous ,,and ,,liquid ,,fuels #bej ,gaseous and ,liquid ,fuels--,coal ,gas--,all-oil ,water ,gas--,pintsch ,gas--,blau ,gas--,water ,gas--,measurement of ,gas--,gas ,meters ,how to ,read the ,index--,prepayment ,meters--,gas-service ,rules--,gas ,ranges--,lighting and ,heating with ,gasoline--,gasoline--,kerosene--,the ,cold-process ,gas ,machine--,the ,hollow-wire ,system of ,gasoline ,lighting and ,heating--,mantle ,gas ,lamps--,open-flame ,gas ,burners--,the ,inverted-mantle ,gasoline ,lamp--,portable ,gasoline ,lamp--,central ,generator ,plants--,central-generator ,gas ,lamps--,boulevard ,lamps--,gasoline ,sad ,irons--,alcohol ,sad ,irons--,alcohol ,table ,stoves--,danger from ,gaseous and ,liquid ,fuels--,acetylene-gas ,machine--,types of ,acetylene ,generators--,gas ,lighters--,acetylene ,stoves4 ,,chapter ,,xiii ,,electricity #cje ,incandescent ,electric ,lamps--,the ,mazda ,lamp--,candlepower--,lamp ,labels--,illumination--,the ,foot-candle--,the ,lumen--,reflectors--,choice of ,reflector--,lamp ,transformers--,units of ,electrical ,measurements--,miniature ,lamps--,effects of ,voltage ,variations--,turn-down ,electric ,lamps--,the ,dim-a-lite--,gas-filled ,lamps--,daylight ,lamps--,miniature ,tungsten ,lamps--,flash ,lights--,the ,electric ,flat-iron--,the ,electric ,toaster--,motors1 ,fuse ,plugs--,electric ,heaters--,intercommunicating ,telephones--,electric ,signals--,buzzers--,burglar ,alarms--,annunciators--,table ,pushes--,bell-ringing ,transformers--,the ,recording ,wattmeter--,to ,read the ,meter--,state ,regulation of ,meter ,service--,electric ,batteries--,battery ,formation--,battery ,testers--,electric ,conductors--,lamp ,cord--,portable ,cord--,annunciator ,wire--,private ,electric ,generating ,plants--,storage ,batteries--,the ,pilot ,cell--,national ,electrical ,code--,electric ,light ,wiring--,outlet ,boxes--,automatic ,door ,switch--,plug ,receptacles--,heater ,switch1 ,pilot and ,receptacle--,service ,switch--,local ,switches--,pilot ,lights--,wall and ,ceiling ,sockets--,drop ,lights4 ,,index #che ,,mechanics ,,of ,,the ,,household ,,chapter ,i ,,the ,,steam ,,heating ,,plant ,the use of steam as a means of heating dwellings is common in every part of the civilized world4 ,plants of all sizes are constructed1 that not only give satisfactory service but are efficient in the use of fuel1 and require the minimum amount of attention4 ,the manufacture of steam heating apparatus has come to be a distinct industry1 and represents a special branch of engineering4 ,many manufacturing companies1 pursue this line of business exclusively4 ,the result has been the development of many distinctive features and systems of steam heating1 that are very excellent for the purposes intended4 ,practice has shown that large plants can be operated more economically than small ones4 ,steam may be carried through underground1 insulated pipes to great distances with but small loss of heat4 ,this has lead to the sale of exhaust steam1 from the engines of manufacturing plants1 for heating purposes and the establishment of community heating plants1 where the dwellings of a neighborhood are heated from a central heating plant2 each subscriber paying for his heat according to the number of square feet of radiating surface his house contains4 ,in the practice most commonly followed1 with small steam heating plants1 the steam is generated in a boiler located at any convenient place1 but commonly in the basement4 ,the steam is distributed through insulated pipes to the rooms1 where it gives up its heat to cast-iron radiators1 and from them it is imparted to the air2 partly by radiation but most of the heat is transmitted to the air in direct contact with the radiator surface4 ,the heating capacity of a radiator is determined by its outside surface area1 and is commonly termed1 radiating surface or heating surface4 ,radiators of different styles and sizes are listed by manufacturers1 according to the amount of heating surface each possesses4 ,radiators are sold at a definite amount per square foot1 and may be made to contain any amount of heating surface1 for different heights from #ab to #de inches4 ,the widespread use of steam as a means of heating buildings is due to its remarkable heat content4 ,when water is converted into vapor the change is attended by the absorption of a large amount of heat4 ,no matter at what temperature water is evaporated1 a definite quantity of heat is required to merely change the water into vapor without changing its temperature4 ,the heat used to vaporize water in a steam boiler is given up in the radiators when the steam is condensed4 ,it is because of this property that steam is such a convenient vehicle for transferring heat from the furnace--where it is generated--to the place to be warmed4 ,this heat of vaporization is really the property which gives to steam its usefulness as a means of heating4 ,heat of ,vaporization4--,the temperature of the steam is comparatively an unimportant factor in the amount of heat given up by the radiator4 ,it is the heat liberated at the time the steam changes from vapor to water that produces the greatest effect in changing the temperature of the house4 ,this evolution of heat by condensation is sometimes called the latent heat of vaporization4 ,it is the heat that was used up in changing the water to vapor4 ,the following table of the properties of steam shows the temperatures and exact amounts of latent heat that correspond to various pressures4 ,when water at the boiling point is turned into steam at the same temperature1 there are required #ife4g ,b4t4u4 for each pound of water changed into steam4 ,in the table1 this is the latent heat of the vapor of water at #j1 gage pressure4 ,as the pressure and corresponding temperature rise1 the latent heat becomes less4 ,at #aj pounds gage pressure1 the temperature of the steam is practically #bdj;,f41 but the heat of vaporization is #idf thermal units4 ,when the steam is changed back into water1 as it is when condensed in the radiators1 this latent heat becomes sensible and is that which heats the rooms4 ,the steam enters the radiators and1 coming into contact with the relatively colder walls1 is condensed4 ,as condensation takes place1 the latent heat of the steam becomes sensible heat and is absorbed by the radiators and then transferred to the air of the rooms4 ,,properties ,,of ,,steam ---------------------------------------- - ,absolute ,gage ,temperature ,latent pressure pressure heat ---------------------------------------- - #j #ad4g #bab4jj #ife4gj #a #ae4j #bac4jd #ifd4if #b #af4j #baf4cc #ifb4fc #c #ag4j #bai4de #ifj4di #d #ah4j #bbj4dj #ieh4cb #e #ai4j #bbe4be #ieh4cj #f #bj4j #bbg4ie #ied4ch #g #ba4j #bcj4fj #ieb4ej #h #bb4j #bcc4aj #iej4fb #i #bc4j #bce4di #idi4jc #aj #bd4j #bcg4ha #idg4cg #aa #be4j #bdj4jg #ide4gf #ab #bf4j #bdb4bd #idd4be #ac #bg4j #bdd4cb #idb4gd #ad #bh4j #bdf4ce #ida4bi #ae #bi4j #bdh4cc #ici4hh #af #cj4j #bej4bf #ich4ej #ag #ca4j #beb4ac #icg4ag #ah #cb4j #bec4ih #ice4de #ai #cc4j #bee4gg #icd4eg #bj #cd4j #beg4eb #icc4cb #ba #ce4j #bei4bb #icb4aj #bb #cf4j #bfj4hh #icj4ib #bc #cg4j #bfb4ej #ibi4gf #bd #ch4j #bfd4ji #ibh4fb #be #ci4j #bfe4fe #ibg4ea ---------------------------------------- - ,whenever water is evaporated1 heat is used up at a rate that in amount depends on its temperature and the quantity of water vaporized4 ,this heat of vaporization is important1 not only in problems which relate to steam heating but in all others where vapor of water exerts an influence--ventilation of buildings1 atmospheric humidity1 the formation of frost1 refrigeration1 and many other applications in practice2 this factor is one of the important items in quantitative determinations of heat4 ,it will appear repeatedly in considering ventilation and humidity4 ,at temperatures below the boiling point of water1 the heat of vaporization gradually increases until1 at the freezing point1 it is #ajib ,b4t4u4 ,water vaporizes at all temperatures--even ice evaporates--and the cooling effect produced by evaporation from sprinkled streets in summer1 or the chilling sensation brought about by the winds of winter are caused largely because of its effect4 ,the evaporation of perspiration from the body is one of the means of keeping it cool4 ,at the temperature of the body #ih4f the heat of vaporization is #ajdf ,b4t4u4 ,steam ,temperatures4--,while the temperature of steam is an unimportant factor in the heating of buildings there are many uses in which it is of the greatest consequence4 ,when steam is employed for cooking or baking it is not the quantity of heat but its intensity that is necessary for the accomplishment of its purpose4 ,steam cookers must work at a temperature suitable to the articles under preparation1 and the length of time required in the process4 ,examination of the table on page #c1 will show that steam at the pressure of the air or #j1 gage pressure1 has a temperature of #bab;,f41 which for boiling is sufficiently intense for ordinary cooking2 but for all conditions required of steam cooking1 a pressure of #be pounds gage pressure is required4 ,the temperature corresponding to #be pounds is shown in the table as #bfg;,f4 ,baking temperatures for oven baking as for bread requires temperatures of #djj;,f4 or higher4 ,to bake by steam at that temperature would require a gage pressure of #ahe pounds to the square inch4 ,the ,british thermal unit is the ,english unit of measure of heat4 ,it is the amount of heat required to raise the temperature of a pound of water #a;,f4 ,from the table it will be seen that steam at #aj pounds gage pressure1 is only #bg4d hotter than it was at #j pounds4 ,in raising the pressure of a pound of steam from #j to #aj pounds1 the steam gained only #bg4d ,b4t4u4 of heat4 ,the amount of heat gained by raising the pressure to #aj pounds is small as compared with the heat it received on vaporizing4 ,the extra fuel used up in raising the pressure is not well expended4 ,it is customary1 therefore1 in heating plants1 to use only enough pressure in the boiler to carry the steam through the system4 ,this amount is rarely more than #aj pounds and oftener but #c or #d pounds pressure4 ,gage ,pressure--,absolute ,pressure4--,in the practice of engineering among ,english speaking people1 pressures are stated in pounds per square inch1 above the atmosphere4 ,this is termed gage pressure4 ,it is that indicated by the gages of boilers1 tanks1 etc41 subjected to internal pressure4 ,under ordinary conditions the term pressure is understood to mean gage pressure1 the #j point being that of the pressure of the atmosphere4 ,this system requires pressures below that of the atmosphere to be expressed as a partial vacuum1 a complete vacuum being #ad4g pounds below the normal atmospheric pressure4 ,in order to measure positively all pressures above a vacuum1 the normal atmosphere is #ad4g pounds2 all pressures above that point are continued on the same scale1 thus3 ,gage pressure #j #ad4g absolute ,gage pressure #aj #aj #ad4g #bd4g absolute ,gage pressure #bj #bj #ad4g #cd4g absolute ,absolute pressures are1 therefore1 those of the gage plus the additional amount due to the atmosphere4 ,all references to pressure in this work are intended to indicate gage pressure unless specifically mentioned as absolute pressure4 ,steam heating as applied to buildings may be considered under two general methods3 the pressure system in which steam under pressure above the atmosphere is utilized to procure circulation2 and the vacuum system in which the steam is used at a pressure below that of the atmosphere4 ,each of these systems is used under a great variety of conditions1 and to some is applied specific names but the principle of operation is very much the same in all of a single class4 ,steam heating plants are now seldom installed in the average home but they are very much employed in apartment houses and the larger residences4 ,in large buildings and in groups of buildings heated from a central point1 steam is used for heating almost exclusively4 ,the type of plant employed for any given condition will depend on the architecture of the buildings and their surroundings4 ,in very large buildings and in groups of buildings1 the vacuum system is very generally employed4 ,this system has1 as a special field of heating1 the elaborate plants required in large units4 ,the low-pressure gravity system of heating is used in buildings of moderate size1 large residences1 schools1 churches1 apartment houses1 and the like4 ,under this form of steam heating is to be included vapor heating systems4 ,this is the same as the low-pressure plant except that it operates under pressure only slightly above the atmosphere and possesses features that frequently recommend its use over any other form of steam heating4 ,the term vapor heating is used to distinguish it from the low-pressure system4 ,the low-pressure gravity system1 with which we are most concerned1 takes its name from the conditions under which it works4 ,the low pressure refers to the pressure of the steam in the boiler1 which is generally #c or #d pounds2 and since the water of condensation flows back to the boiler by reason of gravity1 it is a gravity system4 ,the placing of the pipes which are to carry the steam to the radiators and return the water of condensation to the boiler may consist of one or both of two standard arrangements4 ,they are known as the single-pipe system and the two-pipe system4 ,illustration3 ,,fig4 #a4--;,diagram of a gravity system steam heating plant4 ,fig4 #a shows a diagram of a single-pipe system in its simplest form4 ,in the figure the pipe marked supply and return1 connects the boiler with the radiators4 ,from the vertical pipe called a riser1 the steam is taken to the radiators through branch pipes that all slope toward the riser1 so that the water of condensation may readily flow back into the boiler4 ,the water of condensation1 returning to the boiler1 must under this condition1 flow in a direction contrary to the course of the steam supplying the radiators4 ,in ,fig4 #b is given a simple application of this system4 ,a single pipe from the top of the boiler1 in the basement1 marked supply and return pipe1 connects with one radiator on the floor above4 ,the radiator and all of the connecting pipes are set to drain the water of condensation into the boiler4 ,illustration3 ,,fig4 #b4--;,a simple form of steam heating plant4 ,the furnace fire is controlled by a thermostat and a damper regulator4 ,when the valve is opened to admit steam to the radiator1 the air vent must also be opened to allow the escape of the contained air4 ,the steam will not diffuse with the air in the radiator and unless the air is allowed to escape1 the steam will not enter4 ,as the steam enters the cold radiator1 it is rapidly condensed1 and collects on the walls in the form of dew1 at the same time giving up its latent heat4 ,the heat is liberated as condensation takes place1 and as the dew forms on the radiator walls the heat is conducted directly to the iron4 ,the water runs to the bottom of the radiator and then through the pipes2 back to the boiler4 ,the water occupies but relatively a little space and may return through the same pipe1 while more steam is entering the radiator4 ,as the steam condenses in the radiator1 its reduction in volume tends to reduce the pressure and thus aids additional steam from the boiler to enter4 ,in this manner a constant supply of heat enters the radiator in the form of steam which when condensed goes back to the boiler at a temperature very near the boiling point to be revaporized4 ,it should be kept in mind that it is the heat of vaporization1 not the temperature of the steam that is utilized in the radiator1 and that the heat of vaporization is the vehicle of transfer4 ,the water returning to the boiler may be at the boiling point and the steam supplying the heat to the radiators may be at the same temperature4 ,illustration3 ,,fig4 #c4--;,a gravity system steam heating plant of two radiators4 ,the furnace is governed by a thermostat4 ,fig4 #c is a slightly different arrangement of the same boiler as that shown in ,fig4 #b1 connected with two radiators on different floors4 ,the same riser supplies both radiators with steam and takes the water of condensation back to the boiler4 ,fig4 #d is an example of the single-pipe system applied to a small house4 ,in the drawing1 the boiler in the basement is shown connected with four radiators on the first floor and three on the second floor4 ,the pipes connecting with the more distant radiators are only extensions of the pipes connecting the radiators near the boiler4 ,as in ,figs4 #a1 #b and #c1 all of the pipes and radiators are set to drain back into the boiler4 ,if at any place the pipe is so graded that a part of the water is retained1 poor circulation will result1 because of the restricted area of the pipe1 and the radiators will not be properly heated4 ,this lack of drainage is also a common cause of hammering and pounding in steam systems1 known as water-hammer4 ,the formation of water-hammer is caused by steam flowing through a water-restricted area1 into a cold part of the system1 where condensation takes place very rapidly4 ,the condensation of the steam is so rapid and complete that the resulting vacuum draws the trapped water into the space with the force of a hammer stroke4 ,the hammering will continue so long as the conditions exist4 ,the pipes in the basement are suspended from the floor joists by hangers as shown in the drawing4 ,in practice the pipes in the basement are covered with some form of insulating material to prevent loss of heat4 ,illustration3 ,,fig4 #d4--,the gravity system steam heating plant installed in a dwelling4 ,as stated above1 the single-pipe system may be successfully used in all house-heating plants except those of large size4 ,it requires the least amount of pipe and labor for installation of the circulating system and when well constructed performs very satisfactorily all of the functions required in a small heating plant4 ,one of the commonest causes of trouble in a single-pipe system is due to the radiator connections4 ,the single radiator connection requires the entering steam and escaping water of condensation to pass through the same opening4 ,under ordinary conditions this double office of the radiator valve is accomplished with satisfaction but occasionally it is the cause of considerable noise4 ,at any time the valve is left only partly open the steam will enter and condense because of the lower pressure inside the radiator but the condensed water will not be able to escape4 ,the water has only the force of gravity to carry it out of the radiators and if it meets no opposition will flow back through the pipe to the boiler2 but if it is required to pass a small opening through which steam is flowing in a contrary direction1 the water will be retained in the radiators4 ,single-pipe radiators1 therefore1 work satisfactorily only under conditions which will permit the steam to enter and the water to leave as fast as it is formed4 ,in ordinary use the valve at any time is apt to be left slightly open and this produces undesirable working conditions4 ,in larger buildings1 where greater distances require longer runs of pipe and more complicated connections1 and where the volume of condensed steam is too great to be taken care of in a single pipe1 this system does not work satisfactorily4 ,two-pipe ,system4--,fig4 #e is a diagram of a two-pipe system4 ,here1 each radiator has a supply pipe1 through which the steam enters1 and a return pipe which conducts the water away4 ,the branch pipes from a common supply pipe or riser1 carry steam to the various radiators and all of the return pipes empty into a single return pipe that takes the water back to its source4 ,it will be noticed that in this case the riser also connects at the bottom with the return pipe4 ,this connection is made for the purpose of conducting away the condensation that takes place in the connecting pipes4 ,the water will always stand in these pipes1 at the same height as the water in the boiler4 ,the supply pipe from the boiler1 and the branch pipes connecting the radiators all slope toward the riser4 ,the condensation in the connecting pipes does not pass through the radiators as it returns to the boiler4 ,an exception to this general rule is shown in the radiator on the second floor4 ,in this case the supply pipe slopes downward as it approaches the radiator4 ,to prevent carrying water through the radiator1 a small pipe under the left-hand valve connects with the return pipe and the water is thus conducted to the main return pipe4 ,illustration3 ,,fig4 #e4--;,diagram showing the arrangement of a two-pipe steam plant4 ,fig4 #f is a simple application of the arrangement shown in ,fig4 #e4 ,the steam may be easily traced from the boiler to the radiators1 and back through the return pipes to its source4 ,the pipe marked ,r is the connection between the main supply pipe and the return pipe that takes away the condensation of the riser4 ,it is connected to the main return pipe below the water line of the boiler and1 therefore1 does not interfere in any way with the passage of the steam4 ,each radiator empties its water of condensation into a common return pipe1 that finally connects with the boiler below the water line4 ,illustration3 ,,fig4 #f4--;,a two-pipe steam heating plant4 ,this arrangement may be elaborated to almost any extent and is an improvement over the single-pipe system4 ,it is quite commonly used as a method of steam distribution1 but it lacks the required elements necessary to a positive circulation4 ,as an example3 ,suppose that the plant shown in ,fig4 #f is working and that the radiator on the first floor is hot1 but the valves of the radiator on the second floor are closed and it is cold4 ,the steam entering at the valve ,a of the lower radiator is being condensed as fast as the heat is radiated4 ,the steam will pass on through the valve ,b into the return pipe and as soon as the return pipe becomes hot it will contain steam at practically the same pressure as that in the supply pipe4 ,this is what takes place in every working steam plant4 ,now suppose that it is desired to heat the radiator on the floor above4 ,the steam valve ,a of the upper radiator is opened to admit steam and the return valve is also opened to allow the water to escape4 ,there is steam in both the supply and return pipes of the radiator below at the same pressure1 each tending to send steam into the radiator above at opposite ends4 ,this would make a condition exactly the same as a single-pipe system1 with a supply pipe at both ends of the radiator and the result would1 of course1 be the same as in the single-pipe system4 ,there being no place for the water to escape except against the incoming steam1 the water will sometimes surge back and forth with the customary noises peculiar to such conditions4 ,it must not be understood that this will always occur1 because systems of this kind are in use with fairly good results1 but noisy radiators are not at all rare when working under this condition and the cause is from that described4 ,to overcome this difficulty and change the system into one in which there would be a positive circulation from ,a to ,b1 in each radiator1 allowing the steam always to enter at the valve ,a and escape at ,b1 the system must be changed to that of separate returns4 ,illustration3 ,,fig4 #g4--;,diagram of a separate return steam system4 ,separate-return ,system4--,a diagram of a separate-return system is shown in ,fig4 #g4 ,in this figure1 the radiator1 boiler and supply pipes are the same as those of ,fig4 #e1 but there is a separate return pipe from each of the radiators1 connecting with the main return pipe at a point below the water line of the boiler4 ,examination of this diagram will show that there is an independent circuit for the steam through each radiator4 ,the steam is taken from a common riser as before but after passing through the radiator the water is returned by a separate pipe to the main return pipe at the bottom of the boiler4 ,fig4 #h is an application of separate-return system4 ,it is exactly the same as ,fig4 #f1 except that each radiator has an independent return pipe4 ,steam must always enter the radiators at the valves ,a and leave at the valves ,b4 ,this makes a positive circulation that renders each radiator independent of the others4 ,there is no opportunity for steam to pass through one radiator and interfere with the return water of another2 it1 therefore1 prevents the possibility of hammering or surging so common in poorly designed steam systems4 ,of all the methods of steam heating where the water of condensation is returned to the boiler by reason of gravity this is the most satisfactory4 ,this plant requires a larger amount of pipe than the other systems described and as a consequence the cost of installation is greater but it repays in excellence of service the extra expense incurred4 ,illustration3 ,,fig4 #h4--;,a separate return heating plant4 ,overhead or ,drop ,system4--,there is yet another gravity system of steam heating that is sometimes used in large buildings where economy in the use of pipe is desired2 this is the overhead or drop system shown in ,fig4 #i4 ,it is not a common method of piping and is given here only because of its occasional use4 ,in the arrangement of the drop system1 the supply pipe for the radiators rises from the boiler to the highest point of the system and the branch pipes for the radiators are taken off from the descending pipe4 ,its action is the same as that of a single-pipe system but the advantage gained by the arrangement is that the steam in the main supply pipes travels in the same direction as the returning water of condensation2 the cause of surging in long risers is thus eliminated4 ,the two-pipe systems of steam heating are more certain in action than the single-pipe methods because there is nothing to interfere with the progress of the steam on its way to the radiators4 ,in long branch pipes of the single-pipe system1 the returning water is frequently caught by the advancing steam and carried to the end of the pipe1 when slugging and surging is the result4 ,illustration3 ,,fig4 #i4--;,diagram of the overhead or drop system steam plant4 ,water-filled ,radiators4--,radiators frequently fill with water and are noisy because of the position of the valve4 ,this may be true in any gravity system but particularly so in radiators having a single pipe4 ,when the valve of a single-pipe radiator is opened a very small amount1 the entering steam is immediately condensed but the water cannot escape because the incoming steam entirely fills the opening4 ,under this condition1 the radiator may entirely fill with water4 ,if the valve is then opened wide1 the imprisoned water has an opportunity to escape while the steam is entering1 but the entering steam and escaping water sets up a water-hammer that sometimes is terrific and lasts until the water is discharged from the radiator4 ,the same condition may exist in a two-pipe system1 if the steam valve is slightly opened while the escape valve is closed1 but in a well-designed system the radiator will be immediately emptied when both valves are open4 ,air ,vents4--,all radiators must be provided with air vents4 ,the vent is placed near the top of the last loop of the radiator1 at the end opposite from the entering steam1 as indicated in ,figs4 #b1 #c1 #f1 etc4 ,the object of the vent is to allow the air to escape from the radiator as the steam enters4 ,steam will not diffuse with the air and1 therefore1 cannot enter the radiator until the air is discharged4 ,the air vent may be a simple cock such as is shown in ,fig4 #aj1 that must be opened by hand when the steam is turned on1 to allow the air to escape1 and closed when the steam appears at the vent2 or it may be an automatic vent1 that opens when the radiator cools and closes automatically when the radiator is filled with steam4 ,there are many makes of air vents of both hand-regulating and automatic types2 of the former1 ,fig4 #aj furnishes a common example4 ,the part ,a1 in the figure1 is threaded and screws tightly into a hole made to receive it in the end loop of the radiator4 ,the part ,b is a screw-plug that closes the passage ,c1 leading to the inside of the radiator4 ,when the steam is turned on1 the vent must be opened until the air is discharged1 after which it is closed by the hand-wheel ,d4 ,illustration3 ,,fig4 #aj4 ,,fig4 #aa4 ,,fig4 #ab4 ,,fig4 #ac4 ,,fig4 #aj4--;,a common form of air vent for radiators4 ,,fig4 #aa4--;,an inexpensive automatic radiator air vent4 ,,fig4 #ab4--,monash ,no4 #af automatic air vent4 ,,fig4 #ac4--,the ,allen float1 radiator air vent4 ,automatic ,air ,vents4--,these vents depend for their action on the expansion of a part of the valve due to the temperature of the steam4 ,the valve remains closed when hot and opens when cold4 ,the difference in temperature between the steam and the expelled air from the radiator is the controlling factor4 ,in the automatic vent shown in ,fig4 #aa1 the part ,a is screwed into the radiator loop4 ,the discharge ,c is open to the air or connected with a drip pipe1 which returns the water to the basement4 ,the cylinder ,d1 which closes the passage ,b1 is made of a material of a high coefficient of expansion4 ,the piece ,d1 when cool1 is contracted sufficiently to leave the passage ,b open to the air4 ,when the steam is turned on1 the expelled air from the radiator escapes through ,b and ,c1 but when the steam reaches ,d the heat quickly expands the piece and closes the vent4 ,most automatic vents require adjusting when put in place and occasionally need readjustment4 ,the cap ,o1 of ,fig4 #aa1 may be removed with a wrench and a screw-driver used to adjust the piece ,d1 so as to shut off the steam when the radiator is filled with steam4 ,the expanding piece is simply screwed down until the steam ceases to escape4 ,fig4 #ab is another style of automatic vent1 constructed on the same principle as that of ,fig4 #aa1 but probably more positive in action4 ,in this vent the part ,a attaches to the radiator4 ,the expanding portion ,b is made in the form of a hollow cylinder1 through which the air and steam escape to the atmosphere4 ,it is longer than the corresponding piece in the other vent and is more sensitive because of its greater length and exposed surface4 ,as the piece ,b elongates from expansion1 the upper end makes a joint with the conical piece ,d4 ,the shape of this latter piece gives better opportunity for a tight joint than in the other form of vent and in practice gives better service4 ,fig4 #ac is a cross-section of the ,allen vent4 ,this is an example of a vent which depends for its action on a float4 ,whenever sufficient water accumulates in the body of the vent to raise the float1 it closes the vent by means of its buoyancy4 ,the body of the vent shown in ,fig4 #ac is composed of two concentric cylinders4 ,the float ,e occupies the inner cylinder1 while surrounding it is the outer cylinder ,d4 ,the outer cylinder is entirely closed except a little hole at ,g4 ,the float is made of light metal and fits loosely in the inner cylinder4 ,the steam from the radiator condenses in the vent until the inner cylinder is filled with water1 up to the opening ,a4 ,the float by its buoyancy keeps the opening in ,b stopped1 and no steam can escape4 ,the air of the outer cylinder ,d is expanded by the heat of the steam and most of the air escapes through the hole ,g4 ,when the radiator cools1 the rarefied air in ,d contracts and draws the water from the inner cylinder into the space ,d2 this allows the float to fall and unstop the opening in ,b4 ,when the steam again reaches the vent1 the heat expands the air in ,d and forces the water into the inner cylinder2 the float is again raised and stops the opening in ,b4 ,many other air vents are in common use but most of them operate on one or the other of the principles described4 ,fig4 #aa is a relatively inexpensive vent1 while ,fig4 #ab is higher-priced4 ,illustration3 ,,fig4 #ad4--,steam radiator valve4 ,,fig4 #ae4--,sectional view of a steam radiator valve4 ,steam ,radiator ,valves4--,like most other mechanical appliances that are extensively used1 radiator valves are made by a great number of manufacturers and in many different forms4 ,some possess special features that are intended to increase their working efficiency but the type of radiator valve most commonly used for ordinary construction is that illustrated in ,figs4 #ad and #ae4 ,it is a style of angle valve that takes the place of an elbow and being made with a union joint1 also furnishes a means of disconnecting the radiator without disturbing the pipes4 ,fig4 #ad is an outside view of the valve and ,fig4 #ae shows its mechanical construction4 ,the part ,b screws onto the end of the steam pipe and ,a connects with the radiator4 ,the part ,c-,d is the union4 ,the nut ,c screws onto the valve and makes a steam-tight joint at ,d1 between the parts4 ,in case it is desired to remove the radiator1 it furnishes an easy means of detaching the valve4 ,the composition valve-disc ,e makes a seat on the brass ring directly under it1 to shut off the steam4 ,in case the valve leaks1 the disc may be removed by taking the valve casing apart at ,g4 ,the worn disc can then be replaced with a new one which may be obtained from the dealer who furnished the valve4 ,the only moving part of the valve exposed to the air is at the point where the valve-stem ,s enters the casing4 ,the joint is made steam-tight by the packing ,p4 ,the packing is greased candle wicking that is wound around the stem and held tightly in place by the screw-cap ,h4 ,if the valve leaks at this joint1 a turn or two with a wrench will stop the escape of the steam4 ,,the ,,house-,,heating ,,steam ,,boiler ,house-heating boilers were formerly made of sheet metal and are still so constructed to some extent1 but by far the greater number are now made of cast iron4 ,sheet-metal boilers are constructed at the factory1 ready to be installed1 but the cast-iron type is made in sections and assembled to make a complete boiler1 at the time the plant is erected4 ,sectional boilers are convenient to install1 on account of the possibility of handling the parts in a limited space1 that would not admit an assembled boiler without tearing down a part of the basement for admission4 ,cast-iron boilers as commonly used for heating dwellings are made in two definite styles4 ,the small sizes are cylindrical in form and are used for either steam or hot-water heating4 ,the larger sizes are made as illustrated in ,figs4 #af and #ag1 the former being an outside view1 and the latter showing the internal arrangement of the same boiler4 ,the fire-box1 water space and smoke passages are easily recognized4 ,each division represents a separate section which assembled as that in the figures makes a complete boiler with a common opening as shown at the top of ,fig4 #ag4 ,these boilers are used for residences of large size and for buildings of less than #aj1jjj feet of radiating surface4 ,for large buildings1 the steam is most commonly generated in boilers built for high pressure4 ,in small plants1 intended for either steam or hot-water heating1 the cylindrical style of boiler shown in ,fig4 #ah is commonly used4 ,as constructed by different manufacturers1 the parts differ quite materially but ,fig4 #ah shows all of the essential features and serves to illustrate the different working parts4 ,the sections into which the boiler is divided are indicated on the left-hand side of the figure by the numbers #a to #f4 ,the parts from #a to #e are screwed together with threaded nipples1 joining the central column4 ,the part #f contains the grate and the ash-pit1 with the draft and clean-out doors4 ,illustration3 ,,fig4 #af4 ,,fig4 #ag4 ,,fig4 #af4--,sectional cast-iron boiler for steam or hot-water heating4 ,,fig4 #ag4--;,interior view of the boiler shown in ,fig4 #af4 ,the drawing shows the boiler cut through the middle lengthwise and exposes to view all of the essential features4 ,the fire-box and the spaces occupied by the steam and water are easily recognized4 ,it will be seen that the water space surrounds the fire-box except at the bottom and that the space above the fire-box presents a large amount of heating surface to the flame and heated gases as they pass to the chimney4 ,the arrows show their course2 first through the openings near the center1 then through those further away4 ,the object being to keep the heat as long as possible in contact with the heating surfaces without interfering with the draft4 ,illustration3 ,,fig4 #ah4--,sectional view of the cylindrical type of cast-iron1 sectional boiler4 ,there is no standard method of rating the heating capacity of boilers of this kind and as a consequence1 boilers of different makes--for the same rating--are not the same in actual heating capacity4 ,the boilers are sold by their makers in sizes that are intended to furnish heat sufficient to supply a definite number of square feet of radiating surface4 ,the ratings are quite generally too high for the weather conditions of the ,northwest4 ,a common practice with contractors is to select boilers for a given plant #ej per cent4 and even #ajj per cent4 larger than those rated by the manufacturers for the same amount of radiation4 ,some manufacturers sell their boilers at honest ratings but they are exceptions4 ,in specifying the capacity of a house-heating plant it is common practice to require the boiler to be of such size as will easily heat a definite number of square feet of radiating surface4 ,the radiators are required to possess sufficient radiating surface to keep the house at #gj;,f4 in any weather4 ,in the absence of any rules or specifications for determining the heating capacity of the boiler1 the only means of securing a satisfactory plant is to require a guarantee of the contractor to install a boiler such as will fulfil the conditions stated above4 ,boiler ,trimmings4--,attached to the boiler and required for its safe operation are a number of appliances that demand special attention4 ,the office of each part should be thoroughly appreciated and the mechanical construction should be fully understood4 ,an intimate acquaintance with the details of the plant1 helps to make its operation satisfactory and adds to the efficiency with which it can be made to perform its duty4 ,the ,water ,column4--,in ,fig4 #ah the water column is shown at ,c4 ,it is attached to the boiler by pipes at points above and below the water line1 so as to allow a free passage of the water of the boiler to the interior4 ,the water line should be #c or #d inches above the top heating surface4 ,attached to the water column is the gage-glass1 the try-cocks ,t and ,t and the steam gage ,g4 ,the object of the gage-glass is to show the height of the water in the boiler4 ,it is shown in place on the boiler in ,figs4 #af and #ah and in detail in ,fig4 #ai4 ,the lower part of the gage-glass occupies a position on the boiler about #b inches above the top heating surface4 ,when the boiler is working1 the level of the water should always be visible in the glass and should stand normally one-third to one-half full4 ,illustration3 ,,fig4 #ai4--,the water gage4 ,the water gage is attached to the water column by two brass valves ,v4 ,the valves are provided so that in case the water glass should be broken the openings may be closed4 ,the ends of the glass are made tight by 8stuffing-boxes0 marked ,c1 in the figure4 ,the packing ,s is generally in the form of rubber rings but greased wicking may be used if necessary as in the case of valve-stems4 ,the try-cocks ,t and ,t 7,fig4 #ah7 are also intended to indicate the approximate height of the water in the boiler and should the water glass be broken may be used in its place4 ,the openings of the try-cocks point toward the floor4 ,when a cock is opened1 should steam alone escape1 it will be absorbed by the air1 but if water is escaping1 although much of it will be vaporized and look like steam1 some of the water will be carried to the floor and produce a wet spot4 ,when the cock is opened wide the escaping water from the lower cock should always wet the floor4 ,the drip-cock ,p 7,fig4 #ah7 at the bottom of the gage-glass is for draining the water column and for blowing out any deposit that may collect in the opening of the column4 ,this cock should be opened occasionally to assure the correctness of the gage-glass4 ,illustration3 ,,fig4 #bj4--,typical ,bourdon pressure gage with the face removed4 ,the ,steam ,gage4--,steam pressure is measured in pounds to the square inch above the pressure of the atmosphere4 ,the gages used for indicating the pressure of the steam are made in several forms but the type most commonly used is that shown in ,fig4 #bj4 ,it is known as the ,bourdon type of gage and takes its name from the bent tube ,a1 which furnishes its active principle4 ,the ,bourdon barometer invented in #ahdi employed this form of sensitive tube4 ,in the drawing the face of the gage has been removed to show the working parts4 ,the sensitive part is the flat elastic tube ,a1 which is bent in the form of a circle4 ,when the pressure of the steam enters at ,s the air in the tube is compressed and the tube tends to straighten4 ,the movement of the tube caused by the steam pressure is communicated to the pointer by a link connection and gear as shown in the drawing4 ,the amount of straightening of the tube will be in proportion to the steam pressure and is indicated by the numbers marked on the face of the gage4 ,when the pressure is released1 the tube returns to its original position and the spiral spring ,c turns the hand back to its first position4 ,illustration3 ,,fig4 #ba4--;,cross-section of a pop valve4 ,the ,safety ,valve4--,all steam boilers should be provided with safety valves as a safeguard against excessive steam pressures4 ,of the various types of safety valves1 that known as the pop-valve is most commonly used on house-heating boilers4 ,it is indicated at ,w in ,fig4 #ah and is shown in section in ,fig4 #ba4 ,the part ,a is screwed into the top of the boiler at any convenient place4 ,the pressure of the spring ,c holds the valve ,b on its seat until the internal pressure reaches a certain intensity at which the valve is set1 when it opens and allows the excess steam to escape4 ,when the pressure is reduced1 the spring forces the valve back on its seat4 ,the handle ,d permits the valve to be lifted at any time as an assurance that it is in working order4 ,this should be done occasionally1 as the valve may stick to the seat after long standing and allow the pressure to rise above the point at which it should 8pop40 ,the valve may be set to 8blow off0 at any desired pressure by the adjusting piece ,e4 ,house-heating boilers generally have their safety valves set to blow off at #h or #aj pounds4 ,the ,draft ,regulator4--,as a means of automatic control of the steam pressure1 the draft regulator is frequently used to so govern the fire that when a certain steam pressure is reached1 the direct draft will be automatically closed and the check-draft damper opened4 ,the draft regulator is shown in place at ,d in ,fig4 #ah1 and will also be found in ,fig4 #af4 ,a detailed description of the regulator will be found on pages #fj and #fa4 ,,rule ,,for ,,proportioning ,,radiators ,rules for determining the amount of radiating surface that will be required to satisfactorily heat a building to #gj;,f4 regardless of weather conditions are entirely empirical1 that is1 they are derived from experience4 ,it is evident that no definite rule can be established that will take into account the method of building construction1 the kind and amount of materials that make up the walls and the quality of workmanship employed4 ,these variable quantities coupled with the changing climatic conditions of temperature and wind velocity produce a complication that cannot be overcome in a formula that will give exact results4 ,many rules are in use for this purpose1 no two of which give exactly the same results when applied to a problem4 ,a common practice is to apply one of the rules in use and then under conditions of exceptional exposure1 to add to the amount thus calculated as experience may dictate4 ,the following rule by ,professor ,r4 ,g4 ,carpenter of ,cornell ,university was taken from a handbook published by the ,j4 ,l4 ,mott ,iron ,works of ,new ,york4 ,this company manufactures and deals in all kinds of apparatus entering into steam and hot-water heating and the rule is given as one that has produced satisfactory results4 ,,rule4--,add the area of the glass surface in the room to one-quarter of the exposed wall surface1 and to this add from one-fifty-fifth to three-fifty-fifths of the cubical contents 7one-fifty-fifth for rooms on upper floor1 two-fifty-fifths for rooms on first floor and three-fifty-fifths for large halls72 then for steam multiply by #j4be1 and for hot water by #j4dj4 ,example4--,a room #bj by #ab by #aj feet with glass exposure of #dh feet1 #a_/d of wall exposure 7two sides exposed7 #cbj feet #hj1 #a_/ee of #bdjj #dd4 #dh #hj #dd #agb #j4be #dc feet4 ,if you add #b_/ee the surface would be #ed feet4 ,if you add #c_/ee the surface would be #fe feet4 ,,proportioning ,,the ,,size ,,of ,,mains ,for any size system of steam or water heating the following rule will be found entirely satisfactory for mains #ajj feet long2 for each #ajj feet additional use a size larger ratio4 ,,rule4-- r 7#c4adaf_/;d7,r a_/r #ajj4 r represents ratio of main in inches for each #ajj feet of surface2 d1 diameter of pipe2 ,r1 quantity of radiation carried by size of pipe2 a1 area of pipe in inches4 ,from this the following table has been constructed3 ---------------------------------------- ----- ,diameter ,area ,ratio to ,quantity of of pipe of pipe each #ajj radiation1 steam feet of or water1 on a surface given size pipe ---------------------------------------- ----- #a #a4gfg #b4aj #hd #b #c4ada #a4eg #bjj #b #d4ijh #a4be #djj #c #g4jfi #a4jd #gjj #c #i4fba #j4ij #a1jfb #d #ab4eff #j4gh #a1eij #d #ae4ijd #j4gj #b1bgb #e #ai4fbe #j4fc #c1abj #f #bh4bgd #j4eb #e1ddj #g #ch4dhd #j4de #h1eej #h #ej4bfe #j4dj #ab1eef #i #fc4fag #j4ce #ah1ajj #aj #gh4edj #j4cj #be1cjj ---------------------------------------- ----- ,,forms ,,of ,,radiators ,radiators are much the same in appearance for both steam and hot-water heating4 ,they are hollow cast-iron columns so designed that they may be fastened together in units of any number of sections4 ,the sections are made in size to present a definite number of square feet of outside surface that is spoken of as radiating surface4 ,the amount of radiating surface in any radiator depends on its height and the contour of the cross-section4 ,the radiator sections may be made in the form of a single column as ,fig4 #bb or they may be divided into two1 three1 four or more columns to increase their radiating surface4 ,the following table1 taken from a manufacturer's catalogue1 shows the method of rating the heating capacity of a particular design4 ,in the table1 the first column gives the number of sections in the radiator1 the second column states the length of the radiator in inches4 ,the columns headed heating surface give the heights of the sections in inches and the amount of radiating surface in various radiators of different heights and numbers of sections4 ,as an example3 ,this table refers to the three-column radiators of ,fig4 #bc4 ,such a radiator #cb inches high with #aj sections would contain #de square feet of radiating surface and would be #be inches in length4 ---------------------------------------- ---------------------------- ,heating surface--square feet ---------------------------------------- ------- ,no4 ,length #de in4 #ch in4 #cb in4 #bf in4 #bc in4 #bj in4 of #b in4 high1 high1 high1 high1 high1 high1 sections per #f sq4 #e sq4 #d sq4 #c sq4 #c sq4 #b sq4 section ft4 ft4 ft4 ft4 ft4 ft4 per per per per per per sec4 sec4 sec4 sec4 sec4 sec4 ---------------------------------------- ----------------------- #b #e #ab #aj #i #g #f #e #c #g #ah #ae #ac #aa #i #h #d #aj #bd #bj #ah #ae #ac #aa #e #ab #cj #be #bb #ah #af #ac #f #ae #cf #cj #bg #bb #ai #af #g #ag #db #ce #ca #bf #bb #ai #h #bj #dh #dj #cf #cj #bf #bb #i #bb #ed #de #dj #cc #bi #bd #aj #be #fj #ej #de #cg #cb #bg #aa #bg #ff #ee #di #da #ce #cj #ab #cj #gb #fj #ed #de #ci #cc #ac #cb #gh #fe #eh #dh #db #ce #ad #ce #hd #gj #fc #eb #de #ch #ae #cg #ij #ge #fg #ef #dh #da #af #dj #if #hj #gb #fj #eb #dd #ag #db #ajb #he #gf #fc #ee #df #ah #de #ajh #ij #ha #fg #eh #di #ai #dg #aad #ie #he #ga #fa #eb #bj #ej #abj #ajj #ij #ge #fe #ee #ba #eb #abf #aje #id #gh #fh #eg #bb #ee #acb #aaj #ii #hb #ga #fj #bc #eg #ach #aae #ajc #hf #gd #fc #bd #fj #add #abj #ajh #ij #gh #ff #be #fb #aej #abe #aab #ic #ha #fh #bf #fe #aef #acj #aag #ig #hd #ga #bg #fg #afb #ace #aba #aja #hg #gd #bh #gj #afh #adj #abf #aje #ia #gg #bi #gb #agd #ade #acj #ajh #id #gi #cj #ge #ahj #aej #ace #aab #ig #hb #ca #gg #ahf #aee #aci #aaf #ajj #he #cb #hj #aib #afj #adj #abj #ajd #hh ---------------------------------------- ----------------------- ,fig4 #bb is a radiator made up of eight single-column sections4 ,in ,fig4 #bc is shown five three-column radiators1 varying in height from #bj to #de inches4 ,the sections of steam radiators are joined together at the bottom with close-nipples1 so as to leave an opening from end to end4 ,the sections of hot-water radiators are joined in the same manner1 except that there is an opening at both top and bottom4 ,fig4 #cj shows the openings of a hot-water radiator installed as direct-indirect heater4 ,fig4 #bd illustrates a special form of radiator that is intended to be placed under windows and in other places that will not admit the high form4 ,such a radiator as that shown in the picture is often covered with a window seat and in cold weather becomes the favorite place of the sitting room4 ,another special form is that of ,fig4 #be4 ,as a corner radiator this style is much to be preferred to the ordinary method of connection2 here the angle is completely filled--there is no open space in the corner4 ,illustration3 ,,fig4 #bb4 ,,fig4 #bc4 ,,fig4 #bb4--,single column steam radiator4 ,,fig4 #bc4--,three-column radiators of different heights2 for steam or hot-water heating4 ,wall radiators such as shown in ,fig4 #bf are made to set close to the wall1 where floor space is limited4 ,they are particularly adapted for use in narrow halls1 bathrooms and other places where the ordinary type could not be conveniently used4 ,a radiator that will appeal to all neat housekeepers is that of ,fig4 #bg4 ,it does not stand on the floor as in the case of the ordinary type1 but is hung from the wall by concealed brackets4 ,the difficulty of sweeping under this radiator is entirely avoided4 ,fig4 #bh is a radiator designed to furnish a warming oven for plates and for heating the room at the same time4 ,it is sometimes installed in dining rooms4 ,illustration3 ,,fig4 #bd4--,six-column1 low form of hot-water radiators to be placed under windows4 ,illustration3 ,,fig4 #be4--,two-column corner radiator for steam heating4 ,illustration3 ,,fig4 #bf4--,wall form1 radiator for steam or hot water4 ,the ordinary method of heating by the use of radiators is known as the direct method4 ,the air is heated by coming directly into contact with the radiators and distributed through the room by convection4 ,if the arrangement is such that the air is brought from outdoors and heated by the radiator before entering the room1 it is called the indirect method of heating4 ,such an arrangement is illustrated in ,fig4 #bi4 ,the radiator is located beneath the floor1 in a passage that takes the air from outdoors and after being heated1 enters the room through a register located in the wall4 ,fig4 #cj is still another arrangement known as the direct-indirect method of heating4 ,the radiator is placed in position1 as for direct heating1 but the air supply is taken from outdoors4 ,the radiator base is enclosed and a double damper ,t regulates the amount of air that comes from the outside4 ,when the inside damper is closed and the outside damper is open1 as is shown in the drawing1 the air comes from outdoors and is heated as it passes through the radiator on its way to the room4 ,if the dampers are reversed1 the air circulates through the radiator as in the case of direct radiation4 ,illustration3 ,,fig4 #bg4--,two-column radiator suspended from the wall by brackets4 ,illustration3 ,,fig4 #bh4--;,dining-room radiator containing a warming oven4 ,in the use of the direct or the direct-indirect method of heating the principal object to be attained is that of ventilation1 but quite generally the passages are so arranged that the air may be taken from outdoors or1 if desired1 the air of the house may be sent through the radiators to be reheated4 ,in extremely cold and windy weather it is sometimes difficult to keep the house at the desired temperature when all of the air supply comes from the outside4 ,under such conditions the outside air is used only occasionally4 ,in mild weather it is common to use the outdoor air most of the time4 ,the cost of heating1 when these methods are used1 is higher than by direct radiation1 because the air is being constantly changed in temperature from that of the outside to #gj4 ,illustration3 ,,fig4 #bi4--,ventilation by the indirect method of heating4 ,illustration3 ,,fig4 #cj4--,ventilation by the direct-indirect method of heating4 ,radiator ,finishings4--,in steam and hot-water heating the decoration of the radiators is a much more important item than that of a good-looking surface or one which will harmonize with the setting4 ,until recently radiator finishing has been considered a minor detail and the familiar bronze has been looked upon as a standard covering1 while painted radiators were considered only a matter of taste4 ,the character of the surface is1 however1 the determining factor in the quantity of heat given out by radiators4 ,this has been determined in the experimental laboratory of the ,university of ,michigan by ,professor ,john ,a4 ,allen4 ,comparison was made of bare cast-iron radiators with the same forms painted as indicated in the following table4 ,the bare radiator was taken at #ajj per cent42 the other finishes are expressed in per cent4 above or below that of the bare radiator4 ,condensing capacity1 per cent4 ,no4 #a1 a cast-iron radiator1 bare as received from the foundry #ajj ,no4 #b1 a cast-iron radiator1 coated with aluminum bronze #gh ,no4 #c1 a cast-iron radiator1 three coats of white enamel paint #ajb ,no4 #d1 a cast-iron radiator1 coated with copper bronze #hj ,no4 #e1 a cast-iron radiator1 three coats of green enamel paint #aja ,no4 #f1 a cast-iron radiator1 three coats of black enamel paint #aja ,the author has stated further that1 8,it might be said in general that all bronzes reduce the heating effect of the radiator about #be per cent4 while lead paints and enamels give off the same amount of heat as bare iron4 ,the number of coats of paint on the radiator makes no difference4 ,the last coat is always the determining factor in heat transmission40 ,,pipe ,,coverings ,all hot-water or steam pipes in the basement and in other places not intended to be used for heating should be covered with some form of insulating material4 ,at ordinary working temperature a square foot of hot pipe surface will radiate about #ae ,b4t4u4 of heat per minute4 ,to prevent this loss of heat and the consequent waste of fuel the pipes should be covered with some form of insulating material4 ,pipe coverings are made of many kinds of material and some possess insulating properties that may reduce the loss to as low a point as #ae per cent4 of the amount radiated by a bare pipe4 ,many good insulating materials do not give satisfactory results as pipe coverings because they do not keep their shape1 some cannot be considered in the average plant because of high cost4 ,wood-pulp paper is extensively used as a cheap covering2 it is a good insulator and under ordinary conditions makes a satisfactory covering4 ,a more efficient and also a more expensive covering that is extensively used is that made of magnesia carbonate and known as magnesia covering4 ,aside from these1 other forms made of cork1 hair-felt1 asbestos and composition coverings are sometimes used in house-heating plants4 ,in selecting a pipe covering1 there should be taken into account not only its insulating properties but its ability to resist fire1 dampness or breeding places for vermin4 ,it rests entirely with the owner whether he covers the pipes with a combustible or an incombustible material when the insulating properties are about the same4 ,coverings made of animal or vegetable materials under some conditions furnish a breeding place for vermin4 ,pipe coverings are made in sections about #c feet in length and from #a to #a-c_/h inches in thickness4 ,the sections are usually cut in halves lengthwise to permit being put in place4 ,the sections are covered with common muslin to keep the material in place and sometimes are painted after being installed4 ,painting has nothing to do with their insulating capabilities1 but it preserves the cloth and makes a neat appearance4 ,the sections when put in place are secured by pasting one of the loose edges of the cloth to the surface4 ,the ends of the sections are bound together with strips of metal4 ,fig4 #ca shows the appearance of the pipe when the covering is in place4 ,illustration3 ,,fig4 #ca4--,pipe covering4 ,irregular surfaces like the body of the furnace1 pipe connections1 etc41 are insulated by coverings made from a plaster that is made expressly for such work4 ,it is known as asbestus plaster4 ,the plaster may be purchased in bulk and put in place with a trowel4 ,as it is found in the market the plaster requires only the addition of water to put into working form4 ,the value of a pipe covering is not in proportion to its thickness4 ,experiments with pipe coverings have shown that a thickness of #a-c_/h inches will reduce the radiation #ij per cent41 but doubling the thickness reduces the loss only #e per cent4 ,it1 therefore1 does not pay to make a covering more than #a-c_/h inches thick4 ,vapor-system ,heating4--,this system of heating is not greatly different from the steam plants already described but it is operated under conditions which do not permit the steam in the boiler to rise beyond a few ounces of pressure4 ,since the plant is intended to work at a pressure that is scarcely indicated by an ordinary steam gage1 it has been termed a vapor system to distinguish it from the pressure systems which employ steam1 up to #e pounds or more to the square inch4 ,the heat is transmitted to the radiators in the same manner as in the pressure systems4 ,the heat of vaporization of steam is somewhat greater at the boiling point of water than at higher pressures1 and the lack of pressure1 therefore1 increases its heating capacity4 ,this is shown in the table1 properties of steam1 on page #c4 ,the successful operation of such a plant rests in the delivery of the vapor to the radiators at only the slightest pressure and the return of the condensate to the boiler without noise or obstruction to the circulation at the same time ejecting the contained air4 ,the excellence of the system depends in the greatest measure on good design and the employment of special facilities that allow all water to be discharged from the radiators and returned to the boiler without accumulation at any part of the circulating system4 ,it requires1 further1 the discharge of the air from the system at atmospheric pressure4 ,the system is1 therefore1 practically pressureless4 ,various systems of vapor heating are sold under the names of their manufacturers4 ,each possesses special appliances for producing positive circulation that are advocated as features of particular excellence4 ,the vapor system of heating has met with a great deal of favor as a more nearly universal form of heating than either the pressure-steam plant or the hot-water method of heating4 ,fig4 #ca;a is a diagram illustrating the ,c4 ,a4 ,dunham system of vapor heating4 ,it will be noticed that there are no air vents on the radiators4 ,the air from the radiators is ejected through a special form of trap that is indicated in the drawing4 ,these traps permit the water and air to pass from the radiators but close against the slightly higher temperature of the vapor4 ,this assures the condensation of the vapor in the radiators and excludes it from the return pipes4 ,the water returns to the boiler in much the same manner as in the pressure systems already described but the air escapes through the air eliminator as indicated in the drawing4 ,the system is1 therefore1 under atmospheric pressure at this point and only a slight amount greater in the boiler4 ,illustration3 ,,fig4 #ca;a4--,diagram showing the ,c4 ,a4 ,dunham ,co4's system of vapor heating4 ,the water of condensation is returned to the boiler against the vapor pressure1 by a force exerted by the column of water in the pipe connecting the air eliminator with the boiler4 ,the main return is placed #bd inches or more above the water line of the boiler4 ,it is the pressure of this column that forces the water into the boiler through the check valve1 against the vapor pressure in the boiler4 ,it might be imagined that the water in the boiler and that in the air-eliminator pipe formed a 8,u-tube10 the vapor pressure on the water surface in the boiler1 and the atmospheric pressure on the water in the eliminator standpipe4 ,the slight vapor pressure in the boiler is counterbalanced by a column of water in the eliminator pipe4 ,it is this condition that fixes a distance of #bd inches from the water line to the return pipe2 that is1 the force exerted by a column of water #bd inches high is required to send the water into the boiler4 ,the vapor pressure is controlled by means of the pressurestat1 which is an electrified ,bourdon spring pressure gage1 connected up by simple wiring to the damper motor1 which may be any form of damper regulator4 ,in residential work1 the pressurestat is so connected with a thermostat1 that both pressure and temperature conditions operate and control this damper regulator1 which in turn controls the draft and the fire4 ,the two instruments are so connected that if the pressure mounts to #h ounces and the pressurestat caused the draft damper to close and the check to open1 the thermostat cannot reverse the damper1 regardless of the temperature in the room1 until the pressure drops below the limiting #h-ounce pressure4 ,just so long as the pressure is below #h ounces1 the thermostat is the master in the control of the dampers4 ,the minute that the pressure goes up to #h ounces then the pressurestat takes control4 ,,chapter ,,ii ,,the ,,hot-,,water ,,heating ,,plant ,of the various systems of heating dwellings that by hot-water is considered by many to be the most satisfactory4 ,on account of its high specific heat1 water at a temperature much below the boiling point furnishes the heat necessary to keep the temperature of the house at the desired degree4 ,the temperature of the radiators is generally much lower than those heated by steam but the amount of radiating surface is greater than for steam heating plants of the same capacity4 ,it is because of the relatively low temperature at which the water is used1 that the greater amount of heating surface is required4 ,one objection to the use of hot water as a means of heating is1 that once the heat of the house is much reduced1 the furnace is a long time in raising the temperature to normal4 ,this is due to the fact that the temperature of the water of the entire system must be uniformly raised1 because of its continuous passage through the heater4 ,on the other hand1 this uniformity of the temperature of the water prevents sudden changes in the temperature of the house4 ,water-heating plants work with perfect quiet and may be so regulated to suit the outside temperature that the heat of the water will just supply the amount to suit the prevailing conditions4 ,the care required in the management of the boiler is less than that required in the steam plant because of the fewer appliances necessary for its safe operation4 ,another advantage in the use of the hot-water plant is its adaptability to the temperature conditions during the chilly weather of early fall and late spring1 when a very small amount of heat is required4 ,at such times the temperature of the radiators is but a few degrees warmer than the outside air4 ,the amount of attention necessary for maintaining the proper furnace fire under such conditions is less then for any other form of heating4 ,the increasing use of the hot-water plant for heating the average-sized dwelling attests to its excellence in service4 ,the ,low-pressure ,hot-water ,system4--,a hot-water system consists of a heater1 in which the water receives its supply of heat1 the circulating pipes for conducting the heated water to and from the radiators that supply heat to the rooms1 and the expansion tank that receives the excess of water caused when the temperature is raised from normal to the working degree4 ,in addition to the parts named there are a number of appliances to be described later1 that are required to make the system complete4 ,illustration3 ,,fig4 #cb4--;,diagram of a simple form of hot-water heating plant4 ,a hot-water plant of the simplest form is shown in ,fig4 #cb4 ,the illustration presents each of the features mentioned above1 as in a working plant4 ,the different parts are shown cut across through the middle1 the black portion representing water4 ,not only does the water fill the entire system but appears in the expansion tank when the plant is cold4 ,hot-water heaters are quite generally in the form of internally fired boilers4 ,the fire-box occupies a place inside the boiler and is surrounded1 except at the bottom1 by the water space4 ,commonly1 these boilers are made of cast iron and are constructed in sections1 the same as the steam boiler shown in ,fig4 #af4 ,manufacturers sell a single style for either steam or hot-water heating4 ,the boiler in ,fig4 #cb is cylindrical in form4 ,it is made of wrought iron and contains a large number of vertical tubes through which the heat from the furnace must pass on its way to the chimney4 ,as the water is heated it expands and rises to the top of the boiler because of its decreased weight4 ,since the water in the radiator is really a part of the same body of water1 the heated portion rises through the supply pipe to the top of the radiator4 ,as the hot water rises in the radiator1 it displaces an equal amount of cold water1 which enters the boiler at the bottom4 ,this displacement is constant and produces a circulation that begins as soon as the fire is started and varies with the difference in temperature between the hot water leaving the boiler at the top and the cold water entering at the bottom4 ,as the water in the system is heated and expands1 there must be some provision made to receive the enlarging volume4 ,in this arrangement a pipe connects the bottom of the boiler with the expansion tank located at a point above the radiator4 ,under the conditions represented in the drawing the water does not circulate through the tank and as a consequence the water it contains is always cold4 ,in raising its temperature1 water absorbs more heat than any other fluid and on cooling it gives up an equal amount4 ,as a consequence it furnishes an excellent vehicle for transmitting the heat of the furnace to the rooms to be heated4 ,water1 however1 is a poor conductor and receives its heat by coming directly into contact with the hot surfaces of the furnace1 and gives it up by direct contact with the radiator walls4 ,to transmit heat rapidly and maintain a high radiator temperature1 the circulation of the water in the system must be the best possible4 ,the connecting pipes between the boiler and the radiators must be as direct as circumstances will permit and the amount of radiating surface in each room must be sufficient to easily give up an ample supply of heat4 ,even though the furnace is able to furnish a plentiful supply of heat to warm the house1 it cannot be transmitted to the rooms unless there is sufficient radiating surface4 ,a plant might prove unsatisfactory either because of a furnace too small to furnish the necessary heat or from an insufficient amount of radiating surface4 ,yet another factor in the design of a plant is that of the conducting pipes4 ,both the boiler and the radiators might be in the right proportion to produce a good plant1 but if the distributing pipes are too small to carry the water required1 or the circulation is retarded by many turns and long runs1 the plant may fail to give satisfaction4 ,fig4 #cc shows a complete hot-water plant adapted to a dwelling4 ,it is just such a plant as is commonly installed in the average-sized house but without any of the appliances used for automatic control of temperature4 ,the regulation of the temperature is made entirely by hand1 in so governing the fire as to provide the required amount of heat4 ,in the drawing the supply and return pipes may be traced to the radiators as in the case of the simple plant4 ,the supply pipe from the top of the boiler branches into two circuits to provide the water for the two groups of radiators at the right and left side of the house4 ,to provide any radiator with hot water1 a pipe is taken from the main supply pipe and passing through the radiator it is brought back and connected with the return pipe which conducts the water back to the boiler4 ,illustration3 ,,fig4 #cc4--,the low-pressure hot-water heating system applied to a small dwelling4 ,the expansion tank is located in the bathroom near the ceiling4 ,it is connected with the circulating system by a single pipe which joins the supply pipe as it enters the radiator located in the kitchen4 ,like the expansion tank in ,fig4 #ca the water it contains is always cold4 ,it is provided with a gage-glass which shows the level of the water in the tank and an overflow pipe which discharges into the bathtub1 in case of an overflow4 ,an overflow pipe must always be provided to take care of the surplus when the water in the system becomes overheated4 ,this does not often occur but the provision must be made for the emergency4 ,the overflow pipe is frequently connected directly with the sewer or discharged at some convenient place in the basement4 ,the ,high-pressure ,hot-water ,system4--,in the hot-water plant described the expansion tank is open to the air and the water in the system is subjected to the pressure of the atmosphere alone4 ,the heat of the furnace may be sufficiently great to bring the entire volume of water of the system to the boiling point and cause it to overflow but the temperature of the water cannot rise much above the boiling point due to the pressure of the atmosphere4 ,if the expansion tank is closed1 the pressure generated by the expanding water and the formation of steam will permit the water to reach a much higher temperature4 ,in the table of temperatures and pressures of water on page #c1 it will be seen that should the pressure rise to #aj pounds1 that is1 #aj pounds above the pressure of the atmosphere1 the temperature of the water would be very nearly #bdj;,f4 7#bci4d;,f474 ,the difference in heating effect in hot-water heating plants under the two conditions is very marked4 ,in the low-pressure system the temperature of the radiators cannot be above #bab but the high-pressure system set for #aj pounds pressure will heat the radiators to #bdj1 and a still higher pressure would give a correspondingly higher temperature4 ,the amount of heat radiated by a hot body is in proportion to the difference in temperature between the body and the surrounding air4 ,if we consider the surrounding air at #fj the difference in amount of heat-radiation capacity of the two radiators would be as #ahj is to #acb4 ,the advantage of the high-pressure system lies in its ability to heat a given space with less radiating surface than the low-pressure system4 ,in ,fig4 #cd is illustrated an application of a simple and efficient valve arrangement that converts a low-pressure hot-water system into a high-pressure system without changing in any way the piping or radiators4 ,the drawing shows the boiler and two radiators connected as for a low-pressure system1 but attached to the end of the pipe as it enters the expansion tank is a safety valve ,b and a check valve ,a1 as indicated in the enlarged figure of the valve4 ,the safety valve is intended to allow the water to escape into the expansion tank when the pressure in the system reaches a certain point for which the valve is set4 ,the check valve ,a permits the water to renter the system from the tank whenever the pressure is restored to its normal amount4 ,illustration3 ,,fig4 #cd4--,the high-pressure system of hot-water heating4 ,suppose that such a system is working as a low-pressure plant4 ,the hot water from the top of the boiler is flowing to the radiators through the supply pipe and the displaced cooler water is returning to the bottom of the boiler through the return pipe as in the other plants described4 ,it is now found that the radiators are not sufficiently large to heat the rooms to the desired degree except when the furnace is fired very heavily4 ,it is always poor economy to keep a very hot fire in any kind of a heater1 because a hot fire sends most of its heat up the chimney4 ,if the radiators could be safely raised in temperature1 they would1 of course1 give out more heat and as a result the rooms would be more quickly heated and kept at the required temperature with less effort by the furnace4 ,the difficulty in this case lies solely in there being insufficient radiator surface to supply heat as fast as required4 ,the increase in radiator temperature is accomplished by the pressure regulating valve ,b1 attached to the end of the pipe as it enters the expansion tank4 ,the expansion tank with the regulating valve is shown enlarged at the left of the figure4 ,the valve ,b is kept closed by a weight marked ,w1 that is intended to hold back a pressure of say #aj pounds to the square inch4 ,a pressure of #aj pounds will require a temperature of practically #bdj;,f4 7see table on page #c74 ,the check valve ,a is kept closed by the pressure from the inside of the system4 ,when the pressure of the water goes above #aj pounds--or the amount of the weight is intended to hold back--the valve is lifted and an amount of water escapes through the valve ,b into the tank1 sufficient to relieve the pressure4 ,should enough water be forced out of the system to fill the tank to the top of the overflow pipe1 the overflow water is discharged through this pipe into the sink in the basement4 ,when the house has become thoroughly warmed1 the demand for a high radiator temperature is reduced1 the furnace drafts are closed1 the water in the system cools and as it shrinks the system will not be completely filled4 ,it is then necessary to take back from the tank the water that has been forced out by excess pressure4 ,it is here that the check valve comes into use4 ,so long as there is pressure on the pipes1 this valve is held shut and no water can escape1 but as the inside pressure is released by the cooling there will come a point where the water in the tank will flow back through the valve ,a and fill the system4 ,this is the type of valve used by the ,andrews ,heating ,co4 and designated a regurgitating valve4 ,in practice it gives excellent service4 ,the only danger of excessive pressure in the use of this device is the possibility of the valve becoming stuck to the seat through disuse4 ,any possible danger from such an occurrence may be eliminated by the occasional lifting of the valve by hand4 ,heating-plant ,design4--,a heating plant should be designed by a person of experience4 ,no set of rules has yet been devised that will meet every condition4 ,carpenter's rules given on page #be serve for hot water as well as for steam as a means of determining the radiating surface required for an ordinary building1 but the rules do not take into account the method of construction of the house and the consequent extra radiation demanded for poorly constructed buildings4 ,in many cases the designer must rely on experience as a guide where the rules will not apply4 ,in the case usually encountered1 however1 the rules given will meet the conditions4 ,what was said regarding the size of steam boilers required for definite amounts of heating surfaces1 applies with equal force to hot-water boilers1 because house-heating boilers are commonly used for either steam or hot-water heating4 ,there are no established rules for determining the heating capacities of house-heating boilers4 ,manufacturers' ratings are usually low4 ,there are some manufacturers who make honest ratings for their boilers but they are in the minority4 ,when the heating capacity of a boiler is not known from experience1 the only safeguard against installing a boiler too small for the radiators to be heated1 is to require a guarantee that the plant will give satisfaction when in operation and when considered necessary a certain percentage of the contract price should be withheld until the plant proves itself by actual trial4 ,overhead ,system of ,hot-water ,heating4--,in ,fig4 #ce is illustrated another system of high-pressure hot-water heating that corresponds to the overhead system of steam heating4 ,it differs from the high-pressure system already described in the method of distribution and in the radiator connections4 ,the flow pipe is taken to the attic and there joined to the expansion tank as a point of distribution4 ,on the expansion tank is a safety valve set at #aj or more pounds pressure4 ,the flow of the water is all downward toward the radiators4 ,the circulation through the radiators is also different from the other plants described4 ,the supply pipe joins directly to the return pipe and the connections to the radiators are made at the top and bottom of the same end4 ,the circulation through the radiators in this case is due to the difference in gravitational effect between the hot and colder water at the top and bottom of the radiator4 ,the system requires no air vents on the radiators as all air that might collect in the system goes up to the expansion tank4 ,the safety valve on the expansion tank in this case is the common lever type4 ,the overflow should empty into the sewer and be pitched to prevent any water being retained in the discharge pipe4 ,if water should be retained in this pipe and should freeze1 the system would become dangerous1 because of the possibility of high pressures from a hot fire4 ,illustration3 ,,fig4 #ce4--,the overhead system of hot-water heating4 ,expansion ,tanks4--,fig4 #cf is a form of expansion tank in common use4 ,it may be used for either the high-or low-pressure system4 ,the body of the tank is made of galvanized iron and is made to stand a considerable amount of pressure4 ,the gage-glass is attached at ,b1 and the overflow at ,o4 ,the pipe ,e connects the tank with the circulating system and ,d connects with the cold-water supply as a convenience for filling the system with water4 ,the object in placing the stop-cock ,d near the expansion tank is to avoid overflowing the system in filling4 ,the overflow pipe1 as stated above1 is most conveniently connected with the sewer1 into which the water will run in case of an overflow1 but the other methods shown are commonly used4 ,there should be no valve in this pipe nor in the pipe ,e4 ,illustration3 ,,fig4 #cf4--,the expansion tank4 ,illustration3 ,,fig4 #cg4--,when the expansion tank of a hot-water heating system must be so located that it is apt to freeze1 it must be piped as a radiator4 ,the expansion tank must be so located that there will be no danger of freezing4 ,should it be necessary to place the tank in the attic or where freezing is possible1 the tank must be so connected as to become a part of the circulating system4 ,such an arrangement is shown in ,fig4 #cg4 ,the expansion tank is connected with a supply and return pipe as a radiator4 ,this arrangement is sometimes used but it is not desirable4 ,it is wasteful of heat and there is always a possibility of freezing in case the fire in the furnace is extinguished a sufficient time to allow the water to grow cold4 ,any possibility of danger from excessive pressures in either the low-pressure or the high-pressure system must originate in the expansion tank4 ,it is1 therefore1 desired to again mention the possible causes of danger4 ,any closed-tank system is liable to become overheated4 ,the expansive force of water is irresistible and unless some means is taken to prevent excessive pressure some part of the apparatus is apt to burst4 ,no closed-tank system should be used without a safety valve4 ,the low-pressure or open-tank system requires no safety appliances4 ,so long as there is open communication between the tank and the boiler the pressure cannot rise but slightly above that of the atmosphere4 ,there is only one cause that will lead to high pressure in such a system4 ,if the pipe connecting the expansion tank is stopped an excessive pressure might generate4 ,there is little or no danger of this happening4 ,in the closed-tank system the expansion tank should be of greater capacity than for the open-tank system4 ,its size is commonly about one-ninth of the volume of water used4 ,the larger tank is necessary to prevent too rapid rise of pressure as the temperature of the water rises4 ,the air in the tank acts as a cushion against which the pressure of the expanding water is exerted4 ,the extended use of hot-water heating has led to the invention of many appliances for the improvement of the circulation and heating effects4 ,pulsation valves are used for retaining the water in the boiler until a definite pressure has been attained that will lift the valve long enough to dissipate the pressure4 ,many of these systems possess merit and some of them are great improvements over the simple plant4 ,radiator ,connection4--,the method of connecting the radiators to the distributing pipes depends entirely on local conditions4 ,in a well-balanced system any of the methods shown in ,figs4 #ch1 #ci or #dj might be used with good heating effects4 ,the method of attaching the supply pipe to the radiator is1 however1 an important factor in case of accumulation of air4 ,in ,fig4 #da is shown the form of connection most commonly used4 ,the drawing is intended to represent a cast-iron radiator with the valve at ,d1 and the air vent at ,b4 ,should air collect in the radiator it will rise to the top and displace the water4 ,the water will continue to circulate and heat as much of the radiator as is in contact with the water1 but that part not in contact will receive no heat from the water and will1 therefore1 fail to fulfill its function4 ,as soon as the air vent is opened the air will escape and allow the water to entirely fill the space4 ,illustration3 ,,fig4 #ch4 ,,fig4 #ci4 ,,fig4 #dj4 ,,figs4 #ch ,,to #dj4--,various methods of attaching the supply and return pipes to hot-water radiators4 ,illustration3 ,,fig4 #da4--,the effect of accumulation of air in a hot-water radiator with bottom connections4 ,illustration3 ,,fig4 #db4--,with this method of connections1 if the air collects sufficiently to force the water down to the level ,l1 circulation will stop4 ,in ,fig4 #db a much different condition exists1 when air accumulates4 ,in this mode of connection the water enters through the valve ,v1 and escapes at the bottom of the opposite end4 ,when air fills the radiator to the line ,l1 the circulation is stopped and the radiator will grow cold4 ,the position of the valve on these radiators is of little consequence4 ,the valve is intended merely to interrupt the flow of the water and may occupy a place on either end of the radiator with the same result4 ,hot-water ,radiators4--,radiators for hot-water heating are most commonly of cast iron and in appearance are the same as those used for steam heating4 ,the only difference in the two forms is in the openings between the sections4 ,those intended for steam have an opening at the bottom joining the sections2 while those for hot water have openings at both top and bottom to permit circulation of the water4 ,illustration3 ,,fig4 #dc4--,the hot-water radiator valve4 ,illustration3 ,,fig4 #dc;a4--,details of construction of the hot-water radiator valve4 ,hot-water ,radiator ,valves4--,valves for hot-water radiators differ materially from those used on steam radiators4 ,figs4 #dc and #dc;a show the outside appearance and the mechanical arrangement of the parts of the ,ohio hot-water valve4 ,the part ,a in ,fig4 #dc;a is a hollow brass cylinder attached to the valve-stem1 one side of which has been removed4 ,when it is desired to shut off the supply of heat the handle of the valve is given one-quarter turn and the part ,a covers the opening to the inlet pipe4 ,the supply of water being shut off1 the radiator gradually cools4 ,when the valve is closed a small amount of water is admitted to the radiator through a #a_/h-;inch hole in the piece ,a to prevent the possibility of freezing4 ,air ,vents4--,in the use of the systems of hot-water heating described1 every radiator must be supplied with an air vent of some kind to take away the trapped air which accumulates through use4 ,any kind of a valve will serve as a vent for hand regulation and generally such a cock as is shown in ,fig4 #aj is employed4 ,automatic ,hot-water ,air ,vents4--,it is sometimes desired to use automatic air vents on hot-water radiators4 ,for such work a vent is used that remains closed as long as water is present and will open when the water is displaced by the accumulating air1 but will again close when the air is discharged4 ,in such vents the valve is controlled by a float1 the buoyancy of the float when surrounded by water serving to keep the valve closed4 ,these vents are not so positive in their action as automatic air vents for steam4 ,the change in temperature which controls the steam vent does not take place with hot water4 ,the automatic hot-water vents are not perfectly reliable4 ,they may work with entire satisfaction for a long time and then fail from very slight cause4 ,the failure of a hot-water vent is generally discovered by finding a pool of water on the floor or a wet spot on the ceiling or wall of the floor below4 ,illustration3 ,,fig4 #dd4--;,automatic air vent for hot-water radiators4 ,one type of the automatic hot-water vent that has proven quite successful is shown in ,fig4 #dd4 ,the threaded lug is screwed into the radiator at the proper point4 ,as the water enters the radiator the air is discharged through the vent1 escaping at the opening ,c4 ,when the water has risen to a sufficient height it enters the openings ,g and ,h until enough is present to raise the float ,a4 ,the pointed stem attached closed the hole ,c with sufficient force to make an air-tight joint4 ,the float ,a is a very light copper cylinder4 ,its buoyancy supplies the force to close the vent and its weight opens the vent when the water is displaced by air4 ,it will be readily seen that very slight cause might prevent the performance of its duty4 ,,chapter ,,iii ,,the ,,hot-,,air ,,furnace ,of the methods of heating dwellings other than by stoves1 that of the hot-air furnace is the most common4 ,of the various modes of furnace heating it is the least expensive in first cost and most rapid in effect4 ,in the use of steam heat1 the water in the boiler must be vaporized before its heat is available4 ,with hot-water heating1 the whole mass of water in the entire system must be raised considerably in temperature before its heat can affect the temperature of the rooms1 and consequently in first effect it is very slow4 ,in the use of the hot-air furnace the heat from the register begins to warm the rooms when the fire is started4 ,hot-air furnaces are made by manufacturing companies in a great variety of styles and forms to suit purposes of every kind4 ,in practice the furnace is built in sizes1 to heat a definite amount of cubical space4 ,the maker designs a furnace to heat a certain number of cubic feet of space contained in a building4 ,it must be sufficiently large to keep the temperature at #gj;,f4 on the coldest nights of winter when the wind is blowing a gale4 ,it is evident that with the variable factors entering the problem1 the designer must be a person of experience in order that the furnace meet the requirements4 ,the following table taken from a manufacturer's catalogue shows the method of adapting the product of the maker to any size of dwelling4 ,the volume of the house is calculated in cubic feet and from this result the size of furnace most nearly suited is selected from the table4 ---------------------------------------- ------------------------ ,furnace number #a #b #c #d #e ---------------------------------------- ------------------------ ,weight without casing1 #ihd #a1aaa #a1cdj #a1eca #a1icd lb4 ---------------------------------------- ------------------------ ,estimated capacities in #h1jjj #ab1jjj #bj1jjj #ce1jjj #fj1jjj cubic feet to to to to to #ab1jjj #bj1jjj #ce1jjj #fj1jjj #ajj1jjj ---------------------------------------- ------------------------ ,capacity in number of rooms of ordinary size #c to #e #e to #g #g to #i #i to #ab #ab to #ae in residence heating ---------------------------------------- ------------------------ ,,construction ,illustration3 ,,fig4 #de4--;,interior view of a hot-air furnace4 ,the furnace1 in general construction1 consists of a cast-iron fire-box with its heating surfaces1 through which the flames and heated gases from the fire pass1 on the way to the chimney2 these with the passages and heating surfaces for heating the air compose the essential features4 ,fig4 #de shows such a furnace with the sides broken away to show the internal construction4 ,the flames and gases from the fire-box ,f circulate through the cast-iron drum ,d and are discharged at ,c to the chimney4 ,the drum ,d is made in such form that it presents to the heat from the fire a large amount of heating surface and at the same time offers as little opposition as possible to the furnace draft4 ,the air to be heated enters the furnace through the cold air duct at the bottom1 and after circulating through the drum1 passes out at the openings ,r to the conducting pipes4 ,the cast-iron box ,w is a water tank that should be attached to every hot-air furnace4 ,the water contained in the tank is for humidifying the air as it passes through the furnace4 ,in this furnace the outside casing is of sheet iron1 reinforced with wrought-iron flanges4 ,the front1 which contains the doors of the fire-box1 ash-pit1 etc41 are of cast iron of ornamented design4 ,as the air to be heated passes through the furnace it receives part of its warmth by radiation but most of it is absorbed by coming directly into contact with the heating surfaces4 ,since air is a poor conductor of heat its temperature is raised very slowly2 it should1 therefore1 be kept in contact with the heating surfaces as long as possible to insure an economical furnace4 ,in common practice the ratio of heating surface to grate surface average #ce to #a2 that is1 for each square foot of grate surface there is #ce square feet of heating surface to warm the passing air4 ,should this ratio be increased to #ej to #a the efficiency of the furnace would be much improved4 ,if the ratio of heating surface to the grate surface is too small for its requirements1 the temperature of the air-heating surfaces must be very high to provide the desired amount of heat4 ,under such a condition the efficiency of the furnace would be low1 since in all cases where rapid combustion is required the available amount of heat per pound of coal consumed is low4 ,with a large amount of heating surface1 the air remains in contact with the hot surface a relatively longer period and the desired temperature is reached with the expenditure of a smaller amount of fuel4 ,a momentary exposure of the air to a red-hot surface is far less effective than a prolonged contact with a surface having only a moderate temperature4 ,time is an element of great importance in heating air4 ,in considering the relative merits of two furnaces with the same amount of grate surface1 that with the larger amount of heating surface will evidently be the most efficient4 ,the supply of heat comes primarily from the burning coal on the furnace grate4 ,the grate surface should be large enough in area to permit the required quantity of heat to be generated by the burning fuel with a moderate fire4 ,if the grate surface is too small for the required purpose1 a hot fire will be necessary1 when the normal amount of heat is demanded by the house4 ,during extremely cold weather1 particularly when accompanied by high wind1 the extra heat demanded to keep the house at the desired temperature makes necessary the use of an amount of fuel that cannot be burned on the grate unless the fire is forced4 ,hot fires can be kept up only at the expense of a large amount of heat1 and the resultant efficiency of the furnace is reduced4 ,high furnace temperatures are always attended by a large loss of heat4 ,the vastly greater quantity of air necessary to create the combustion1 the high temperature of the chimney gases and the increased velocity of the heated gases through the furnace1 all tend to increase the amount of heat that is sent up the chimney1 and to decrease the percentage of heat that is delivered by the furnace4 ,in order to heat the house economically the furnace must be large enough to easily generate the required amount of heat demanded in the most severe weather4 ,furnace-gas ,leaks4--,the presence of furnace gas in the atmosphere of a house is not only annoying but may be a source of danger4 ,gas leaks are commonly due to the imperfect union of the various parts of which the furnace is composed4 ,cast-iron furnaces are constructed in sections that are assembled to form a complete plant4 ,in assembling1 the various parts of contact must be carefully joined to prevent the gases in the fire-box from escaping into the air-heating space4 ,in the manufacture of cast-iron furnaces it is practically impossible to form gas-tight joints by the contact of the metal alone4 ,in the erection of the furnace all doubtful joints are filled with stove putty4 ,furnaces of good design require the use of the least amount of this material4 ,stove putty is composed of finely divided graphitic carbon that is made into a paste suitable for filling all imperfect joints4 ,when the putty hardens it withstands the heat to which it is subjected1 without shrinking4 ,in the course of time1 however1 the putty may be displaced and leave openings through which the furnace gases may leak into heating space and thus enter the house4 ,leaks of the kind may be stopped by renewing the putty which may be obtained from any dealer in stoves4 ,location of the ,furnace4--,the location of the furnace will generally be governed by the exposure of the house and the location of the chimney4 ,in all exposed rooms on the windward side of the house the temperature will be lower and the air pressure higher than in other parts of the house4 ,the increase in atmospheric pressure makes it necessary to supply to such rooms the hottest air practicable4 ,the conducting pipes1 therefore1 should be most directly connected with the furnace and with the least run of horizontal pipe4 ,the proper place for the furnace is as near as possible the coldest place of the house4 ,it is a common practice to place registers near the inner corner of the room1 in order to economize in conducting pipe1 in horizontal runs4 ,a small amount of economy in first cost is thus secured but the efficiency of the apparatus is sacrificed4 ,the greatest objection to placing the registers and conducting pipes in the outer walls of buildings is that of loss of heat1 due to exposure to the outside cold and the resulting loss in circulation4 ,losses of this kind may be prevented by covering the ducts with the necessary non-conducting material4 ,the registers should occupy a place in the room nearest the entering cold air4 ,illustration3 ,,fig4 #df4--,method of conducting warm air from the furnace to the registers4 ,flues4--,it is customary to place the conducting pipes for the first floor in such a way as to use only the shortest connections4 ,the flues used for the second floor produce1 as in a chimney1 a greater velocity of flow to the air and as a consequence larger horizontal pipes are used at the furnace4 ,all horizontal pipes should have upward slant1 as much as the basement will permit4 ,the velocity of the air in the conducting flues will depend on two factors3 the height of the flue1 and the temperature of the air4 ,to prevent the loss of the temperature of the air1 the flue should be covered with at least two layers of asbestus paper bound with wire4 ,wall flues are commonly flattened and occupy a place in the wall between the studding4 ,each flue should have a damper at the furnace1 that will permit the heat to be shut off from any part of the house4 ,rules for proportioning of registers and conducting flues to suit rooms of various sizes are entirely empirical4 ,the sizes of registers and flues found satisfactory in practice is generally a guide for the designer4 ,the following table is taken from a manufacturer's catalogue and gives a list of sizes that have proven satisfactory under a great variety of conditions and may be taken as good practice3 ,,first ,,floor ---------------------------------------- ------- ,sizes of ,diameter of ,size of ,height of registers pipes rooms ceilings in inches in inches in feet in feet ---------------------------------------- ------- #ab by #ae #ab #ah by #bj #aa #aj by #ad #aj #ae by #ae #aj #i by #ab #i #ad by #ae #i #h by #ab #i #ac by #ac #i ---------------------------------------- ------- ,,second ,,floor ---------------------------------------- ------- #aj by #ad #aj #ah by #bj #aj #i by #ab #i #af by #af #i #h by #ab #h #ac by #ac #h #h by #aj #g #ab by #ab #h ---------------------------------------- ------- ,the furnace is not only a means of heating the house but may be a means of ventilation as well2 to this end it is desirable to arrange the air supply of the furnace to connect with the outside air4 ,this arrangement assures a supply of oxygen even though no special means is arranged for discharging the vitiated air from the rooms4 ,illustration3 ,,fig4 #dg4--;,interior construction of a combination hot-water and hot-air furnace4 ,combination ,hot-air and ,hot-water ,heater4--,in the case of large houses heated by hot air it is sometimes better to use two or more furnaces than to attempt to carry the heat long distances in the customary pipes4 ,where heat is required in rooms located at a distance more than #cj feet1 it is advisable to use a combination hot-air and hot-water heater1 the distant rooms being heated by hot-water radiators4 ,a furnace arranged for such a combination is shown in ,fig4 #dg4 ,this furnace contains1 first1 the essential features of a hot-air furnace2 next1 it includes a hot-water plant4 ,the fire-box and air-heating surfaces are easily recognized4 ,the arrows show the course of the air entering at the bottom of the furnace1 which after being heated by passing over the heating surfaces1 escapes at the openings marked warm air1 to the distributing pipes4 ,illustration3 ,,fig4 #dh4--,the hot-air furnace as it appears in the house4 ,inside the air-heating surfaces are three hollow cast-iron pieces ,w1 that form a part of the walls of the fire-box4 ,these pieces1 with their connecting pipes1 form the water-heating part of the furnace1 which supplies the hot water for the radiators4 ,the pieces ,w1 with the connecting pipes and radiators1 form an independent heating plant1 with a fire-box in common with the hot-air furnace4 ,the returning water from the radiators enters the heating surfaces ,w1 through the pipe marked return pipe4 ,the heated water is discharged from the heaters into that marked flow pipe which conducts it to the radiators4 ,such a furnace is1 therefore1 two independent systems1 one for hot air and the other for hot water1 but with a single fire-box4 ,this furnace1 like the simple hot-air furnace1 is rated1 first in the amount of space it will heat with hot air and in addition1 by the number of square feet of hot-water radiating surface that will be kept hot by the hot-water heater4 ,in ,fig4 #dh is shown the location of the furnace in a cottage with the conducting pipes to the various rooms4 ,the registers in the first floor are generally set in the floor but if desired they may be placed in the walls4 ,those on the second floor are placed in the walls because of convenience4 ,the conducting pipes pass through the partitions between the studding4 ,illustration3 ,,fig4 #di4--;,details of air ducts and damper regulator used with the hot-air furnace4 ,in all well-arranged hot-air heating plants provision is made so that the air for heating may be taken from the outside4 ,it does not follow that the supply of fresh air should always come from outdoors2 there are times during extremely cold weather1 accompanied by high winds1 when ventilation is ample without the outside source of supply4 ,since it is never desirable to take the air supply from the basement1 such an arrangement as is shown in ,fig4 #di1 or a modification of the same plan is commonly employed4 ,the duct ,a from the outside and ,b from the rooms above connect with the air supply for the furnaces4 ,a damper ,c arranged to move on a hinge1 is so placed as to admit the air from either source as desired4 ,the damper may be placed so as to take part or all of the air from the outside by adjusting the handle at the proper place4 ,,chapter ,,iv ,,temperature ,,regulation ,the method used for regulating the temperature of a house will depend on its size1 the conditions under which it is to be used and the method of heating4 ,in small houses the temperature may be satisfactorily governed entirely by hand1 that is1 the furnace drafts may be changed by hand to suit the varying conditions of temperature4 ,a more satisfactory method is that of thermostatic regulation1 in which a thermostatic governor and a motor automatically control the furnace dampers so as to keep a constant temperature at one point1 generally the living room4 ,where hot-water or steam heating plants are used1 another device is frequently employed to keep the temperature of the heat supply at a constant degree4 ,this is known as the automatic damper regulator4 ,the damper regulator is one of the boiler accessories which so governs the drafts of the furnace as to keep a constant water temperature in the hot-water heater or a constant steam pressure in the steam boiler4 ,in some cases both the damper regulator and the thermostat are used as a more complete means of temperature control4 ,hand ,regulation4--,as a means of changing the dampers of the furnace from the floor above1 to suit the prevailing conditions1 the arrangement shown in ,fig4 #di does away with the necessity of a journey to the basement1 to remedy each change of temperature4 ,a plate is fastened to the wall at any convenient place1 to which the end of a chain is attached as shown in the figure4 ,this connects with a second chain1 the ends of which are fastened1 one to the direct draft or ash-pit damper ,f1 and the other to the check draft ,e1 in the chimney4 ,as the furnace appears in the drawing1 the direct draft is closed and the check draft is open4 ,by changing the ring from ,g to ,h1 the movement of the chain opens ,f1 and closes ,e1 admitting air to the furnace4 ,when the temperature of the room is raised sufficiently1 the drafts are restored to their original position by replacing the ring at ,g4 ,sometimes one or more intermediate points are made on the plate between ,g and ,h1 which permits both drafts to be kept partly open and fewer changes are required to keep the temperature approximately normal4 ,illustration3 ,,fig4 #ej4--;,cross-section of damper regulator for steam boiler4 ,illustration3 ,,fig4 #ea4--,steam boiler for house heating1 with the damper regulator1 in place1 attached to the dampers4 ,damper ,regulator for ,steam ,boiler4--,the damper regulator used on a steam boiler is a simple device that automatically controls the draft dampers by reason of the changing pressures of the steam4 ,the object of the damper regulator is to prevent the generation of steam in the boiler beyond a certain pressure at which the valve is set4 ,this point is usually #c or #d pounds below the pressure at which the safety valve would act4 ,if in proper working order the damper regulator will so control the dampers that the boiler will always contain a supply of steam1 but the pressure will not reach a point requiring the action of the safety valve4 ,fig4 #ea illustrates its connections with the furnace dampers4 ,in ,fig4 #ah the regulator appears at ,d4 ,in external appearance and in operation of the dampers1 it is the same as the regulator for a hot-water boiler but its internal construction is simpler4 ,fig4 #ej shows its construction4 ,it is attached to the steam space of the boiler at ,e4 ,the steam pressure acts directly on the flexible metallic diaphragm ,b4 ,as the pressure of the steam approaches the desired amount the diaphragm is raised and with it the lever ,v4 ,a chain ,d1 attached to the end of the lever1 opens the check draft1 and another at ,c closes the draft damper4 ,when the steam pressure falls1 the diaphragm lowers the lever and the dampers are restored to their original position4 ,the same movements are repeated with each rise and fall of the steam pressure4 ,illustration3 ,,fig4 #eb4--;,damper regulator for hot-water boiler4 ,damper ,regulators for ,hot-water ,furnaces4--,the damper regulator for a hot-water boiler automatically controls the dampers of the furnace so as to keep the water of the boiler approximately at a constant temperature4 ,the regulator is shown in ,fig4 #eb4 ,the ends of the lever are connected to the direct-draft and check-draft dampers1 as in the case of the damper regulator for the steam plant4 ,a cross-section of the working parts shows the details of construction4 ,the lever d is operated by a diaphragm g1 which tightly covers a brass bowl1 containing a mixture of alcohol and water1 of such proportions as will produce a vapor pressure at the desired temperature1 say #bjj4 ,the hot water from the boiler passes through the valve1 entering at a and leaving at b4 ,when the water reaches the desired temperature1 the contained liquid vaporizes and a pressure is produced that is sufficient to lift the diaphragm and the lever4 ,the chain attached to the right-hand end closes the direct-draft damper2 at the same time the other end of the lever opens the check draft1 and the supply of air to the furnace fire is entirely cut off4 ,as soon as the water has cooled sufficiently1 the vapor pressure in the bowl is reduced1 allowing the weight ,w to depress the diaphragm and the lever is restored to its first position4 ,the weight ,w is for adjusting the valve to the desired temperature4 ,the plug f tightly closes the orifice through which the liquid is introduced into the bowl4 ,the object of the damper regulator on a hot-water boiler is to govern the fire of the furnace so as to keep the water in the boiler at the desired temperature4 ,in case there is a demand for heat at any part of the house1 a supply of hot water will always be on hand4 ,it has nothing to do with the regulation of the temperature of the house4 ,the control of the house temperature is the office of the thermostat4 ,the thermostat is a mechanical device for automatically regulating temperature4 ,it may be arranged to operate the valve of a single radiator or register and so control the temperature of a room1 or as commonly used in the average dwelling1 the controller may be placed to govern the temperature of the living room and in so doing keep the furnace in condition to satisfactorily heat the remainder of the house4 ,thermostats are made in a variety of forms by different manufacturers but they may be divided into two general classes3 the electric1 and the pneumatic types4 ,the electric thermostat depends on an electric current as a means of controlling the action of the motor which in turn operates the furnace dampers so as to maintain a constant heat supply4 ,the pneumatic thermostat regulates the supply of heat by means of pneumatic valves4 ,it will be considered later in discussing mechanical ventilation4 ,this type of temperature regulation is particularly adapted to large buildings4 ,fig4 #ec illustrates one style of electric thermostat that is very generally used for temperature regulation in the average dwelling4 ,it consists of three distinct parts--the controller1 the electric battery and the motor4 ,in the drawing the motor is shown connected with a steam valve1 such as may be used for furnishing steam for a series of radiators4 ,it may with equal facility be attached to the dampers of a furnace or other heating apparatus4 ,the controller occupies a place on the wall of the room to be heated and makes electric connections between the battery and the motor4 ,whenever the temperature varies from the required degree1 a change of electric contact in the controller starts the motor1 and the radiator valve or the furnace drafts are opened or closed as occasion requires4 ,the controller appears in ,fig4 #ed as commonly seen in use4 ,the upper part carries a thermometer and the pointer ,a indicates the temperature to be maintained in the room4 ,the middle division indicates #gj;,f4 ,each division to the right of the middle point raises the temperature #e4 ,each division to the left lowers the temperature a like amount4 ,in addition to the ordinary type this controller is furnished with a time attachment by means of which the controller may permit the temperature of the room to fall to any desired degree at night and raise it again in the morning at the time for which it is set4 ,this is accomplished by a little alarm clock shown at the bottom of the controller in ,fig4 #ed4 ,the indicator ,b is arranged to correspond with the indicator ,a2 the middle point representing #gj;,f4 ,to set the time attachment1 the alarm is wound and set as in any alarm clock1 #a_/b hour earlier than the desired time for rising4 ,the indicator ,b is set for the day temperature and ,a is set for the temperature desired during the night4 ,at the appointed time the alarm moves the indicator ,a to the desired point for the day and the controller raises the temperature accordingly4 ,fig4 #ee shows the mechanism that is exposed to view when the cover of the controller is removed4 ,the bent strip ,c is the part that is influenced by the change of temperature4 ,it is made of two thin strips of metal1 one of brass and the other of steel4 ,the two strips are soldered firmly together4 ,any change in temperature will affect the strip and cause it to bend and touch the contact point--,k or ,j4 ,the bending of the strip is due to the unequal expansion of the brass and steel due to the change of temperature4 ,brass expands #b4d times as much as steel with the same change of temperature4 ,the amount of bending is sufficient to make an appreciable movement in a small fraction of a degree change4 ,the brass part of ,c is on the left and since it expands the greater amount1 a rising temperature causes ,c to come into contact with the point ,j4 ,when this happens the motor is started and makes one-half cycle4 ,in so doing it shuts off the air supply of the furnace1 opens the check draft and at the same time the motor changes the electric contact from ,j to ,k4 ,when the temperature begins to fall1 the brass contracts in the same ratio to the steel as it expands during the rising temperature and as a consequence the bar bends to the left4 ,when the strip touches the point ,k the motor again makes one-half circle1 admitting air once more to the furnace1 closes the check draft and shifts the electric contact back to ,k4 ,when properly started the thermostat will regulate the temperature within a degree of temperature4 ,the ,thermostat ,motor4--,the thermostat motor automatically opens and closes the furnace dampers or the valve that admits steam to the radiators as heat is demanded by the controller4 ,the motor1 as shown in ,fig4 #ec1 consists of a system of gears and a brake ,s1 which regulates the speed1 a cam ,m1 and armature ,i1 for starting and stopping the motor1 and the electromagnet ,h-,h which operates the bar ,i4 ,two lever arms ,l1 one in front and the other at the back of the motor furnish means for attachment to the valve or furnace dampers4 ,an emergency switch at ,d is shown in detail in ,fig4 #ef4 ,the battery ,b furnishes the current which energizes the magnets and an iron weight supplies the motive power for the motor4 ,the description of the operation of the motor applies to the steam valve shown in ,fig4 #ec4 ,the same motor might be used for opening and closing of the dampers of the furnace in any kind of heat supply4 ,the method of communicating the motion of the motor arms to the dampers of the furnace will be described later4 ,the connections with the furnace drafts are shown in ,figs4 #c1 #f1 #h1 #cd1 etc4 ,suppose that the valve for admitting steam to the radiators1 as that in ,fig4 #ec1 is closed and that the temperature of the house is falling4 ,the strip ,c of the thermostat controller is moving toward ,j4 ,when contact is made1 the current from the battery ,b energizes the magnets ,h-,h and the bar ,i is lifted4 ,as the bar ,i is raised the catch ,j is released and permits the motor to start4 ,the bar ,i is held suspended by the cam ,m until the arm ,l has made one-half revolution1 when the lug ,k drops into the depression in the cam made to receive it and the catch ,j engages with the brake and stops the motor4 ,illustration3 ,,fig4 #ec4--,thermostat complete with the regulator1 battery and motor1 attached to a steam supply valve4 ,during this movement the arm ,l has lifted the valve arm ,n and the valve admits steam to the radiators1 at the same time the contact ,m has been shifted from the right-hand contact to the left1 and the electric circuit is ready to be made in the controller at the point ,k4 ,when the temperature has fallen a sufficient amount the controller bar ,c will make contact at ,k and the motor will again make a half cycle1 changing the valve back to its original position4 ,this process will be kept up so long as the motor is wound and there is sufficient fuel in the furnace to raise the temperature4 ,fig4 #ee shows the method of connecting the electric wires from the battery to the controller4 ,a three-wire cable connects the battery1 and makes contacts as indicated at ,h1 ,k and ,j4 ,the wires are shown attached to the motor as in ,fig4 #ee4 ,a wire is taken from either pole of the battery and attached to one of the ends of the magnet coil4 ,passing through the magnet the wire is attached to the frame of the motor4 ,this makes the cam ,m a part of the electric circuit4 ,the other two wires are attached to the brass strips on each side of the arm ,l4 ,the strips are insulated from the frame4 ,the electric circuit through the magnet is made alternately by contact with the strips at right and left of the arm ,l4 ,illustration3 ,,fig4 #ed4--,thermostatic regulator with clock attachment for control of day and night temperature4 ,in case the motor1 through neglect1 runs down1 a safety switch at ,d 7,fig4 #ec7 disconnects the battery and keeps it from being discharged4 ,this switch is shown in detail in ,fig4 #ef4 ,when the weight has reached its limit1 the piece ,c on the chain comes into contact with ,d and lifting it out of contact1 breaks the circuit4 ,when the motor is again wound1 ,c engages with ,e and restores the contact4 ,the switch is so arranged that when open1 the valve will always be closed4 ,illustration3 ,,fig4 #ed;,a4--,showing the clock attachments to the thermostatic regulator4 ,illustration3 ,,fig4 #ee4--,mechanism of the thermostatic regulator4 ,combined ,thermostat and ,damper ,regulator4--,it is evident that1 in heating a house by steam1 the damper regulator governs only the steam pressure of the boiler4 ,in the use of a thermostat alone1 the regulation is that of the temperature of the rooms only1 and has nothing to do with the steam pressure4 ,as an example3 ,suppose that in cold weather the house is cold and that the gage of the steam boiler shows no pressure4 ,the desire is to get up steam as soon as possible4 ,in so doing a hot fire is made with a large amount of fuel4 ,as soon as the steam begins to form1 the pressure rises rapidly4 ,when the radiators have become hot and the steam is no longer taken away as fast as it is formed1 the pressure of the steam in the boiler keeps on rising4 ,the thermostat will not close the furnace dampers until the temperature of the rooms is normal4 ,this may require so great a length of time as to produce a great excess of steam that cannot be used at the time and the pressure will be relieved by the safety valve4 ,this may not be dangerous but it is disagreeable4 ,to prevent the safety valve from blowing except in case of emergency1 a combined thermostat and draft regulator is used4 ,in such a combination1 the draft regulator closes the draft as soon as the pressure reaches the desired point1 after which the thermostat does the regulating according to suit the temperature of the house4 ,in ,fig4 #b is shown such a combination attached to a boiler4 ,the cord from the regulator1 instead of extending directly to the direct-draft damper1 passes over the pulley ,p and connects to the thermostat cord4 ,the regulator may now close the damper to suit the steam pressure1 but after the temperature in the rooms is normal1 the amount of heat necessary to maintain the desired degree is regulated entirely by the thermostat which opens and closes the dampers regardless of the position of the damper regulator4 ,if occasion should require but a very slight amount of steam to keep the house at the desired temperature1 the thermostat will govern the drafts aright4 ,if the steam pressure is in danger of becoming excessive1 the damper regulator will govern the drafts4 ,illustration3 ,,fig4 #ef4--;,automatic switch which opens the battery circuit when the thermostat motor weight1 reaches its limit4 ,thermostat-motor ,connections4--,the arrangement of cords and pulleys used for attaching the thermostat motor to the furnace dampers will depend very much on local conditions4 ,the motor can be placed in any convenient position so that the connecting cords will act most directly4 ,the motor opens and closes the direct draft and check draft in accordance with the demand for heat4 ,the connections for all kinds of furnaces are made in much the same manner4 ,the pulleys supplied with the motor are placed to work as freely1 and the cords to pull as directly as possible4 ,in ,fig4 #eg the motor is connected with a hot-air furnace4 ,the cord ,d is attached to the front arm of the motor and connects with the direct-draft damper ,f4 ,the cord ,c connects the rear arm of the motor with the check-draft damper at ,e4 ,in the position of the dampers shown1 the direct-draft damper is closed and the air is entering the chimney through the check draft ,e4 ,while this damper is open there is very little induced draft to supply the fire with air that might leak through the crevices around the ash-pit door1 but the gases from the furnace are completely carried away to the chimney by the air entering at ,e4 ,illustration3 ,,fig4 #eg4--,thermostat motor connected with the dampers of a hot-air furnace4 ,in ,figs4 #c1 #f1 #h1 #cd1 etc41 the same motor is connected with the furnaces of various other systems of heating4 ,the object is the same in all2 when less heat is required1 the air supply is cut off and the furnace fire subsides2 when more heat is demanded the air is again admitted to produce greater combustion4 ,the check draft is an important feature as it checks the flow of air through the furnace regardless of the position of the direct-draft damper4 ,even should the direct draft be left open1 the check draft when open would destroy in a great measure the supply of air entering the furnace4 ,,chapter ,v ,,management ,,of ,,heating ,,plants ,the following instructions on the care and management of steam and hot-water heating plants is printed with permission of the ,american ,radiator ,co4 ,they were prepared as a guide to the successful operation of the ,ideal heating plants but apply with equal force to other plants of a similar character4 ,general ,advice4--,no set rules can be given for caring for every boiler alike--chimney flues are not alike--some have strong draft1 some are average and some are weak4 ,there is much more difference in the heat-making qualities of coal than is commonly known1 and it is important that the right size coal for the draft be used4 ,these rules apply to most all fuels4 ,a little trying of this way or that way of leaving the dampers 7when regulators are not used7 often discovers the better way4 ,it is well to vary from the rules a little if any of them do not seem to bring about the best results4 ,with good1 average chimney flue draft and the right kind of fuel1 these rules will govern the large majority of cases4 ,the ,economy of ,good ,draft4--,in many cases a boiler with sluggish draft will burn more coal than a boiler with good draft4 ,in the first case the fuel may be said to 8rot0--in lacking air supply the gases pass off unburned4 ,the 8nagging0 which a boiler has to take under these conditions increases the waste of fuel4 ,a boiler under sharp1 strong draft maintains a clear intense fire and burns the gases--getting the larger amount of heat from the coal4 ,general ,firing ,rules4-- #a4 ,put but little coal on a low fire4 #b4 ,when adding coal to the boiler1 open the smoke-pipe damper 7inside the smoke pipe7 and close the cold-air check damper4 ,this will make a draft through the feed doorway inward and prevent the escape of dust or gas into the cellar when the feed door is open to take fuel4 ,put these parts back to their regular places after feeding4 #c4 ,when it can be done1 in feeding a large amount of coal 7as for night7 leave a part of the fire or flame exposed1 so that the gases may be burned as they arise4 #d4 ,when a regulator is not used1 learn to use the dampers correctly and according to the force of the chimney draft4 ,learn to use cold-air check damper4 ,often1 when closing1 the ash-pit draft damper does not check the fire enough2 opening the cold-air check damper will check it about right4 ,increasing or lessening the pressure of a steam boiler must be done by changing the weight on the regulator bar4 #e4 ,carry a deep fire or a high fire2 let the live coals come up to the feed door--even in mild weather when from #d to #f inches of ashes stand on the grate4 ,illustration3 ,,fig4 #eg;a4--,indicates the general condition of the furnace fire during very cold weather4 ,the fuel should fill the fire-pot to ,c4 ,the ashes should not be allowed to accumulate beyond ,b1 on the grate4 ,there should be no more ashes than appear at ,h1 in the ashpit4 #f4 ,in severe weather give the heater the most careful attention the last thing at night4 #g4 ,do not overshake or poke the fire in mild weather2 once in a while shake enough to give place for a little more fuel4 #h4 ,do not let ashes bank up under the grate in ash-pit4 ,grate bars are very hardy1 but it is possible to warp them with carelessness4 ,taking up the ashes once a day is the best rule1 even if but little has fallen into the pit4 #i4 ,keep the boiler surfaces and flues clean2 a crust of soot #a_/d inch in thickness causes the boiler to require half as much more fuel than when the surfaces are clean4 #aj4 ,if convenient1 have a water hose to spray the ashes when cleaning out the pit4 #aa4 ,attend the boiler from two to four times per day4 ,in mild weather1 running with a checked fire1 morning and night is usually often enough4 ,in severe weather1 once in early morning1 again at mid-day1 again at five or six o'clock and finally thorough attention at from nine to eleven o'clock in the evening4 #ab4 ,if1 through burning poor coal1 the fire pot gets full of ashes1 or slate and clinkers massed together1 the quickest way to get a good active fire is to dump the grate and then build a new fire--from the kindling up4 #ac4 ,if a hard clinker lodges between the grate bars1 do not force the shaking1 but first dislodge the mass with a poker or slicing bar4 ,then the grate will operate without damage4 ,weather and ,time of ,day4--,in severe weather keep the fire pot full of coal1 and run the heater by the dampers or regulator 7if one is used74 ,thoroughly clean the grate twice a day4 ,let the top of the fire in front be level with the feed door sill4 ,bank up the coal higher to the rear4 ,in moderate weather there should be from #b to #f inches of ashes between the live coal and the grate4 ,as the weather grows colder keep the grate and the fire pot a little cleaner--sometimes it helps to run the poker or slicing bar over it through the clinker door4 ,with some fuels this is never necessary4 ,night ,firing4--,in very cold weather1 when the house should be kept warm all night1 clean the grate well at a late hour--the last thing4 ,clear the bottom of the fire pot of all ashes and clinkers so that the grate is covered with clear-burning1 red-hot coals1 then fill the pot full of fuel4 ,if possible1 leave some of the flame exposed to burn the gases4 ,leave the drafts on long enough to burn off some of the gas1 then check the heater for the night4 ,thus there is plenty of coal to burn during the night and some on which to commence early in the morning4 ,some drafts do not make it necessary to leave the dampers on to burn off the gas after feeding4 ,with the ash-pit draft damper closed and the cold-air check damper open at night1 but part of the coal is burned and there is much of it not burned in the morning4 ,so1 by reversing the dampers in the early morning the fire starts up quickly and often the house may be well warmed before any coal is put into the fire pot4 ,some boilers are run the other way--a very poor way4 ,if the grate is cleared off in very cold weather and coal added at five or six o'clock in the afternoon1 by eleven o'clock at night nearly one-half of the coal is burned and the grate is covered over with a mass of ashes and clinkers4 ,with little coal remaining1 to shake the grate will quite likely put out the remaining fire2 to put fresh coal on a low fire reduces further its declining temperature4 ,the result is a cold house that will grow colder until a new fire is started4 ,often in cold weather with this poor way of night firing1 it takes one or more hours of forced firing to warm the house in the morning1 and all the coal saved the night before is more than used to get the house or building 8heated up0--while the people who should be comfortable have to get up1 bathe and take breakfast in chilly rooms4 ,at no time in the day is heat more wanted than about the time of getting up and starting the day4 ,a fire well cared for late in the evening makes a warm house all night4 ,and so it follows that it is much easier to add a little more heat in the morning4 ,and surely less coal is burned1 for the forcing of a fire part of the time often overheats1 and wastes coal4 ,first-day ,firing4--,in the morning of moderate winter weather1 with the ash-pit draft damper open1 before adding any coal allow the fire to brighten up if it seems to be low2 then 7for such conditions7 spread over a thin layer of fresh coal and set the drafts for a brisk fire4 ,after the new fire is well started add as much coal as may be necessary to last until next firing4 ,do not shake much if any--just enough to give space for more coal4 ,then by setting the regulator 7if one is used71 or1 by closing the ash-pit draft damper and opening the cold-air check damper a little1 the boiler should keep up its work until the next firing time4 ,in severe weather1 if the boiler has been attended to at night as directed in the section on 8night firing10 the drafts can be turned on and the boiler run for half an hour before adding coal4 ,or1 if more convenient to give it immediate attention1 the grate can be thoroughly shaken and enough coal added to last until mid-day4 ,often the cold-air check damper will need to be entirely closed and the ash-pit draft damper partly open if the heater is a water boiler4 ,if a steam boiler1 the regulator should then be set to maintain the number of pounds of pressure wanted and so left4 ,other-day ,firing4--,in severe weather more coal should be added about noon1 sometimes the draft may be left on for a few minutes and then checked4 ,and in such weather it is often well to give the boiler further attention at five or six o'clock4 ,in severest weather the boiler should not be attended more than four times a day2 and generally not less than three times4 ,often much coal is wasted by 8nagging0 the fire--poking1 shaking and feeding it until it becomes 8dyspeptic40 ,a sure cure is a little common sense in regular feeding1 etc4 ,economy and ,fuels4--,in running many boilers for moderate weather better results follow if the grate is not shaken too much or too often4 ,sometimes in moderate weather a body of ashes on the grate checks the fire and there is enough heat without a useless burning of fuel4 ,many houses are overheated in moderate weather and too much coal burned by running the boiler as for zero weather4 ,so we repeat--it is not wise to overshake or overfeed a boiler in moderate weather4 ,the fire should be in such shape that if a change comes at night there is a basis for a good fire to start on4 ,when the grate is shaken but once during the #bd hours 7during moderate weather7 late at night is the best time4 ,when one stops to think that heating is needed during about #g months out of the year1 and that a greater portion of this time is usually moderate weather when a very little heat is needed1 it must be seen that the science of running the heater to save coal is to apply common sense rules of limiting the feeding and the attention in such periods4 ,in severe weather we believe in giving the boiler a liberal quantity of fuel regularly and at the right time4 ,the time to save coal is when there is no need for burning it4 ,this is where a great many people make errors in running the boiler--in forgetting to 8let up0 on the shaking and feeding in moderate weather4 ,with some drafts and for boilers using hard coal or coke1 good economical results often are secured by opening the feed door a little when it is desired to check the fire in moderate weather4 ,this depends on the draft4 ,for ,burning ,soft ,coal4--,some types of boilers are made to burn soft coal with economy1 with least work4 ,some types are made specially to burn the meaner grades of soft coal4 ,firing to prevent smoke is a source of economy and these ways of running should be followed--specially with large sectional boilers4 ,there are two types of soft coal1 viz43 ,the free-burning coal1 which breaks apart when burning1 allowing the gases to freely escape2 and the fusing-coking coal1 which1 when burning1 first fuses into a solid burning mass with a hard crust over the top1 slowly coking as it burns4 ,the latter kind is most valuable for house-heating boilers because the gases are more thoroughly consumed4 ,the fusing-coking coal is worth about #bj per cent4 more for this purpose than the free-burning coal4 ,the gases should be allowed to pass off from the coal slowly4 ,leave air inlet on the feed door open if draft permits4 ,if possible1 use uniform sizes of coal4 ,avoid using coal having too much dust--the 8run-of-the-mine0 may be lower in price but its heat-making value is also low4 ,for the purpose of slow burning of soft coal1 it is well in feeding at night to let the fire burn up freely so that the coals are very live with heat4 ,then fill in enough coal to last all night--leaving some of the live coals uncovered if possible4 ,with large sectional boilers this exposure should be at the rear of the fire so that the flame will pass over the live coals4 ,thus the gases coming off from the fresh coal are burned and a larger amount of the full heat-producing value of soft coal is made use of and with less smoke4 ,after a boiler is so fed1 the dampers 7unless an automatic regulator is used7 should be left about as follows3 ,ash-pit draft damper open a little or closed1 as draft may require4 ,cold-air check damper open about one-eighth to one-third distance of the opening4 ,smoke-pipe damper about one-half closed4 ,a little experiment with the draft will usually tell the operator the best way of leaving these dampers4 ,it will be found in the morning that the entire charge of coal is well burned or partly coked4 ,the coked fuel1 or that which sticks together in a mass1 should be broken up by the poker and more added generally as by rules given in other sections4 ,it must always be remembered that the soft coals mined in different parts of the country have widely varying heat-making capacities4 ,to obtain satisfactory results brands must be selected which have an established reputation for excelling results in small boilers4 ,for ,burning ,coke4--,it is best to keep the pot full of fuel--keeping a large body of coke under a low fire rather than a little fuel under a strong fire4 ,it must be remembered that coke makes a very 8hot fire0 because the coke is free-burning4 ,care should be taken not to leave drafts on too long in boilers not having regulators4 ,coke burns best for house-heating purposes with less draft than is required for coal1 therefore to keep a low fire the ash-pit draft damper should be kept closed1 and the smoke-pipe damper almost entirely closed4 ,the regulator 7when used7 can be set to keep the dampers about as here advised4 ,coke is practically smokeless and its quick-burning character makes a cut-off damper in the smoke pipe 7which will stay fixed as it may be set7 quite necessary4 ,it is well to keep a layer of ashes on the grates and when shaking stop before red-hot coals come through the grate4 ,the coke then burns more slowly1 which increases its effectiveness4 ,with some drafts it may be well to 8bank the fire0 at night with coke--pea coal size4 ,this is a matter of experiment1 and depends on the character of the chimney draft4 ,fire should be tended regularly--two times a day1 or four at the outside4 ,with an extra strong draft1 at night the fuel should be packed down by tamping with the back of a shovel4 ,with ordinary condition of draft1 crushed coke1 small egg size1 should be used4 ,other ,rules for ,water ,boilers--,to ,fill ,system4--,open the feed-cock when the heater is connected with a city or town water supply2 if not1 fill by funnel at the expansion tank4 ,fill until the gage-glass on the expansion tank shows about half full of water4 ,in filling the system see that all air cocks on the radiators are closed4 ,then beginning with the lower floor1 open the air cocks on each radiator1 one at a time1 until each radiator is filled2 then close the air cock and take the next radiators on upper floors until all are filled1 after which let the water run until it shows in the gage-glass of the water tank4 ,after the water is heated and in circulation1 vent the radiators by opening the air valves as before4 ,then again allow the water to run into the system until it rises to the proper level in the expansion tank gage-glass4 ,always keep the apparatus full of water unless the building be vacated during the winter months1 when the water should be drawn off to prevent freezing4 ,never draw water off with fire in the heater4 ,to draw off water1 open the draw-off cock at the lowest point in the system1 and then open air cocks on all radiators as fast as the water lowers beginning with the highest radiator4 ,air-vent ,valves on ,radiators4--,in order to secure the full benefit of the heating surface of a hot-water radiator1 the inside of the section must be free of air4 ,when a radiator is 8air-bound0 it means that parts of the sections are filled with air in pockets which remain until the air is allowed to pass off through the vent valve4 ,air will gather from time to time at the highest points inside the radiators1 especially in those placed in the upper stories of the building4 ,these air accumulations inside cut down the working power of a radiator exactly in proportion as they rob the inside of the casting of proper contact with heated water4 ,air pockets not only reduce effective heating surface1 but they also prevent the circulation of hot water4 ,therefore1 it is well once in a while to take the little key provided by the heating contractor and open the air valves on radiators to allow the air 7if any7 to escape4 ,when a radiator does not work as well as usual1 open the air valves until the water flows1 which indicates that the air has been fully released4 ,then close the valve4 ,valves on ,cellar ,mains4--,if cut-off valves have been placed on the main and return pipes in the cellar1 see that the valves on one line of main and return pipes 7at least7 are open when the boiler is under operation4 ,be sure that the system is open to circulate water through the supply and return pipes before building a fire in the boiler4 ,end of the ,season4--,at the close of the heating season clean all the fire and flue surfaces of the boiler4 ,let the water remain in the system during the summer months4 ,no bad results will follow if the system is not refilled more often than once in #b or #c years4 ,but1 generally1 it is thought that best results are secured by emptying the system once a year 7after fire is out7 and refilling with fresh water4 ,it is a very good idea to take down the smoke pipe in the spring1 thoroughly clean and put it back in place4 ,leave all doors open on the boiler in the summer time4 ,other ,rules for ,steam ,boilers--,to ,fill ,boiler4--,open the feed-cock when the heater is connected with city or town water supply2 if not1 fill through the funnel4 ,let the water run until the gage-glass shows about half full of water4 ,in the first filling1 after the water has boiled1 get up a pressure of at least #aj pounds1 draw the fire and blow off the boiler under pressure through draw-off cock to remove oil and sediment1 after which refill with fresh water to the water line4 ,this is best done usually by the steam-fitter4 ,the damper regulator will control the pressure of steam1 closing the damper when the pressure is raised beyond the desired point and opening the damper when the pressure falls below that point4 ,by removing the weight on the lever1 different degrees of pressure can be kept up4 ,the regulator should be allowed to control the drafts without interference4 ,examine the water glass often to see that the water line is at the proper height4 ,if lower than normal open the supply pipe until the water runs in and stands at the proper level4 ,it is best when no water stands in the glass1 nor shows at the bottom of the try-cock1 to quickly dump the grate and do not put water into the boiler again until it is cooled off4 ,if there is one or more shut-off valves on the main or return pipes1 before starting a fire see that one line of piping at least 7main and return7 is open to circulate the steam4 ,to ,control ,radiators4--,when it is desired to shut off steam from any radiator 7if the regular radiator valves are used71 close the valve tight1 and when it is turned on see that the valve is wide open4 ,a valve partly turned off will cause the radiator to fill with water4 ,this rule applies only to one-pipe heating systems4 ,the ,air ,valves4--,if little keyed air valves 7sometimes called 8pet-cocks07 are used1 follow generally the same directions as outlined for hot-water radiators on page #di--only1 of course1 in releasing the air from the radiator open the valve with the key provided and close it just as soon as the steam unmixed with air comes through the nose of the valve4 ,if 8automatic0 air valves are used they must be carefully adjusted by the steam-fitter and then left to operate without undue interference4 ,end of the ,season4--,at the close of the heating season fill the steam boiler with water to the safety valve and let it thus stand through the summer4 ,also thoroughly clean all the fire and flue surfaces of the boiler and at the opening of the next season withdraw the water and refill with fresh water to the water line1 starting the boiler as before4 ,it is advisable to have a competent steam-fitter blow off the boiler under pressure and thus give the inside a thorough cleaning when the boiler is first set up and ready for fire4 ,a low-pressure boiler1 using good water1 rarely needs blowing off after it is once cleaned at time of setting up4 ,,the ,,right ,,chimney ,,flue ,the area of the flue should never be less than #h inches in diameter if round1 or #h by #h inches if square--unless for a very small heating boiler or tank heater4 ,nine or #aj inches round1 or #h by #ab rectangular is a good average size4 ,the flue should generally have a little more area than that of the connecting smoke pipes4 ,draft force depends very much on the height of the flue4 ,the chimney top should run above the highest part of the roof and should be so located with reference to any higher buildings nearby that the prevailing wind currents will not form eddies which will force the air downward in the shaft4 ,often a shifting cowl which will always turn the outlet away from the source of adverse currents will promote better draft4 ,the flue should run as nearly straight up from the base to the top outlet as possible4 ,it should have no other openings into it but the boiler smoke pipe4 ,sharp bends and offsets in the flue will often reduce the area and choke the draft4 ,the flue must be free of any feature which prevents a free area for the passage of smoke4 ,the outlet must not be capped with any device which makes the area of the outlet less than the area of the flue4 ,the best form of flue is a round tile--in such there is less friction than in the square form and the spiral ascent of the draft moves in the easiest and most natural manner4 ,if the flue is made of brick only1 the stack should be at least two #d-;inch courses in thickness4 ,if there is a soot pocket in the flue below the smoke-pipe opening1 the clean-out door should always be closed4 ,if this soot pocket has other openings in it--from fireplaces or other connections--such arrangements are very liable to check the draft and prevent best action in the boiler4 ,the smoke pipe should not extend into the flue beyond the inside surface of the flue1 otherwise the end of the pipe cuts down the area of the flue and injures its drawing capacity4 ,the inside of a flue should be smooth 7pointed or plastered74 ,when the courses are laid with the mortar bulging out from the joints the friction within the flue is very much increased4 ,often a troublesome flue is corrected by lowering some sharp-edged weight by a rope which should be worked against the sides of the flue until the clogging is scraped off4 ,a new chimney when 8green0 will not have a good drawing capacity4 ,short use dries out the mortar and better results follow4 8,smokey0 ,chimneys4--,the failure of draft in flues may be due to a variety of causes1 one of which is illustrated in ,fig4 #eg;b4 ,the short chimney on the left side of the roof shows the course of the wind as it passes over the ridge of the roof and why the draft in such a chimney is retarded whenever this condition exists4 ,the force of the wind1 as it comes into contact with the roof1 causes a compression of the air on the windward side and a rarification on the lee side4 ,this inequality of pressure causes a downward sweep of the wind as indicated by the arrows4 ,the effect on the low chimney is to retard the draft and sometimes the pressure is great enough to reverse the action of the flue and force the smoke into the house4 ,the only remedy for such a condition is an extension of the chimney that will raise its top above the ridge4 ,illustration3 ,,fig4 #eg;b4--,effect of the wind in causing down draft in low chimneys4 ,the same effect is often produced by a neighboring building or a border of trees that are higher than the chimney and dense enough to effect the wind pressure4 ,,chapter ,,vi ,,plumbing ,the term plumbing is usually understood to cover all piping and fixtures that carry water into the house and remove the waste material in the form of sewage4 ,it does not include the pipes of the heating system4 ,although the work of installing heating plants is frequently done by plumbers1 pipe fitting and plumbing are two distinct trades4 ,in the process of building a house the rough plumbing is put into place as soon as the structure is enclosed and the rough floors are laid4 ,the rough plumbing includes the soil pipe1 into which the waste pipes from the various fixtures empty1 and those pipes which must occupy a position inside the partition walls and beneath the floors4 ,the connections here described are for a city dwelling and apply to the custom of local conditions4 ,the same system might be used for a country residence except in regard to the water supply and method of sewage disposal4 ,plants of this type are discussed in the chapter on septic tanks4 ,fig4 #eh shows a cross-section of the street1 exposing the sewer ,s1 the water main ,w1 and the connections with the house4 ,the side of the house has been removed to permit a view of the water and sewer pipes1 connecting with the bathroom1 kitchen1 laundry and other basement fixtures4 ,the lateral sewer or house drain1 which connects the house with the street sewer ,s1 is provided with a trap ,g1 located1 in this case1 just outside the basement wall4 ,the house drain is made of vitrified tile1 laid so as to grade into the street sewer with the greatest possible pitch4 ,the sections are laid as true as conditions will permit and the joints are all carefully filled with cement mortar to prevent leakage4 ,the object of the trap ,g is to prevent sewer gas from entering the house from the main sewer4 ,the trap prevents the gas from passing because the water in the bend of the trap forms a water seal1 beyond which the polluted air from the sewer cannot travel4 ,illustration3 ,,fig4 #eh4--;,cross-section of a city street showing the watermain and sewer pipe with their connections to a dwelling4 ,next inside the trap is the vent pipe ,e1 that extends to the surface of the ground4 ,in this case it is just outside the basement wall4 ,the top is covered with a metal cap4 ,another arrangement often made to accomplish the same purpose is shown in ,figs4 #fa and #fb1 where a piece of soil pipe in the form of a bend is made to take the place of the cap4 ,inside the basement and extending up through the partition walls to the roof is the waste stack or soil pipe ,a4 ,this pipe as is explained in detail later1 is made of cast iron and is put together with calked lead joints4 ,the top of the stack at the point where it passes through the roof is shown in ,fig4 #ei4 ,in extending through the roof the pipe ,a must make a water-tight joint to prevent water from leaking through4 ,this is accomplished by means of the metal plate ,d1 which is set under the shingles and the piece ,c1 that is soldered to ,d4 ,the joint between ,c and ,a is best made with lead the same as the other joints of the stack4 ,in the case of very high stacks1 the bottom should be supported by a pier or iron pipe rest4 ,besides being supported at the base the stack should be secured to the side walls or floor beams at each floor4 ,this is to keep the pipe from moving out of place and the consequent opening of joints4 ,illustration3 ,,fig4 #ei4--;,detail of soil pipe connection4 ,illustration3 ,,fig4 #fj4--;,cross-section of cellar-drain4 ,all of the waste pipes from the bathroom1 kitchen and basement drain into the waste stack4 ,the cellar drain for draining the basement is shown at ,t in ,fig4 #eh4 ,it also appears in detail in ,fig4 #fj4 ,the plate ,b1 in the latter figure1 is set flush to the surface of a depression in the floor that serves as a collecting point for water4 ,the floor is constructed to drain toward this point4 ,the plate is perforated to let the water through and is generally hinged so that in case of stoppage the cover may be raised4 ,the bell-shaped piece under the cover surrounds the piece ,c1 to form a water seal when the level of the water is at ,a4 ,in addition to this water seal there is generally a trap between the drain and the sewer as shown in the drawing4 ,the method of connecting the bathroom waste pipes with the stack is shown in ,fig4 #ii and will be described later4 ,all of the sewage of the house is emptied into the stack by the most direct route1 and from the stack it is conducted as directly as possible into the sewer4 ,from the drawing it will be seen that all openings to the sewer are sealed in two separate places1 once at the outlet to prevent the air from the street sewer entering the house drain ,g1 and again at each opening to prevent escape of the sewer gas from the drain into the house4 ,illustration3 ,,fig4 #fa4 ,,fig4 #fb4 ,,fig4 #fa4--;,house drain with outside vent1 and running trap placed inside the basement wall4 ,,fig4 #fb4--;,house drain with outside vent1 and running trap placed outside the basement wall4 ,the openings at ,e and ,a at each end of the stack permit a constant circulation of air for ventilation4 ,the length of the stack and its location causes it to act as a chimney and the draught produced takes the air in at ,e1 and discharges it at the top4 ,in large houses there is sometimes added a vent stack to produce further ventilation1 but in the average dwelling the arrangement here shown covers the common practice4 ,in ,figs4 #fa and #fb are shown in detail two methods of arranging the sewer connections in the basement to permit of the removal of obstructions in case the pipes at any time become stopped4 ,the trap1 vent1 etc41 are easily recognized4 ,with the arrangement as shown in ,fig4 #fb1 the clean-out is so placed as to give access to the inside of the pipe4 ,should an accumulation or obstruction of any kind become lodged in the pipe1 the stop in the clean-out is removed and a flexible metal rod is used to remove the stoppage4 ,the trap outside the wall has an opening through which the obstruction may be reached in case it cannot be removed from the first clean-out4 ,the disadvantage in using the outside trap1 as here shown1 is that it can be reached only by excavation4 ,fig4 #fa shows another common method of installation4 ,here the trap is placed inside the basement wall4 ,this gives an easier means of opening the trap than ,fig4 #fb affords and accomplishes the same purpose4 ,the connections with the stack are the same as in ,fig4 #fb4 ,obstructions in the sewer pipe are most likely to become lodged in the trap and for this reason the trap should occupy a position that is reasonably easy of access4 ,the outside trap as described above is quite generally installed in buildings of all kinds1 but its use is by no means universal4 ,in some communities it is not used at all1 and many plumbers consider it only an added means of causing stoppage and an extra expense to install4 ,the object of the outside trap is to keep the air of the street sewer from entering the house drain4 ,it is at once inferred that the air of the street sewer is more dangerous than that of the house drain4 ,the street sewers1 however1 are ventilated at each street corner and at each manhole4 ,there cannot then be much difference in the air of the two places4 ,the traps on the fixtures that prevent sewer gas from entering the house would be just as efficient if the outside trap did not exist4 ,while the methods shown in ,figs4 #fa and #fb are considered good practice1 there is considerable objection to the vent being placed near the dwelling1 because of the sewer gas that is forced out1 whenever a sudden discharge of water goes into the drain4 ,each time a closet is flushed1 a large volume of water enters the stack and completely fills the pipe4 ,when this occurs1 the descending water forces out the air of the pipe ahead of it1 and a gush of offensive air filled with sewer gases is forced out of the vent4 ,it is evident that such a vent1 located near an open window or where it will reach the nostrils of the inhabitants is a thing not greatly to be desired4 ,outside traps when placed near the surface sometimes freeze4 ,the circulation of air through the vent is occasionally sufficient in cold weather to freeze the water and stop the trap4 ,illustration3 ,,fig4 #fc4--;,corporation cock with lead connecting pipe4 ,water ,supply4--,the water supply taken from the street main is conducted to the house by the pipe shown in ,fig4 #eh1 at ,c4 ,this pipe is generally of lead as piping of that metal is the most durable for underground work4 ,iron used under the same conditions will last only a few years4 ,the connection is made with the water main by use of a corporation cock4 ,this is a special style of cock that is shown in ,fig4 #fc4 ,in the figure the cock is connected with a short piece of lead pipe that is used for making connection with the service pipe in the house4 ,illustration3 ,,fig4 #fd4--;,curb cock as it appears attached to the service pipe4 ,located at the left of ,c1 in ,fig4 #eh1 is the curb-cock1 used for shutting off the water from the city lot4 ,the curb-cock1 being underground1 is reached through an iron tube by means of a wrench attached to a long iron rod4 ,the curb-cock has a protective covering in the form of an iron pipe4 ,the lower end of the pipe screws into the body of the cock4 ,the top end comes just above the grade line of the curb and is covered with an iron screw-cap4 ,the curb-cock is shown in detail in ,fig4 #fd4 ,the pipe ,b is fastened to the valve at ,d and ,a is the screw-cap4 ,in opening and closing the wrench fits over the part ,c of the valve4 ,on entering the building the supply pipe should be provided with a stop and waste-cock for shutting off the water from the house and draining the pipes that compose the system of circulation4 ,at ,v1 in ,fig4 #eh1 is indicated a stop and waste-cock with the waste pipe ,b connected with the sewer4 ,this cock is shown in detail in ,figs4 #fe and #ff4 ,the cock is so made that when closed there is a small opening at ,a1 that allows the water from the system to escape through the waste pipe4 ,from the water supply1 the cold-water pipes may be traced in the drawing directly to each of the fixtures of the house4 ,the hot-water pipe leaves the range boiler at the top and connects with each fixture using hot water1 thus making the circuit complete4 ,details of the piping which provides hot water is described under range boiler1 page #aaf4 ,illustration3 ,,fig #fe4--,stop and drain cock with lever handle4 ,illustration3 ,,fig4 #ff4--,stop and drain cock with ,t handle4 ,,water ,,cocks ,the development of modern plumbing has brought about the use of a great number of household mechanical appliances1 that have received trade names little understood by the average person4 ,the lack of distinguishing terms1 or language in which to describe plumbing fixtures1 often leads to embarrassment1 when such articles are to be described to workmen4 ,common household valves and cocks are so classified by the trade1 that mistakes are often made in their designation1 because of a limited knowledge of the use of the various articles4 ,a little consideration of the different classes of fixtures will make it possible to state to a tradesman the exact article in question4 ,the term valve is intended to define an appliance that is used to permit1 or prevent1 the passage of a liquid through the opening or port which it guards4 ,the term is so general in its application that there are hundreds of different kinds of valves4 ,even for a single purpose there are many styles of a given kind4 ,a cock was originally a rotary valve or spigot used for drawing water4 ,today there are many kinds of cocks that are not rotary in their movement4 ,it would be impossible in this work to describe in detail all of the kinds of cocks and valves used in household plumbing4 ,it will1 therefore1 be the aim to confine attention to one article of a type and to choose such examples as are in general use and that are good representatives of their classes4 ,illustration3 ,,fig4 #ff;a4--,kitchen sink with ,fuller bibb-cocks4 ,bibb-cocks4--,on the kitchen sink1 the water faucets1 such as those shown in ,fig4 #ff;a1 are termed bibb-cocks by the plumber4 ,if the nozzle is plain1 it is a plain bibb4 ,if the nozzle is threaded so that a hose connection may be attached as in ,fig4 #fg1 it is a hose bibb4 ,bibb-cocks are found in three general styles3 compression bibbs1 ground-key bibbs1 and ,fuller bibbs4 ,the compression bibb takes its name from the method of closing the valve4 ,fig4 #fh gives an example of its mechanical construction4 ,this is a plain solder bibb because the shank ,a is to be attached by a solder joint4 ,if the part ,a contained a thread to make a screw joint1 such as ,fig4 #fg1 it would be a plain1 compression1 screw bibb4 ,fig4 #fh is another style of compression bibb-cock1 largely used on sinks2 this cock1 being finished with a flange1 is a compression flange bibb4 ,illustration3 ,,fig4 #fg4--;,compression hose bibb4 ,illustration3 ,,fig4 #fh4--;,compression flange bibb4 ,illustration3 ,,fig4 #fi4--;,cross-section of plain compression bibb-cock for a solder joint4 ,fig4 #fi shows quite clearly the mechanical arrangement of the compression cock4 ,when the handle is turned the nut ,c lifts the valve from its seat ,b1 allowing the water to escape4 ,the piece ,d is generally made of composition rubber that may be bought at the dealers for a trifling amount but it may be replaced temporarily with a piece of leather4 ,the part ,e is packing1 to keep the water from leaking out around the stem4 ,the packing may be obtained from the dealer especially for the purpose or it may be made of a disc of sheet rubber4 ,in fact1 anything that can be put into the space will answer the purpose temporarily4 ,the valve is closed by compression1 hence the name compression cock4 ,all cocks made to open and close in the same manner are compression cocks4 ,illustration3 ,,fig4 #gj4--;,cross-section of plain self-closing bibb-cock for lead pipe4 ,illustration3 ,,fig4 #ga4--;,cross-section of lever handle1 plain bibb4 ,illustration3 ,,fig4 #gb4--;,cross-section of plain ,fuller bibb for lead pipe4 ,self-closing ,bibbs4--,in ,fig4 #gj is one example of the many styles of self-closing bibb-cocks4 ,when the handle of this cock is turned1 the steep-pitched screw ,a opens the valve and at the same time compresses the spiral spring ,b1 when the handle is released1 the valve is pressed back on its seat by the spring4 ,self-closing cocks are used to prevent the waste of water at drinking fountains1 wash basins and other places where the water is apt to be left running through carelessness4 ,lever-handle ,bibbs4--,fig4 #ga is an example of the lever-handle1 ground-key bibb-cock4 ,the key is the piece ,a1 which is tapered and forms a ground joint with the part ,b4 ,the cock takes its name from the form of the handle4 ,the term ground-key means that the key has been ground into place with emery dust4 ,this cock is kept from leaking by adjustment of the screw ,c4 ,fuller ,cocks4--,these cocks take their name from their inventor4 ,they are made to suit every condition for which water cocks are used4 ,their universal use attests to their utility and excellence in service4 ,fig4 #gb shows the principle on which all ,fuller cocks work4 ,the varying conditions under which the cocks are used require a great many forms1 but the working principle is the same in all4 ,in these cocks1 the valve is a rubber plug or ball that is drawn into the opening by an eccentric piece attached to the handle4 ,the piece ,d in the drawing is the rubber plug that is drawn against the opening by the crank ,b1 which is worked by the lever handle ,a4 ,this cock may be repaired1 in case it leaks1 by unscrewing it at the joint nearest the plug4 ,a wrench and a pair of pliers are all the tools required4 ,the pieces ,d must be obtained from the dealer4 ,the part ,j is the packing that keeps the water from leaking out around the stem4 ,the screw-cap ,h forces a collar ,i down on the packing to keep it water-tight4 ,illustration3 ,,fig4 #gc4--,repairs for ,fuller cocks4 ,the parts for the ,fuller cock that may be obtained for repair are shown in detail on ,fig4 #gc4 ,the ball1 which appears in ,fig4 #gc at ,d1 is the part that receives the greatest amount of wear4 ,if the cock at any time fails to stop the flow of water1 a new ball may be put in place by the aid of a wrench and a pair of pliers4 ,the water being first shut off from the system1 the cock is unscrewed and the cap ,e removed with a pair of pliers4 ,the worn ball is then removed and a new one substituted4 ,wash-tray ,bibbs4--,a special style of cock is made for laundry wash trays in both the ,fuller and compression types4 ,of these the ,fuller type is the most convenient as the handle is placed on the side and but one movement is required to open the cock4 ,this style of cock is used on the wash trays shown in ,fig4 #hc4 ,basin ,cocks4--,water cocks for wash basins are made in two general types--the compression and the ,fuller types of cocks4 ,their mechanism is much the same as for other similar styles adapted to the use for basins4 ,the self-closing cocks used so largely on wash basins are compression cocks4 ,fig4 #gd is an example of ,fuller basin cock in general use4 ,compression cocks for the same purpose are shown on the wash basin in ,fig4 #ij4 ,illustration3 ,,fig4 #gd4--;,fuller basin cock4 ,pantry ,cocks4--,in general form1 pantry cocks are the same as those used for basins except that the outlet is elongated4 ,illustration3 ,,fig4 #ge4--,sill cock in place attached to the water pipe4 ,illustration3 ,,fig4 #gf4--;,cross section of sill cock4 ,sill ,cocks4--,as a means of attaching garden hose or lawn sprinklers1 sill cocks are placed on the side of the building at any place convenient for their use4 ,fig4 #ge illustrates the method of attaching the cock to the water supply4 ,fig4 #gf shows in cross-section its mechanical arrangement4 ,the part ,a is screwed into the water supply1 and ,b furnishes the hose attachment4 ,the valve is operated the same as any other compression valve4 ,in ,fig4 #ge the cock is shown at ,a with a garden hose attached4 ,the pipe to which ,a is attached passes into the basement and connects to the water supply4 ,the stop-cock ,b is used to shut off the water4 ,when the stop-cock ,b is closed1 ,a should be opened1 so that the pipe will drain4 ,if this is neglected during freezing weather1 the pipe is apt to freeze and burst4 ,valves4--,the distinction between a cock and a valve is not at all definite4 ,custom has determined that in certain places a cock shall stop the flow of a liquid but in another place1 perhaps of a similar nature1 a valve shall accomplish the same purpose4 ,the chief distinction between a cock and a valve is that of its external form4 ,in ,figs4 #gg1 #gh and #gi are three examples of valves that are very generally used on pipes carrying any kind of fluid4 ,the valves are shown in cross-section to display the arrangement of the mechanism4 ,illustration3 ,,fig4 #gg4--;,cross-section of globe valve with detachable valve disc4 ,illustration3 ,,fig4 #gh4--;,cross-section of angle globe valve4 ,illustration3 ,,fig4 #gi4--;,cross-section of gate valve4 ,fig4 #gg is an example of the common globe-valve4 ,the name was originally intended to define a valve the body of which was in the form of a globe4 ,the hand-wheel ,h1 attached to the screw-stem ,s1 raises the valve ,a when desired4 ,the valve makes close contact with the seat ,c1 by means of a composition rubber disc ,b4 ,the disc ,b may be renewed when worn out as in the case of the radiator valve already described4 ,fig4 #gh represents an angle globe-valve4 ,in general construction it is quite similar to ,figs4 #ad and #ae1 but the valve ,v in this case is a cone-shaped piece of brass1 which makes a seat in a depression provided for it4 ,the valve ,v and the seat are formed as desired and then ground into contact with emery dust or other abrasive material1 to assure a perfectly tight joint4 ,when this valve becomes worn and begins to leak1 it may be repaired by regrinding1 but such work requires the services of a pipe-fitter4 ,the tendency of modern practice is to use valves with the detachable discs1 such as that of ,fig4 #gg1 because they are easily repaired4 ,the valve shown in ,fig4 #gi is known as a gate-valve4 ,the upper part1 including the screw and stem1 is the same as the globe style but the valve proper is made in the form of two flat gates ,a-,a4 ,when the valve is closed1 as it appears in the drawing1 the gates are forced against the seats by the cone-shaped piece ,b1 which acts as a wedge1 to tightly close the opening4 ,when the hand-wheel is turned to open the valve1 the gates are raised and are taken entirely out of the path of the flowing liquid4 ,gate-valves are used in places where it is desired to obstruct the flow as little as possible4 ,they are somewhat more expensive than globe-valves but are considered worth the extra expense in service4 ,kitchen and ,laundry ,fixtures4--,the development in modern plumbing has wrought many changes in the styles of household fixtures but none has been so great as that in the kitchen sink4 ,the old style1 insanitary1 wooden sink has been almost entirely replaced by those made of pressed steel or enameled iron4 ,they are made in every desired size and to suit all purposes4 ,they may be plain or galvanized as occasion may require1 or the enameled sink is obtainable at a very slight addition in price4 ,the enameled sink has reached a degree of perfection where its durability is unquestioned1 and as a consequence kitchen furniture is vastly improved at but little advance in cost4 ,illustration3 ,,fig4 #hj4--,model kitchen4 ,illustration3 ,,fig4 #ha4--,white enamel kitchen sink4 ,a modern kitchen in which gas is used as fuel is shown in ,fig4 #hj4 ,simplicity and neatness of arrangement are the noticeable features4 ,this kitchen is intended to suit the average-sized dwelling and contains all necessary plumbing1 cooking and heating apparatus4 ,the hot-water boiler is here shown attached to an instantaneous heater4 ,the common kitchen sink is supplemented with a slop sink and covered with a drain board4 ,this simple kitchen may be elaborated to any extent4 ,fig4 #ha shows a kitchen sink of white enamel with two enameled drain boards4 ,the drain boards are sometimes covered with perforated rubber mats4 ,illustration3 ,,fig4 #hb4--,model laundry4 ,illustration3 ,,fig4 #hc4--;,enamel wash trays in a basement laundry4 ,in ,fig4 #hb is shown an example of the modern basement laundry4 ,the wash-boiler heater is shown on the left4 ,an automatic instantaneous water heater is on the right4 ,the stationary tubs or wash trays occupy the center of the picture4 ,in detail these wash trays appear in ,fig4 #hc4 ,these are enamel-covered ware and are provided with the wash-tray bibb-cocks described above4 ,this type of plumbing represents the most modern of sanitary arrangements4 ,,the ,,bathroom ,with the present-day improvements in plumbing1 and the perfection in the manufacture of porcelain and enameled iron1 the bathrooms of houses of moderate cost have become places of cleanliness1 attractive1 relatively free from offending odors and supplied with all necessary sanitary fixtures4 ,illustration3 ,,fig4 #hd4--,model bath room for the average dwelling4 ,enameled iron has reached a state of perfection where it rivals porcelain in beauty4 ,the forms of the various bathroom pieces have been modeled for convenience in use and grace of form1 at the same time the strife of the designer has been to produce articles that not only look well but are convenient and easily kept clean4 ,bathrooms need not be expensive in order to be convenient1 attractive and useful4 ,the bathroom shown in ,fig4 #hd is such as is installed in dwellings of moderate price4 ,it possesses every feature necessary to usefulness and comfort4 ,in this room the furnishings are all of enameled iron4 ,the floor is covered with linoleum and the wainscoting with enamel paint4 ,bath ,tubs4--,bath tubs are made in sizes that vary in length from #d-a_/b to #f feet4 ,they are constructed in a variety of forms and of materials to suit all conditions of service4 ,for domestic use they are very generally made of enameled iron4 ,this form of construction produces serviceable and handsome furnishings for the bathrooms of the modest house as well as for the sumptuous bath of the most pretentious residence4 ,an elaboration of ,fig4 #hd might include the ,sitz bath shown in ,fig4 #he and the fittings may be chosen from a great variety of forms4 ,the recent styles of enameled tubs are1 in design1 much handsomer than those with the roll rim and in form such as permits a clean room with the minimum of labor4 ,they are also provided with more convenient water and drainage fixtures4 ,illustration3 ,,fig4 #he4--,sitz bath4 ,the tub of ,fig4 #hf sets flat on the floor and makes a close joint with the wall4 ,it thus prevents the accumulation of dust that is difficult to remove4 ,in addition the fixtures are arranged in a more commodious manner and the general appearance is most pleasing4 ,the arrangement of the fixtures in ,fig4 #hg gives still greater convenience and being arranged with a shower and protecting curtain1 provides all of the conveniences of a luxurious bath without greatly increased cost over the simple tub4 ,the fixtures in this design are all in position of greatest convenience and attached to pipes that are concealed in the wall4 ,illustration3 ,,fig4 #hf4--;,enameled iron bath tub4 ,illustration3 ,,fig4 #hg4--;,bath tub with shower4 ,the fixtures usually provided with the tub are double ,fuller or compression cocks for hot and cold water1 the overflow and strainer1 for the discharge of the water into the sewer in case the tub overflows1 and a drain and bath plug4 ,the double ,fuller cock is shown in ,fig4 #hh4 ,it is made to open and close by the same sort of mechanism as is shown in ,fig4 #ga1 a description of which appears on page #ij4 ,illustration3 ,,fig4 #hh4--;,double ,fuller cock for bath tubs4 ,the overflow is shown in detail in ,fig4 #hi4 ,the part ,a appears inside the tub4 ,it is made water-tight around the edge ,c by a rubber washer that is clamped tight to the surfaces by the nut ,b4 ,in case of leakage1 the overflow may be removed for repair by unscrewing the union attached to the piece ,d and removing the nut ,b4 ,illustration3 ,,fig4 #hi4 ,,fig4 #hi;a4 ,,fig4 #hi4--,overflow attachment for bath tubs1 lavatories1 etc4 ,,fig4 #hi;a4--,drain attachment for bath tubs1 lavatories1 etc41 showing locknut and union connection4 ,the drain-pipe connection is shown in ,fig4 #hi;a4 ,the plug ,d and the flange ,a show inside the tub4 ,the flange is made water-tight by a rubber washer that the nut ,b clamps tight to the tub4 ,the part ,c is a union which permits the tub to be detached from the drain pipe4 ,repairs to this joint may be made as in the overflow4 ,illustration3 ,,fig4 #ij4--,old style marble finished lavatory4 ,illustration3 ,,fig4 #ia4--,types of lavatory plumbing not now used in good practice4 ,wash ,stands and ,lavatories4--,wash stands for bathrooms are obtainable in many forms1 either plain or ornate1 to suit every condition and style of architectural finish4 ,illustration3 ,,fig4 #ib4--;,enameled iron wall wash basin4 ,illustration3 ,,fig4 #ic4--;,enameled iron pedestal wash basin4 ,they are made in marble1 porcelain and enameled iron1 the last being the most commonly used4 ,they are made to suit the part of the room to be occupied1 whether that is against a wall1 a corner1 or to stand on a pedestal on the floor4 ,those intended to fasten to the wall may be supported by brackets or suspended at the back from pieces secured in the wall4 ,in ,figs4 #ij and #ia are shown samples of marble-finished wash basins4 ,in former years basins of this type were very much in use1 and until the introduction of the modern porcelain and enameled ware1 it was the highest type of sanitary plumbing4 ,the water cocks and traps are of the same style and grade as appear on the most modern examples of enameled ware of ,figs4 #ib1 #ic and #id4 ,the water cocks used in ,fig4 #ij are of the compression type4 ,all of the others are of the ,fuller type4 ,the basin in ,fig4 #ic is provided with extra shut-off cocks on the water pipe under the basin4 ,they are added to the plumbing merely as a convenient means of shutting off the water for repair4 ,the wash stand is usually provided with hot and cold water cocks1 a waste pipe with its traps and overflow connections4 ,illustration3 ,,fig4 #id4--;,corner wash basin4 ,traps4--,the waste pipes from the wash basin and bath tub are always provided with some form of trap1 to prevent air from entering the room from the sewer1 charged with offending odors4 ,traps are made in many forms1 but the purpose of all is to prevent the escape of sewer gas4 ,the plain trap ,s1 shown in ,fig4 #ie1 is that used under the basin in ,fig4 #ia4 ,it makes a tight joint by means of the nut ,b and a rubber washer as in the case of other joints of the kind4 ,the parts ,c and ,e are unions that permit the pipe or bowl to be removed without disturbing the remainder of the plumbing4 ,from the form of the trap it will be seen that the ,u-shaped part below the dotted line ,f will always remain full of water and so prevents the escape of air from the sewer4 ,in case the trap becomes stopped the obstruction will likely become lodged in this part of the pipe4 ,to clean the trap the screw-plug ,d is taken out with a pair of pliers and the obstruction removed with a wire4 ,the traps used in ,figs4 #ij and #ib are the same in principle as ,fig4 #ie but are made to discharge into a pipe placed in the wall instead of under the floor4 ,the trap in ,fig4 #id is a form known as the bottle-trap that is sometimes used in the more expensive plumbing4 ,illustration3 ,,fig4 #ie4--,the ,s trap of nickel-plated brass tubing4 ,illustration3 ,,fig4 #if4--,the ,bower non-siphoning trap4 ,illustration3 ,,fig4 #ig4--,the drum type of non-siphoning trap4 ,illustration3 ,,fig4 #ih4--;,an ,s trap made of lead pipe4 ,another style much used with lavatories is the ,bower trap shown in ,fig4 #if4 ,in this trap the water comes down the pipe ,b and pushing aside the hollow rubber ball ,a1 enters the space surrounding it and is discharged at ,c4 ,the ball1 being light1 is held against the end of the pipe by the water and acts as a stopper to prevent evaporation from taking place4 ,open traps1 such as ,fig4 #ie1 if left standing for a long time1 may lose sufficient water by evaporation to destroy the water seal and allow the sewer gas to escape4 ,in the use of the ,bower trap such occurrence is much less likely to take place4 ,fig4 #ig is another trap much used on sinks2 it is known under the trade name of the ,clean ,sweep trap4 ,the part ,c is much larger than the common trap and the water seal is less likely to be broken4 ,the clean-out is larger and the interior is easy of access in case of stoppage4 ,the simplest and most commonly used trap in cheap plumbing is that of ,fig4 #ih4 ,it is a lead pipe bent in the form of an ,s4 ,it is the same in shape as ,fig4 #ie and performs its work as well but does not have the means of detachment shown in the latter4 ,traps of many other forms are in use but all have the same function to perform and the mechanical make-up is much the same as those described4 ,illustration3 ,,fig4 #ii4--;,a method of bath-room plumbing using the drum trap4 ,the plan of attachment of the various bathroom fixtures of the soil pipe must always depend on local conditions4 ,the object is to conduct the waste water to the sewer in such a way as to give the least opportunity for stoppage and to prevent sewer gas from escaping into the house4 ,to accomplish this purpose the pipes and traps are arranged according to a plan proposed by the architect1 plumber or other person familiar with the principles of plumbing4 ,since these pipes are placed in the walls and under the floors1 where they are not readily accessible1 it is necessary that their arrangement be made with care and that the workmanship be such as to assure correct installation4 ,in ,fig4 #ii is shown a common method of connecting bathroom fixtures with the sewer4 ,the drawing shows a bathroom with the floor broken away to show the pipe connections with the bath tub1 wash basin and closet4 ,the overflow pipes ,o and ,v and the drain pipes ,d and ,r from the wash basin and bath tub empty into a large lead drum-trap ,t1 set under the floor4 ,this trap takes its name from its shape4 ,it is set in position as dictated by the conditions under which it is used4 ,the nickeled plate ,p1 screwed into the top of the trap1 comes just above the bathroom floor4 ,this plate is easily removed in case of stoppage4 ,it is made air-tight by a rubber ring placed under the cover and which makes a joint with the top edge of the drum4 ,it will be noticed that the waste pipes from the bath tub and wash basin enter the trap near the bottom and discharge at the opposite side near the top4 ,the water will stand in the trap and pipes level with the bottom of the discharge pipe and thus form a seal that prevents the escape of sewer gas4 ,this is a common form of non-siphoning trap4 ,it is non-siphoning because it cannot lose its seal by reason of the siphoning effect of the water as it passes through the waste pipes on its way to the sewer4 ,another form of non-siphoning trap is the clean sweep trap shown in ,fig4 #ig4 ,such traps as ,figs4 #ie and #ih are siphoning traps1 since it is possible1 in this form of trap1 for the water to be so completely siphoned that not enough remains to form a seal4 ,the small drawing1 marked ,detail ,l1 is another method of connecting the same arrangement of fixtures4 ,the waste pipe enters the trap as before but discharges immediately opposite4 ,the level of the water stands in the pipes as indicated by the dotted line4 ,back-venting4--,to prevent the possibility of loss of seal by siphoning and the escape of sewer gas1 traps are back-vented to the main stack or to a separate vent stack4 ,the venting is accomplished by joining a pipe to the top of the trap or to some point in its immediate neighborhood1 and connecting this with the main stack or the vent stack4 ,the water in a trap so vented will be open to the air from both sides and consequently can never be subject to siphonic action4 ,in the average-sized dwelling where non-siphoning traps are used1 back-venting is not necessary1 but in large houses and in plumbing where siphon traps are used1 vent pipes must be attached to the traps to assure a satisfactory system4 ,fig4 #ajj furnishes an example of back-venting1 applied to the bathroom shown in ,fig4 #ii4 ,in the former figure the bath tub and wash basin are connected with the waste pipe by siphon traps4 ,a siphon trap may lose its seal in two ways3 by self-siphonage1 or by aspiration caused by the discharge of the water from other fixtures4 ,in the discharge of the siphon trap1 such as ,b1 in ,fig4 #ajj1 the long leg of the siphon1 formed by the discharge pipe1 may carry away the water so completely that not enough remains in the trap to form a seal4 ,again1 the discharge of the water from the bath tub through the waste pipe tends to form a vacuum above it and in some cases the seal in ,b is destroyed by the water being drawn into the vertical pipe4 ,the possibility of either of these occurrences is prevented by back-venting4 ,illustration3 ,,fig4 #ajj4--;,an example of back-vented plumbing as applied to the bathroom4 ,in ,fig4 #ajj1 a pipe from the main stack is connected with the bend of the trap at ,b and also to the waste pipe outside the trap at ,t4 ,a vent is also taken from the drain ,c1 at a point just below the trap in the closet seat4 ,the object of all of the vents is to prevent the tendency of the formation of a vacuum from any cause that will carry away the water seal of the trap and allow sewer gas to enter the house4 ,the closet seat also contains a trap which will be described later4 ,it connects with soil pipe ,s1 leading to the sewer by a large lead pipe ,c4 ,all of the pipes under the floor1 leading to the soil pipe1 should be of lead4 ,the pipes above the floor are generally of iron or nickel-plated brass4 ,all of the connections in the lead pipes are made with wiped joints2 that is1 the connections are made by wiping hot solder about the joint1 in a manner peculiar to this kind of work1 in such a way as to solder the pipes together4 ,the joints made in this manner are perfectly and permanently tight4 ,lead pipes are used under such conditions1 because lead is the least affected by corrosion of any of the metals that could be used for such work4 ,soil ,pipe4--,the soil pipe1 of which the waste stack or house drain is composed1 is made of cast iron and comes from the factory covered with asphaltum paint4 ,it may be obtained in two grades1 the standard and extra heavy4 ,the only difference is in the thickness of the pipe4 ,the former is commonly used in the average dwelling4 ,one end passes through the roof and the other end joins to the vitrified sewer tile under the basement floor4 ,the joints must be perfectly tight1 because a leak in this pipe would allow sewer gas to escape into the house4 ,one end of each section is enlarged sufficiently to receive the small end of the next section4 ,the joints are made with soft lead4 ,the pipes are set in place and a roll of oakum is packed into the bottom of the joint1 after which molten lead is poured into the joint1 filling it completely4 ,the oakum is used only to keep the lead in the joint until it cools4 ,after the lead has cooled it is packed solidly into the joint with a hammer and calking tool4 ,the calking is necessary because the lead shrinks on cooling and makes a joint that is not tight4 ,well-calked joints of this kind are air-tight and permanent4 ,detail ,n 7,fig4 #ii7 shows the arrangement of the parts of the joint as indicated at ,a4 ,the blackened portion represents the lead as it appears in the joint4 ,detail ,m 7,fig4 #ii7 shows the methods of attaching the closet seat to the lead waste pipe ,c4 ,the end of the lead pipe is flanged at the level of the floor1 as shown at ,c in the detail drawing4 ,the depression ,d1 around the connection1 is then filled with glazier's putty and the seat is forced down tightly in place and fastened with lag screws4 ,the pipe ,c1 from the closet1 and that from the trap ,t1 being of lead1 a special joint is necessary in connecting them with the soil pipe1 because a wiped joint cannot be made with cast iron4 ,to make such a connection the end of the lead pipe is 8wiped0 onto a brass thimble1 heavy enough to allow it to be joined to the soil pipe by a calked lead joint4 ,the brass thimble is then joined to the cast-iron pipe by a calked lead joint4 ,illustration3 ,,fig4 #aja4--,the wash-out closet4 ,illustration3 ,,fig4 #ajb4--,the wash-down closet4 ,water ,closets4--,water closets are made in a great number of styles to suit the architectural surroundings and the various conditions under which they are to be used4 ,many forms of water closets are manufactured to conform to special conditions1 but those commonly used in the bathrooms of dwellings are of three general types4 ,the mechanical construction of each is shown in the following drawings1 ,figs4 #aja1 #ajb and #ajc showing respectively in cross-section the principle of operation of the washout closet1 the washdown closet and the siphon-jet closet4 ,washout ,closets4--,this type of closet has in the past been used to a very great extent4 ,it does not perform the work it has to do1 so perfectly as the others1 because the shallowness of the water in the bowl allows it to give off odors1 and because it is difficult to keep clean4 ,the action of the closet is as follows3 ,when the closet is flushed the water enters the rim at ,a1 and the greater portion of it is washed downward at ,b to dislodge the contents of the bowl4 ,a lighter flush is sent through the openings in the side1 which serves to wash the entire surface4 ,the direction of discharge is forward1 where it dashes against the front of the bowl and then falls into the trap4 ,the only force received to carry the water to the trap is from falling through the distance from the point where it strikes the front4 ,the flushing action is obtained from the use of a large volume of water4 ,as the discharged matter is dashed against the front of the bowl1 the flushing action of the water is not sufficient to remove all the stains2 the result is an accumulation of filth4 ,this part of the bowl is out of sight2 hence1 it is seldom kept clean4 ,the name washout comes from the action of the water to wash out the contents of the bowl4 ,illustration3 ,,fig4 #ajc4--,the siphon-jet closet4 ,illustration3 ,,fig4 #ajd4--;,a poor design of wash-down closet4 ,washdown ,closets4--,as shown in ,fig4 #ajb1 the action of this closet is to wash the contents of the bowl directly down the soil pipe4 ,the depth of the water at ,a is much greater than at the corresponding point in the washout closets2 as a consequence fecal matter is almost submerged4 ,the main objection to this closet is that it is noisy4 ,fig4 #ajd shows another form of washdown closets4 ,this closet is open to objection because of faulty design2 the part ,a is difficult to keep clean because of its shape4 ,siphon-jet ,closet4--,what is considered by many to be the most satisfactory closet yet designed1 is that of the siphon-jet type shown in ,fig4 #ajc4 ,the flushing action of this closet is entirely different from that of the others described4 ,the flushing water enters at ,a and fills the rim ,b4 ,part of the water washes the sides of the bowl1 while the remainder flows through the jet ,c1 and is discharged directly into the outlet4 ,the ejected water enters the outlet ,d1 which1 as soon as it fills1 acts as a siphon to draw the water into the soil pipe4 ,this closet is most positive in its action1 since the discharge is made by the siphon and also receives the additional momentum due to the water flowing through the jet4 ,its action is attended with but little noise4 ,illustration3 ,,fig4 #aje4--,siphon-jet closet with the high flush tank4 ,illustration3 ,,fig4 #ajf4--;,form of closet not now used in good practice4 ,flush ,tanks4--,the water closet depends for its action on one of two general types of flush tanks1 the high and the low forms4 ,the tank is automatically filled with water and when wanted1 a large volume of water is suddenly discharged into the sewer1 carrying with it the contents of the seat4 ,the tank again fills and is ready for use when required4 ,as illustrations of high flush tanks1 those shown in ,figs4 #aje and #ajf furnish examples of a simple and efficient form4 ,the details of the mechanism of this type of tank are shown in ,fig4 #ajg4 ,the pipe from the water supply is attached at ,g to the automatic valve ,f1 which keeps the tank filled with water4 ,the piece ,f of the valve is held against the opening by the pressure exerted through the float ,e4 ,the float is a hollow copper ball4 ,as the ball is lifted it exerts a pressure in proportion to the amount it is submerged4 ,when the water reaches the level ,a-,a1 the valve is tightly closed4 ,as the water is discharged from the tank the ball follows the level of the water and opens the valve1 allowing the water to enter and again fill the tank4 ,illustration3 ,,fig4 #ajg4--;,details of construction of a simple type of siphon flush tank4 ,the siphon is made of cast iron1 and in the figure is shown cut through the center4 ,the lower end fits loosely in the piece ,k1 and makes a water-tight joint around its outer edge1 by resting on a rubber ring ,c-,c4 ,the right-hand side of the siphon is open at ,h1 and when the tank is full1 the level of the water is at ,a-,a1 which is almost at the top of the division plate4 ,to discharge the tank1 the chain ,l1 attached to the lever ,b1 is pulled down2 this action raises the siphon from its seat4 ,as soon as the siphon is lifted1 the water rushes through the opening around ,c-,c1 into the pipe ,k2 this causes a partial vacuum to form in ,d1 and the water is lifted over the division plate ,k1 and flows out at ,d1 forming the siphon4 ,as soon as the siphonic action begins the siphon may be dropped back on the seat and the water will continue to discharge until the tank is empty4 ,low-down ,flush ,tank4--,the low-down flush tank for water closets has met with so much favor that it has to a great extent displaced the high tank4 ,the reason for this is because of its advantages over the other style4 ,the low tank is more accessible1 more easily kept clean1 and better adapted to low ceilings4 ,it is used successfully as a siphon tank1 but other forms are in use with satisfactory results4 ,fig4 #ajh gives a perspective view of one style of this type of tank attached to a siphon-jet closet4 ,figs4 #aji and #aaj give the details of the construction of two forms of this type of tank1 both of which have given efficient service4 ,the drawing shows the tanks with the front broken away to give a view of the working parts4 ,the water enters the tank and is discharged at the points indicated4 ,the float and supply valve works exactly as described in the high tank4 ,the drawing in ,fig4 #aji shows the tank in the act of discharging4 ,the discharge valve is raised as shown at ,e4 ,when the water is completely discharged1 the float occupies the position shown dotted4 ,when the float reaches this dotted position1 its weight pulls down the piece ,a4 ,this releases the lever ,b1 and the attached stopper ,e1 which falls and closes the discharge orifice4 ,while the tank is filling with water1 a stream flows through the small pipe ,d1 to replenish the water in the closet that has been discharged in siphoning4 ,when the tank is full of water1 the pieces ,a and ,b occupy the positions shown dotted4 ,to discharge the tank the trip is pushed down4 ,this action raises the lever to the position ,b1 and with it the attached stopper ,e4 ,the piece ,c falls and the opposite end ,a holds ,b suspended until the tank is completely discharged4 ,illustration3 ,,fig4 #ajh4--,siphon-jet closet with low-down tank4 ,illustration3 ,,fig4 #aji4--;,details of construction of low-down flush tank4 ,the action of the tank shown in ,fig4 #aaj is the same as the others except that of the discharge mechanism4 ,in the drawing1 the tank is full of water ready to be discharged when required4 ,a hollow rubber ball ,e serves as a stopper for the discharge pipe4 ,the ball is kept in place1 when the tank is filling1 by the pressure of the water above it4 ,the discharge is started by pressing down the trip on the front of the tank4 ,this raises the ball from its seat1 and being lighter than water1 it floats1 thus leaving the discharge pipe open until the tank is empty1 when the ball is again back on its seat4 ,as the tank fills the pressure of the water above prevents the ball from again floating1 until lifted from its seat4 ,the supply valve and refilling pipe ,d is the same in action as in the other tank4 ,illustration3 ,,fig4 #aaj4--;,details of construction of the float-valve1 low-down flush tank4 ,illustration3 ,,fig4 #aaa4--,method of using the plumber's friend1 in removing obstructions4 ,opening ,stopped ,pipes4--,it occasionally happens that pipes leading from the various toilet fixtures become stopped because of accumulations or by articles that accidentally pass the entrance4 ,in case the pipe has a trap connection the stoppage is most likely to occur at that point4 ,usually the obstruction may be removed by detaching the screw-plug of the trap and removing the accumulation with a wire4 ,closet seats furnish an inviting receptacle for waste material of almost every kind4 ,stoppages are not uncommon and are generally found in the trap4 ,one method of removing obstruction is by use of the plumbers' friend4 ,this device is shown at ,p-,r1 in ,fig4 #aaa4 ,it consists of a wooden handle ,p attached to a cup-shaped rubber piece ,r4 ,the plumbers' friend is shown in the figure1 placed to remove an obstruction ,s that is lodged in the trap4 ,a sudden downward thrust causes the rubber cap ,r to entirely fill the closet outlet and the resulting pressure to the water is generally sufficient to force the obstruction through the trap to the soil pipe4 ,illustration3 ,,fig4 #aab4--,method of removing obstructions from a stopped drain-pipe4 ,the kitchen sink is another place that affords opportunity for accumulation that stops the waste pipe4 ,accumulation of grease in the trap is a common cause of trouble4 ,this may be remedied to some extent by the use of potash or caustic soda4 ,when the pipe is stopped and the trouble cannot be reached from the trap1 a common method of removing the stoppage is that suggested in ,fig4 #aab4 ,a piece of heavy rubber tubing is forced over the water tap and the other end tightly wedged into the drain pipe2 the water is then turned on and generally the pressure is sufficient to force the accumulation down the pipe4 ,sewer ,gas4--,the prevalent fear of the deleterious effect of escaping sewer gas is one that has been magnified to an unwarrantable degree4 ,among bacteriologists it is very generally recognized that none of the dreaded diseases to which the human kind is susceptible are transmitted by gases4 ,the one possible harmful effect recognized in sewer gas by scientists is that produced by carbon monoxide4 ,sewer gas often contains1 from escaping illuminating gas1 sufficient carbon monoxide to produce the poisoning effect characteristic of that gas but the possibility of danger is quite remote4 ,the leakage of sewer gas is detected by the sense of smell sooner than in almost any other way4 ,while leaks in sewer pipes are unhygienic in that they are conducive to undesirable atmospheric conditions1 they should not be looked upon as the agents through which transmissible diseases are carried4 ,to the average person the term sewer gas conveys the impression of a particularly loathsome form of vaporous contagion1 capable of distributing every form of communicable disease4 ,to the scientific mind it means no more than a bad odor4 ,sewer gas is really nothing but ill-smelling air4 ,,range ,,boilers ,the hot-water supply to the household is of so much importance1 that the installation of the range boiler should be made with great care1 and an understanding of the principle on which it works should be fully appreciated by all who have to do with its management4 ,the ability of the boiler to supply the demands put upon it depends in a great measure on its size and the arrangement of its parts1 but proper management is necessary to assure a supply of hot water when required4 ,range boilers are used for storing hot water heated by the water-back of the kitchen range or other water heater1 during a period when water is not drawn4 ,it serves as a reserve supply where the heater is not of sufficient size to heat water as fast as is demanded4 ,as commonly used1 range boilers are galvanized-steel tanks made expressly for household use4 ,they are standard in form and may be bought of any dealer in plumbing or household supplies4 ,in capacity they range from #bj to #bjj gallons and are made for either high-or low-pressure service4 ,they are said to be tested at the factory to a pressure of #bjj pounds to the square inch and are rated to stand a working pressure of #aej pounds4 ,range boilers are galvanized after they are made and coated both inside and out4 ,the coating of zinc received in the galvanizing process helps to make their seams tight and at the same time renders the surface free from rust4 ,there is no definite means of determining the size of tank to be used in any given case1 because of the varying demands of a household but a common practice is to allow #e gallons in capacity to each person the house is able to accommodate4 ,the ,water-back4--,the most common method of heating water for the range boiler is by use of the water-back or water-front of the kitchen range4 ,the water-back is a hollow cast-iron piece that is made to take the place of the back fire-box lining of the range4 ,in some ranges the heater occupies the front of the fire-box instead of the back1 in which case the heater becomes the water-front4 ,the arrangement of pipes connecting the source of water supply with the boiler is such that cold water is constantly supplied to the tank as the hot water is drawn4 ,if no water is drawn from the tank1 it will continue to circulate through the tank and heater1 the water becoming constantly hotter4 ,the connecting pipes are usually of iron but sometimes pipes of copper or brass are used4 ,the joints should be reamed to remove the burr that is formed in cutting4 ,the angles should be #de-;degree bends or better still #ij-;degree bends in connecting the heater with the tank so as to cut down the amount of friction as much as possible4 ,illustration3 ,,fig4 #aac4--;,a common method of connecting the range boiler to the water-back4 ,in ,fig4 #aac is shown a standard range boiler connected to the range4 ,the water is brought into the top of the tank through the pipe a-a1 and passing through it enters the water-back by means of the pipe b4 ,after passing through the water-back the water again enters the tank through the pipes c and d1 as indicated by the arrow4 ,the flow pipe 7carrying the out-going water7 from the water-back may be connected with the tank at e1 as shown dotted or in some cases the connections are made at both places4 ,the velocity of circulation depends on the vertical height of the column of hot water and the greater height will1 therefore1 improve the circulation and thus increase the efficiency of the heater4 ,the circulation of the water through the tank and heater is produced by its change in weight as the water is heated4 ,as the hot water comes from the water-back it rises in the pipe because it is lighter in weight than the cooler water of the tank4 ,in the case of the pipe shown dotted in ,fig4 #aac the longer vertical rise will give a greater upward velocity of the hot water and consequently a better circulation through the entire circuit4 ,the construction of the water-back is shown in the small drawing4 ,the connections are made at b and c as before4 ,a division plate in the water-back causes the water flowing in at b to follow the length of the heater at the bottom and return at the top as indicated by the arrow1 when it is discharged at ,c4 ,the hottest water is always at the top of the tank and the temperature grades uniformly from the hottest at the top to the coolest at the bottom4 ,the reason for extending the pipe a so far down into the tank is that the cold water may not mingle with the hot water and reduce its temperature on entering the tank4 ,near the top of the pipe a is a small hole f that is intended to prevent the water from being siphoned from the tank in case a vacuum is formed in the cold-water pipe4 ,in this arrangement the water enters and leaves at the top of the tank4 ,in case the supply is shut off at any time the tank is left almost full of water1 because the siphoning effect cannot extend below the small hole f4 ,excessive ,pressure4--,accidents due to the explosion of hot-water backs are not at all rare and it should be borne in mind that there is danger of excessive pressure being formed should the pipes b and c become stopped4 ,under normal conditions the pressure generated by the heated water is relieved by the water in the tank being forced back into the supply pipe4 ,the pressure in the tank1 therefore1 cannot become greater than that of the source of supply1 but if b and c should become stopped with the water-back full of water a dangerous pressure might result4 ,the greatest danger from this cause is that of freezing4 ,it frequently happens that houses are closed during cold weather and the water-back is left undrained4 ,the water freezes and when a fire is started in the range1 the ice in the water-back is the first to melt4 ,in a short time steam will be generated that will soon produce a sufficient pressure to burst the water-back4 ,this has happened many times with disastrous results4 ,such dangers may be avoided by the exercise of a reasonable amount of care in the management of the range4 ,to drain the water-back1 the water is first shut off at the point where the supply pipe enters the house4 ,the water in the range boiler is then drawn off by means of the cock h4 ,illustration3 ,,fig4 #aad4--;,blow-off for removing sediment4 ,blow-off ,cock4--,when a considerable amount of sediment is carried in the water the range boiler acts as a settling tank and the deposit accumulated at the bottom will in time amount to a source of trouble4 ,the accumulation is shown in ,fig4 #aad4 ,the part ,w1 which connects with ,b1 is sometimes provided with a blow-off cock that will admit of a discharge of the sediment4 ,more commonly the piping is arranged as shown in ,fig4 #aac1 when sediment is removed by occasionally drawing water from the cock h4 ,illustration3 ,,fig4 #aae4--,method of connecting the range boiler when placed on the floor below the heater4 ,location of ,range ,boiler4--,it is sometimes desired to place the range boiler on a different floor1 either above or below the range4 ,while such arrangements are entirely possible the circulation of the water is not so good as that described above4 ,the weight of the two columns of water in the connecting pipes are so nearly balanced that good circulation is not always possible4 ,in ,fig4 #aae the connections are shown1 where the tank is located in the basement4 ,in connecting the water-back to the tank under such conditions the piping is relatively the same as is shown in the dotted connections of ,fig4 #aac1 but the connections are longer4 ,the circulating pipe comes from the bottom of the tank and leads to the bottom of the water-back4 ,the flow pipe from the top of the water-back is extended up to a distance equal or greater than the distance from the water-back to the bottom of the tank4 ,the hot water is taken from the top of the flow pipe at any place above the tank4 ,double ,heater ,connections4--,two heaters are sometimes connected to one range boiler1 each circuit being independent of the other4 ,under such conditions one or both heaters may be used4 ,when the tank is connected as shown in ,fig4 #aaf the pipe a1 from the bottom of the tank1 branches and leads to b and b1 at the bottom of each of the heaters4 ,the flow pipes from the top of the heaters enter the tank at separate places1 the lower heater sending its water into the side of the tank at c1 and the upper heater flowing into the pipe d1 at the top of the tank4 ,it would be perfectly possible to reverse the connections for the flow pipes in the arrangement of ,fig4 #aaf and attain the same results4 ,in such combinations the heaters are sometimes piped tandem1 the water flowing through each of the heaters in turn4 ,this1 however1 is not the best method to employ1 for if only one of the heaters is used the second acts to cool the water4 ,illustration3 ,,fig4 #aaf4--;,double connections for the range boiler where a heater is placed in the basement for occasional use4 ,horizontal ,range ,boilers4--,it occasionally happens that in a small kitchen there is no convenient floor space for the range boiler and it becomes necessary to suspend it from the ceiling4 ,it is perfectly possible to station the ordinary range boiler in such a position and have it work fairly well but from the location of the cold-water inlet1 only that part of the range boiler above the cold water pipe is actually used for storage4 ,the water in the lower half constantly mixes with the entering cold water before it is heated by passing through the water-back4 ,when hot water is drawn from the top of the range boiler1 cold water enters by the cold-water pipe and reduces the temperature of most of the lower half4 ,fig4 #aag illustrates such an arrangement4 ,in this case the pipes connected with the water-back are those that correspond to the circulating pipes a and e in ,fig4 #aac4 ,suppose the range boiler is full of water1 and that it is being heated4 ,the lower pipe at the left-hand end is conducting the water to the water-back and it is being returned to the range boiler by the upper pipe at the same end4 ,when the hot water is drawn from the top of the range boiler by the hot-water pipe1 the entering cold water mixes with hot water in most of the lower half of the range boiler before it has been heated by passing through the water-back and so reduces the temperature of most of the lower half of the tank4 ,illustration3 ,,fig4 #aag4--,method of connecting the vertical range-boiler in a horizontal position4 ,illustration3 ,,fig4 #aah4--;,horizontal range-boiler suspended from the ceiling4 ,a much better tank for the purpose is that indicated in ,fig4 #aah4 ,this is a tank made particularly for such a location4 ,the cold water enters at the bottom of the tank and also leaves the bottom on its way to the water-back4 ,circulation takes place through the water-back as before but when hot water is drawn from the top of the tank1 the entering cold water at the bottom mixes with only that at the lower part of the tank and so cools but a small amount of the hot water in storage4 ,hot-water tanks of this kind are tapped for pipe connections in two places on both the top and bottom sides and also at the ends as shown in the drawing4 ,tank ,heaters4--,when the demand for hot water is sufficient to warrant a separate hot-water heater the apparatus similar to ,fig4 #aai is used4 ,with such a heater1 the conditions of overheated water--to be described later--may be almost entirely avoided4 ,in this case the connections are arranged similarly to those of the range boiler but a separate furnace takes the place of the water-back4 ,the heater is simply a small furnace made expressly for heating water4 ,connected with the discharge pipe p is a draft-regulating valve which controls the drafts of the heater4 ,the draft-regulator is set to so control the furnace that water at the desired temperature will always be in the tank4 ,the mechanism of this regulator is the same as the draft-regulator described under hot-water heating plants4 ,overheated ,water4--,under ordinary conditions the water contained in the range boiler is below the atmospheric boiling point 7#bab;,f47 but at times when a hot fire is kept up in the range for a considerable period1 the temperature will rise to a degree much above that amount4 ,the temperature to which the water will rise will depend on the pressure of the water supply4 ,as an example--suppose the gage pressure of the water supply is #be pounds4 ,the temperature corresponding to that pressure is #beh;,f4 ,the temperature of the water in the tank will rise to that amount but not further because any additional temperature will produce a higher pressure1 but a higher pressure would be greater than the pressure of the water supply and hence will back the water into the supply pipe4 ,this condition of things1 then1 acts as a safety valve to the tank to prevent excessive pressures4 ,illustration3 ,,fig4 #aai4--;,independent hot-water heater with temperature regulator4 ,when the water at a high temperature is drawn from the tap a considerable part of it will instantly vaporize1 because of the reduced pressure4 ,if water at a pressure of #be pounds is drawn from the faucet1 the temperature1 #beh;,f41 is sufficient to send all of the water instantly into steam4 ,this high temperature will scald at the slightest touch4 ,the water drawn from the faucet will continue to vaporize as it comes into the air until the water in the tank is cooled by the incoming cold water4 ,the only means of relieving the overheated condition is to open the faucet a slight amount and allow a portion of the heated water to be drawn off4 ,it is evident from what has been said of the range boiler that it operates under a variety of conditions4 ,it is first a storage tank in which is accumulated the water1 heated from a greater or less period of use of the range4 ,should the range fire be maintained through the day or night the supply of hot water will be excessive and superheating is the result4 ,if the heater is to be used during short periods of time1 the piping should be arranged to produce the best circulation2 on the contrary1 should the heater be used continuously--as in the case of a furnace coil--a slow circulation through the tank is most to be desired and the piping should be arranged for that purpose4 ,in the use of furnace heaters1 superheating is likely to occur during cold weather when a hot fire must be used over a long period of time4 ,in order to conserve the heat accumulated under such conditions a hot-water radiator is frequently connected with the range boiler through which to dispose of the excess heat4 ,this radiator may be placed in any desired position and so connected by a valve as to discontinue its use at any time4 ,illustration3 ,,fig4 #abj4--,the range boiler connections when a furnace coil is used for hot-water heating4 ,furnace ,hot-water ,heaters4--,it is sometimes more convenient to use the furnace as a means of heating water than the kitchen range4 ,such an arrangement is shown in ,fig4 #abj1 where a loop of pipe in the fire-box of the furnace takes the place of the water-back4 ,the arrangement of the pipes in the range boiler are as before1 the water entering the tank through the pipe ,a1 circulates through the pipes ,b and ,c1 receiving its heat while passing through the loop in the furnace1 in exactly the same way as in the water-back4 ,it would be quite possible to also connect the kitchen range with the tank as shown by the dotted lines indicating the water-back4 ,such an arrangement would virtually be that shown in ,fig4 #aaf1 where the two heaters on different floors are connected with the boiler4 ,instantaneous ,heaters4--,in isolated bathrooms where no constant supply of hot water is available1 instantaneous hot-water heaters are much used4 ,in many houses where a range fire is used intermittently1 particularly during the summer months1 a like method is used for the hot-water supply4 ,these heaters are made in many forms to suit any condition4 ,some are very simple1 being made of a gas heater1 the heat from which is held against a long coil of pipe or a large amount of heating surface in other form1 through which the water circulates on its way to the tap4 ,others are quite elaborate1 being made entirely automatic in their action4 ,the ,ruud heater1 for example1 is so constructed that when the hot-water faucet is opened the reduced water pressure starts a gas heater in contact with a series of pipe coils through which the water circulates4 ,as soon as the water faucet is closed the water pressure automatically closes the gas valve1 cutting off the supply of gas4 ,a little gas jet used for igniting the burner is left constantly burning1 ready to light the gas whenever hot water is required4 ,fig4 #aba illustrates a simple form of instantaneous heater that is relatively inexpensive and has met with a great deal of favor4 ,a sheet-iron casing encloses a sinuous1 multiple coil of pipes through which the water passes4 ,the heat furnished by a ,bunsen burner of a large number of small jets is evenly distributed over the bottom of the heater4 ,the heating coils are arranged to interrupt the heat passing through the casing and absorb as much as possible4 ,to do good work such a heater must be connected by a pipe to a chimney flue which furnishes a good draught4 ,instantaneous water heaters should not be used in bathrooms unless the products of combustion from the heater are carried away by a chimney4 ,the combustion of the required amount of gas produces a large volume of carbonic acid gas which if allowed to remain in the room is not only deleterious but may be a positive danger to life4 ,cases of asphyxiation from this cause are not at all rare4 ,illustration3 ,,fig4 #aba4--;,gas heater for hot-water supply4 ,illustration3 ,,fig4 #abb4--;,hot-water supply with gas heater1 connected to the range boiler4 ,fig4 #abb shows the heater connected with a range boiler4 ,in this case the heater may be considered as taking the place of the water-back4 ,it may1 however1 be used as an auxiliary heater4 ,in the picture of the kitchen shown in ,fig4 #hj1 an instantaneous heater is shown attached to the range boiler4 ,it is located in this case between the kitchen range and the boiler4 ,,chapter ,,vii ,,water ,,supply ,the use of water enters into each detail of the affairs of everyday life and forms a part of every article of food2 its quality has much to do with the health of the family1 and its convenience of distribution lends greatly to the contentment of its members4 ,the family water supply should be as carefully guarded as means will permit1 and judicious care should be exercised to prevent the possibility of its pollution4 ,where the source of the water is known1 it should be the subject of unremitting attention4 ,water comes originally from rain or snow and as it falls1 it is pure4 ,water1 however1 in falling through the air absorbs the contained vapors and washes the air free from suspended organic matter in the form of dust1 so that when it reaches the earth rain water contains some impurities4 ,as the water is absorbed by the earth1 it comes into contact with the mineral matter and organic materials of animal and vegetable origin contained in the soil2 and as water is a most wonderful solvent1 it soon contains mineral salts and possibly the leachings from the organic substances through which it passes4 ,the impurities usually found in well water are in the form of mineral salts that have been taken up from the earth1 but other contaminating materials may come from the surface and be carried into the well by accidental drainage4 ,water that is colorless and odorless is usually considered good for drinking and in the absence of more accurate means of determination may be used as a test of excellence2 but it often happens that water possessing these qualities is so heavily freighted with mineral salts as to be the direct cause of impaired health4 ,again1 water that appears pure may be polluted with disease-producing bacteria to such an extent as to endanger the lives of all who use it4 ,the fact that a source of drinking water bears a local reputation for purity1 because of long usage1 cannot be taken as a test of its actual purity until it has been subjected to chemical and bacterial examination4 ,it must not be inferred that all water is likely to be unsuitable for drinking2 there is1 however1 a possibility of the water being polluted from natural sources and from accidental causes1 that are sometimes preventable2 and the only means of determining the purity of water is by chemical and bacterial examining4 ,water ,analysis4--,in order to be assured as to the quality of drinking water1 it should be subjected to analysis and the result of the analysis inspected by a physician of good standing4 ,such analysis may usually be obtained free of charge from the ,state ,board of ,health and if asked1 the ,chief ,chemist will usually give his opinion regarding the quality as drinking water4 ,in chemical water analysis1 the total amount of solids1 regardless of their nature is taken as indicative of its excellence for drinking purposes4 ,these solids may be either in suspension and give the water a color or produce a turbidity1 or they may be entirely in solution and the water appear colorless4 ,english authorities on the subject place the allowable proportion of solids at #ejj parts to the million4 ,any water that contains more than #ejj parts to the million is condemned for drinking purposes4 ,water containing #ejj parts or less to the million is considered good4 ,the ,standard of the ,american ,board of ,health permits the use of water for city supply that contains #ajjj parts of solid matter to the million4 ,the amount of solids contained in water is not at all a definite indication of its quality for drinking purposes1 as may be inferred from the widely varying amounts permitted by the different authorities1 but it gives an indication of its character because of the known physiological action of the contained solids4 ,chemical analysis alone cannot be taken as a complete indication of the character of water1 because such analysis shows nothing of the bacteria that may be present4 ,the organic matter may indicate the possible presence of bacteria1 but microscopic examination will be required to determine its harmful properties4 ,as examples of the chemical constituents of potable waters1 the following furnish illustrations of different types of water in general use4 ,pokegama ,water4--,the water from ,pokegama ,spring at ,detroit1 ,minn4 is used widely through the ,northwest as a table water4 ,it is considered to be a very excellent drinking water because of the low amount of solids and the absence of any deleterious constituents4 ,the complete chemical analysis as reported by the ,north ,dakota ,pure ,food ,laboratory is as follows3 ,grains per gallon ,sodium chloride #j4jbjj ,sodium sulphate #j4jceg ,sodium carbonate #c4ibhh ,calcium carbonate #aa4ciig ,lime carbonate #j4jjaf ,magnesium carbonate #c4hhif ,sodium phosphate trace ,potassium sulphate #j4ddce ,silica #j4ddaf ,organic matter #j4ajjf -------- ,total #bj4bfaa ,the total solids1 #bj4bfaa grains per gallon1 equivalent to #cdf4he parts per million1 is very low and composed of carbonates of sodium1 calcium and magnesium1 none of which are in any way harmful even in much larger quantities4 ,the amount of organic matter is practically nothing4 ,river ,water4--,the water supply of the city of ,fargo1 ,n4 ,d41 is taken from the ,red ,river of the ,north1 which after being filtered through a mechanical filtration plant is supplied to the water system of the city4 ,the river water in its raw state is considered unfit for drinking because of the amount of organic matter present at different times of the year4 ,analysis of raw water from intake pipe1 ,april #ad1 #aiac3 ,parts per million ,chlorine #aj ,equivalent as sodium chloride1 salt #af ,volatile and organic matter #hj ,mineral solids #ahj ---- ,total solids #bfj ,in this water neither the solids nor the organic matter are at all high but during a part of each year there are many pathogenic germs present1 the contained typhoid bacillus being the most feared4 ,the following is an analysis after the water has been filtered1 ,april #ad1 #aiac3 ,parts per million ,chlorine #ab ,equivalent as sodium chloride1 salt #ah ,volatile and organic matter #de ,mineral solids #adj ---- ,total solids #ahe ,it will be noticed that in the process of filtration there has been removed from the water #ce parts to the million of organic matter and with probably #ii per cent4 of the pathogenic bacteria4 ,in addition there has been removed #dj parts to the million of mineral solids1 the removal of which has changed a very hard water to that which is reasonably soft4 ,the process of filtration has changed water that is generally condemned for drinking to one that is considered remarkably good4 ,artesian ,water4--,the analysis of the sample of artesian water given below is an example of the water analysis made by the ,north ,dakota ,pure ,food ,laboratory4 ,it furnishes an illustration of the type of reports that are returned from samples of water submitted for examination4 ,this report was in the form of a letter which was taken at random from the files of the laboratory4 ,sample of artesian water ,no4 #aicf from ,moorhead1 ,minn43 ,parts per million ,chlorine #gj ,equivalent as sodium chloride1 salt #aaf ,volatile and organic matter #ij ,mineral solids #dee ---- ,total solids #ede 8,the solids in this water are made up of sodium chloride1 salt1 #aaf parts2 volatile and organic matter1 #ij parts2 lime sulphate1 a trace2 lime carbonate1 a slight amount2 magnesium carbonate1 a slight amount2 and the balance of the solids are all wholly made up of sodium bicarbonate4 ,this water is low in solids and of good quality40 ,medical ,water4--,the solids that occur most commonly in spring and well water appear in the form of mineral salts4 ,it frequently happens that salts giving a cathartic action are present in sufficient quantity to render the water objectionable when used for drinking4 ,sodium chloride or common salt frequently occurs in quantity sufficient to be distinctly noticeable4 ,magnesium sulphate 7,epsom salts7 and sodium sulphate 7,glauber salts71 both of which are well-known laxative salts1 very commonly occur in well water4 ,the carbonates of calcium and sulphur also frequently found in well water are inert in physical action when taken in drinking water4 ,the presence of laxative salts in spring water has given great celebrity to many springs both in ,europe and ,america that are famous as cures for all manner of human ills4 ,such curative value as these springs possess is derived from the cathartic salts contained by the water4 ,the table of contents of the ,saratoga ,congress ,water as given by ,dr4 ,woods ,hutchinson shows the solids of one of the most celebrated of ,america's medicinal waters4 ,grains per gallon ,sodium chloride #che ,magnesium carbonate #ef ,calcium carbonate and sulphate #aaf ,sodium bicarbonate #i ,sodium iodide #d ,bromide1 iron1 silica trace ----- ,total solids #egj ,when reduced to ordinary measure and given their common names the mineral solids in a gallon of this water will be approximately3 ,common salt #h teaspoonfuls ,magnesium #a teaspoonful ,lime and plaster of ,paris #b teaspoonfuls ,baking soda #a_/f teaspoonful ,bromides and iodides #a_/ab teaspoonful ,the total solids1 #egj grains per gallon1 contained in ,saratoga water1 gives the remarkably high content in total solids1 of #igeh parts per million2 this is almost ten times the limit of the ,american standard4 ,while such water would not do for constant consumption1 it is taken for considerable periods of time with beneficial results and is recommended by many authorities as a water of great medicinal potency4 ,while most medical authorities condemn the use of water high in solids1 the ideal drinking water is neither soft water nor distilled water--that is1 water that is perfectly free from any saltiness--but one that contains a moderate amount of the ordinary constituents of the earth4 ,it is reasonably safe to assume that any unpolluted water containing as high percentage of solids as #ajjj parts of total solids to the million1 and that is agreeable to the taste1 would be safe for drinking4 8,chemical analysis in general indicates the possible pollution of water4 ,a relatively high content of organic substances1 nitrate1 chlorides and sulphates1 might indicate contamination1 particularly when ammonia is also present4 ,on the other hand1 a high content of just one of the above-mentioned substances1 be it organic1 chloride1 nitrate or sulphate1 may originate from the natural soil strata40 ,organic ,matter4--,organic matter may come from peat swamps1 decaying leaves and grasses2 or it may come from decayed animal matter which finds its way into the soil2 or worst of all it may come from cesspools or other sewage4 ,while the presence of organic matter does not necessarily indicate the presence of disease-producing bacteria1 it is a medium in which such germs live and multiply2 for that reason it is an indicator of possible harm4 8,waters containing a high percentage of organic substances and among them products of putrefaction are frequently used without damage but they are capable of producing gastro-intestinal catarrh1 phenomena of excitement and paralysis as well as death4 ,of the many pathogenic bacteria that sooner or later may get into the water1 those of cholera and typhoid are of special importance4 8,pathogenic bacteria occur but rarely and when once they find their way into a water1 they generally do not multiply but remain for a greater or lesser period viable4 8,bacteria enter wells by three different modes3 first1 from surface water that is washed from the soil by rain2 second1 from faulty construction of the curbing2 and third1 from bacteria entering the soil from vaults1 etc40 7,van ,es74 ,ammonia4--,in the analysis of water the presence of ammonia is an indicator of organic matter4 ,ammonia is not of itself injurious but it indicates the presence of matter in which bacteria find conditions suited to their growth4 ,free ammonia is usually considered an indicator of recent pollution1 while albuminoid ammonia indicates the presence of nitrogenous matter that has not undergone sufficient decomposition to form ammonia compounds4 ,hardness in ,water4--,water that holds no mineral matter in solution is 8soft water0 and when soap is added will readily form a lather4 ,the presence of lime or magnesia is commonly the cause of 8hardness0 in water4 ,either of these minerals1 when present form an insoluble curd when the soap is added to the water and the soap will not form a lather until enough soap has been added to unite with the mineral matter present4 ,the hardening agents are usually in the form of bicarbonates and sulphates4 ,all soap used in neutralizing the hardening agents is wasted1 because a lather will not form until all of the hardening materials are neutralized4 ,it is evident that the softening of water for domestic purposes is beneficial1 both because of the less amount of soap required and because of the absence of the curd4 ,hardness in water may occur in two forms--as temporary hardness or as permanent hardness4 ,when bicarbonate predominates as the hardening agent1 the water is said to be temporarily hard because1 when heated to boiling1 the bicarbonate is precipitated and the water is thus softened4 ,when softening of such water is to be done on a large scale1 chemical treatment is more satisfactory4 ,water containing bicarbonate of lime may be softened by adding a pound of lime to #ajjj gallons or #a pound of lime to #afe cubic feet of the water4 ,this quantity of lime is sufficient to remove #aj grains of the bicarbonate to the gallon4 ,when the mineral matter is in the form of sulphates1 mainly sulphate of lime or magnesia1 the water is said to be permanently hard1 because boiling will not soften it4 ,such water may be softened by adding soda ash or impure carbonate of soda4 ,one pound to #a-a_/d pounds of 8washing soda0 to each #ajjj gallons of water will render such water soft2 by its action the sulphate of lime is precipitated and settles to the bottom of the container2 the water may then be siphoned off leaving the precipitate in the bottom4 ,iron in ,water4--,water containing iron is found in many wells and springs4 ,while iron is not harmful1 it is objectionable to taste and stains most things with which it is long in contact4 ,it may be precipitated with lime and removed as the sulphate of magnesia described in the preceding paragraph4 ,water ,softening with ,hydrated ,silicates4--,by ,w4 ,l4 ,stockham1 assistant chemist1 ,north ,dakota ,experiment ,station4 8,the use of chemicals in softening water requires the mechanical removal of the separated materials by skimming1 settling or filtering and it is difficult to determine just how much chemical to add4 ,a new process for softening water1 and one that has awakened great interest because of its efficiency1 employs hydrated silicates of aluminum or iron combined with soluble bases4 ,this process softens water from practically any condition or hardness4 8,the form of apparatus in use varies from a portable jar1 with an inlet at the top and an outlet at the bottom1 to the more complex tanks for industrial and domestic purposes4 ,a plant for domestic use might consist of a #bj-;gallon tank for containing the softening material and a second tank in which is prepared the salt solution for reactivating the softener4 ,the two tanks with their valves and connections constitute the apparatus4 ,the softener1 supported by a porous plate1 sieve1 or layer of gravel1 completely fills the first tank and the water to be treated passes through the interspaces between the granules4 ,in some plants the water passes through a layer of marble chips before coming into contact with the softener4 ,the apparatus may be attached temporarily to the faucet or connected permanently with the water system4 ,a gravity system may be employed where the water pressure is lacking4 8,the softener is put on the market in granular form and may be purchased and used with apparatus other than that furnished by manufacturers4 ,the granules are about #a_/d inch in diameter and permit a ready passage of the water through the interspaces4 ,the material lasts indefinitely4 8,as the water passes through the apparatus1 the large exposed surface of the granules entirely absorbs the calcium and magnesium1 which produce hardness1 making it soft and ready for immediate use4 ,the water does not require being in contact with the softener any longer than the time taken to pass through and it emerges almost as fast as from the faucet4 ,the softener must be reactivated after it has softened a certain amount of water4 ,this is accomplished by filling the tank with a common salt solution which is contained in the second tank4 ,the water supply is temporarily shut off and the salt solution allowed to fill the softening tank4 ,after remaining in contact with the granules for a time the chemical action of the salt releases the calcium and magnesium1 which are flushed out with the excess of salt solution1 into the sewer4 ,the softener thus renewed is ready for softening another supply of water4 ,since this renewal is a simple application of the law of mass action1 an excess of the salt must be used4 ,the renewal may be repeated indefinitely4 8,the amount of any particular sample of water which can be softened before renewal depends on the amount of material in the apparatus and the hardness of the water4 ,five gallons of the water per pound of softener would not be far from the average capacity4 ,where a large amount of soft water is required at one time1 it may be prepared in advance and accumulated in a tank or cistern4 8,the cost of softening1 aside from the original cost of the plant1 is nominal1 as the value of the salt solution is the only expense4 8,the water produced by this process is absolutely soft and suitable for drinking1 domestic and industrial purposes4 ,in the case of very hard water the saving in soap for washing is more than equal to the cost of operation4 ,there are at least three firms manufacturing softening plants of the kind at the present time3 ,the ,permutite ,co4 of ,new ,york2 the ,cartright ,co4 of ,chicago1 whose product is called ,borromite2 and the ,des ,moines ,refining ,co41 manufacturers of ,refinite4 8,a comparative test of various forms of water-softening materials may be obtained from the ,regulatory ,department1 ,north ,dakota ,agricultural ,college40 ,chlorine4--,the presence of chlorine in water may indicate the presence of polluting matter in the form of sewage but only when the amount is considerably above the normal amount of chlorine that is contained in the soil in the community from which the water is taken4 ,an increase of the chlorine in the water would indicate a probable pollution from sewage4 ,polluted ,water4--,well water that is roily or that possesses objectionable taste or odor may be suspected of containing polluting matter and should be boiled before being used for drinking purposes until such time as may be required to have it examined4 ,sickness due to the use of polluted water does not necessarily develop as specific diseases1 unless the water contains disease-producing bacteria4 ,typhoid fever1 one of the commonest and most dreaded of diseases1 is usually transmitted by water4 ,typhoid is a disease of human origin1 the germ of which develops in the alimentary tract of the human kind alone4 ,the germs may be spread by the waste from the typhoid patient by being thrown on the ground where it is taken up by the water and passes into streams or it may enter wells from privies or cesspools4 ,a single case of typhoid has been known to so pollute the water of a stream1 as to produce an epidemic of the disease throughout the entire length of the stream1 among the people who drank its water2 while water from a polluted well often transmits disease to a neighborhood4 ,illustration3 ,,fig4 #abc4--,some of the common causes of pollution of wells1 and the means of transmitting disease1 such as typhoid1 etc4 ,pollution of ,wells4--,the water from wells is often polluted by seepage through the earth from sources that might be prevented4 ,fig4 #abc illustrates some of the commonest sources of contamination that through carelessness or ignorance are located in the neighborhood of the family water supply4 ,the drainage from such sources of pollution is often directed toward the well and many cases of ill-health1 disease or death are the direct consequences of drinking its water4 ,it may be readily observed1 in the case of the well illustrated1 that the more water that is pumped from the well1 the greater will be the tendency of the water from each of the sources of pollution to reach the well4 ,another common cause of contamination of well water is that of imperfect well curbs that allow the waste water or surface water to flow into the well4 ,the area about the well should be graded to allow no standing water1 and the waste should be conducted away without permitting it to collect in standing pools4 ,drainage from manured fields or other places where disintegrating animal or vegetable matter may be absorbed by water is often the cause of temporary pollution1 where the water is carried to low-lying wells4 ,wells located in low areas that receive the drainage from such places may be suspected of pollution during the spring or early summer1 when during the remainder of the year the water is pure4 ,in connection with any water suspected of pollution1 it is well to remember that by boiling the water used for drinking1 its harmful properties are entirely destroyed4 ,safe ,distance in the ,location of ,wells4--,in the location of a well1 the distance of safety from sources of pollution will depend1 in a considerable measure1 on the character of the soil and the quantity and concentration of the pollution material entering the ground water4 ,when coming from the surface1 the danger is usually neither great nor difficult to avoid2 but when cesspools and privies in the neighborhood are sunk to a considerable depth in porous earth1 from which the supply of water is drawn1 the polluting material may reach the well undiluted4 ,no absolute radius of safety can be given1 but certain generalizations as to conditions may be made as to character of soil and the different topographical conditions which surround a safe location4 ,in ordinary clay1 or in clay mixed with pebbles and in soils of the same general nature1 through which the water circulates by seepage1 the pollution is not likely to be carried to a distance of #ajj feet4 ,clay offers marked resistance to the passage of water1 which in beds of #c to #e feet thick will act as protection from pollution from above4 ,in sandy soils the movement of water is faster than in clayey soils1 but #aej feet may be taken as a safe distance1 unless the downward slope of the land carries the polluting material directly to the well4 ,surface ,pollution of ,wells4--,in dug wells1 pollution from the surface is due most commonly to careless construction and lack of care4 ,in ,fig4 #abd is indicated the most common cause of surface pollution4 ,the figure represents a well that has been curbed with planks4 ,through lack of care the earth has sunken at the top1 permitting the surface water to flow into the well4 ,the top of the well is on a level with the surface and covered with loosely laid boards which allow the waste water to drip through the joints4 ,such a well1 even though the source of supply is good1 will likely yield water of inferior quality4 ,in bored wells1 polluting water may enter through the uncemented joints of the tiling or through the joints in the staves of wooden tubing2 in drilled or driven wells1 through leaky joints or holes eaten in the iron casing by corrosive waters4 ,by cementing the interior surface of stone-or brick-curbed wells1 by replacing wood with cement or other impervious curbs and by substituting new pipes for leaky iron casings1 the entrance of polluting water may be prevented4 ,in the average home the water supply is most commonly taken from a well1 the water from which comes through the earth from unknown sources1 and the character of chemical salts or organic matter the water contains will depend on the kind of soil through which it passes before reaching the well4 ,the water from wells1 whether deep or shallow1 is generally of relatively local origin1 it being absorbed by the soil and carried to the water stratum by percolation4 ,if the soil contains soluble mineral salts the water will contain these materials in quantities depending on the amount of the salts present in the earth4 ,if the earth contains organic matter as pathogenic bacteria the water is likely to contain these bacteria in like numbers as they are present in the soil through which the water filters4 ,illustration3 ,,fig4 #abd4--,undesirable form of well curbing4 ,as usually encountered1 the water-bearing earth occurs in sheets rather than in veins or streams4 ,the movement of the water in such areas follows the contour of the earth and is influenced by the varying amount of rain or snowfall and the atmospheric pressure4 ,the lateral movement is often only a few inches a day and in some places no lateral movement occurs at all4 ,underground streams of any kind are not usually found except in limestone regions4 ,as a rule1 a well is formed by digging or boring into the earth until a stratum of water-bearing soil is encountered1 the type of the well being determined by the character of the earth and the location of the water-bearing soil4 ,the water from the surrounding area fills the opening to the height of the saturated soil4 ,as the water is pumped from the well it is replenished by the flow from the surrounding earth4 ,if the soil is porous1 as in the case of gravel1 the water will refill the well almost as fast as it is taken away by the pump4 ,if the soil is dense and the inward flow is slow1 the well when once exhausted may be a long time in refilling4 ,water ,table4--,the upper level of the saturated portion of the soil is known as the water table4 ,it has a definite surface that conforms to the broader surface irregularities4 ,while a definite1 determinable water table appears only in porous soil1 it exists even in dense rocks4 ,it rises and falls in wet seasons and in drought4 ,in exceptionally wet seasons the water table may be at or above the surface4 ,under such conditions the opportunities for the pollution of wells is much increased4 ,in particularly dry seasons the water table may sink below the bottom of the well1 when it is said to 8go dry40 ,the water table follows the surface contour in a manner depending on the character of the soil4 ,it is flattest in sand or gravel areas but in clay it follows the contour of deep slopes with but slight variation4 ,the ,devining ,rod4--,the use of the devining rod1 for the purpose of locating suitable sites for wells1 has been supposed by many to be a gift possessed by a chosen few4 ,the devining rod is a forked branch of witch hazel1 peach or other wood1 which when held in the hands and carried over the ground1 is supposed to indicate the presence of water by bending toward it4 ,in most cases the operators are entirely honest in their belief and in a large proportion of trial their efforts have been successful in locating desirable wells2 but it has many times been proven that the movement of the rod is due to an unconscious muscular movement of the arms and hands1 in places where the operator has previously suspected the presence of water4 ,the operator of the devining rods is most successful in regions where water occurs in sheets1 such as often occur in gravel or pebbly clay4 ,the successful use of the devining rod cannot be explained by any scientific reasons4 ,there have been invented a number of devining rods1 claimed by their inventors to be based on scientific laws2 but the government has not yet granted patents to appliances of the kind4 ,selection of a ,type of ,well4--,the chief factor which controls the selection of a type of well is the nature of the water-bearing earth1 the amount of water required1 the cost of construction and the care of the resulting supply4 ,if a large amount of water is to be demanded of a well1 to be dug in soil through which the water percolates slowly1 the well must be large in diameter1 in order that the necessary supply may be accumulated4 ,if the earth is porous and yields its water readily1 a small iron pipe driven into the ground may supply the desired amount4 ,the character of the water-bearing material is of the greatest importance in determining the yield of the well4 ,in quicksand1 water is usually present in ample quantities1 yet owing to the extremely fine particles of which the quicksand is composed1 its presence as a water-bearing soil is highly undesirable4 ,flowing ,wells4--,flowing wells are obtained in places where water is confined in the earth1 under sufficient pressure to lift it to the surface1 through an opening made to the water-bearing stratum4 ,these are known as artesian wells1 from the fact that they were first used in ,artois 7anciently called ,artesium7 in ,france4 ,in order that water may have sufficient head to lift it to the surface1 it must be confined under impervious clay or other bed of earth1 and with its source at a level considerably higher than its point of exit4 ,the source of supply for flowing wells is often at a great distance4 ,because of the fact that flowing wells are shut off from the surface by an impervious layer of earth1 the possibility of pollution from the surface is effectively prevented4 ,any contamination of the water must come from a distance and enter the water at its source4 ,as pollution rarely extends through the ground to any great lateral distance1 artesian waters are seldom polluted4 ,the water from artesian wells often is heavy with mineral matter and in many cases is unfit for drinking on that account4 ,,construction ,,of ,,wells ,wells are constructed by different methods1 depending on the character of the soil in which they are sunk4 ,their excavation is usually accomplished by one of three general methods3 by digging2 by driving a pipe into the earth until it penetrates the water-bearing stratum2 or by boring a hole with an enlarged earth auger1 into the water-bearing soil4 ,artesian wells are made by drilling with a device suitable for making a small and very deep hole4 ,dug ,wells4--,in shallow wells the water seeps through the soil from local precipitation4 ,deep wells are those from which the water is brought to the surface through an impervious geologic formation1 as a bed of clay or rock1 and from a depth greater than that from which water may be lifted by atmospheric pressure4 ,the fact that a deep well originates from a source that entirely differs from that of the shallow well accounts for the difference in chemical composition which frequently exists in the water from the two types of wells in the same neighborhood4 ,the form of the dug well is generally that of a cylindrical shaft #d feet or more in diameter and of depth depending on the location of the water-bearing stratum4 ,where the character of the soil is such that the seepage is slow and the water does not flow into the well as fast as the pump will remove it1 the well must contain a considerable volume to supply the period of greatest demand4 ,wells of this kind are commonly walled with brick or stone to keep the sides in place and to prevent the entrance of surface waters4 ,the top of this curb should be brought above the surface of the ground and should be made water-tight to prevent the entrance of surface waters4 ,the space around the curb1 at the surface1 should be graded to drain the water away from the well4 ,there should be no chance for the water to collect in pools about the well2 it should be conducted away in a gutter to the place of final disposal4 ,the well should be covered with a platform of concrete or planking which will allow no water to enter from the surface4 ,wells of this order are sometimes dug to great depth before the water-bearing stratum is encountered2 this may sometimes be reached only after a great amount of expense and labor4 ,the historic ,joseph ,well1 near ,cairo1 ,egypt1 is an open shaft1 #ah by #bd feet in area1 sunk through solid rock #afj feet4 ,open ,wells4--,open wells have long been condemned as insanitary4 ,the familiar open well of the 8,old ,oaken ,bucket0 type is an inviting receptacle for the deposit of all manner of refuse1 which once inside remains until it is disintegrated4 ,these wells become the final resting place of many small animals and all manner of creeping things1 in search of water4 ,the open top receives wind-blown matter in the form of leaves and dust1 much of which is in the nature of polluting material4 ,illustration3 ,,fig4 #abe4--;,ideal form of well curbing with cover and drain made of concrete4 ,the ,ideal ,well4--,in the case of a well which yields pure water1 every precaution should be taken to prevent its pollution4 ,the ideal form of construction is that shown in ,fig4 #abe4 ,in this well1 the curbing ,c is of heavy concrete that extends above the natural surface of the ground1 to prevent the entrance of surface water1 and that from seepage through the upper stratum of the soil4 ,the reinforced-concrete top forms a close joint with the curb to prevent the entrance of waste water and all animal life4 ,the pump is of iron1 secured to the well cover by bolts1 set in the concrete4 ,the trough of concrete ,g conducts the waste water from the well to a safe distance4 ,the earth about the well is so graded as to permit no water to stand in pools4 ,coverings of ,concrete4--,the use of concrete for the coverings of wells1 cisterns and springs has become a recognized form of the best construction4 ,it is not more expensive than other good materials and when properly executed it forms an imperishable protection and gives a neat appearance4 ,the spring cover in ,fig4 #abf1 and the cistern top in ,fig4 #abg are illustrations of its application4 ,artesian ,wells4--,artesian wells are made by boring into the earth until the drill reaches the artesian stratum1 the internal pressure forces the water through the opening to the surface4 ,they are usually small in diameter and often of great depth4 ,in some areas the artesian flow is found a few feet below the surface1 but generally it is much deeper and #cjjj feet is not an unusual depth4 ,the pressure and amount of flow from these wells is sometimes sufficient to permit the water being used for the generation of power4 ,small waterwheels are not uncommonly driven in this way and the power used for the generation of electricity for lighting and running small household appliances4 ,driven ,wells4--,in localities where the nature of the soil gives opportunity1 wells are made by driving a pipe to the required depth4 ,wells of this character are usually made in places where the water-bearing soil is of sand or gravel4 ,the pipe terminates in a sand-point such as that of ,fig4 #abh4 ,this sand-point is a perforated pipe with a pointed end1 that facilitates driving4 ,the perforations1 as shown in the point ,p1 form a strainer which allows the water to enter the pipe but prevents the sand from filling the opening4 ,illustration3 ,,fig4 #abf4--;,concrete cover for a spring4 ,illustration3 ,,fig4 #abg4--;,concrete cistern top4 ,in the use of driven wells1 the water-bearing soil must be sufficiently open to allow the water to flow into the pipe as fast as the pump takes it away4 ,bored ,wells4--,in many localities the water-bearing stratum is of such nature as to give a ready flow of water but yet not sufficient to permit of the use of a sand-strainer2 if1 however1 the opening is somewhat enlarged1 the water will enter with sufficient rapidity to supply a pump4 ,in such cases bored wells are quite generally used4 ,they are made by boring a hole of the required size with an earth auger4 ,these wells are made of any size up to #b feet in diameter4 ,they are often called tubular wells because they are lined with iron tubing or tile1 to prevent the earth from refilling the hole4 ,illustration3 ,,fig4 #abh4--;,driven well with a sand-point strainer4 ,cleaning of ,wells4--,very few dug wells are so constructed as to exclude dust and washings from the ground4 ,it is1 therefore1 necessary that they be occasionally cleaned4 ,accumulations from these causes may be sufficient to hinder the entrance of the water to the well and thus lessen its capacity4 ,gases in ,wells4--,one of the commonest gases found in wells is carbon dioxide 7carbonic acid gas74 ,it may be detected by lowering a lighted candle or lantern to the bottom4 ,if the gas is present in dangerous quantity1 the flame will be extinguished4 ,death from asphyxiation due to this gas is not an uncommon occurrence1 to persons descending into wells4 ,before entering a well1 the test described above should be applied1 as a precaution against accident4 ,carbon dioxide is a colorless1 odorless gas in which a person will drown as readily as in water4 ,peculiarities of ,wells4--,owing to the formation of the water-bearing earths1 from which they receive their water1 many wells possess marked peculiarities of behavior that often give rise to local reputation because of their vagaries4 ,these characteristics have been classified into breathing wells1 blowing wells1 sucking wells1 etc4 ,these effects are in almost every case due to variation of barometric pressure4 ,the ordinary level of the water in a well is governed by the variation of rainfall1 melting of snow or the release of water by the thawing of frozen ground4 ,it often occurs1 however1 that the head of water is markedly influenced by storms1 when a rise of the level of the water occurs at the time of low barometric pressure during the storm period4 ,this effect is often noticed in flowing wells4 ,many wells1 at the approach of storms1 yield roily water to such an extent that where the water is normally clear it may become for a period entirely unfit to drink1 because of the matter held in suspension4 ,all of these effects are accounted for by the varying atmospheric pressure4 ,at the time of high barometer1 a well that ordinarily flows freely will have to be pumped1 the additional pressure of the air holding back the water to an extent representing several feet of head4 ,the change of an inch in the barometric pressure will produce slightly more than a foot in head of water4 ,at the time of storms1 the barometer is sometimes abnormally low which will produce a corresponding rise of water in the well4 ,at such time the free flow of water into a dug well1 from the usual source of supply1 will cause such a rapid flow of water through the passages in the earth as to carry with the water the sediment that produces roily water in the well4 ,this sediment will settle after a while and the water will again be clear4 ,breathing ,well4--,wells of this kind are most common in areas where the water-bearing earth is of rock formation2 particularly in limestone areas1 where caves and cavities are common4 ,it sometimes happens that in the neighborhood of a well there is a cavity in the earth of considerable volume1 the only entrance to which is through the well and that being under usual conditions covered by water1 a foot or more in depth4 ,with such a formation the conditions are right for a breathing well4 ,at times of high barometer the water is depressed and the air will flow into the cavity through the well1 when the well is said to inhale4 ,this inward flow of air will continue until the air pressure in the cavity is equal to that of the outer air2 and if the cavity is large and the opening small1 the inward flow of air may continue for hours1 even for days4 ,with a fall of barometric pressure1 the air in the cavity1 being at a higher pressure than the external air1 the air will flow outward and the well is said to exhale4 ,freezing ,wells4--,in cold climates1 particularly in territory possessing cavernous limestone deposits1 breathing wells often freeze in winter4 ,when large volumes of frigid air are drawn into a well1 the amount of heat taken from the water is sufficient to freeze it1 and stop the supply of water4 ,this effect is sometimes remedied by plugging the well at the top1 so that the influx of cold air is prevented and the water does not freeze4 ,,pumps ,pumps for lifting and elevating water are made of both wood and iron in almost endless variety2 but for domestic purposes they are of two general types--the lift pump and the force pump--which include features that are common to all4 ,the lift pump is intended for use in lifting water from low-head cisterns and wells1 the depth of which is not beyond the head furnished by atmospheric pressure4 ,the force pump performs the work of a lift pump and in addition forces the water from the outlet at a pressure to suit any domestic application4 ,these pumps are made by manufacturers in a great variety of forms1 but the essential parts are the same in all pumps intended for a single purpose4 ,the principle of operation is the same in all pumps of any type4 ,the difference in mechanism of pumps intended for the same purpose is only in the form and arrangement of the parts4 ,the ,lift ,pump4--,the kitchen pump is an example of the lift pump4 ,it is universally used for household purposes where water is to be raised from cisterns1 etc41 and is most commonly made throughout of cast iron4 ,fig4 #abi illustrates one form1 sometimes called the pitcher pump1 because of the slight resemblance to the article4 ,it frequently carries the name cistern pump from the fact that it very generally is used to lift water from cisterns4 ,although water may be raised #cd feet with a theoretically perfect pump and with a barometric pressure of #cj inches the actual limit is much lower4 ,in use1 #bj feet is probably about the limit and #aj feet or less is that of common practice4 ,a pump that requires 8priming0 would raise water #ae feet with considerable difficulty for reasons that will appear later4 ,in ,fig4 #abi is shown a sectional view of the working parts of the kitchen pump1 the action and general form of which apply to any lift pump4 ,the body of the pump contains a cylinder1 in which closely fits a piston ,p1 containing a valve ,a4 ,at the bottom of the cylinder is an additional valve ,b4 ,the piston and two valves constitute the working parts of the pump4 ,the water is lifted through the pipe ,s1 and is discharged at ,d4 ,illustration3 ,,fig4 #abi4--,sectional drawing of the kitchen pump showing its working parts4 ,the action of the pump is as follows3 ,with the piston at the bottom of the cylinders and with no water in the pump1 the handle is forced down1 which action raised the piston4 ,in so doing the air below it is rarefied4 ,the reduction of pressure due to the rarefication of the air allows the water to rise in the pipe ,s correspondingly4 ,after repeated strokes of the piston1 the water reaches the valve ,b1 which raises to let it pass1 but immediately closes at the end of the upward stroke4 ,when the space between the piston and the valve ,b is filled with water1 each descent of the piston forces the water through the valve ,a2 and when the piston is raised1 the water is lifted out through the spout4 ,the valve ,a is a loose piece of cast iron1 surfaced on the lower side to make good contact with the piston4 ,the valve ,b is of cast iron fastened to a piece of leather by a screw4 ,the leather makes a joint with the valve-seat and furnishes an excellent valve for its use4 ,in order to keep the plunger ,p tight in the cylinder1 it is surrounded with a leather gasket4 ,should this gasket become worn1 as it will in time1 the plunger fits loosely in the cylinder and the pump will lift the water with difficulty1 because of the leakage around the gasket4 ,should the valve ,b leak1 the water will gradually run back into the pipe ,s1 and the pump when left idle will lose its 8priming40 ,the plunger and the valve ,b are the parts most likely to get out of order4 ,if the gasket around the piston ,p is very much worn1 and there is no water in cylinder1 the pump will require priming before the water can be raised4 ,if the pump contains no water and is left standing for a considerable time1 the leather parts of the valve dry out and shrink2 when the pump is again put into use1 the valves will fail to work properly1 until the leathers are again water-soaked4 ,water is poured into the top of the pump until the cylinder is filled1 and as soon as the leather becomes water-soaked and fills the cylinder1 the piston will again perform its function4 ,illustration3 ,,fig4 #acj4--,method of attaching the house pump to kitchen sink4 ,illustration3 ,,fig4 #aca4--,sectional drawing of the force pump showing its working parts4 ,the ,force ,pump4--,the house force pump is often used in place of the ordinary lift pump1 when no other means is at hand for providing water under pressure4 ,it furnishes a limited means for lawn sprinkling and gives some degree of fire protection in isolated places4 ,it may be made a part of the kitchen sink as shown in ,fig4 #acj1 by use of the attachment that appears in detail under the sink4 ,this type of pump may be used in small water-supply plants1 such as that of ,fig4 #adc2 or in connection with small pressure tanks for the same purpose4 ,it differs somewhat in construction from the lift pump1 in that it has no valve in the piston and is provided with a check valve and an air chamber for generating pressure to the discharged water4 ,fig4 #aca shows the essential parts of the force pump and furnishes a means of describing its operation4 ,all force pumps possess the same parts and the operation described applies with equal force to all4 ,a valve ,a is located in the bottom of the cylinder and the check valve ,b prevents the return of the water to the cylinder after it has been forced out of the pump4 ,the action of the pump in raising the water is the same as in the lift pump but when the water fills the cylinder and the piston descends1 the water is forced through the valve ,b and out at ,d4 ,if the outlet pipe is slightly smaller than the opening in the valve ,b1 some of the water will enter the air chamber ,c and compress the air4 ,the pressure thus generated will immediately tend to force the water out and in course of ordinary pumping will send out a steady stream instead of the intermittent flow of the lift pump4 ,without the air chamber1 the flow from this pump will be a series of pulsations that attain maximum force with each descent of the piston4 ,illustration3 ,,fig4 #acb4--,tank pump1 commonly used in small domestic water supply plants4 ,tank ,pump4--,the type of pump used with a water-supply plant will depend entirely on the amount of water that is used4 ,if the supply of water to be provided is for only one or two people the house force pump such as that of ,fig4 #acj will suffice2 but when a greater number of people are to be supplied1 a force pump of the type shown in ,fig4 #acb is quite generally used4 ,these pumps are made in a variety of patterns and are commonly termed tank pumps4 ,the one shown in the ,fig4 #acb is a double-acting force pump in that the cylinder receives and discharges water at each stroke of the piston4 ,the air chamber is located at ,a4 ,directly beneath the air chamber is the valve chest in which are located the valves which regulate the entrance and discharge of the water4 ,as used in the average domestic plant the cylinders are #c or #d inches in diameter4 ,,well ,,pumps ,the pumps intended for raising water from wells are practically the same in construction as the house pump1 except that they are intended to deliver a greater volume of water and sometimes to work under a different condition1 as that of the deep well pump4 ,well pumps have1 therefore1 assumed certain standard forms that differ only in the styles of mechanism employed by different manufacturers4 ,the one shown in ,fig4 #acc furnishes a good example of a general-purpose iron pump which may be used either as a force pump or a lift pump4 ,it represents also the general construction of a deep-well pump1 where the water must be lifted from a level1 below that at which a lift pump will work4 ,the piston and valves are enclosed in the cylinder ,c1 placed below the surface of the water in the well4 ,this cylinder also appears in section in the small drawing1 showing the details of the valve4 ,the operation of this pump is identical to that of the lift pump already described1 but the addition of an air chamber gives it the necessary facility to produce a continuous flow of water4 ,in order to prevent the air in the air chamber from escaping1 the pump rod is surrounded with the necessary stuffing-box which is usually packed with candle wicking to assure a good joint4 ,in deep wells the tube is elongated sufficiently to place the cylinder ,c below the surface of the water in the well4 ,such pumps are operated either by hand or by power4 ,wooden ,pump4--,the wooden pump of ,fig4 #acd furnishes a good illustration of a type that was formerly used in great numbers4 ,it is an inexpensive and efficient pump made almost entirely of wood except the cylinder which is quite generally made of iron1 lined with enamel4 ,the valve and the piston with its valves are made of wood1 but faced with leather to insure tight joints4 ,the piston is also provided with leather packing to make it tight in the cylinder4 ,the action of the pump is the same as that already described4 ,the wooden tube is made in sections joined together by taper joints that are driven into place4 ,illustration3 ,,fig4 #acc4--,sectional view of a well with an iron cylinder pump1 placed for deep-well pumping4 ,illustration3 ,,fig4 #acd4--,sectional view of a well and wooden pump for shallow pumping4 ,the piece at the side of the pump is provided to drain the water from above the piston1 as a precaution against freezing during extremely cold weather4 ,the rod1 when raised1 opens an orifice that leads to the inside of the pump and permits the water to drain into the well4 ,pumps for ,driven ,wells4--,the method of constructing driven wells--that of driving a pipe into the earth to the water-bearing stratum of sand or gravel--requires a special end to prevent the pump tube from becoming stopped4 ,in order that the fine material may not enter and fill the lower end of the tube1 a sand-point is used1 such as that shown in ,fig4 #abh4 ,it is made of perforated brass tubing and provided with a sharpened end to facilitate driving4 ,the perforations act as a strainer that keeps out all but the fine particles which will pass the pump valves4 ,sand-points are made with strainers of various degrees of fineness to suit the different conditions of soils4 ,these strainers may in the course of time become filled with particles of the soil that lodge in the perforations and the outside become so encrusted as to prevent the entrance of the water4 ,in such case1 the pipe must be pulled out of the ground and the point replaced by a new one4 ,in ,fig4 #abh is shown a driven well with the sand-point in the water-bearing stratum4 ,if the small particles of earth clog the strainer the pump will 8work hard0 and yield only a portion of the water the soil is capable of giving when the strainer is clear4 ,deep-well ,pumps4--,the principle of operation as described in the lift pump takes advantage of the atmospheric pressure to lift the water above the first valve4 ,the limiting distance to which water can be lifted by the atmospheric pressure will depend on the altitude and the atmospheric pressure4 ,with the normal atmospheric pressure at sea level1 water can be lifted1 theoretically1 #cd feet1 but in practice the limiting value is never even approximated4 ,the pump is usually placed within #aj of #ab feet of the water and #bj feet is about the limit of distance4 ,the reason for this is because of the impossibility of keeping the joints tight in the valve and tubing4 ,where water is to be raised from a deep well1 the cylinder with its piston is placed near the water and the tube and rod1 as that of ,fig4 #acc1 connects the cylinder with the pump stock4 ,after the water has passed the valve in the piston1 it may be readily lifted to the pump stock4 ,in this way water is raised from wells of great depth4 ,tubular-well ,cylinders4--,tubular wells that are cased with iron pipe are provided with a special type of pump cylinder that admits of deep-well operation4 ,the casing of the well being in place1 the cylinder shown in ,fig4 #ace is forced down the casing to its proper place1 the spring ,s holding it in place until it is firmly secured4 ,a special seating tool is now lowered into the casing and attaches at ,t to the coupling2 as the tool is turned1 rubber packing ,r is expanded1 locking the cylinder firmly to the casing4 ,this makes a complete pump cylinder1 which with the piston ,p in place is operated as any other pump4 ,illustration3 ,,fig4 #ace4 ,chain ,pumps4--,in shallow wells and other sources of supply1 where water is to be lifted only a short distance1 chain pumps have been used to a great extent1 because of their quick action4 ,this pump1 as shown in ,fig4 #acf1 elevates the water by an endless chain being drawn through the tube1 the lower end of which is below the surface of the water4 ,the chain is provided at intervals with discs or rubber or iron1 that fit the bore of the tube and form pistons which elevate the water as they ascend4 ,the chain passes around a wheel in the upper part of the box and is worked by the crank4 ,chain pumps are not usually employed to elevate water a greater height than #bj feet4 ,they are not efficient pumps and are not sanitary because of the opportunity they give for admitting polluting material to the well4 ,their one advantage is that of quick action in elevating water short distances4 ,illustration3 ,,fig4 #acf4--;,chain pump often used in shallow wells4 ,,rain-,,water ,,cisterns ,cisterns for the storage of rain water have been used from the time immemorial and are constructed in a great variety of forms4 ,for household use they are often made in the form of wooden or metal tanks1 either elevated or placed in the basement2 the greater number1 however1 are of the underground variety made of brick or concrete4 ,wooden cisterns are made by manufacturers in different sizes and shipped to the user 8knocked down20 that is1 they are taken apart and the staves1 bottom and hoops are shipped1 packed in small space to save space in transportation4 ,under some conditions they give good service but are apt to leak at times and require attention on that account4 ,in damp basements they give out the disagreeable odor of damp wood4 ,tanks made of galvanized iron are much used as cisterns for temporary use4 ,they are inexpensive and give good service but are short-lived4 ,possibility of leakage is their greatest disadvantage4 ,underground cisterns are built either in the basement or outside the house4 ,they are quite generally made jug-shaped1 but are often constructed of concrete in square and rectangular form4 ,when built of brick the walls are often made of a single course1 but walls made of two courses of brick are considered better practice4 ,the walls and floor are made water-tight by plastering with an inch or more of cement mortar4 ,when cisterns are made of concrete1 the floor should be put in #f inches in depth and as soon after as possible the walls are put up4 ,in good construction the walls are #h inches in thickness of concrete1 made of #a part good ,portland cement1 #b parts clean sand and #d parts crushed stone4 ,if the cistern is square or rectangular in form the walls should be reinforced with woven wire or steel rods1 to prevent cracking4 ,the curb of the cistern should extend above the surface of the ground sufficiently to prevent surface water from entering1 and the top should be covered with a wood-lined sheet-metal cover to prevent freezing4 ,filters4--,unfiltered cistern water is not1 as a rule1 fit for drinking purposes because of pollution from dust and impurities washed from the roof1 but for bathing and laundry work filtered rain water is greatly to be desired4 ,as rain water comes from the roofs of buildings1 there is washed into the cistern a considerable quantity of dust1 leaves1 bird droppings and other polluting materials which contaminate and discolor the water4 ,this foreign matter is not injurious for the purposes intended1 but to render the water clear it should be filtered before using4 ,filters for cisterns are quite generally made of soft brick laid in cement mortar1 the face of the brick being left uncovered4 ,fig4 #acg illustrates a simple and efficient form of filter made of a single course of brick4 ,a space one-fourth to one-third of the volume of the cistern is left for the filtered water4 ,the opening at the top of the wall must be large enough to admit a man1 for some sediment will collect even in the filtered water and the filter must be occasionally cleaned4 ,illustration3 ,,fig4 #acg4--;,cross-section of a brick curbed cistern with a brick filter wall4 ,illustration3 ,,fig4 #ach4--;,cross-section of a concrete cistern with a brick dome filter4 ,the filter shown in ,fig4 #ach is dome-shaped and built of brick4 ,the water is pumped from inside the filter and the suction of pumping filters the water as it is used4 ,in this case the filtering action is accelerated by reason of the reduced pressure inside the filter as the water is pumped4 ,the chief disadvantage in this form of filter is the small area exposed for the filtering action and the relatively greater amount of work required for pumping the water1 due to the partial vacuum formed as the water is pumped4 ,the cistern in ,fig4 #aci is provided with a catch basin which acts as a strainer for removing leaves1 etc41 that would stain the water4 ,it is made in the form of a concrete basin and partly filled with gravel4 ,the filter in this case is formed by a depression in the cistern floor4 ,a section of tile is placed on the floor1 and around it is filled the filtering material of gravel and sand4 ,filters of this kind are often filled with charcoal or other materials that are expected to purify the water4 ,they are usually inefficient because their value as absorbers of polluting agents is short-lived and unless the materials are frequently renewed they are valueless and sometimes a detriment to rapid filtration4 ,illustration3 ,,fig4 #aci4--;,cross-section of a concrete cistern1 containing a sand filter4 ,,the ,,hydraulic ,,ram ,in places where its use is possible1 the hydraulic ram is a most convenient and inexpensive means of mechanical water supply4 ,it is simple in construction1 requires very little attention and its cost of operation is only the labor necessary to keep it in repair4 ,whenever a sufficient supply of water will admit of a fall of a few feet1 the hydraulic ram may be used as a pump for forcing the water to a distant elevated point1 where it may be utilized for all domestic purposes4 ,the water may be used directly from the ram or stored in an elevated tank as a reserve supply2 or accumulated in a pressure tank1 where additional pressure is required4 ,the hydraulic ram has been used since #agif1 when it was invented by ,joseph de ,montgolfier4 ,the principle of its operation is that of the utilization of the energy of flowing water4 ,the running water is made to give up a portion of its momentum to elevate a part of the water1 and transport it to a considerable distance4 ,if the source of supply and the fall is sufficient1 almost any amount may be elevated and carried to a great distance4 ,large rams are sometimes used as a means of water supply for small towns4 ,in the use of the double-acting ram1 one source of water may be used to operate the ram and water from an entirely different source may be delivered4 ,it sometimes happens that a muddy stream and a clear spring are so located1 that the water of the stream can be utilized to furnish the energy for conveying the spring water to a point where it is desired for use4 ,this is accomplished by the double-acting ram in a most efficient manner4 ,single-acting ,hydraulic ,ram4--,fig4 #adj represents the installation of a single-acting hydraulic ram1 placed to take water from a spring ,e1 and deliver it to an elevated tank at the house on the hill4 ,illustration3 ,,fig4 #adj4--;,hydraulic ram driven by the water from a spring4 ,in case the ram must be located at a considerable distance from the spring in order to attain the required fall1 a standpipe ,d--slightly larger than the supply pipe--is used to take advantage of the full force of the water4 ,in long pipes1 the friction of the flowing water absorbs a considerable amount of the energy of flow and a standpipe1 located as indicated at ,d1 in the picture1 will assure the full force of the flowing water in the ram4 ,the ram is commonly placed in an underground pit as protection from freezing during cold weather1 and a drain from the bottom of the pit conducts the waste water away4 ,the supply pipe or drive pipe ,b and delivery pipe ,c are buried underground below the frost line as a protection from freezing4 ,in ,fig4 #ada a sectional view of the ram shows all of the working parts4 ,the air chamber ,g is shown partly filled with water2 the impetus valve ,d is that part of the ram which checks the flow of the running water and forces a part of it through the valve ,e1 at the bottom of the air chamber4 ,illustration3 ,,fig4 #ada4--;,cross-section of a single-acting hydraulic ram4 ,when inactive the valve ,d stands open and as the water enters from the pipe ,a1 it flows through the valve to the waste pipe but as soon as the full force of the water bears on the valve it will suddenly close4 ,this sudden stop of the flowing water will lift the valve ,e1 and the energy of flow1 due to its sudden stopping1 will force some of the water into the chamber ,g4 ,as this action occurs the upward pressure against the valve ,d is released and it reopens but immediately closes again as the water begins to flow4 ,this process is kept up1 each closure of the valve sending a little water into the air chamber4 ,as the water gradually fills the air chamber1 it is subjected to the same action as was described in the pressure tank1 the air above the surface being compressed and the pressure developed in the space ,g forces the water out through the delivery pipe where it attains a force that is a factor of the height of the original fall4 ,the air in the chamber ,g1 is subject to the same conditions of loss as that of the pressure tank1 and to be assured of a supply to give pressure to the water1 some air must be carried into the chamber with the water4 ,for this purpose the valve ,f provided4 ,after the chamber is partially filled1 there occurs a reaction in the flow of water at each closure of the valve1 which causes a little air to be drawn in through the valve ,f with each impulse4 ,this air bubbles up through the water and enters the chamber where it assures an elastic cushion for closing the valve ,e4 ,the flow of water from the supply pipe is regulated at ,h by a nut on the stem of the impetus valve which permits its regulation4 ,closing the valve slightly causes a less supply of water to be delivered2 opening the valve wider gives a greater supply4 ,illustration3 ,,fig4 #adb4--,sectional view of a double-acting hydraulic ram4 ,the ,double-acting ,hydraulic ,ram4--,the diagram of ,fig4 #adb illustrates the working principle of the double-acting hydraulic ram mentioned above2 where the water from a muddy stream is used to drive the ram and that from a separate source1 as a spring is delivered4 ,the construction of the double-acting ram is similar to the single-acting ram1 but a separate pipe ,s discharges spring water directly below the valve which acts just as though it had entered at the drive pipe4 ,the ram in this case is receiving water from the drive pipe ,d1 which operates the valve and furnishes power for elevating the spring water4 ,the spring water enters the ram through the pipe ,s1 to keep the space ,t filled1 directly under the valve4 ,the water which enters the air chamber is1 therefore1 only that from the spring4 ,a standpipe is arranged as shown in the figure1 with a check valve to prevent the water in the ram from being forced back into the spring water pipe after entering the ram4 ,,domestic ,,water-,,supply ,,plants ,until recent years1 no thought was given to private water-supply plants1 in any except the more pretentious residences4 ,it was formerly supposed that the cost of machinery and installation of such plants prohibited the use of a water system in the average home4 ,as an item of expense in building1 a satisfactory water-supply system may be installed at a lower cost than is paid for plumbing and bathroom fixtures4 ,in recent years much attention has been given to the design of small water-supply plants for isolated homes1 such as are required for suburban and rural dwellings1 with the result that the necessary apparatus to suit any conditions may be obtained of any enterprising dealer4 ,the degree of completeness with which the plant is to be arranged will depend on the funds to be expended1 but in the most modest dwelling some form of water-supply plant is possible4 ,where opportunity is given to make the plant complete1 its appointments of construction may be elaborated to almost any extent4 ,a suburban or country residence may be made as perfect in point of toilet1 kitchen and laundry conveniences1 as where city water and sewer service are available4 ,the water-supply plant may be operated by hand or by power1 and if so desired may be made completely automatic in action4 ,gravity ,water-supply ,plant4--,in point of simplicity1 the plant shown in ,fig4 #adc represents a water system that answers every purpose of a cottage and yet is only an elevated tank for storage of water1 combined with a house force pump4 ,the tank in this case may be made of wood or metal and is open at the top4 ,the water is sent into the tank by the pump1 and gravity furnishes the force for carrying it to the fixtures in the kitchen and bathroom4 ,in using a tank of the kind shown in the drawing1 provision should be made for the possibility of leakage4 ,this is arranged for by having the tank set in a shallow pan1 so constructed that in case of accident the water may be carried away without doing damage4 ,this type of plant is not usually employed in cold climates1 unless some provision is made to prevent the water in the tank from freezing4 ,tanks of this kind are sometimes used in cold climates but a much more desirable plant for the purpose is described below4 ,in ,fig4 #adc the water from the cistern ,w is raised by the pump ,p1 which also forces it into the tank above the kitchen4 ,the gravitational force given the water1 because of its elevated position is all that is necessary to carry the water to the fixtures in the bathroom and kitchen sink4 ,as shown in the drawing1 it furnishes a complete water system that will perform all of the requirements of water distribution for a small family4 ,illustration3 ,,fig4 #adc4--,sectional view of a cottage containing a simple gravity water-supply plant4 ,the pipes from the range boiler are attached to the water heater1 which forms a part of the kitchen range as explained on pages #aaf to #abj4 ,it receives the supply of cold water directly from the tank through the pipe marked ,c1 and the hot water from the range boiler is supplied through the pipe ,h4 ,cold water is also taken from the tank directly to each of the cold-water taps4 ,the pump ,p is a house pump1 such as is shown in ,fig4 #acj4 ,it is a small force pump1 designed to suit the conditions of domestic use and is made to send water into the sink or into the supply tank as desired4 ,pressure-tank ,system of ,water ,supply4--,the water-supply plant shown in ,fig4 #add is another simple construction1 somewhat more elaborate than the last1 so arranged that the danger of freezing is practically eliminated4 ,this is a simple pressure-tank system in which a tightly built metal water tank takes the place of the elevated tank of the previous figure1 and a tank pump is used for lifting and giving pressure to the water4 ,it is a more complete plant than the first and intended to accommodate a larger dwelling4 ,the drawing shows all of the fixtures and connecting pipes that are required in the average home4 ,it shows all of the appliances for connecting the pressure tank and range boiler with the wash trays in the basement1 with all of the fixtures in the bathroom and with the fixtures in the kitchen sink4 ,the range boiler is the same as those previously described and connected to the heater in an identical manner4 ,the original source of supply in this case is a cistern1 sunk below the basement floor4 ,the water is lifted from the cistern by the pump and forced into the pressure tank through a pipe near the bottom where it furnishes the supply for the house4 ,the pressure tank may be of any size to suit the requirements of the house and may be placed in either a vertical or horizontal position4 ,it is sometimes galvanized1 as a precaution against rust1 but this is not a necessary requirement4 ,the pipe which conveys the water from the pump connects with the tank near the bottom4 ,as the water enters1 the contained air above its surface is compressed into smaller and smaller space4 ,the pressure that is developed by the compressed air furnishes the force by which the water is driven out of the tank and through the distributing pipes to the various parts of the system4 ,if the air in the tank when empty is compressed to one-half its original volume1 then the gage pressure will be about #ae pounds to the square inch2 if the air is compressed to one-third its original volume1 that is1 when the tank is two-thirds full of water1 the gage pressure will be about #cj pounds to the square inch1 which is enough to supply water at any point of a two-story building with ample force4 ,by pumping more water into the tank1 a pressure of #ej or #fj pounds may be obtained without difficulty2 but #dj pounds is generally sufficient for all the demands of a house plant4 ,this is an application of the ,boyle's law which as stated in text books of physics is3 8,the temperature remaining the same1 the pressure on confined gas varies inversely as its volume40 ,as the volume of such a confined body of gas is made smaller1 the pressure increases in like ratio4 ,the desired pressures are easily attained with a hand force pump such as is shown in the drawing4 ,illustration3 ,,fig4 #add4--,the pressure-tank system of water supply as it appears in a dwelling4 ,the gage-glass ,g on the side of the tank is intended to show the height of the water in the tank at any time1 and the pressure gage attached to the supply pipe shows the amount of pressure sustained by the water4 ,the ,pressure ,tank4--,the water leaves the tank by a pipe attached near the bottom and branches to supply each fixture1 to which the water is to be conducted4 ,in the drawing1 the pipe may be traced from the point where it leaves the tank to the various fixtures4 ,the cold-water pipe terminates at the range boiler1 for at that point the hot-water system begins4 ,the range boiler is connected by two pipes to the water heater in the kitchen range4 ,the water heater is a part of the fire-box of the kitchen range and so long as the fire is kept burning1 water is heated and stored in the range boiler4 ,where the house is furnace-heated1 the furnace fire is sometimes utilized for heating the water by use of a coil of pipe above the fire and which may take the place of the range heater4 ,various other means are also employed for heating the water as described under range boilers4 ,in ,fig4 #ade is shown a nearer view of a pressure tank with the pump attached4 ,the pump is in this case identical in its action to the one shown in ,fig4 #acb1 but differs slightly in mechanical design4 ,the drawing shows the gage-glass ,g1 for indicating the height of water2 the pressure gage ,p1 which indicates the pressure to which the water is subjected2 the attachment of the supply pipe ,s1 and the delivery pipe ,d4 ,the water tap ,t is provided to draw off the water when the tank is to be emptied4 ,illustration3 ,,fig4 #ade4--,the pressure tank complete1 with the pump and gages as used for domestic water supply4 ,in operation1 the air in the pressure tank furnishes the force which sends the water through the pipes to the various points1 and forces it through the taps at the desired rate4 ,if for any reason the air in the tank escapes1 the propelling force is destroyed4 ,this may occur by reason of absorption of the air by the water1 due to the pressure to which it is subjected2 or to small air leaks that may develop in the joints1 which allow the air to escape4 ,to overcome the possibility of these occurrences1 arrangement is made whereby air may be pumped into the tank by the same pump as that which supplies the water4 ,in this way1 the air is introduced with the water1 which bubbles up through it to the surface4 ,if at any time the pressure in the tank is lost1 it may be replaced by pumping air alone into the tank4 ,power ,water-supply ,plants4--,where the pump is expected to furnish water to any considerable amount beyond that for household use1 it is desirable that the plant be power-driven4 ,if the work of watering stock1 lawn sprinkling1 etc41 is intended1 the tank and pump must be enlarged to suit the desired amount of water1 and a gasoline engine1 windmill or electric motor will be used for power4 ,where local conditions will permit1 a hydraulic ram may be substituted for the pump and the pressure tank used for additional pressure and storage4 ,illustration3 ,,fig4 #adf4--,tank pump operated by a small gasoline engine4 ,fig4 #adf shows a plant in which the pump is driven by a gasoline engine4 ,in the figure1 the engine ,e is shown connected by a belt to a speed-reducing device or 8jack10 marked ,j4 ,the object of this machine is to reduce the speed of rotation and charge it to the required motion for operating the pump4 ,the jack is connected to the pump by a rod attached to a large gear1 so as to produce the desired crank motion2 and the opposite end of the rod is attached to the pump handle4 ,the rod may be detached at any time and the pump worked by hand4 ,electric ,power ,water ,supply4--,fig4 #adg shows another type of power plant in which an electric motor operates the pump4 ,in this style of plant1 the pulley on the electric motor ,m is connected by a belt to the large wheel ,w1 from which the crank motion is secured for driving the pump ,p4 ,this machine is provided with an automatic starting and stopping device1 which automatically controls the supply of water in the system4 ,whenever the pressure in the tank falls to a certain point1 the change of pressure produced on the diaphram valve ,a starts the motor1 and the pump sends water into the tank until the pressure in the tank again reaches the amount for which the valve is set1 at which time the valve disconnects the electric contact to the motor and the pump stops working4 ,illustration3 ,,fig4 #adg4--,pressure tank supplied by an electrically driven pump4 ,wind-power ,water ,supply4--,in ,fig4 #adh is shown a larger and more complete plant than the former1 in which a windmill furnishes the power for pumping and a large underground tank is utilized for the main supply of water4 ,the tank marked1 ,well ,water ,pressure ,tank1 in this case is so placed that the end is exposed in the well curb1 where the height of the water may be observed at any time4 ,the pump is operated as any other of its kind1 but is provided with an automatic pressure cylinder1 which controls the operation of the mill through the rise and fall of the water in the tank4 ,at any time the water in the tank falls to a certain point1 the pump is thrown into gear by the pressure cylinder1 and the water is pumped into the tank until a definite height is reached2 at this point the pump is automatically thrown out of gear and remains inactive until an additional supply of water is required4 ,the plant is therefore automatic in its action and requires only that the mill be kept oiled and in running order4 ,as shown in the drawing1 the large tank receives its supply of water from the well and aside from providing a reserve supply furnishes power for pumping cistern water4 ,the water from the large tank is piped into the house for use as required1 and from the same pipe is taken a hydrant for lawn sprinkling2 in addition1 this water is piped to the barn where it is used for watering stock4 ,a branch of the same pipe is intended to operate a water lift1 which in turn furnishes the house with soft water from the rain-water cistern for bathing1 laundry1 and kitchen purposes4 ,illustration3 ,,fig4 #adh4--,this diagram shows the arrangement of domestic water-supply apparatus1 in which a windmill furnishes the pressure necessary for operating the entire plant4 ,the ,water ,lift4--,the water lift is a combined water engine and pump1 the motive power for which is the pressure from the well-water tank4 ,the soft water1 pumped by the water lift1 is stored in the smaller pressure tank marked ,soft ,water ,pressure ,tank in the drawing1 and furnishes a supply for the purposes mentioned4 ,the water lift is so constructed that when the pressure in the soft-water tank equals the pressure in the well-water tank1 the lift will stop working and will not start again until water has been drawn from the taps4 ,whenever water is drawn from any part of the system1 the pressure will be reduced and the lift will immediately begin pumping more water and will continue until the pressure of the two tanks are the same4 ,the system is entirely automatic1 each part depending on the power originally supplied by the windmill4 ,the plant could be just as successfully operated by substituting a gasoline engine or other source of power for the windmill4 ,the machinery for such a plant is not at all complicated neither is it difficult to manage1 yet it is complete in every particular and furnishes an almost ideal arrangement for a country or suburban home4 ,illustration3 ,,fig4 #adi4--,the water lift4 ,in order to be assured of a supply of water over periods of atmospheric quiet1 the well-water tank must be sufficiently large to supply water for #c or #d days2 but in case of emergency water may be pumped by hand4 ,a nearer view of the water lift is shown in ,fig4 #adi4 ,in the figure1 the right-hand cylinder with its valve ,v is the water engine which furnishes the power for operating the pump1 enclosed in the left-hand cylinder4 ,the water pressure of the main supply furnishes the energy which drives the engine1 the piston rod of which is attached to the pump piston4 ,the engine receives its supply of water through the pipe marked ,inlet and the waste water is discharged to the sewer by the waste pipe on the opposite side of the cylinder4 ,the operation of the lift is governed by an automatic regulator which so controls the engine that it starts pumping whenever the pressure in the system falls to a certain point4 ,the regulator marked ,adjustable ,regulator in the drawing may be adjusted to suit the water pressure desired in the distributing system4 ,illustration3 #a ,air ,chamber ,nut #b ,brass ,tube for ,air ,chamber #c ,air ,chamber #d ,brass ,cock #e ,cap ,screw #f ,leather ,washer #g ,handle ,pin #h ,pitman #i ,handle #aj ,brass ,covered ,piston ,rod #aa ,fulcrum #ab ,fulcrum ,pin #ac ,brass ,stuffing ,nut #ad ,cap #ae ,fulcrum ,ring #af ,fulcrum ,ring ,pin #ag ,plunger #ah ,cylinder #ai ,cap ,screw #bj ,lower ,valve #ba ,brass ,valve ,seat #bb ,base #bc ,bottom ,brass ,ferrule #bd ,bottom ,nut ,,fig4 #aej4--,the terms by which the parts of a force pump are designated4 ,,chapter ,,viii ,,sewage ,,disposal ,the disposal of sewage1 in a convenient and sanitary manner is a problem of serious importance in the equipment of isolated dwellings with modern household conveniences4 ,the manner of heating1 lighting and of water supply are questions of selection among a number of established systems1 but the problem of sewage disposal must in a great measure be determined by local conditions4 ,unless the natural surroundings are such as will permit sewage to be emptied directly into a stream of considerable volume1 the problem of its safe disposal becomes one of serious importance4 ,sewage is understood to mean the fluid waste from the kitchen1 toilet and laundry and has nothing whatever to do with garbage4 ,sewage disposal has to do with conducting away the house waste and disposing of it in a sanitary manner4 ,sewage disposal does not necessarily have anything to do with sewage purification2 although a sewage disposal plant may be so constructed as to discharge a purified effluent1 it usually is understood to have to do alone with its disposal in a manner that does not offend the aesthetic sense4 ,a simple sewage plant is anything that will take the sewage away from the house in such a way as to produce no unsightly accumulations that will decay and produce offensive odors4 ,a sewage purification plant is one in which the raw sewage from the house drain is first liquefied1 after which the liquid is passed into a filter where it undergoes a process of bacterial disintegration and the organic matter reduced to the inorganic state1 where no further change is possible4 ,the water which flows from such a filter is clear and sparkling1 and is often taken for spring water4 ,the degree of purification given to the sewage will depend on the style of filter and the length of time necessary for the water to pass through it4 ,sewage is composed of organic matter in a fluid or part fluid condition1 contained in a large volume of water4 ,it is not usually the dark1 heavy1 foul-smelling fluid that is imagined by many1 but a turbid liquid possessing only a few of the qualities usually ascribed to sewage4 ,under favorable conditions practically all of the organic matter will be readily dissolved and the sewage will become entirely liquid4 ,as a liquid1 the raw sewage is in the most favorable condition for rapid decay and if left standing in the air it soon develops properties that render it highly objectionable4 ,the decay of all organic matter is a process of disintegration that ultimately ends in the elements from which it came4 ,in the disposal of sewage1 the aim is to permit this disintegration to take place under conditions that will be least offensive to the aesthetic sensibilities1 and in some cases to render it free from harmful properties should there be present the bacteria of communicable disease4 ,the successful disposal of sewage from cities is accomplished under a great variety of conditions4 ,it is much easier to arrange for sewage purification on a large scale than in a small way4 ,the reason for this is that in the care of a city the sewage-disposal plant is under the supervision of a competent person1 whose business it is to see that the conditions are kept at the highest efficiency4 ,private plants are left almost entirely without care1 until they fail from causes that are usually preventable4 ,sewage may be successfully purified under a great many conditions1 but no type of plant has as yet proven itself successful that does not receive intelligent attention4 ,the most successful of small sewage disposal plant is the septic tank system alone or in connection with an adequate form of bacterial filter4 ,cesspools are not to be countenanced by people of intelligence4 ,the cesspool has been so universally condemned by authorities on sanitation1 that all intelligent people look upon it as a thing filthy beyond description4 ,although the septic tank is little more than an improved cesspool1 the condition under which it acts is entirely different from that which takes place in the latter and with care and watchfulness1 it may be made to work to a degree of perfection that is surprising4 ,the one great cause of the failure of small sewage-disposal plants is the lack of proper care4 ,the process of sewage purification as now practised in the most successful plants is largely mechanical1 but bacterial action plays a part of great importance in the completion of the process4 ,it consists of two stages3 the tank treatment1 in which the sewage is liquefied2 and the process of filtration where the liquefied sewage--commonly called the effluent--from the septic tank undergoes a process of filtration and bacterial purification4 ,the ,septic ,tank4--,the septic tank alone1 as used for sewage disposal1 is often termed a sewage purifying plant1 when in reality it is only intended to change the sewage into a form in which it can be readily carried away4 ,the word septic means putrifying1 and when applied to sewage disposal it furnishes a convenient term but has nothing to do with purification4 ,the septic tank furnishes only the first stage of the purifying process1 and although its effluent may be clear and possess little odor1 it is nevertheless unpurified4 ,the septic tank discharges an effluent of more or less completely digested sewage1 instead1 as in the cesspool1 of permitting it to remain a constantly festering mass1 to be slowly absorbed by the earth4 ,the sewage is first collected in a tank of sufficient size to contain the discharge from the house for #bd hours4 ,in the process of digestion which the sewage undergoes while in the tank1 it is rendered almost entirely liquid2 at the same time it is acted upon by the bacteria that are developed1 and that tend to reduce the sewage to its elemental form4 ,the effluent liquid which passes out of the tank is almost colorless and possesses relatively little odor4 ,the tendency of the change which takes place in the tank is to nitrify the organic matter but under ordinary conditions the action is not fully complete4 ,the effluent sometimes undergoes but little change except to be reduced to a liquid4 ,if the effluent is now allowed to flow into a ditch where it will stand in pools1 further putrification will take place with its resulting annoyance4 ,in case the septic tank is to be used alone1 the effluent should be conducted to a stream for final disposal4 ,a septic tank must be built to accommodate a certain number of people and of sufficient size to take care of the entering sewage4 ,the action which goes on in the tank will render the contents almost entirely fluid1 and under good conditions the sewage will be completely digested4 ,when working properly1 a thick scum will form on the surface1 through which filters the gases that are liberated in the process of disintegration4 ,the formation of the scum is an indication that the filter is doing its best work4 ,should the tank be required to take care of more sewage than it can conveniently handle1 the scum will not form and the effluent will be turbid because of the undigested matter4 ,the change that takes place in the sewage while it remains in the tank is first that of being liquefied and then disintegrated by bacterial action4 ,that such a change does take place is evidenced by the residue that is found in the tank in the process of cleaning4 ,this is a black granular substance1 composed mostly of humus and commonly known as sludge4 ,the amount of accumulated sludge is relatively small1 and the operation of cleaning is not necessary more than twice a year and is not the disagreeable task one might suppose4 ,the ,septic ,tank ,with a ,sand-bed ,filter4--,in places where the use of the septic tank alone is not possible1 it sometimes happens that the natural conditions are such as will permit the effluent to be drained directly into the soil4 ,with such a condition1 the effluent goes into a filter bed composed of gravel or other loose material1 where it undergoes still further bacterial action and if the process is complete1 the water which comes from the filter bed is clear and odorless4 ,under good conditions it is clear sparkling water and contains but a small amount of impurities4 ,septic tanks are made in many forms but that illustrated in ,figs4 #aea and #aeb is commonly used4 ,in ,fig4 #aea the tank is shown in position to receive the sewage from the house drain1 where it is to undergo the first treatment and then to be conducted to a filter bed made of porous tile1 set in loose soil4 ,the tank is shown in detail in ,fig4 #aeb4 ,it is a cemented brick cistern with an opening to the surface that contains a double cover as a protection during cold weather4 ,a brick partition divides the tank into spaces ,g and ,h1 that contain volumes that are to each other as #a to #b4 ,the tank is of such size as will hold a volume of sewage equal to #bd hours' use2 that is1 it is expected that any portion of sewage will remain in the tank for that length of time4 ,the sewage enters at ,a1 in such a way as will give the least disturbance of the liquid of the tank4 ,an opening ,c allows the liquid to pass from ,h into ,g1 where any additional sewage entering ,h will displace an equal amount in ,g1 which will pass out at ,b to the filter bed4 ,the partition ,d is high enough so that the scum that forms on the surface will not pass directly into the space ,g4 ,the entrance and exit pipes are made of vitrified sewer tile with the openings below the surface4 ,illustration3 ,,fig4 #aea4--,sectional view of a septic tank1 connected with a sand-bed filter2 for the disposal of sewage from a residence4 ,as the sewage enters the tank ,a1 a considerable portion will sink to the bottom1 while some will float to the top where a thick scum will gather4 ,by far the greatest portion of solids will be readily dissolved in the water and the remainder will be still further reduced to liquid form by bacterial solution4 ,the process of disintegration that goes on evolves a considerable amount of carbon dioxide and ammonia which filters through the scum4 ,the process that now goes on in the tank is that of liquefying the organic matter and changing it from organic to the inorganic state4 ,the bacteriologist recognizes in the process of sewage disintegration the work of two classes of bacteria1 the aerobic or those bacteria that work by reason of air and do their work only in its presence and the anaerobic or those that work in the absence of air4 ,in the action of the sewage-disposal plant both kinds of bacteria are at work4 ,if1 in the final stage where the sewage passes into the filter1 air can be carried into the earth the action will be hastened4 ,illustration3 ,,fig4 #aeb4--,section of the septic tank in ,fig4 #aea showing details of construction4 ,it is evident that1 since the sewage entering the tank is almost entirely dissolved1 under ideal action this system would give very little trouble1 but actually as the sewage enters the tank the disturbance caused by the incoming water forces some of the undigested matter into the outlet and being carried into the filter bed it will be deposited at the first opportunity4 ,this will cause the filter bed to fill up with undigested sewage at the point nearest the entrance1 and in course of time it will stop the pipe because of this accumulation4 ,to avoid such an occurrence1 tanks have been built in which an automatic siphon discharges the effluent whenever a certain quantity has collected4 ,such a tank is shown in ,fig4 #aec4 ,with this arrangement1 the sewage enters the first tank at ,a1 and passes into the second tank at ,b4 ,at ,s is shown an automatic siphon1 so made that when the effluent has collected to the height of the water line1 the siphon automatically discharges the contents of the tank4 ,this is known as a dosage tank because periodically a dose of the effluent is discharged into the filter bed4 ,the volume discharged is sufficient to fill the greater portion of the bed1 and force out the air in the loose soil4 ,as the water filters from the bed the air is drawn in to take its place and gives the bacteria which work in the presence of air an opportunity to do their work4 ,the work done by this filter bed is first to filter out any suspended matter carried in the effluent which will lodge on the surface of the filter material and then to undergo the slow process of integration1 and to permit the oxidation of the dissolved sewage4 ,if this matter is deposited faster than it disintegrates then the filter will fill up and finally refuse to work4 ,illustration3 ,,fig4 #aec4--,sectional view of a two-chamber septic tank with a dosage siphon4 ,the ,septic ,tank and ,anaerobic ,filter4--,in places where the use of the simple septic tank is not possible and where the character of the soil will not permit of a natural sand-bed filter1 an anaerobic filter may be constructed through which to pass the effluent from the septic tank4 ,the anaerobic filter is one in which anaerobic bacterial action is given opportunity to reduce the organic matter in the sewage to its elemental condition4 ,the filter may be constructed in any form that will permit the process of filtration to be carried out in a way that will afford good anaerobic action4 ,the extent to which the purification is to be carried will determine the form and size of the filter4 ,in ,fig4 #aed is shown such a plant1 where a combined septic tank and anaerobic filter discharges its effluent into a filter ditch in which the purifying process is continued through a bed of gravel of any desired length4 ,the figure illustrates a plant that was designed for a country residence4 ,the septic tank and anaerobic filter are located relatively as shown in the drawing1 the filter ditch following the course of a roadway4 ,the water is finally discharged into a little stream1 where it mingles with the water from a spring1 and flows through a meadow4 ,illustration3 ,,fig4 #aed4--,sectional view of a septic tank combined with an anrobic filter2 together with the details of construction and plan of arrangement4 ,the septic tank in ,fig4 #aed is quite similar in construction to the others described except that a section of sewer tile takes the place of the brick wall between the two parts of the tank4 ,the opening ,o1 through which the effluent is discharged1 is located a little above the center of the tank4 ,the anaerobic filter is a tank1 rectangular in cross-section1 made with brick walls and cemented on the inside4 ,the effluent from the septic tank enters the anaerobic filter in a chamber1 that is separated from the main tank by a wooden grating against which rests the filter material4 ,as indicated in the drawing1 the bottom is filled with coarse material2 stones or broken tiles about #d inches in diameter4 ,above this is a layer of material about #b inches in diameter and above that another layer of #a-;inch material2 the top is made of gravel4 ,this forms the anaerobic filter1 in which takes place the bacterial action away from the presence of air4 ,the interspaces in the filter material allows the effluent from the septic tank to seep through and deposit the particles of matter held in suspension4 ,the arrangement is such as is best suited to the anaerobic action4 ,here1 shut away from the light and air1 the organic matter in the effluent undergoes disintegration just as would happen in the earth4 ,it is evident that some of the matter that should remain in the septic tank and be removed as sludge will be carried into the anaerobic filter4 ,this will1 of course1 form an insoluble deposit that will accumulate and in the course of time the filter will become clogged4 ,it should be expected that such a filter will ultimately need renewing1 for this reason the top is made of a slab of reinforced concrete that may be raised to allow the removal and refilling of the filter material4 ,the automatic siphon discharges the water from the chamber ,s1 whenever it fills4 ,the discharged water from the siphon is conducted into a drain tile1 placed in a ditch filled with gravel or other loose material1 which serves as an additional filter and in which the water undergoes a still further purification4 ,this filter ditch is constructed as indicated in longitudinal section4 ,the water from the siphon enters the tile ,c and seeping through the filling is drained away in the tile shown at ,d4 ,the tiles are not set close together1 but the joints are left open and covered by pieces of broken tile as shown in ,h4 ,this is to prevent the filter material from entering the tile and thus stopping the ready flow of the water4 ,the filter ditch of the plant will be constructed according to the contour of the ground and will follow the natural drainage4 ,the course of the ditch--if it is desired to use one--will accommodate itself to the character of the ground4 ,the final discharge of the water will be determined by the natural drainage4 ,that a plant of this kind will work perfectly when new is is beyond a doubt but that it will continue indefinitely to give perfect satisfaction is not reasonable to expect4 ,the septic tank will require cleaning1 probably once a year4 ,the anaerobic filter will require renewing at intervals1 depending on the amount of sewage the filter is required to take care of and the rate at which the plant is worked1 probably once in #d or #e years4 ,if the septic tank is of insufficient size to readily digest the sewage1 the accumulation of sludge in the anaerobic filter will be greater than should occur4 ,it would be only reasonable to suppose that the siphon will sometimes refuse to discharge4 ,even though it is an automatic siphon1 circumstances may cause it at times to fail to act4 ,for this reason the manhole is placed so that the siphon may be inspected and repaired1 should it be necessary4 ,it must not be supposed that once such a plant is in place that all of the work is over4 ,the success of a good sewage-disposal plant of this kind demands eternal vigilance4 ,illustration3 ,,fig4 #aee4--,septic tank with a settling basin and windmill pump4 ,in the level areas where the possibilities of natural drainage is not good1 it sometimes occurs that plants such as those described are not permissible4 ,to overcome such conditions the plant in ,fig4 #aee represents an installation where the effluent is carried several hundred feet through a drain tile before it is finally discharged into an outlet4 ,this plant is made up of two separate tanks1 the first acting as a septic tank1 while the second tank is a settling chamber4 ,the water from the second chamber is pumped by windmill power and discharged into a drain tile at the required height through which it is carried to the place of final deposit4 ,limit of ,efficiency4--,much that has been written on the subject conveys the impression that the septic tank alone1 used under various conditions1 will eliminate disease germs and all offending features of sewage and render it a pure water with a small amount of residue remaining in the tank4 ,that such is not the case is all too evident to many who have constructed plants expecting perfect results and have attained only partial success4 ,it is not reasonable that a plant giving satisfaction under the usual conditions could accomplish its purpose under stress of work4 ,it is quite evident that the amount of sewage from any source cannot be constant4 ,it is equally evident that the effluent from the plant cannot always be the same2 but with reasonable limits of variation1 a suitably designed tank ought to take care of the sewage from a house at all times and discharge an effluent that is reasonably clear and without offending odor4 ,it should be kept in mind that1 as commonly used1 the chief office of the septic tank is to do away with the things that offend the senses1 and not to make an effluent that might serve as drinking water4 ,it must also be kept in mind that if the disease germs enter the plant because of sickness in the house that there is every possibility that the germs will be in the discharged water4 ,the plant must be located as is directed by the natural surroundings but the drainage must be away from buildings and particularly from wells4 ,small sewage plants are reasonably efficient and add immensely to the comfort and healthful conditions of the home4 ,they are not perfect in their action but there is excellent reason to believe that the plant of ideal construction will yet be attained4 ,in a flat country where drainage is difficult1 the form of plant must be modified to suit the prevailing conditions but some form of working plant can always be devised4 ,small plants do not give so efficient results as those of large size but they do very acceptable work4 ,to do good service they must receive attention but the actual amount of labor they demand is small4 ,small sewage-disposal plants are not expensive nor difficult to construct1 and for the amount of labor and money expended they give returns that cannot be estimated4 ,in determining the character of plant to be constructed1 in any particular place1 local conditions will in a great measure decide the type to be used4 ,the degree of purity to which it will be necessary to reduce the effluent will depend on the location of the plant and the means of final disposal4 ,if the effluent can be run into a stream of sufficient volume1 the septic tank alone will probably answer the purpose4 ,the septic tank reduces sewage to a liquid form which has some odor4 ,it may be carried away in an open ditch which has good flow1 but if allowed to collect in pools it will undergo further putrescence and be objectionable4 ,it may be possible to use a small creek for final disposal but one in which the effluent from a septic tank alone would be objectionable4 ,in such a case the use of the septic tank combined with an anaerobic filter would probably give a permissible degree of purity4 ,with a plant composed of a septic tank and anaerobic filter1 sewage is rendered almost free from odor and the effluent will not undergo further putrescence when collected in pools4 ,in many cases it is desired to purify the effluent still further1 either because of lack of means for final disposal or because the effluent would contaminate the water into which it is discharged4 ,in such cases the plant will consist of the septic tank1 an anaerobic filter and a filter ditch or sand-bed filter4 ,the effluent from such a plant will be clear sparkling water that might be mistaken for spring water4 ,the design and construction of sewage-disposal plants has been made a subject of investigation in a number of ,state engineering experiment stations4 ,in addition1 manufacturers of cement have prepared descriptive literature that is sent gratis on application4 ,these bulletins contain detailed information as to the working properties and construction of private plants to suit the various conditions of disposal4 ,the following is taken by permission of the ,universal ,portland ,cement ,co4 from their bulletin on 8,concrete ,septic ,tanks40 ,illustration3 ,,fig4 #aef4--,septic tank4 ,this shows the construction as if cut away along a center line following its length1 also a section of the siphon chamber and a plan of the whole construction4 ,illustration3 ,,fig4 #aef;a4--,photographic reproduction of a concrete septic tank1 similar to that of ,fig4 #aec4 ,the tank requires only the cover to make it complete4 8,the design in ,fig4 #aef shows a septic tank as it would appear if partly cut away to expose the interior to view1 and as if cut in half along a center line following its length4 ,this type will be found to operate effectively where final disposal is accomplished by sub-surface irrigation4 ,this system once started is self-operating due to the siphon shown in the second1 or right-hand compartment1 which at regular intervals empties the contents and discharges them into the line of tile from which the liquids leach out through joints into the soil4 ,in a tank constructed as shown in the design mentioned1 it is very important to use a siphon to empty the second compartment at intervals instead of allowing a continuous outward flow of contents1 because of the tendency for drains to become clogged when liquids are constantly trickling through4 8,the size of tank required for residence use depends upon the quantity of sewage to be handled in the first chamber during a day of #bd hours2 therefore1 this compartment should be large enough to contain an entire day's flow4 ,this frequently amounts to from #cj to #ej gallons per person per day1 so the required capacity can readily be computed from these figures1 although it must be remembered that the required depth for the tank should be figured from the top of the concrete baffle wall or partition which separates the first and second compartments4 ,another point to bear in mind is that the width of the first compartment should be about one-half its length40 ,,chapter ,,ix ,,coal ,coal is of prehistoric origin1 formed from accumulation of vegetable matter1 supposed to be the remains of immense forests4 ,in past ages the deposits underwent destructive distillation from great heat and was subjected to pressure1 sufficient to compress it into varying degrees of hardness4 ,coal is composed of carbon1 hydrogen and oxygen1 with small quantities of nitrogen and varying amounts of sulphur and ash4 ,the coals from different geological formations vary in quality from the hard dry anthracites to the soft wet lignites1 with the intermediate bituminous coals2 all of which furnish fuels that when burned will produce amounts of heat1 depending on their composition1 the quantity of moisture contained and the conditions of their combustion4 ,carbon1 of which coal is principally composed1 exists in different combinations1 depending on the condition of its formation4 ,part of the carbon is combined with hydrogen to form hydrocarbon that may be driven off when heated1 and which forms the volatile portion of the coal4 ,the remainder of the carbon appears in the form of coke--when the volatile matter is driven off--and is said to be fixed4 ,the fixed carbon and volatile constituents together make up the combustible4 ,other ingredients of coal that require attention are the moisture1 and the incombustible matter that forms ash4 ,moisture varies in quantity from as low as #j4ge per cent4 in hard coal to #ej per cent4 in lignite4 ,the amounts of ash in different coals vary from #c to #cj per cent4 of the weights of the fuel4 ,the heating value of coals differs in amount by reason of the variable quantities of fixed and combined carbons1 moisture and ash4 ,different coals are compared in value by the number of ,b4t4u4 per pound of dry coal that can possibly be developed when burned1 and with these factors are given the percentages of moisture and ash4 ,there are no distinct demarkations between different grades of coal4 ,the classifications are made because of their chief characteristics and they commonly are graded as anthracites1 semi-anthracites1 semi-bituminous and bituminous coals4 ,these classes comprehend the most common commercial coals of the ,united ,states4 ,aside from those named are forms of coal that are occasionally found1 such as graphitic anthracite1 cannel coal1 etc41 and the various lignites4 ,the value of coal as a heat-producing agent is represented by the ,b4t4u4 it is capable of turning to useful account4 ,the price of coal should be based on the amount of heat it is capable of generating when burned4 ,in considering the value of coal for any particular purpose1 thought must be taken as to its characteristic properties1 for coals that produce excellent results for one purpose may be very unsatisfactory in others4 ,soft coal containing a large percentage of volatile matter usually produces a great amount of smoke and unless carefully fired this will condense and form accumulations of soot that are objectionable4 ,for reasons of this kind bituminous coals are often sold at a lower price than their rated heating value might indicate4 ,anthracite or hard coal possesses bright lustrous surfaces when newly fractured1 that when handled do not soil the hands4 ,it contains a high percentage of carbon1 a small amount of volatile matter and little moisture4 ,it is greatly in demand as a domestic fuel because it burns slowly with an intense heat1 practically without flame and produces no smoke4 ,it invariably commands a higher price than soft coal1 but in heating value is not superior to the better grades of soft coal4 ,in furnaces for house heating the use of soft coal often gives better satisfaction than hard coal4 ,the grades of hard coal found in the market will vary with the demand in any locality but those recognized by the trade are3 ,egg ,coal will pass through #b-;inch mesh screen4 ,stove ,coal will pass through #b-;inch mesh screen4 ,chestnut ,coal will pass through #a-;inch mesh screen4 ,pea ,coal will pass through -inch mesh screen4 ,no4 #a ,buckwheat ,coal will pass through -inch mesh screen4 ,no4 #b ,buckwheat ,coal will pass through -inch mesh screen4 ,no4 #c ,buckwheat ,coal will pass through -inch mesh screen4 ,hard coal of stove and chestnut sizes are those most commonly used for domestic heating1 because they are well suited for furnaces and heating stoves4 ,of the two sizes chestnut coal is most largely used and on account of the greater demand1 the price for this size is usually somewhat in advance of the others2 at the same time the smaller sizes--pea and buckwheat coals--are less in price for the same grade of coal4 ,under conditions that will permit their use the latter coals are an economical form of fuel4 ,bituminous or soft coal represents the chief fuel of commerce4 ,the market prices of these coals are determined largely by reason of their reputation as desirable fuel4 ,the variations in price depend on the physical qualities1 rather than on the amount of heat evolved in combustion4 ,the compositions of coals vary markedly in different localities and often in the same locality several grades are produced4 ,it sometimes happens that from different parts of a mine the coal will differ very much in heat value4 ,bituminous coals are roughly classified as coking and free-burning4 ,the former is valuable for gas manufacture and for production of coke4 ,the coking coals fuse on being heated1 allowing the volatile portion to escape2 and when the gas has been all distilled1 the residue is coke4 ,when used for gas making1 the volatile portion forms the illuminating gas4 ,when burned in a furnace1 the gases from soft coal burn with a yellow flame and usually with considerable smoke4 ,the classification of bituminous coals differ somewhat in the ,east from that of the ,west4 ,eastern bituminous coals are commonly graded3 ,a4 ,run-of-mine coal unscreened coal as taken from the mine4 ,b4 ,lump coal that which passes over a bar screen with #a-a_/d-;inch openings4 ,c4 ,nut coal that which passes through a bar screen with #a-a_/d-;inch openings and over one with #c_/d-;inch openings4 ,d4 ,slack all that which passes through a #c_/d-;inch bar screen4 ,western bituminous coal3 ,e4 ,run-of-mine coal the unscreened coal as taken from the mine4 ,f4 ,lump coal--divides as #f-;inch1 #c-;inch and #a-a_/d-;inch according to the diameter of the mesh through which the pieces pass the screens4 ,g4 ,nut coal--varying from #a-a_/d-;inch size to #c_/d-;inch in diameter4 ,h4 ,screening all coal which passes a #a-a_/d-;inch screen including the dust4 ,heat derived from coal--or any other fuel--in the process of combustion is due to oxidation4 ,combustion or burning is caused by rapid oxidation4 ,when oxygen combines with carbon in sufficient quantities1 carbon dioxide is formed and at the same time heat is liberated4 ,in burning fuel1 if the carbon is completely oxidized and changed into carbon dioxide1 the greatest amount of heat is produced4 ,the required oxygen is furnished by the air1 which through the dampers of the furnace regulates the rate of combustion4 ,oxidation of ,hydrocarbons4--,in the oxidation of hydrocarbons1 as that of burning coal gas1 the combination of the elements forms carbon dioxide and water4 ,the presence of the water1 formed in combustion1 is often shown in the formation of moisture on the bottom of a cold vessel when placed over a gas flame4 ,the same effect is observed in a newly lighted kerosene lamp1 when the film of moisture forms inside the cold lamp chimney4 ,as soon as the surfaces become heated the moisture is evaporated4 ,occasionally1 the accumulation of moisture in chimneys1 from this cause1 is sufficient during extremely cold weather to form ice in the part of the chimney exposed to the outside air4 ,chimneys have been known to become so stopped by accumulation of ice from this cause as to materially interfere with the draft4 ,the fixed carbon of the coal1 when oxidized1 has a constant heating value of #ad1jjj ,b4t4u4 per pound4 ,the volatile hydrocarbons develop amounts of heat when burned1 depending on their composition1 and differ in coals from different localities4 ,the heat obtained from the volatile part of coal depends on its chemical composition and differs very materially2 it may be as high as #ba1jjj ,b4t4u4 per pound1 or as low as #ab1jjj ,b4t4u4 per pound4 ,a high percentage of volatile matter usually indicates a fuel that will produce a large volume of smoke1 which--unless the combustion is complete in the furnace--will deposit soot as soon as it is condensed1 either in the chimney or in the outside air4 ,the ash has no heating value1 and the contained moisture has a negative heating effect1 because considerable heat is required to evaporate and raise it to the temperature of the gases of the furnace4 ,in burning fuel the moisture uses up the heat of combustion in proportion as it appears in the coal4 ,the moisture is bought as coal but requires heat to get rid of it2 so the percentage of water in coal should be considered very carefully4 ,it is customary in comparing the heating values of coals1 to state the proportionate parts of fixed carbon1 volatile matter1 moisture and ash as well as the ,b4t4u4 per pound of dry coal4 ,the heat value in ,b4t4u4 per pound of fuel is usually obtained by burning samples in a calorimeter from which the heat per pound is calculated4 ,the heat value of fuels used in power plants are often determined by careful tests of the amount of power derived for each pound of fuel burned in the furnace4 ,this is done by weighing the fuel burned and measuring the water evaporated4 ,the ashes are weighed and this weight together with the weight of moisture present is subtracted from that of the coal to determine the amount of combustible of the fuel4 ,the final results are expressed by the number of pounds of water evaporated per pound of combustible and also the weight to water evaporated per pound of coal burned4 ,semi-bituminous coal represents a class between the hard and soft grades4 ,it contains less carbon and more volatile matter than hard coal4 ,it burns with a short flame with very little smoke and is valuable as a furnace fuel4 ,the ,pocahontas coal of ,west ,virginia is an example of this class4 ,semi-bituminous coal is often called smokeless coal1 because in burning it produces relatively little smoke4 ,it will be noted in the table of heat values on page #aib that coal of this variety has high heat-producing properties4 ,it is a very friable coal and for that reason is apt to contain considerable dust4 ,as a furnace fuel it produces--when carefully fired--very satisfactory results4 ,graphitic ,anthracite4--,this is a type of coal found in ,rhode ,island and ,massachusetts which resembles both graphite and anthracite coal4 ,it is gray in color1 very hard and burns with extreme difficulty4 ,cannel ,coal4--,this is a variety of bituminous coal1 rich in hydrocarbons4 ,it burns with a bright flame without fusing and is often used for open fires4 ,lignite4--,this is a type of fuel that in point of geological formation represents the condition between true coal and peat4 ,lignite occurs in immense deposits throughout the middle portion of the western half of the ,united ,states1 where beds #bj feet in depth are not uncommon4 ,it varies in color from black to brown and in many localities is known as brown coal4 ,when newly mined1 lignite contains a large percentage of water1 sometimes as high as #ej per cent4 ,on account of this large moisture content it has a relatively low calorific value1 but when dry the amount of heat evolved per pound compares very favorably with soft coal4 ,peat4--,as a fuel1 peat has been used very little in the ,united ,states on account of the abundance of the better grades of fuel1 but in many parts of the country it is used locally to a considerable extent4 ,in peat bogs from which the fuel is taken1 the peat is formed from grasses and sedges which in time produce a carbonaceous mass that becomes sufficiently dense to be taken out in sections1 with a long narrow spade4 ,the peat is then built into piles where after drying it is ready to be burned4 ,wood4--,on account of its relative scarcity and correspondingly high price1 wood is no longer a commercial fuel of any consequence4 ,the low heating value of wood as compared with coal makes it a prohibitive fuel except in forest localities4 ,wood is commonly sold by the cord and no attention is given by dealers to its value in heat-producing capacity4 ,the desirability of wood as a fuel is chiefly that of reputation4 ,it is usually considered that hickory is the ideal fire wood1 dry maple a close second and that oak is next in desirability as fuel2 following which are ash1 elm1 beech1 etc41 depending on the density of the wood4 ,the price of wood per cord depends on the nearness and abundance of supply4 ,the actual heating values of different woods as determined by ,gottlieb show that per pound of dry wood there is little difference in heat value between different kinds of hard woods1 and that pine gives per pound the highest value of all4 ,the table given below was taken from 8,steam0 published by the ,babcock-,wilcox ,co4 ,per cent4 of ,b4t4u4 per ,kinds of wood ash pound ,oak #j4cg #h1caf ,ash #j4eg #h1dhj ,elm #j4ej #h1eaj ,beech #j4eg #h1eia ,birch #j4bi #h1ehf ,fir #j4bh #i1jfc ,pine #j4cg #i1aec ,poplar #a4hf #g1hcd ,willow #c4cg #g1ibf ,in considering this table it must be kept in mind that the values are for dry wood per pound4 ,as given in ,kent's 8,engineer's ,pocket ,book0 the weights of different fuel woods per cord 7thoroughly air-dried7 are about as follows3 #a cord hickory or hard maple #d1ejj pounds equal to #a1hjj pounds coal #a cord white oak #c1hej pounds equal to #a1edj pounds coal #a cord beech1 red and black oak #c1bej pounds equal to #a1cjj pounds coal #a cord poplar1 chestnut and elm #b1cej pounds equal to #idj pounds coal #a cord average pine #b1jjj pounds equal to #hjj pounds coal ,the above values in pounds of coal may be taken to represent average bituminous coals4 ,as given by ,suplee's 8,mechanical ,engineers' ,reference ,book10 eight samples of coals representing bituminous coals from mines east of the ,mississippi ,river give an average heating value of #ac1gee ,b4t4u4 per pound4 ,charcoal4--,this is made from wood by driving off the volatile constituents2 the residual carbon1 which forms the charcoal is a fuel that burns without smoke or flame4 ,charcoal is made by piling wood in a heap1 which is covered with earth4 ,in the bottom of the heap a fire generates the necessary heat for distilling off the volatile matter4 ,charcoal holds to wood the same relation that coke bears to coal4 ,coke4--,this is the residue from the distillation of coal4 ,it comprises from #fj to #gj per cent4 of the original coal and contains most of the carbon and all of the ash of the coal4 ,coke is gray in color and has a slightly metallic luster2 it is porous1 brittle and in handling gives out something of a metallic ring4 ,it is often sold for fuel as a byproduct by gas factories4 ,in heating value gas-coke gives about #ad1jjj ,b4t4u4 per pound when dry and as a consequence is rated as an excellent fuel4 ,clean coke burns without flame and is capable of producing an intense heat4 ,on account of its porous nature it occupies a relatively large volume per ton4 ,it is most successfully burned in stoves and furnaces with large fire-boxes4 ,gas-coke1 which is the residue from the gas retorts1 is somewhat inferior in heating value to coke made in ovens but it is an excellent fuel where furnaces are adapted to its use4 ,gas-coke is often stored1 by piling it in heaps1 in the open and on account of its porous nature it absorbs considerable moisture4 ,where exposed to the weather the amount of contained moisture depends on the amount of rain or snow the coke has absorbed4 ,this amount is easily determined by weighing a fair sample and driving off the moisture in an oven4 ,the sample should be weighed several times until the weight remains constant4 ,briquettes4--,briquetted coal and other fuels are produced by compressing coal dust or other powdered fuel1 mixed with coal tars or other bituminous binder in sufficient quantity to cause the adhesion of the particles when pressed into form under great pressure4 ,owing to the relative cheapness of fuel1 briquettes have been used but very little in the ,united ,states4 ,with the advance in the price of coal of the past few years1 they have found a place on the market and have become a common form of fuel4 ,the heat value of briquettes will depend on the kind and quality of material that enters into their composition4 ,quite generally1 they produce heat equal to the average grade of soft coal4 ,in the ,northwest briquettes made of ,west ,virginia semi-bituminous coal sell at the same price as run-of-mine coal of the same quality4 ,their use has proven satisfactory as a furnace fuel and they will very likely be sold in increasing quantities4 ,comparative ,value of ,coal to ,other ,fuels4--,until a comparatively recent time1 coal has been sold by weight and reputation alone2 but conditions are rapidly approaching1 which will require it to be sold according to its composition and heating value4 ,among manufacturers and others using large quantities of fuel1 the practice of contracting for coal by specification is becoming increasingly common4 ,the determining factors are the amounts of moisture1 ash1 sulphur1 carbon1 and volatile matter the coal contains1 as well as the size of the pieces and freedom from dust4 ,in a few of the most progressive cities1 coal dealers are required to supply coal for schools and other municipal uses1 which has been subject to the approval of the ,city ,engineer4 ,the time is not far distant when dealers will be required to submit samples of all fuel1 for sale to the public1 to the examination of the municipal authorities4 ,the following table of the heating values of various fuels is taken from ,benson's 8,industrial ,chemistry40 ,,british ,,thermal ,,units ,,for ,,one ,,cent ,,from ,,different ,,fuels ,acetylene1 from carbide at #aj cents per pound #fjj ,denatured alcohol1 at #dj cents per gallon #b1jjj ,air gas 7from gasoline1 #hj;,b at #be cents per gallon7 #c1jjj ,water gas1 at #a per #ajjj cubic feet #c1jjj ,coal gas1 at #a per #ajjj cubic feet #f1ejj ,gasoline1 at #bj cents per gallon #g1ejj ,kerosene1 at #ae cents per gallon #aa1jjj ,natural gas1 at #ej cents per #ajjj cubic feet #ah1jjj ,charcoal1 at #aj cents per bushel 7#ae pounds7 #bj1jjj ,petroleum at #e cents per gallon #cj1jjj ,producer gas1 from anthracite1 #g per ton #cj1jjj ,producer gas1 from coke1 #e per ton #cf1jjj ,anthracite1 at #g per ton #df1jjj ,producer gas1 from soft coal1 at #c per ton #ej1jjj ,coke1 at #e per ton #ed1jjj ,mond producer gas from soft coal1 at #c per ton #fe1jjj ,soft coal1 at #c per ton #hj1jjj ,price of ,coal4--,the value of coal as a fuel will depend on the amount of heat it is capable of producing when burned2 its price should therefore be determined by the heating value per pound of fuel as purchased4 ,secondary determining factors in price are those of convenience of handling and the difficulty in burning the fuel such as the size and uniformity of the pieces1 the formation of clinkers1 smoke and accumulation of soot4 ,soft coals1 containing a large amount of volatile matter1 usually produce much soot and smoke and as a consequence sell for a lower price than coals that produce little smoke4 ,the selection of fuels will depend on the type of heating plant in use1 whether by stoves or by furnaces4 ,if by stoves1 whether it is possible to use soft coal as a fuel4 ,the automatically fed stove1 of the base-burner type1 are usually designed for the use of hard coal and in such stoves the use of soft coal would not be possible4 ,other stoves and furnaces are usually capable of burning soft coal with varying degrees of satisfaction1 depending on the design and surrounding conditions4 ,the following prices1 from the local market1 show the usual ratings of various fuels in common use4 ,these prices vary with the locality and somewhat with the season4 ,it is usually possible to purchase coal at some reduction in price during the summer months when the demand for coal is light4 ,hard coal--stove size #aj4be per ton ,hard coal--nut size #aj4ej per ton ,semi-bituminous--run-of-the-mine #i4jj per ton ,pennsylvania bituminous--run-of-the-mine #g4ej per ton ,soft coal--,ohio--run-of-the-mine #g4ej per ton ,soft coal--,illinois--bituminous--run-of-the- mine #g4ej per ton ,soft coal--,iowa--bituminous--run-of-the-mine #g4ej per ton ,briquettes-mixture semi-bituminous coal dust #i4jj per ton ,wood 7oak71 sawed1 stove length and split #h4ej per cord ,the price of coal is determined in many localities by the distance from the sources of supply and the means of transportation4 ,the fact that coals from all of the principal mining areas from ,pennsylvania1 west to ,iowa1 are sold at points in the ,northwest for the same price1 is due in greatest measure to transportation rates on the ,great ,lakes4 ,the prices of ,eastern coals at ,duluth are such that in competition with ,western coals they are sold at the same price as is shown by the table4 ,it is usually impossible for the average householder1 or even the dealer1 to determine definitely the exact locality from which his fuel is mined4 ,even when such information is obtainable1 the quality is still in doubt1 unless analysis is obtainable by sample4 ,the data given in the following tables is such as will furnish a fair knowledge of the relative heating values of coals from the principal mining areas of the ,united ,states4 ,the data was obtained from a considerable number of authorities but chiefly from the reports of the ,united ,states ,geological ,survey4 ,the different items are not intended to be exact1 they merely represent reliable average conditions4 ,the varying conditions of available heat and percentage of moisture given in the following table are such as to be of little use to those unaccustomed to problems of this kind1 unless a systematic method of comparison is made of the different fuels4 ,,approximate ,,composition ,,and ,,calorific ,,value ,,of ,,typical ,,american ,,coals ---------------------------------------- ----------------------- #c #g #b ,number1 #e #f ,b4t4u4 #a ,kind of of ,moisture,volatile,fixed pound per #h ,locality coal samples matter carbon dry coal ,ash examined ---------------------------------------- ----------------------- ,pa4 ,anthracite #ab #e4je #e4eb #hb4ed #ab1fhb #aa4ec ,md4 ,semi- #e #b4ci #ag4gc #ge4dd #ad1ecj #g4dj bituminous ,pa4 ,semi- #ae #c4fj #ai4bf #gd4df #ad1baa #h4cb bituminous ,w4 ,va4 ,semi- #ab #b4ej #ai4jj #ge4gj #ad1geh #e4bd bituminous ,ala4 ,bituminous #f #c4ee #bi4ii #ei4bd #ac1ebb #aj4gc ,ark4 ,bituminous #b #a4db #af4eh #gc4cg #ad1bje #aj4je ,colo4 ,bituminous #f #i4hi #cg4cd #eb4ec #ab1cbe #aj4cb ,ill4 ,bituminous #bb #aj4ca #cf4gc #ej4eb #aa1ejd #ab4gc ,ia4 ,bituminous #h #g4gb #ci4ae #ej4ed #ab1fef #aj4cc ,kan4 ,bituminous #c #d4be #cb4bj #ea4ag #ab1jca #ac4ge ,ky4 ,bituminous #i #e4ii #cd4eh #ef4ef #ac1cda #h4hf ,mo4 ,bituminous #i #aa4eb #cg4he #dh4aa #ab1cih #ad4jd ,ohio4 ,bituminous #ad #e4fe #ch4ea #ej4ei #ab1hci #aj4fe ,okla4 ,bituminous #c #e4gb #cd4hc #eb4gf #ab1fdh #ab4da ,n4,m4 ,bituminous #a #ab4ag #cf4ca #ea4ag #ab1abf #ab4eb ,pa4 ,bituminous #ae #b4dd #cc4da #eh4ca #ac1gcb #h4dj ,tenn4 ,bituminous #d #b4ec #cf4eh #eh4ba #ad1jih #e4dg ,tex4 ,bituminous #c #c4hd #ce4je #dh4ii #ab1cjb #ae4if ,va4 ,bituminous #e #b4ga #ca4cb #fb4dg #ad1jbe #f4ib ,w4 ,va4 ,bituminous #aj #b4fa #cc4ib #eh4hj #ad1jid #g4bg ,colo4 ,lignite #f #ai4ge #de4ba #de4he #aj1gii #h4ic ,n4 ,d4 ,lignite #e #ce4ic #dd4cc #dc4ba #aj1dbj #ab4de ,tex4 ,lignite #f #cj4hf #dd4jf #ci4ba #aj1big #af4gf ,wyo4 ,lignite #d #ad4ga #dh4dg #dd4di #aa1fjh #g4jce ---------------------------------------- ----------------------- ,the following table was prepared from the date of that preceding combined with the prices of various coals to be obtained in the local market4 ,the table is intended to present a method of comparing the values of fuels from different coal areas4 ,the consumer is interested to know the amount of heat purchased in the form of fuel4 ,the table shows in the column headed 8,heat per #a10 the number of ,b4t4u4 purchased for #a in coal2 the number of available ,b4t4u4 in the different kinds of coal may be taken as a relative comparison of their values as fuel4 ,the gas-coke in the table is that sold by the local gas company4 ,the amount of moisture in this case is relatively high because of the fact that the coke is stored in a yard exposed to the weather1 where it absorbs all precipitated moisture4 ,a less amount of moisture would give a higher value for the same fuel4 ---------------------------------------- ------------------------ ,b4t4u4 per ,price ,per ,b4t4u4 to#ajj cost per cent41,b4t4u4 perevaporate per #ajj ,heat ,kind of coal ton water #ajj pounds water pounds per #a ---------------------------------------- ------------------------ #a1ccf1efe ,bituminous #g4ej #b4dd #a1cdj1jjj - #c1dci --------- #c1efd1jjj ,pennsylvania #j4cge ,b4t4u4 ---------------------------------------- ------------------------------ ,semi- #a1dae1fhe bituminous #i4jj #c4jf #a1dbj1jjj - #d1cae --------- #c1ade1jjj ,west ,virginia #j4de ,b4t4u4 ---------------------------------------- ------------------------------ #a1aja1jab ,gas-coke #g4jj #aj4jj #a1aag1ijj - #af1hhh --------- #c1ade1jjj #j4ce ,b4t4u4 ---------------------------------------- ------------------------------ ,north #fjg1bhb ,dakota #d4ej #ce4ij #ffh1jjj - #ej1gbh ------- #b1gjc1jjj lignite #j4bbe ,b4t4u4 ---------------------------------------- ------------------------------ #a1jag1fjb ,bituminous #g4ej #aj4ca #a1jcb1jjj - #ad1cih --------- #b1ihj1jjj ,illinois #j4cge ,b4t4u4 ---------------------------------------- ------------------------------ #iid1ebi ,bituminous #g4ej #ac4aj #a1jab1jjj - #ah1dga ------- #b1feb1jjj ,iowa #j4cge ,b4t4u4 ---------------------------------------- ------------------------------ #a1bbe1ije ,hard coal #aj4ej #c4je #a1bcj1jjj - #d1aie --------- #b1cce1jjj ,pennsylvania #j4ebe ,b4t4u4 ---------------------------------------- ------------------------------ ,semi-bituminous coal commands considerable favor as a house-heating fuel1 because of the fact that it burns with much less smoke than bituminous coal4 ,in available heat it is considerably above the ,western bituminous coal and it sells at a price #a4ej higher per ton4 ,the reason for the difference in price is not so much on account of its heating value1 as because of relatively small amount of smoke produced in combustion4 ,other coals capable of producing more heat are sold at less price because of smoke and soot produced in burning4 ,hard coal at #aj4ej is the most expensive coal of all4 ,the ratio of available heat units per #a for hard coal1 as compared with the best soft coal1 is as #bc is to #ce4 ,this means that at the stated prices those who burn hard coal pay the additional price1 because of the physical properties it possesses4 ,in constructing the above table1 #ajj pounds of coal was taken as a unit of comparison4 ,the price per ton is that given in the table of local prices4 ,the per cent4 of moisture and the ,b4t4u4 per pound of fuel was taken from table on page #aib4 ,in explaining the method by which the different items were obtained1 it will be necessary to discuss briefly the condition of combustion and the heat losses that take place when fuel is burned4 ,the moisture in the fuel is the undesirable part1 because it requires a large amount of heat to dispose of it4 ,it is looked upon as so much water1 that must be raised in temperature from that in which it is taken from the coal bin to the temperature and condition of vapor in which it passes into the chimney4 ,when the fuel enters the furnace the water is heated to the boiling point4 ,in changing temperature it absorbs #a ,b4t4u4 for each pound of water1 through each degree of change4 ,suppose that1 as in the case of ,pennsylvania bituminous coal which contains #b4dd pounds of water to each #ajj pounds of coal1 the coal entering the furnace was at #ej;,f4 ,to raise its temperature to the boiling point 7#bab;,f47 required a change of #afb4 ,the #b4dd pounds of water raised this amount #afb #b4dd #cie4bh ,b4t4u4 ,to change the #b4dd pounds of water1 into steam at the atmospheric pressure requires #ifi4g ,b4t4u4 7heat of vaporization71 practically #igj ,b4t4u4 per pound of water4 ,the heat required to vaporize #b4dd pounds of water is #b4dd #igj #bcff4hj ,b4t4u4 ,the vapor is now raised in temperature1 to that of the furnace1 which we may assume is #abjj;,f4 ,the furnace being at atmospheric pressure the vapor merely expands in volume as a gas4 ,the specific heat of steam at atmospheric pressure is #j4dfd2 that is1 #a pound of steam requires only #j4dfd ,b4t4u4 to raise it a degree1 and #b4dd pounds of water will absorb #j4dfd #b4dd #abjj #acef4jj ,b4t4u4 ,of this last amount of heat1 approximately #ej per cent4 is recovered as the gases pass through the furnace4 ,the total loss of heat due to the evaporation of the water is ,raising temperature from normal to #bab #cie ,b4t4u4 ,evaporation #b1cff ,b4t4u4 ,changing temperature of vapor1 less #ej per cent4 #fgh ,b4t4u4 ------------ ,total heat loss #c1dci ,b4t4u4 ,in the #ajj pounds of coal under consideration1 there is #ajj pounds1 less #b4dd pounds of water1 or #ig4ef of dry coal1 each pound of which contains #ac1gcb ,b4t4u4 as given by the table on page #aic4 ,this gives #ig4ef #ab1fhb #a1cci1gec practically #a1cdj1jjj ,b4t4u4 ,from this quantity is subtracted the loss of heat1 #cdci4 #a1cdj1jjj - #cdci #a1ccf1efa ,b4t4u4 ,this represents the total available heat in #ajj pounds of coal4 ,if this quantity is now divided by the cost of #ajj pounds of coal at #g4be per ton1 the result1 #c1efd1jjj ,b4t4u41 will be the available heat bought for #a as given in column #g of the table4 ,,chapter ,x ,,atmospheric ,,humidity ,the physical effect of atmospheric humidity has come to be recognized by all who deal in problems of house heating1 sanitation and hygiene4 ,the difference in effect of dry atmosphere1 from that of air containing a desirable degree of moisture1 is very noticeable in all buildings that are artificially heated4 ,the effect of dry air is made apparent in the average home during the winter months by the shrinking of the woodwork and furniture4 ,the absorption of the moisture from the building which is usually termed 8drying out10 causes the joints in the floors and casements to open1 doors to shrink until they fail to latch and drawers that have opened with difficulty during the summer then work freely4 ,winter time is the season of prevalent colds1 chaps and roughness of the skin1 not so much on account of cold weather as because of dry air4 ,the skin which is normally moist is kept dry by constant evaporation with the attending discomfort of an irritated surface and the results which follow4 ,the humidity of the air in which we live and on which we depend for life has much to do with the bodily comfort we derive in existence1 and is suspected of being the cause of many physical ailments4 ,ventilation engineers not only recognize this condition but have found means of controlling it4 ,it is possible to so control atmosphere temperature and humidity of buildings as to produce any desired condition4 ,humidity of the ,air4--,the amount of water vapor in the air is called the humidity of the air4 ,it may vary from a fraction of a grain per cubic foot in extremely cold weather1 to #bj grains per cubic foot during the occasional hot weather of summer4 ,since the amounts of moisture that air will hold depends on its temperature1 and as the air is ordinarily only partly saturated1 the varying amount of moisture are expressed either as relative humidity and stated in per cent4 saturation or in the actual weight of water in grains per cubic foot and known as absolute humidity4 ,the relative humidity of the atmosphere is the amount of moisture contained in a given space as compared with the amount the same air could possibly hold at that temperature4 ,warm air will hold more moisture than the same air when cold4 ,air absorbs water like a sponge to a point of saturation4 ,when the air is filled with moisture1 any change which takes place to reduce the temperature also reduces its capacity to hold the water vapor and the excess is deposited as dew4 ,this supersaturation ordinarily takes place near things which lose their heat faster than the surrounding air and the nearest colder surface acts as a condenser to receive the drops of dew4 ,grass being in convenient position is the commonest receptacle for dew formation4 ,if the dew forms in the air it falls as rain1 but if the temperature of the dew-point is below freezing1 the dew immediately freezes and snow is the result4 ,in the consideration of problems that involve atmospheric moisture1 both relative and absolute humidity are factors of common use1 that are capable of exact determination4 ,the relative humidity of the air is most readily determined and as it expresses the state of the atmosphere in which plants and animals live and thrive1 as opposed to other conditions of humidity in which they sometimes sicken and die1 it is one of the indicators of the quality of atmospheric air4 ,in the subject of ventilation1 which is undertaken later1 it will be found that a definite knowledge of atmospheric humidity has much to do with the successful operation of ventilation apparatus4 ,most people recognize the 8balmy air of ,june0 without realizing just why at the same temperature other seasons are not so delightful4 ,in reality it is the condition of atmospheric humidity combined with an agreeable temperature that gives the kind of air in which we find the greatest degree of comfort4 ,the effect of moderately warm humid air is that of higher temperature than the thermometer indicates4 ,when the atmosphere is near the point of saturation1 the evaporation which usually goes on1 from the surface of the body1 practically ceases4 ,in summer time a temperature of #he;,f4 with relative humidity of #ij per cent4 saturation seems warmer than a temperature of #ajj at #dj per cent4 saturation1 because of the cooling effect produced by the increased evaporation due to the drier air4 ,in winter1 when most of the time is spent indoors1 in an atmosphere that is very dry1 the sensation of discomfort produced by the lack of humidity oftentimes leads to physical derangements that would never appear under more desirable conditions4 ,the cause of many ailments of the nose1 throat and lungs during the winter months is attributed by physiologists to breathing almost constantly the dry vitiated indoor air4 ,the cause of dry air in buildings is not difficult to explain2 it is a great deal more difficult to realize that the lack of water breeds so much discomfort4 ,in order to express the condition of humidity that may exist in the average dwelling1 office or school-room during the winter1 it is most convenient to refer to the results of varying atmospheric conditions that are given in ,table #a--,properties of ,air--which appears below4 ,in the second column of the table1 under the heading 8,weight of vapor per cubic foot of saturated air10 will be found the amount of moisture in grains per cubic foot that will be required to humidify air at different temperatures4 ,it will be seen that at #aj the air will contain1 when fully saturated1 only #a4aa grains of water1 while at #gj temperature the same air would hold #h grains of water4 ,these amounts will be found in the column opposite the temperature readings4 ,it is at once evident that when saturated air at #aj is raised to normal temperature #gj1 the original amount of moisture is contained in an atmosphere capable of holding #h grains of water4 ,its relative humidity will therefore be #a4aa_/h1 practically #ad per cent4 saturated4 ,unless moisture is received by the air from some other source this condition will produce a very dry atmosphere4 ,the normal atmospheric temperature of #gj;,f4 with a relative humidity of #ej to #fj per cent4 saturation produces a condition that is one of agreeable warmth to the average person in health and is recognized as the atmosphere most desirable4 ,to some1 this state of temperature and humidity is that of too much warmth and a temperature of #fh1 with the same humidity1 is most agreeable4 ,at the same temperature1 a reduction of the humidity to #bj per cent4 saturation will produce a feeling of discomfort and the sensation will be that of a lack of heat4 ,the cause for this latter feeling is due to excessive evaporation of moisture from the body4 ,,table ,i4--,,properties ,,of ,,air ------------------------------------- ,weight of vapor per ,weight of ,temperaturecubic foot ofcubic foot of of the air saturated airsaturated air ------------------------------------- ,fahrenheit ,grains ,grains #aj #a4aa #ehi4d #aa #a4ae #ehh4a #ab #a4ai #ehf4h #ac #a4bd #ehe4e #ad #a4bh #ehd4b #ae #a4cb #ehb4i #af #a4cg #eha4f #ag #a4da #ehj4c #ah #a4dg #egi4a #ai #a4eb #egg4h #bj #a4eh #egf4e #ba #a4fc #ege4c #bb #a4fi #egd4j #bc #a4ge #egb4g #bd #a4ha #ega4e #be #a4hg #egj4b #bf #a4ic #efi4j #bg #b4jj #efg4g #bh #b4jg #eff4e #bi #b4ad #efe4c #cj #b4ba #efd4a #ca #b4bi #efb4h #cb #b4cg #efa4f #cc #b4de #eff4d #cd #b4ec #eei4b #ce #b4fb #eeh4j #cf #b4ga #eef4h #cg #b4hj #eee4f #ch #b4hi #eed4d #ci #b4ii #eec4b #dj #c4ji #eeb4j #da #c4ai #eej4h #db #c4cj #edi4f #dc #c4da #edh4d #dd #c4eb #edg4b #de #c4fd #edf4a #df #c4gf #edd4i #dg #c4hh #edc4g #dh #d4ja #eda4c #di #d4ad #edb4e #ej #d4bh #edj4b #ea #d4db #eci4j #eb #d4ef #ecg4i #ec #d4ga #ecf4g #ed #d4hf #ece4e #ee #e4jb #ecd4d #ef #e4ah #ecc4b #eg #e4cd #ecb4a #eh #e4ea #ecd4i #ei #e4fi #ebi4h #fj #e4hg #ebh4f #fa #f4jf #ebg4j #fb #f4be #ebf4c #fc #e4de #ebe4b #fd #f4fe #ebd4j #fe #f4hg #ebb4j #ff #g4jh #eba4g #fg #g4cj #ebj4j #fh #g4ec #eai4d #fi #g4gf #eah4c #gj #h4jj #eag4b ,the evaporation of moisture is always accompanied with the loss of heat required to produce such change of condition4 ,this is known as the heat of vaporization and represents a definite amount of heat that is used up whenever water is changed into vapor4 ,no matter what its temperature may be--whether hot or cold--when water is vaporized1 a definite amount of heat is required to change the water into vapor4 ,water may be evaporated at any temperature2 even ice evaporates4 ,a common instance of the latter is that of wet clothes which 8freeze dry0 in winter weather when hung on the clothes line4 ,the rate at which evaporation takes place depends on the dryness of the surrounding air and the rapidity of its motion4 ,in dry windy weather evaporation is most rapid4 ,as before stated1 whenever water evaporates--at no matter what temperature--a definite quantity of heat is necessary to change the water into vapor4 ,the exact amount of heat required to produce this change varies somewhat with the temperature and atmospheric pressure but it always represents a large loss of heat4 ,at the boiling point of water 7#bab;,f47 the heat of vaporization is #igj ,b4t4u4 for each pound of water evaporated1 but at a lower temperature it is greater than that amount4 ,at the temperature of the body 7#ih4f7 the heat necessary to evaporate a pound of moisture from its surface is #ajde ,b4t4u4 ,it is the absorption of heat due to evaporation that cools the air of a sprinkled street4 ,the more rapid the evaporation the more pronounced is the decline of temperature in the immediate vicinity4 ,the same effect is produced when moisture is evaporated from the surface of the body4 ,the acceleration of evaporation caused by a breeze or the blast of air from an electric fan is that which produces the chilling sensation to the body4 ,during winter weather the effect of the cold wind is rendered more severe by evaporation of moisture from the body4 ,in health1 the body being in a slightly moist condition1 the evaporation which goes on from its surface is what keeps it cool in warm weather1 but if on account of excessive dryness of the surrounding air the evaporation is very rapid1 a sensation of cold is the result4 ,not only does excessively dry air produce the sensation of chilliness but the loss of heat from the body due to sudden or long exposure effects the general health and is conducive to chills that are followed by fever4 ,in health the temperature of the body is constant and normally #ih4f;,f42 any condition that reduces that temperature tends toward a lowering of vitality and the consequent inability to withstand the attack of disease4 ,in a very dry atmosphere the skin1 instead of being slightly moist1 is kept dry1 the result of which is the irritation that produces chaps and roughness of the surface4 ,reports of the ,u4 ,s4 ,weather ,department show that the relative humidity of ,death ,valley1 which is the driest and hottest known country1 during the driest period of the year--between ,may and ,september--averages #ae4e per cent4 saturation4 ,in winter1 many buildings1 particularly offices and school buildings are not far from that atmospheric condition1 constantly4 ,under the usual conditions of house heating1 there is an almost absolute lack of means to give moisture to the air4 ,almost without exception steam-heating plants and hot-water heating plants in office buildings and dwellings are without any provision for changing the atmospheric humidity4 ,in school buildings that are not kept under a more desirable condition of temperature and humidity1 the general health is impaired and the behavior of the pupils very markedly influenced4 ,the tension of a school-room full of fidgety nervous children can be very promptly and greatly reduced by the introduction of water vapor into the air to #ej per cent4 saturation4 ,all modern school buildings1 auditoriums1 etc41 are provided--aside from the heating plants--with means of ventilating in which the entering air is washed and humidified to the desired degree1 before being sent into the rooms4 ,the popular conception of the hot-air furnace method of heating is that it produces particularly dry air1 when in reality it is the only type of house-heating plant in which any provision is made for adding water to the air4 ,these furnaces are usually furnished with a water reservoir by use of which the humidity may be raised to a desirable point4 ,much of the water which enters the air of the average home1 during winter weather1 comes from the evaporation that goes on in the kitchen4 ,usually on wash days the humidity is raised to a marked degree and that day is commonly followed by a short period of agreeable atmospheric condition4 ,the arrangement of many houses is such that a much-improved condition of humidity might be obtained from the kitchen by continuous evaporation of water from a tea-kettle4 ,,relative ,,humidity ,depression of wet-bulb thermometer 7t-t'7 ---------------------------------------- -------------- ,air temp4 t #a4j #b4j #c4j #d4j #e4j #f4j #g4j #h4j #i4jaj4j ---------------------------------------- -------------- #ce #ia #hb #gc #fd #ee #df #cg #bi #bj #ab #cf #ia #hb #gc #fe #ef #dh #ci #ca #bc #ad #cg #ia #hc #gd #ff #eh #di #da #cc #be #ag #ch #ia #hc #ge #fg #ei #ea #dc #ce #bg #ai #ci #ib #hd #gf #fh #fj #eb #dd #cg #bi #ba #dj #ib #hd #gf #fh #fa #ec #df #ch #ca #bc #da #ib #hd #gg #fi #fb #ed #dg #dj #cc #bf #db #ib #he #gg #gj #fb #ee #dh #da #cd #bh #dc #ib #he #gh #gj #fc #ef #di #dc #cf #bi #dd #ic #he #gh #ga #fd #eg #ea #dd #cg #ca #de #ic #hf #gi #ga #fe #eh #eb #de #ci #cc #df #ic #hf #gi #gb #fe #ei #ec #df #dj #cd #dg #ic #hf #gi #gc #ff #fj #ed #dg #da #ce #dh #ic #hg #hj #gc #fg #fj #ed #dh #db #cf #di #ic #hg #hj #gd #fg #fa #ee #di #dc #cg #ej #ic #hg #ha #gd #fh #fb #ef #ej #dd #ci #ea #id #hg #ha #ge #fi #fc #eg #ea #de #dj #eb #id #hh #ha #ge #fi #fc #eh #eb #df #da #ec #id #hh #hb #ge #gj #fd #eh #ec #dg #db #ed #id #hh #hb #gf #gj #fe #ei #ed #dh #dc #ee #id #hh #hb #gf #ga #fe #fj #ee #di #dd #ef #id #hh #hb #gg #ga #ff #fa #ee #ej #de #eg #id #hh #hc #gg #gb #ff #fa #ef #ea #df #eh #id #hi #hc #gg #gb #fg #fb #eg #eb #dg #ei #id #hi #hc #gh #gc #fh #fc #eh #ec #dh #fj #id #hi #hd #gh #gc #fh #fc #eh #ec #di #fa #id #hi #hd #gi #gd #fh #fd #ei #ed #ej #fb #id #hi #hd #gi #gd #fi #fd #fj #ee #ej #fc #ie #ij #hd #gi #gd #gj #fe #fj #ef #ea #fd #ie #ij #he #gi #ge #gj #ff #fa #ef #eb ---------------------------------------- -------------- ---------------------------------------- -------------- ,air temp4 t #aa4jab4jac4jad4jae4jaf4jag4jah4jai4jbj4 j ---------------------------------------- -------------- #ce #d #cf #f #cg #i #a #ch #ab #d #ci #ad #g #dj #af #i #b #da #ah #aa #e #db #ba #ad #g #j #dc #bc #af #i #c #dd #bd #ah #ab #e #de #bf #bj #ad #h #b #df #bh #bb #af #aj #d #dg #bi #bc #ag #ab #f #a #dh #ca #be #ai #ad #h #c #di #cb #bf #ba #ae #aj #e #ej #cc #bh #bb #ag #ab #g #b #ea #ce #bi #bd #ai #ad #i #d #eb #cf #cj #be #bj #ae #aj #f #j #ec #cg #cb #bg #bb #ag #ab #g #c #ed #ch #cc #bh #bc #ah #ad #i #e #j #ee #ci #cd #bi #be #bj #ae #aa #f #b #ef #dj #ce #ca #bf #ba #ag #ab #h #d #eg #da #cf #cb #bg #bc #ah #ad #aj #e #a #eh #db #ch #cc #bh #bd #bj #ae #aa #g #c #ei #dc #ci #cd #cj #be #ba #ag #ac #i #e #fj #dd #dj #ce #ca #bg #bb #ah #ad #aj #f #fa #de #dj #cf #cb #bh #bd #bj #af #ab #h #fb #df #da #cg #cc #bi #be #ba #ag #ac #i #fc #dg #db #ch #cd #cj #bf #bb #ah #ad #aa #fd #dh #dc #ci #ce #ca #bg #bc #bj #af #ab ---------------------------------------- -------------- ,,relative ,,humidity 7,continued7 ,depression of wet-bulb thermometer 7t-t7 ---------------------------------------- ------------------- ,air temp4 #a4j #b4j #c4j #d4j #e4j #f4j #g4j #h4j #i4j #aj4j #aa4j t ---------------------------------------- ------------------- #fe #ie #ij #he #hj #ge #gj #ff #fb #eg #ec #dh #ff #ie #ij #he #hj #gf #ga #ff #fb #eh #ec #di #fg #ie #ij #he #hj #gf #ga #fg #fb #eh #ed #ej #fh #ie #ij #he #ha #gf #gb #fg #fc #ei #ee #ea #fi #ie #ij #hf #ha #gg #gb #fh #fd #ei #ee #ea #gj #ie #ij #hf #ha #gg #gb #fh #fd #fj #ef #eb #ga #ie #ij #hf #hb #gg #gc #fi #fd #fj #ef #ec #gb #ie #ia #hf #hb #gh #gc #fi #fe #fa #eg #ec #gc #ie #ia #hf #hb #gh #gc #fi #fe #fa #eh #ed #gd #ie #ia #hf #hb #gh #gd #gj #ff #fb #eh #ed #ge #if #ia #hg #hb #gh #gd #gj #ff #fc #ei #ee #gf #if #ia #hg #hc #gh #gd #gj #fg #fc #ei #ee #gg #if #ia #hg #hc #gi #ge #ga #fg #fc #ei #ef #gh #if #ia #hg #hc #gi #ge #ga #fg #fd #fj #eg #gi #if #ia #hg #hc #gi #ge #ga #fh #fd #fj #eg #hj #if #ia #hg #hc #gi #gf #gb #fh #fd #fa #eg #hb #if #ib #hh #hd #hj #gf #gb #fi #fe #fb #eh #hd #if #ib #hh #hd #hj #gg #gc #gj #ff #fc #ei #hf #if #ib #hh #he #ha #gg #gd #gj #fg #fc #fj #hh #if #ib #hh #he #ha #gh #gd #ga #fg #fd #fa #ij #if #ib #hi #he #ha #gh #ge #ga #fh #fe #fb #ib #if #ib #hi #he #hb #gh #ge #gb #fi #fe #fb #id #if #ic #hi #hf #hb #gi #ge #gb #fi #ff #fc #if #if #ic #hi #hf #hb #gi #gf #gc #gj #fg #fd #ih #if #ic #hi #hf #hc #gi #gf #gc #gj #fg #fd #ajj #if #ic #ij #hf #hc #hj #gg #gd #ga #fh #fe #ajb #if #ic #ij #hf #hc #hj #gg #gd #ga #fh #fe #ajd #ig #ic #ij #hg #hd #hj #gg #gd #gb #fi #ff #ajf #ig #ie #ij #hg #hd #ha #gh #ge #gb #fi #ff #ajh #ig #ic #ij #hg #hd #ha #gh #ge #gb #gj #fg ---------------------------------------- ------------------- ---------------------------------------- ------------------ ,air temp4 #ab4j #ac4j #ad4j #ae4j #af4j #ag4j #ah4j #ai4j #bj4j t ---------------------------------------- ------------------ #fe #dd #dj #cf #cb #bh #be #ba #ag #ac #ff #de #da #cg #cc #bi #bf #bb #ah #ae #fg #df #db #ch #cd #cj #bg #bc #bj #af #fh #dg #dc #ci #ce #ca #bh #bd #ba #ag #fi #dg #dd #dj #cf #cb #bi #be #bb #ai #gj #dh #dd #dj #cg #cc #cj #bf #bc #bj #ga #di #de #da #ch #cd #ca #bg #bd #ba #gb #di #df #db #ci #ce #cb #bh #be #bb #gc #ej #df #dc #dj #cf #cc #bi #bf #bc #gd #ea #dg #dd #dj #cg #cd #cj #bg #bd #ge #ea #dh #dd #da #ch #cd #ca #bh #be #gf #eb #dh #de #db #ch #ce #cb #bi #bf #gg #eb #di #df #db #ci #cf #cc #cj #bg #gh #ec #ej #df #dc #dj #cg #cd #ca #bh #gi #ed #ej #dg #dd #da #cg #cd #ca #bi #hj #ed #ea #dg #dd #da #ch #ce #cb #bi #hb #ee #eb #di #df #dc #dj #cg #cd #ca #hd #ef #ec #ej #dg #dd #da #ch #ce #cb #hf #eg #ed #ea #dh #de #db #ci #cg #cd #hh #eh #ee #eb #di #df #dc #da #ch #ce #ij #ei #ef #ec #ej #dg #dd #db #ci #cg #ib #ei #eg #ed #ea #dh #de #dc #dj #ch #id #fj #eg #ed #eb #di #df #dd #da #ci #if #fa #eh #ee #ec #ej #dg #de #db #dj #ih #fa #ei #ef #ec #ea #dh #df #dc #da #ajj #fb #ei #eg #ed #eb #di #dg #dd #db #ajb #fc #fj #eg #ee #eb #ej #dg #de #dc #ajd #fc #fa #eh #ef #ec #ea #dh #df #ad #ajf #fd #fa #ei #ef #ed #ea #di #dg #de #ajh #fd #fb #ei #eg #ed #eb #ej #dg #de ---------------------------------------- ------------------ ,the prevailing impression seems to exist that when air is heated1 it loses its moisture4 ,in reality1 air that is heated only attains a condition in which its capacity for containing moisture is increased4 ,if after being heated to a high degree--and is relatively very dry--the air is reduced to its original temperature1 the amount of moisture will be the same as was originally contained4 ,in heating houses with hot air1 the seemingly dry condition is usually due to temperature alone4 ,when a hot-air furnace is provided with the customary reservoir for moistening the discharged air1 it may be made to produce excellent conditions of atmospheric humidity4 ,the heated air readily absorbs the water evaporated in the furnace from the water reservoir and enters the rooms as relatively dry air but containing more moisture than the outside air2 when it has been reduced in temperature by mixing with the cooler air of the house1 its moisture content remains unaltered and at the lower temperature its relative humidity is increased4 ,relative ,humidity4--,suppose that on a damp day the outside temperature is #ej and that the atmosphere is #ij per cent4 saturated4 ,the air that comes into the house at this temperature and humidity is heated to #gj4 ,the rise of temperature gives the air the property of absorbing additional moisture so that the relative humidity which was #ij per cent4 is now much less4 ,from the table relative humidity1 will be seen that at #ej temperature and #ij per cent4 saturation the air contains #c4fg grains of moisture4 ,when the air is heated to #gj1 it still contains the original amount of moisture but its relative humidity has decreased with the change of temperature4 ,it is really the amount of moisture present--#c4fg grains--divided by the amount necessary to saturate the air at #gj1 which is #h grains2 this gives approximately a relative humidity #dj per cent4 saturation4 ,as the temperature goes lower1 less and less moisture is required to saturate the air4 ,if saturated air at #j;,f41 which contains #j4dh grain of water1 is raised to #gj;,f4--where #h grains of water is required for saturation--the percentage of saturation would be #j4dh_/h or #f per cent4 ,the ,hygrometer4--,the instrument most commonly employed for determining atmospheric humidity is the hygrometer4 ,this appliance is composed of two thermometers mounted in a frame with a vessel for holding water4 ,one of the thermometers is intended to register the temperature of the air and is called the dry-bulb thermometer4 ,the bulb of the other--the wet-bulb thermometer--is covered with a piece of cloth or other porous material which is kept saturated with water1 absorbed from the water holder4 ,the dryness of the air is indicated in the wet-bulb thermometer by the decline of temperature due to evaporation4 ,the rate of evaporation from the wet-bulb covering will vary with the humidity and if the air is very dry the wet-bulb thermometer will register a temperature several degrees below that of the other thermometer4 ,if the air is saturated with moisture1 no evaporation will take place and the thermometers will read alike4 ,the relative humidity of the air as indicated by the readings of the thermometers is taken directly from a humidity table4 ,the table is made to suit any condition of atmospheric humidity and the determinations require no calculation4 ,illustration3 ,,fig4 #aeg4--;,hygrometer of ,u4 ,s4 ,weather ,bureau type2 for determining atmospheric humidity4 ,fig4 #aeg shows the ,u4 ,s4 ,weather ,bureau pattern hygrometer such as is used at the weather stations4 ,the wet-bulb thermometer has a muslin or knitted silk covering which dips into a metal water cup as shown in the figure4 ,it is important that the covering of the wet bulb be kept in good condition4 ,the evaporation of the water from the covering leaves in the meshes particles of solid matter that were held in solution in the water4 ,the accumulation of the solids ultimately prevent the water from thoroughly wetting the wick4 ,an observation consists in reading the two thermometers and from the difference between the wet-bulb reading and that of the dry-bulb1 the relative humidity is taken directly from the table4 ,to illustrate1 suppose that the dry-bulb thermometer reads #fj and that the wet-bulb reads #ef4 ,the difference between the two readings is #d4 ,in the table of relative humidity on page #bjb1 #fj is found in the column headed1 ,air temp4 t1 and opposite that number in the column headed #d is #gh1 which indicates that under the observed conditions the air is #gh per cent4 saturated with moisture4 ,this table is suited for air temperatures from #ce;,f4 to #hj;,f4 and depressions of the wet-bulb thermometer from #a;,f4 to #bj;,f4 ,the table1 therefore1 has a range of variations which will admit humidity determinations for all ordinary conditions4 ,illustration3 ,,fig4 #aeh4--,the hygrodeik4 ,a form of hygrometer in which relative humidity is found directly from a diagram4 ,the ,hygrodeik4--,in ,fig4 #aeh is shown a form of hygrometer known as a hygrodeik1 by means of which atmospheric humidity may be determined without the use of the tables4 ,in the figure the wet-bulb and dry-bulb thermometers are easily recognized4 ,a glass water bottle ,w is held to the base of the instrument by spring clips which permit its removal to be filled with water4 ,between the thermometers is a diagram chart from which the atmospheric humidity is taken4 ,an index arm1 carrying a movable pointer ,p1 permits the instrument to be set for any observed thermometer readings4 ,the index is really a graphical method of expressing the figures given in the table on pages #bjb-bjc4 ,in the picture the wet-bulb thermometer reads #fe1 the dry-bulb thermometer #gg4 ,to determine the relative humidity under these conditions the movable arm is swung to the left and the pointer ,p placed on the left-hand scale at the line #fe4 ,the arm is then swung to the right until the pointer touches the downward curving line beginning at #gg1 the dry-bulb reading4 ,the lower end of the arm ,h now points to the relative humidity1 where #eb per cent4 is indicated by the scale at the bottom of the index4 ,the same result is obtained from the table of ,relative ,humidity4 ,the readings of the thermometers in the figure give a difference in temperature of #ab1 the dry-bulb thermometer reads #gg4 ,referring this data to the humidity table1 the column marked #ab1 for the depression of the wet-bulb thermometer and opposite #gg in the air temperature column1 is found #ec which indicates the per cent4 of saturation4 ,the hygrodeik gives further the temperature of the dew-point1 on the scale to the right2 and the absolute humidity may be found by following the upward curving line nearest the pointer1 at the end of which line is given the value in grains of moisture per cubic foot4 ,the hygrodeik or other instrument of the kind is very largely used in places where relative humidity is regularly observed by those of limited experience1 as in school-rooms1 auditoriums1 etc4 ,such records are not intended to be perfectly accurate and the readings of the hygrodeik are very well-suited for the purpose4 ,in using the hygrometer and the hygrodeik the instruments are stationary2 they are usually hung on the wall in a convenient location for observation and are placed to avoid accidental drafts in order that the conditions surrounding the observation may be the same at all times4 ,the evaporation which takes place from the wet bulb is due to natural convection and does not always reach the maximum amount4 ,the evaporation is furthermore influenced by accidental variations and consequently the results cannot be considered exact4 ,illustration3 ,,fig4 #aei4--,psychrometer of ,u4 ,s4 ,weather ,bureau type2 for accurate determination of atmospheric humidity4 ,under conditions that demand more exact humidity records than are obtainable with hygrometer1 the psychrometer furnishes means of making more accurate observation4 ,the psychrometer shown in ,fig4 #aei is of the form used by the ,u4 ,s4 ,weather ,department4 ,like the hygrometer1 it is composed of a wet-bulb and a dry-bulb thermometer but no water cup is attached to the instrument for moistening the wick of the wet bulb4 ,when ready for use the wick is wet with water before each observation4 ,the greater accuracy to be attained by the use of this instrument is on account of the maximum evaporation which is obtained from the wet bulb for any atmospheric condition4 ,the evaporation which takes place from the wet-bulb thermometer in quiet air is not so great as that which occurs if the same air is in motion4 ,in moving air1 however1 there is a certain maximum rate beyond which no further evaporation will take place4 ,the motion of the air may be produced either by blowing on the bulb with a fan or air blast1 or by whirling the thermometer4 ,with the psychrometer the latter method is used4 ,this instrument is provided with a handle which is pivoted to the frame and about which it is swung to produce a maximum evaporation from the wick4 ,when a motion of the air is attained sufficient to produce a saturated atmosphere about the bulb1 the temperature will remain constant4 ,a velocity of air or the motion of the wet-bulb thermometer #aj feet per second is that usually taken as the rate for observation and the swinging is kept up #c or #d minutes or until the temperature of the wet-bulb thermometer remains stationary4 ,illustration3 ,,fig4 #afj4--;,dial hygrometer4 ,then the temperature of each thermometer is read and the humidity found in the table4 ,relative humidity determinations may be made at temperatures below the freezing point if sufficient precaution is taken in the observations4 ,when the instrument is not in use1 it is kept in the metallic case shown in the picture1 to protect it from injury4 ,dial ,hygrometers4--,various forms of hygrometers are in use1 in which a pointer is intended to indicate on a dial the percentage of atmospheric humidity4 ,that shown in ,fig4 #afj is one of the common forms4 ,instruments of this kind depend for their action on the absorptive property of catgut or other materials that are sensitive to the moisture changes of the air4 ,these instruments give fairly accurate readings in a small range for a limited time1 but they are apt to go out of adjustment from causes that cannot be controlled4 ,unless they are occasionally compared with a standard humidity determination1 their readings cannot be relied upon for definite amounts of atmospheric moisture4 ,the ,swiss ,cottage 8,barometer40--,fig4 #afa is one of the instruments of absorptive class that are sometimes used as weather indicators4 ,the images which occupy the openings in the cottage are so arranged that with the approach of damp weather the man comes outside and at the same time the woman moves back into the house4 ,in fair weather the reverse movement takes place4 ,the figures are mounted on the opposite ends of a light stick which is fastened to an upright pillar4 ,the movement of the images is caused by the change in length of a piece of catgut which is secured to the pillar and also to the frame of the house4 ,any change in atmospheric humidity causes a contraction or elongation of the catgut which moves the pillar and with it the images4 ,since stormy weather is accompanied by a high degree of humidity and fair weather is attended with dry atmosphere1 the movement of the images indicates in some degree the weather changes2 but the device is not in any way influenced by atmospheric pressure and hence is not a barometer4 ,illustration3 ,,fig4 #afa4--,swiss cottage 8,barometer40 ,this device is arranged to show the condition of atmospheric humidity by the movement of the images4 ,it is not really a barometer4 ,dew-point4--,dew is formed whenever falling temperature of the air passes the point where saturation occurs4 ,the reduction of the temperature of air raises the relative humidity because of the diminished capacity to contain moisture4 ,as the temperature declines there will come a point at which the air is saturated and any further decrease of temperature will cause supersaturation4 ,at this point the moisture will be deposited on the cooler surfaces in the form of drops4 ,the temperature at which dew begins to form is known as the dew-point4 ,the sweating of cold water pipes1 the dew that forms on a water glass and other relatively cold surfaces is caused by a temperature below the dew-point of the air4 ,,dew-,,point ,,table ,dew-point in degrees ,fahrenheit1 barometer pressure #bi inches ---------------------------------------- ------------- ,air ,vapor ,depression of wet-bulb thermometer 7t-t7 temp4 press4---------------------------------- ------ t e #a4j #b4j #c4j #d4j #e4j #f4j #g4j #h4j ---------------------------------------- ------------- #cj #j4afd #bg #be #bb #ah #ad #i #c -#e #ca #j4agb #bi #bf #bc #bj #af #aa #e -#b #cb #j4ahj #cj #bg #bd #ba #ag #ac #h #a #cc #j4ahg #ca #bh #be #bb #ai #ae #aj #c #cd #j4aie #cb #bi #bg #bd #bj #af #ab #f #ce #j4bjc #cc #cj #bh #be #bb #ah #ad #h #cf #j4baa #cd #ca #bi #bf #bc #bj #ae #aa #cg #j4bai #ce #cb #cj #bg #bd #ba #ag #ac #ch #j4bbh #cf #cc #ca #bh #bf #bc #ai #ad #ci #j4bcg #cg #cd #cb #bi #bg #bd #ba #af #dj #j4bdg #ch #ce #cc #ca #bh #be #bb #ah #da #j4bef #ci #cg #cd #cb #bi #bf #bc #bj #db #j4bff #dj #ch #ce #cc #cj #bh #be #ba #dc #j4bgg #da #ci #cf #cd #ca #bi #bf #bc #dd #j4bhg #db #dj #ch #ce #cb #cj #bg #bd #de #j4bih #dc #da #ci #cf #cd #ca #bi #bf #df #j4caj #dd #db #dj #cg #ce #cb #cj #bg #dg #j4cbb #de #dc #da #ci #cf #cd #ca #bh #dh #j4ccd #df #dd #db #dj #cg #ce #cb #cj #di #j4cdg #dg #de #dc #da #ci #cf #cd #ca #ej #j4cfj #dh #df #dd #db #dj #cg #ce #cb #ea #j4cgc #di #dg #de #dc #da #ci #cf #cd #eb #j4chg #ej #dh #df #dd #db #dj #cg #ce #ec #j4djb #ea #di #dg #de #dc #da #ci #cf #ed #j4dag #eb #ej #di #dg #dd #db #dj #ch #ee #j4dcb #ec #eb #ej #dh #df #dc #da #ci #ef #j4ddh #ed #ec #ea #di #dg #de #dc #dj #eg #j4dfe #ee #ed #eb #ej #dh #df #dd #db #eh #j4dhb #ef #ee #ec #ea #di #dg #de #dc #ei #j4dii #eg #ef #ed #eb #ej #dh #df #dd #fj #j4eag #eh #eg #ee #ec #ea #di #dg #de #fa #j4ecf #ei #eh #ef #ed #eb #ea #di #df #fb #j4eee #fj #ei #eg #ee #ed #eb #ej #dh #fc #j4ege #fa #fj #eh #ef #ee #ec #ea #di #fd #j4eie #fb #fa #ei #eh #ef #ed #eb #ej #fe #j4faf #fc #fb #fj #ei #eg #ee #ec #ea #ff #j4fch #fd #fc #fa #fj #eh #ef #ed #ec #fg #j4ffa #fe #fd #fb #fa #ei #eg #ef #ed #fh #j4fhd #fg #fe #fc #fb #fj #eh #eg #ee #fi #j4gjg #fh #ff #fd #fc #fa #fj #eh #ef #gj #j4gcb #fi #fg #ff #fd #fb #fa #ei #eg #ga #j4geg #gj #fh #fg #fe #fc #fb #fj #eh #gb #j4ghc #ga #fi #fh #ff #fe #fc #fa #fj #gc #j4haj #gb #gj #fi #fg #ff #fd #fb #fa #gd #j4hch #gc #ga #gj #fh #fg #fe #fd #fb #ge #j4hff #gd #gb #ga #fi #fh #ff #fe #fc #gf #j4hif #ge #gc #gb #gj #fi #fg #ff #fd #gg #j4ibf #gf #gd #gc #ga #gj #fh #fg #fe #gh #j4ieg #gg #ge #gd #gb #ga #fi #fh #ff #gi #j4ihi #gh #gf #ge #gc #gb #gj #fi #fg #hj #a4jbb #gi #gg #gf #ge #gc #gb #gj #fi ---------------------------------------- ------------- ---------------------------------------- ------------- ,air ,vapor ,depression of wet-bulb thermometer 7t-t7 temp4 press4---------------------------------- ------ t e #i4j #aj4j #aa4j #ab4j #ac4j #ad4j #ae4j #af4j ---------------------------------------- ------------- #cj #j4afd -#bj #ca #j4agb -#ad -#ej #cb #j4ahj -#i -#bi #cc #j4ahg -#e -#bj #cd #j4aie -#b -#ad -#ej #ce #j4bjc #a -#h -#bh #cf #j4baa #d -#d -#ai #cg #j4bai #g -#a -#ab -#dd #ch #j4bbh #i #c -#g -#be #ci #j4bcg #ab #f -#c -#af #dj #j4bdg #ad #h #a -#aj -#ce #da #j4bef #af #aa #d -#e -#ba #db #j4bff #ag #ac #g -#a -#ac -#ei #dc #j4bgg #ai #ae #aj #c -#g -#bh #dd #j4bhg #ba #ag #ab #f -#b -#ag #de #j4bih #bb #ai #ad #h #b -#i -#cg #df #j4caj #bd #bj #af #aa #e -#d -#bj #dg #j4cbb #be #bb #ah #ac #h #j -#ab -#ec #dh #j4ccd #bg #bc #bj #ae #aj #d -#f -#be #di #j4cdg #bh #be #ba #ag #ac #g -#b -#ae #ej #j4cfj #bi #bg #bc #ai #ae #i #b -#h #ea #j4cgc #ca #bh #be #ba #ag #ab #f -#c #eb #j4chg #cb #bi #bf #bc #ai #ad #i #a #ec #j4djb #cd #ca #bh #bd #ba #af #aa #e #ed #j4dag #ce #cb #bi #bf #bc #ai #ad #h #ee #j4dcb #cf #cd #ca #bh #bd #ba #af #aa #ef #j4ddh #ch #ce #cb #bi #bf #bc #ai #ad #eg #j4dfe #ci #cf #cd #ca #bh #bd #ba #af #eh #j4dhb #dj #ch #ce #cb #bi #bf #bb #ah #ei #j4dii #db #ci #cg #cd #ca #bh #bd #bj #fj #j4eag #dc #da #ch #ce #cb #bi #bf #bb #fa #j4ecf #dd #db #ci #cg #cd #ca #bh #bd #fb #j4eee #df #dc #da #ch #ce #cb #cj #bf #fc #j4ege #dg #de #db #dj #cg #cd #ca #bh #fd #j4eie #dh #df #dd #da #ch #cf #cc #cj #fe #j4faf #di #dg #de #dc #dj #cg #cd #ca #ff #j4fch #ea #dh #df #dd #db #ci #cf #cc #fg #j4ffa #eb #ej #dh #de #dc #dj #ch #ce #fh #j4fhd #ec #ea #di #dg #dd #db #ci #cf #fi #j4gjg #ed #eb #ej #hd #df #dc #da #ch #gj #j4gcb #ee #ec #ea #di #dg #de #db #dj #ga #j4geg #eg #ee #ec #ea #di #df #dd #da #gb #j4ghc #eh #ef #ed #eb #ej #dh #de #dc #gc #j4haj #ei #eg #ee #ec #ea #di #dg #dd #gd #j4hch #fj #eh #ef #ed #ec #ej #dh #df #ge #j4hff #fa #fj #eh #ef #ed #eb #ej #dg #gf #j4hif #fb #fa #ei #eg #ee #ec #ea #di #gg #j4ibf #fd #fb #fj #eh #ef #ed #eb #ej #gh #j4ieg #fe #fc #fa #ei #eh #ef #ed #eb #gi #j4ihi #ff #fd #fb #fa #ei #eg #ee #ec #hj #a4jbb #fg #fe #fd #fb #fj #eh #ef #ed ---------------------------------------- ------------- ,the temperature at which dew forms will depend on the amount of moisture present in the air1 but with a definite humidity and air pressure it will always occur at the same temperature4 ,if the dew-point is above freezing1 the dew will form as drops of water1 but if it is at or slightly below the freezing point1 the dew will appear as frost4 ,white frost is formed when the dew-point is only a few degrees below the freezing point4 ,a ,black frost occurs when the atmospheric humidity is so low that dew does not form until the temperature is much below the freezing point4 ,to ,determine the ,dew-point4--,the dew-point may be found by a number of methods1 usually described in works on physics but practical determinations are made with a hygrometer or psychrometer and a dew-point table4 ,accurate determinations must be made by the use of the psychrometer2 those made by the hygrometer are approximate4 ,suppose the reading of the dry-bulb thermometer is #fh and that this is designated as t2 at the time the wet-bulb temperature is #eg and is called t4 ,the depression of the wet bulb for these temperatures 7t-t7 is #aa4 ,in the dew-point table above is found in the dry-bulb column1 opposite this number in the column headed #aa--under depression of the wet-bulb thermometer--is #di1 which is the dew-point for the observed conditions4 ,as another illustration1 suppose the dry bulb of the psychrometer marks #fe and the wet bulb indicates #ef;,f42 then #fe-ef equals #i of the cold produced by evaporation4 ,the dew-point is determined in exactly the same way as with the hygrometer4 ,opposite #fe1 in the dry-bulb column of the dew-point table1 under the column of differences marked #i1 is found the dew-point for the observed conditions4 ,this is #di at which temperature dew will begin to form4 ,frost ,prediction4--,the formation of dew is always attended with a liberation of heat--the heat of vaporization--which tends to check the further decline of temperature4 ,the heat thus developed is usually sufficient to prevent the fall of temperature beyond a very few degrees1 but at times when there is little moisture in the air the fall of several degrees of temperature is necessary before the heat liberated by the forming dew balances the heat lost by radiation and the temperature remains stationary4 ,this condition of things was pointed out many years ago by ,tyndall1 who in his book on 8,heat0 states3 8,the removal for a single summer's night of the aqueous vapor which covers ,england would be attended by the destruction of every plant which a freezing temperature would kill40 ,the frosts of late spring and early fall which occur at times of dry air and cloudless sky are often caused by local conditions that are not forecasted by the weather department and often may be successfully combated4 ,at the time of suspected frost1 the temperature of the dew-point in relation to the freezing point determines the probability of a freezing temperature4 ,if the dew-point occurs at #aj or more above the freezing point there will be little danger of a killing frost4 ,as the difference in temperature between the dew-point and the frost point decreases1 the danger of frost increases4 ,if the dew-point falls at the freezing point1 frost is a certainty4 ,in using the table on page #bad1 the open diagonal line may be considered the danger line and any dew-point falling below the temperature thus indicated will be considered dangerously near the frost point4 ,this table differs from the other dew-point table only in the range of temperature4 ,the dew-point is found in exactly the same way as before4 ,in the use of the psychrometer and table as a means of frost prediction it is first necessary to make a reading of the wet-bulb and dry-bulb temperature described above4 ,the dry-bulb reading is found in the left-hand column of the table2 then follow the horizontal line opposite the figure1 till the perpendicular column is reached indicating the difference in reading between the dry and wet bulb4 ,the number at the meeting will be the temperature of the dew-point4 ,for example1 suppose the dry bulb stands at #fe and the wet bulb at #ee1 the difference being #aj and dew-point under these conditions will be #dg4 ,if the dew-point is #aj or more above the freezing point there is no danger of a frost1 but if the conditions are such as to give a temperature difference less than #aj above the freezing point there would be danger4 ,if the dew-point falls below the open diagonal line of the table there is danger and that danger increases as the difference in degrees between the freezing point and the dew-point becomes less4 ,as another illustration1 suppose that at sunset at the time of suspected frost the dry-bulb thermometer read #ed and the depression of the wet bulb showed #aj4 ,referring to the table it will be seen that for these conditions the dew-point falls at #cc which is only #a above the freezing point4 ,it is highly probable that frost would form4 ,,dew-,,point ,,table ,,for ,,frost ,,prediction ,depression of the wet-bulb thermometer ---------------------------------------- ----------------- ,dry- bulb #a #b #c #d #e #f #g #h #i #aj #aa #ab #ac temp4 ---------------------------------------- ----------------- #gj #fi #fg #ff #fd #fb #fa #ei #eg #ee #ec #ea #di #dg #fi #fh #ff #fd #fc #fa #ei #eh #ef #ed #eb #ej #dh #df #fh #fg #fe #fc #fb #fj #eh #eg #ee #ec #ea #di #df #dd #fg #ff #fd #fb #fa #ei #eg #ee #ed #eb #ej #dg #de #dc #ff #fd #fc #fa #fj #eh #ef #ed #eb #ej #dh #df #dd #fe #fc #fb #fj #ei #eg #ee #ec #ea #di #dg #de #db #da #fd #fb #fa #ei #eg #ef #ed #eb #ej #dh #df #dc #dj #fc #fa #fj #eh #ef #ee #ec #ea #di #dg #dd #db #da #ch #fb #fj #ei #eg #ee #ec #eb #ej #dh #de #dc #ci #cg #fa #ei #eh #ef #ed #eb #ej #dh #df #dd #db #da #ch #ce #fj #eh #eg #ee #ec #ea #di #dg #de #dc #ci #cf #cc #ei #eg #ef #ed #eb #ej #dh #df #dd #dj #ch #dc #cb #eh #ef #ee #ec #ea #di #dg #de #db #da #ci #cf #cc #cj #eg #ee #ed #eb #ej #dh #df #dd #dj #cg #ce #ca #bh #ef #ed #ec #ea #di #dg #dd #db #da #ci #cf #cc #cj #bf #ee #ec #eb #ej #dh #df #dc #dj #cg #cd #ca #bh #be #ed #eb #ej #di #df #dd #db #da #ci #cf #cc #cj #bg #bc #ec #ea #di #dg #de #dc #dj #cg #cd #ca #bh #be #bj #eb #ej #dh #df #dd #db #da #ch #cf #cc #cj #bg #bc #ah #ea #di #dg #de #dc #dj #cg #cd #ca #bh #be #ba #af #ej #dh #df #dd #db #da #ch #cf #cc #cj #bg #bc #ai #ad #di #dg #de #dc #dj #cg #cd #ca #bh #be #ba #ag #aa #dh #df #dd #db #da #ch #cf #cc #cj #bg #bc #ai #ad #i #dg #de #dc #dj #cg #ce #cb #bi #be #bb #ag #ab #f #df #dd #db #da #ci #cf #cc #cj #bg #bd #bj #ae #aj #c #de #dc #dj #cg #ce #cb #bi #bf #bb #ah #ac #g -#a #dd #db #da #ci #cf #cc #cj #bg #bd #bj #af #aa #d -#e #dj #cg #ce #cb #bi #bf #bc #ai #ad #h #a -#i #dc #da #ci #cf #cd #ca #bh #be #ba #ag #ab #f -#b -#ae #db #dj #ch #ce #cc #bi #bf #bc #ai #ae #i #c -#f -#bb #da #ci #cf #cd #ca #bh #be #bb #ag #ac #g #j -#aa -#cb #dj #ch #ce #cc #cj #bg #bd #bj #af #aa #d -#d -#af -#gd #ci #cg #cd #cb #bi #bf #bb #ah #ad #h #b -#h #bc #ch #cf #cc #ca #bh #bd #ba #ag #ab -#f -#a -#ab -#ce ---------------------------------------- ----------------- ,prevention of ,frost4--,from the discussion of frost formation it is evident that1 the temperature of the dew-point being the determining factor in its probable occurrence1 any expedient that may be used either to increase the humidity or to conserve the radiation of heat would prevent a dangerous decline of temperature4 ,frost prevention is practised in all fruit-growing regions and the method pursued depends on the kind of vegetation to be protected4 ,in the protection of orchards the use of smudge pots are probably the commonest means for preventing the loss of heat4 ,the object is to create a cloud of smoke over and about the orchard so that it forms a protective covering which prevents the escape of the heat4 ,in the case of a light frost--that is1 where the temperature falls only a few degrees below the frost point--the plants in small gardens and flower beds may be prevented from freezing by liberal sprinkling with water4 ,this is done to raise the humidity of the atmosphere surrounding the vegetation4 ,most vegetation withstands the temperature at the freezing point without particular injury1 and the freezing of part of the water liberates heat in sufficient quantity to prevent a further decline of temperature4 ,this heat liberated on the freezing of water is described in physics as the heat of fusion and in changing part of the water into ice sufficient heat is liberated to check the further fall of temperature4 ,humidifying ,apparatus4--,opportunity for adding moisture1 in the desired quantity1 to the air of the average dwelling is limited to the evaporation of water in the heating plant1 from vessels attached to the radiators or that which goes on in the kitchen4 ,household humidifying plants are within the range of possibility but there is not yet sufficient demand for their use to make attractive their manufacture4 ,in the hot-air furnace a water reservoir is usually a part of the chamber in which the air supply is heated4 ,the water in the reservoir is heated to a greater or lesser degree1 depending on the temperature of the furnace and vaporized both by heat and by the constantly changing air4 ,in the use of a steam plant or hot-water heating plant the opportunity of humidifying the air is very limited4 ,one method is that of suspending water tanks to the back of the radiators from which water is vaporized4 ,while this method is fairly efficient as a humidifier it is inconvenient and therefore apt to be neglected4 ,in houses heated by stoves there are sometimes water urns attached to the top of the frame which are intended for the evaporation of water but as a rule they are not of sufficient size to be of appreciable value4 ,the quantity of water required to humidify the air of a house will depend first1 on the temperature and humidity of the outside air2 second1 on the cubic contents of the building2 third1 on the rate of change of air in the building4 ,if the ventilation is good the rate of atmospheric change is rapid and the amount of water in consequence must be correspondingly increased4 ,the data included in the following table showing the relative humidity and amount of water required were taken from a seven-room frame dwelling in ,fargo1 ,n4 ,d41 during particularly severe winter weather4 ,the relative humidity determinations were made with a hygrodeik each day at noon4 ,the house was heated by a hot-air furnace arranged to take its air supply from the outside4 ,the air supply is recorded under ,cold-air intake4 ,the furnace was provided with a water pan for humidifying the air supply4 ,the amount of water evaporated each day is recorded in the column headed ,evap4 in #bd hours4 ,the outside temperature ranged from -#ab;,f4 to -#ba;,f4 ,the weather was clear and calm except the last day1 ,jan4 #ab1 which was windy4 ,the higher humidity on that day was no doubt due to the greater amount of heat required from the furnace and the consequent evaporation of the water from the water pan4 ,the humidity determinations made by a hygrodeik1 as before explained1 are only approximately correct but sufficiently exact for practical purposes4 ,the temperature is given in degrees ,fahrenheit4 ,in the table it will be noticed that the outside air was used only a part of the time because of the severity of the weather4 ,attention is called to the quantity of water required to keep the humidity at the amount shown4 ,this averages #bg-a_/b quarts per day4 ,at the time these observations were made the physics lecture-room at the ,north ,dakota ,agricultural ,college averaged #ah to #bj per cent4 saturation during class hours1 with observations made from a similar instrument4 ,this is a steam-heated room with only accidental means of adding water to the air4 ,the result was an atmosphere #c-a_/b per cent4 above that of ,death ,valley4 ,,hot-,,air ,,furnace ,readings taken at #ab o'clock noon each day ---------------------------------------- ----------------------- ,temp4 ,wet ,dry ,per ,evap4 ,in ,date outsidebulbbulb cent4 #bd hours ,cold-air intake saturatedquarts pints ---------------------------------------- ----------------------- ,dec4 #ac -#ac #ed #fc #ec ,closed #h a4m4 ,dec4 #ad -#ah #ee #ff #dg ,open ,dec4 #ae -#bj #eg #fh #di #ba ,closed #g a4m4 ,dec4 #af -#ah #eg #fg #ea #bj #a ,closed #g a4m4 ,dec4 #ag -#bb #eh #fi #dh #ah #a ,closed #g a4m4 ,dec4 #ah -#af #ee #fe #ea #ag #a ,closed #f3cj a4m4 ,dec4 #ai -#aj #eg #fh #dg #bj #a ,closed #h a4m4 ,dec4 #bj #j #ei #gj #di #ac ,not open at night ,jan4 #h -#ab #eh #ga #dc #ah ,closed ,jan4 #i -#ag #eg #ga #ci #be ,open #bd hours ,jan4 #aj -#af #eh #fi #de #bg #a ,open #aj hours ,jan4 #aa -#ba #fj #ge #dj #cj ,closed ,jan4 #ab -#ae #fj #gc #df #cj ,closed ---------------------------------------- ----------------------- ,the amounts of water evaporated may seem large to those who are unaccustomed to quantitatively consider problems in ventilation but the small amount of water in the air at -#ba must produce a very dry atmosphere when it is raised to #gj in temperature4 ,the amount of moisture in air at #bj;,f4 and at #hj per cent4 humidity is only #a4eh grains to the cubic foot4 ,if this air is now raised to #gj the moisture will still be #a4eh grains where there should be #d grains of water to make #ej per cent4 humidity4 ,it therefore will require the addition of practically #b4db grains of water for each cubic foot of entering air in order to bring it up to #ej per cent4 humidity4 ,in a case with the above conditions of atmosphere1 suppose it is desired to know the amount of water that would be taken up in humidifying the air for a school-room of size to accommodate #dj pupils4 ,the prescribed quantity of air for this purpose is #cj cubic feet per minute for each pupil4 ,the air is to be maintained at a humidity #ej per cent4 saturated4 ,the problem will be one of simple arithmetic4 ,if each pupil is to receive #cj cubic feet of air per minute or #ahjj cubic feet per hour1 the #dj pupils receiving #ahjj cubic feet per hour will require #dj #ahjj #gb1jjj cubic feet of air per hour4 ,to each cubic foot of the air is to be added #b4gd grains of water1 #gb1jjj #b4db #afd1bdj grains of water4 ,reducing this to pounds1 #afd1bdj #gjjj #bc4df pounds or #b4gg gallons of water per hour4 ,in practice the room will show a higher amount than #ej per cent4 humidity with this addition of the amount of water1 because of the water vapor that is exhaled from the lungs of the pupils4 ,that a considerable amount of water vapor is added to the atmosphere by breath exhalation is made evident from the moisture condensed by breathing on a cold pane of glass4 ,in any unventilated room occupied by a considerable number of people the humidity is thus increased a very noticeable amount4 ,the change in humidity of the air in a closed room filled with people is very pronounced4 ,the constant exhalation of moisture from the lungs is sufficient to saturate the air in a short time4 ,the heavy atmosphere of overcrowded1 unventilated rooms is due to moisture exhalation1 body odors and increased carbonic acid gas4 ,as the humidity of the atmosphere is increased a sensation of uncomfortable warmth is the result of the lesser evaporation4 ,,chapter ,,xi ,,ventilation ,the purity of air in any habitable enclosure is determined by the amount of ,,co 7,carbonic acid gas7 included in its composition4 ,the process of ventilation is that of adding fresh air to the impure atmosphere of houses1 until a desirable quality is attained4 ,in the opinion of hygienists1 when air does not exceed #f to #h parts of ,,co1 by volume in #aj1jjj1 the ventilation is desirable4 ,ordinary outdoor air contains about #d parts of ,,co to #aj1jjj1 while very bad air may contain as high as #hj parts to the same quantity4 ,the quantity of air required for the ventilation of a building is determined by the number of people to be provided4 ,the amount of air required per individual per hour necessary to produce a desired condition of ventilation is determined by adopting a standard of purity to suit the prevailing circumstances4 ,in hospitals where pure air is considered of greatest importance #djjj and #ejjj cubic feet per inmate per hour is not uncommon4 ,the practice of supplying #cj cubic feet of air per person per minute 7#ahjj cubic feet per hour7 seems to fulfill the average requirements4 ,it is the amount commonly specified for school-rooms4 ,the quantity of fresh air required per person to insure good ventilation will depend on the type of building to be supplied and varies somewhat with different authorities4 ,the ,de ,chaumont standard is that of #a cubic foot of air per second or #cfjj cubic feet per hour1 for each person to be accommodated4 ,de ,chaumont assumed a condition of purity which will permit less than #b parts in #aj1jjj of ,,co over that carried by country air4 ,in considering the same problem from the basis of permissible ,,co1 if #f parts of ,,co in #aj1jjj represents purity of the required air1 then #cjjj cubic feet per person per hour is necessary4 ,likewise1 the varying amounts for different degrees of purity are given by ,kent in the following table4 ,the upper line gives the permissible number of parts of ,,co per #aj1jjj1 while below each factor appears the number of cubic feet of air required per hour for each person supplied4 ---------------------------------------- ----------------- #f #g #h #i #aj #ae #bj ,parts of ,,co per #aj1jjj ---------------------------------------- ----------------- #c1jjjb1jjja1ejja1bjja1jjjedecge ,cubic feet of pure air per hour ---------------------------------------- ----------------- ,it is generally recognized1 that it is possible to live under conditions where no attempt is made to change the air in a building4 ,it is also an established fact that the only preventive and cure for tuberculosis is that of living constantly in an atmosphere of the purest air4 ,the greatest attainable degree of health is enjoyed by those who live in the open air1 because oxidation is one of the most efficient forms of prevention and elimination of disease1 and an abundance of pure air is the only assured means of sufficient oxidation4 ,the ,de ,chaumont standard is intended to represent the limit beyond which the sense of smell fails to detect body odors or 8closeness0 in an occupied room4 ,the amount of ,,co that air contains is not an absolute index of its purity1 but it gives a standard under ordinary conditions1 makes possible the requirement of a definite quantity of air4 ,if it were possible to express the amount of oxygen contained in the atmosphere1 the same relative condition might be attained4 ,the ordinary man exhales #j4f cubic foot of ,,co per hour4 ,some forms of lighting apparatus produces this gas in greater amounts4 ,the ordinary kerosene lamp gives out #a cubic foot of ,,co per hour4 ,a gas light using #e cubic feet of gas per hour produces #c4ge cubic feet of ,,co in the same time4 ,any form of combustion permitting the products to escape into the air of the room tends to lower the quality of the atmosphere by adding to its content of ,,co4 ,the prevailing impression that impure air is heavy and settles to the floor is erroneous4 ,impurities in the form of gases and vapors 7principally carbonic acid gas and odors7 diffuse throughout the entire space1 and the entering fresh air tends to dilute the entire volume4 ,as a quantative problem1 ventilation consists in admitting pure air into an impure atmosphere in amount to give a definite degree of purity4 ,this is accomplished by admitting sufficient air to completely change the atmosphere at stated intervals1 or to provide a definite quantity for each inhabitant4 ,the methods by which ventilation may be accomplished will depend on the type of building to be ventilated and the apparatus it is possible to use4 ,when the use of mechanical ventilation appliances are permissible1 any desired degree of atmospheric purity may be maintained at all times1 under any condition of climate or change of weather4 ,in buildings where mechanical ventilation cannot be considered as that of the average dwelling1 the problem is one of producing an average condition of reasonably pure air by natural convection4 ,in the average dwelling1 ventilation is accomplished by the natural draft produced in chimneys or air flues1 by partially opened windows and by the force produced by the movement of the outside air4 ,in some buildings a better condition of ventilation is attained by ordinary means than at first sight seems possible4 ,the fact that it is difficult to keep a house at the desired temperature during cold weather indicates that a considerable quantity of outside air is constantly entering and heated air is leaving the building4 ,it may be1 however1 that the ventilation under such condition is unsatisfactory1 even though the amount of air which enters the building is sufficient in quantity to produce a desirable atmosphere4 ,if the places of entrance and exit are so located that the entering air has no opportunity to mix with the air of the building1 the advantage of its presence is lost4 ,in the burning of fuel in stoves and furnaces1 the amount of oxygen necessary for combustion is supplied by the air which is first taken into the house and thus forms its atmosphere before it can enter the heater4 ,theoretically1 about #ab pounds of air are required for the combustion of a pound of coal1 but in practice a much larger amount actually passes through the heater4 ,as given by ,suplee1 from #ah to #bd pounds of air are actually used in burning #a pound of coal4 ,if #bj pounds of air per pound of fuel is taken as an average1 there will be required #aih cubic feet of air per pound of coal consumed4 ,in a building that requires #aj tons of coal to be used during the winter months1 this would necessitate the average use of #aigg cubic feet of air per hour1 which must be drawn into the house before it can enter the stoves4 ,this air acts as a means of ventilation and if it is used to advantage would furnish a supply sufficient in amount to produce excellent ventilation1 considerably more than enough for two people4 ,the amount of air drawn into the house in this way is further increased by that which passes into the chimney flue through the check-draft dampers1 when the fires are burning low4 ,the aim of architects is to construct buildings as completely windproof as possible1 but that such construction is attained in only a slight degree is sometimes very evident during cold weather4 ,no matter how tightly constructed buildings may be1 most of the contained air filters through the cracks and crevices of the walls or through the joints of the windows and door frames1 because there is seldom any special provision made for its entrance4 ,during extremely cold and windy weather the amount of air that enters the house in this way--because of the air pressure on the windward side--is sometimes sufficient to keep the temperature at an uncomfortably low degree4 ,under such conditions1 the air drifts through the building faster than it can be raised to the desired temperature and the rooms on the windward side of the building cannot be kept comfortably warm4 ,illustration3 ,,fig4 #afb4--;,a simple expedient for the prevention of drafts and improving ventilation4 ,the common method of ventilation in dwellings is that of partially open windows4 ,the air thus admitted1 being colder and consequently heavier than that at the temperature of the room1 sinks to the lowest level4 ,in so doing it creates drafts that produce discomfort and act only in the smallest degree to produce the desired effect of ventilation4 ,the effect of window ventilation may be greatly improved by a simple expedient illustrated in ,fig4 #afb4 ,in this1 the entering air meets a deflector in the form of a board or pane of glass that directs the cold air upward where it mingles with the heated air with the least production of a noticeable draft4 ,this is the most efficient method of house ventilating where no special provision is made for the admission of fresh air4 ,the object sought in ventilating a room is to keep up the quality of the air by constant addition of fresh air1 and in order to bring about a uniform purification of the entire atmosphere the entering air must be mixed with that already in the enclosure4 ,if the discomforts of drafts are to be avoided1 this mixing process must be brought about by admitting the cold air at the upper part of the room4 ,illustration3 ,,fig4 #afc4--;,a chimney flue used as a ventilator4 ,warm air rises to the top of the room because it is lighter than the colder air beneath it4 ,the coldest air is always lowest in point of elevation and unless there is some means to stir up the entire volume this condition will always remain the same4 ,when the easiest means of air for entering and leaving are near the floor1 the cold entering air and that which goes out will always be in the lower part of the room1 even when the supply is amply large4 ,if no opportunity is given for the fresh air to mix with that already in the room1 a poor average quality will result4 ,in the process of ventilation1 the entering air should be admitted at1 or directed toward1 the highest part of the room1 so that the pure cold air may have a chance to mix with that which is warmest4 ,air is not a good conductor of heat1 and in mixing warm and cold air the cold particles will tend to float downward and take up heat from the warmer air with which it comes into contact1 and thus produces a more uniform temperature4 ,illustration3 ,,fig4 #afd4--,method of admitting cold air into rooms so as to produce the best condition of ventilation4 ,the condition most to be desired is that of admitting cold air at a point where it will most readily mingle with the warm air from the source of heat4 ,the reduction in temperature that must take place from this mixture will produce a gravitational circulation4 ,unfortunately this is not always possible to attain in an old building1 but in the construction of a new building air ducts placed to admit air at points near the ceiling and located with reference to the supply of heat will bring about the best effect of ventilation4 ,the air which enters a room should1 therefore1 be near the top or so directed that the entering shaft will carry it upward4 ,the air which is taken out of the room should leave from a point near the floor4 ,in so doing it will tend to produce a more uniform quality and a more even distributor of the heat4 ,in order that the most desirable quality of atmosphere may be attained1 there should be a constant supply of pure air entering and an equal amount discharging from the house4 ,in the better-constructed dwelling such a condition is often provided through a ventilating flue that is a part of the chimney4 ,this flue is arranged with registers placed to take air from the parts of the house requiring the greatest amount of air4 ,such an arrangement is shown in the picture in ,fig4 #afc4 ,fig4 #afd shows the method of ,fig4 #afc combined with a direct means of admitting fresh air from the inside4 ,the fresh air ducts should be provided with dampers to control the effect of extreme cold and wind4 ,quantity of ,air ,discharged by a ,flue4--,any change of temperature of air produces a change equal to #a_/dia part of its volume1 for each degree variation4 ,if a cubic foot of air is raised in temperature #a;,f41 its volume is #a_/dia part larger than the original volume1 and its buoyancy in the surrounding air is increased correspondingly4 ,air that has a temperature higher than that surrounding it will tend to rise because it is lighter4 ,the air rising from a hot-air register or from a heated surface are illustrations of this condition4 ,since the change of volume--or what is the same thing1 its tendency to rise--increases #a_/dia for each degree difference in temperature1 the upward velocity of highly heated air will be very great4 ,in warm air that fills a chimney flue or a room1 the same tendency exists1 the warmest air rises to the highest point and if the air can escape1 as in the case of a chimney1 a draft will result4 ,the draft of a chimney1 in quiet air1 is due to the difference in temperature between the air inside the flue above that outside the house4 ,a chimney that does not 8draw0 and causes a stove to 8smoke10 will often produce sufficient draft after the flue has been warmed4 ,the upward movement of the warmer air in the flue produces a constantly increasing velocity1 until it reaches the top of the chimney4 ,this is an accelerated velocity that may be calculated by use of the formula given in physics1 to express the velocity of accelerated motion4 ,the well-known formula ,v 7#b;gh7 may be modified to express the conditions existing in a flue and permit of the calculation of the quantity of air discharged4 ,the upward flow of air in a chimney flue being due to the difference in temperature of the air in the flue over the outside air1 the flow of air from the rooms will continue as long as the difference in temperature exists4 ,moreover1 the air that is discharged from the rooms will be replenished from the outside1 and for the air sent out of the flue a corresponding amount will be brought into the rooms through any openings that exist--door or windows or through cracks or crevices1 depending on the completeness with which the house is closed4 ,in no case is a house air-tight4 ,the air pressure registered by the barometer is always the same inside as that outside the building4 ,during cold weather1 when the windows and doors are closed1 the air is escaping through the chimney and also through every little crack and chink in the top of the rooms where the air is warmest4 ,the colder air is entering at the same time through the joints about windows1 door casings1 through the crevices in the walls and particularly through the open joints made by the baseboards and the floor4 ,this latter entrance of cold air is one of the commonest causes of cold floors4 ,the shrinkage of the baseboards and floors from the quarter-round moulding which forms the joint leaves openings through which cold air is freely admitted from partitions and outside walls4 ,the cold1 heavier air remains near the floor because it can rise only when heated or forced upward by a draft4 ,if the same air were permitted to enter at points near the ceiling and mingle with the warmest air in the room1 a more uniform temperature would result1 as well as better ventilation4 ,the entering cold air1 mixing with the warm air at the top of the room1 would be reduced in its temperature and weight4 ,the heavier air in falling would diffuse with the air beneath it and thus improve the general quality of the atmosphere4 ,it is important to remember that the discharge of air through a chimney flue will depend1 in considerable amount1 on the rate the new air is able to enter the house4 ,in a new1 tightly constructed house1 the flue is often capable of discharging air much faster than it can enter1 when it must find its way in through accidental openings4 ,in such cases an open door or window immediately improves the draft of the stove4 ,the ventilation in the average dwelling is and must be accomplished by natural draft that is generated through difference in temperature of the air4 ,the possibility of providing an acceptable system of continuous ventilation is confined to the draft of the chimney or to a flue provided especially for that purpose4 ,such being the case1 the dimensions of flues constructed for ventilation should be the subject of investigation4 ,the work that a chimney or ventilating flue has to do is continuous and will last throughout its lifetime2 its proportions should therefore be considered with more than passing care4 ,it has been stated that the method of calculating volumes of air that will pass through a flue is based on the formula used to express the velocity of accelerated motion4 ,the fundamental formula must be changed to suit the conditions produced when air is heated and made buoyant by expansion4 ,as has been stated1 the change in temperature of air #a;,f4 causes an increase or decrease #a_/dia part of its volume for each degree change4 ,any portion of air1 warmer than that which surrounds it1 tends to rise because of its lighter weight2 the tendency to rise increases with the difference in temperature4 ,the draft of a flue is caused by this condition of difference in temperature between the air inside the flue and the outside atmosphere4 ,in order that this general condition may be expressed in the simplest form let3 ,t the temperature inside the flue in degrees ,f4 t the temperature outside the flue in degrees ,f4 ,h the height of the flue in feet4 ,the quantity 7,t-t7_/#dia expresses the difference in temperature in degrees1 divided by the change of volume for each degree4 ,this gives the constant upward tendency of the air in passing through the flue4 ,if this quantity is placed in the formula ,v 7#b;gh71 so as to exert its influence through the height of flue ,h1 the condition may be expressed3 ,v 7#b;g77,t-t7_/#dia7;,h7 ,the factor g1 representing the acceleration of gravity1 is constant and equal to #cb feet per second4 ,the quantity #b;g may be removed from under the radical and the formula becomes3 ,v #h777,t-t7_/#dia7;,h7 ,the formula may now be used to express the volume of discharge of air from a flue4 ,suppose such a flue contains an area of #a square foot in cross-section and that it is desired to estimate the air discharged from the flue per hour4 ,the value of g is given in feet per second1 and in order to make the formula express the volume of air discharged in cubic feet per hour1 it must be multiplied by the number of seconds in an hour4 ,volume discharged in cubic feet per hour #fj #fj #h777,t-t7_/#dia7;,h7 #bh1hjj777,t-t7_/#dia7;,h7 ,this formula applies to conditions such as will permit uniform movement of the air in a straight flue1 uninfluenced by irregular1 odd-shaped passages and rough surfaces4 ,moreover1 it is supposed that the air may enter the house as rapidly as it escapes4 ,the theoretical discharge will1 in most instances1 be less than the calculated amount1 because the air cannot enter the house as fast as it may be discharged by the flue4 ,it is a common custom to consider the theoretical flue only #ej per cent4 efficient4 ,as applied to the formula1 the constant #bh1hjj when reduced #ej per cent4 will become #ad1djj1 and will be so used in the calculations as follows4 ,as an illustration of the application of the formula1 suppose that the temperature in the house and in the flue is #gj;,f4 and that the outside temperature is #bj;,f4 ,the height of the chimney is #cj feet4 ,the area of the flue is #a square foot4 ,volume #ad1djj 777,t - t7_/#dia7;,h7 #ad1djj777gj - #bj7_/dia7 #cj7 #be1adj cubic feet per hour4 ,such a ventilating flue would be sufficient in size1 under the conditions given1 to furnish air at the rate of #be1adj cubic feet per hour or #cj cubic feet per minute to #ac persons1 provided of course that the air could enter the building at the rate demanded4 ,where no provision is made for the air to enter the building it must find its way by the accidental openings4 ,a common illustration of this effect may be noticed in the rate at which the fire of a stove will burn in a tightly closed room4 ,the opening of a door or window causes an immediate increase of combustion1 because of the extra air supply4 ,it is evident that in well-constructed houses other means should be provided for admitting air than that of accidental opening4 ,the following table calculated by the above formula gives the quantity of air in cubic feet per hour discharged through a flue of #a square foot cross-section4 ,the table shows the calculated discharge from flues of heights varying from #ae to #dj feet1 and with temperature differences from #aj to #ajj between the outside air and that of the house4 ---------------------------------------- ----------------------------- ,height ,temperature of air in the flue above that of external air of flue ---------------------------------------- --------------- in feet #aj #ae #bj #be #cj #ej #ajj ---------------------------------------- ----------------------- #ae #g1ihj #i1gbj #aa1bhj #ab1eej #ac1hjj #ag1hbj #be1adj ---------------------------------------- ----------------------- #bj #i1ahj #aa1ahj #ac1jhj #ad1ebj #ae1ijj #bj1ebj #bi1jdj ---------------------------------------- ----------------------- #be #aj1bfj #ab1fjj #ad1ebj #af1bfj #ag1hbj #bb1ihj #cb1dfj ---------------------------------------- ----------------------- #cj #aa1bhj #ac1hjj #ae1ijj #ag1hbe #ai1ejj #be1adj #ce1ehj ---------------------------------------- ----------------------- #ce #ab1ahj #ad1hhj #ag1afj #ai1bjj #ba1jfj #bg1ahj #ch1djj ---------------------------------------- ----------------------- #dj #ac1jbj #ae1ijj #ah1cfj #bj1ebj #bb1ejj #bi1jdj #dj1ihj ---------------------------------------- ----------------------- ,in ,fig4 #afc is illustrated the form of chimney that is often used for the ventilation of dwellings4 ,this is built with three flues4 ,the flue to the left--marked ,a at the top--is intended to carry away the smoke and gases from the kitchen range4 ,the flue to the right is that to which is connected the smoke pipe from the furnace4 ,the flue in the middle marked ,b is for ventilation4 ,occupying as it does the space between the other two1 it is kept warm by the heat of the other flues and the draft is thus increased4 ,openings to the flue are shown in the different floors at the points ,r and ,s4 ,the openings are furnished with registers which may be regulated to suit the weather conditions4 ,the dimensions of such a flue may be calculated by the formula given or the area may be taken from the table to correspond with required conditions4 ,in all cases flues should be made ample in size1 as they must often do their maximum work under the poorest conditions for the production of good draft4 ,the amount of air discharged from the flue as given in the table is due to the gravitational effect alone4 ,the suction produced by the wind adds in a very large degree to the amount of air discharged4 ,the quantity of air that will flow from a #cj-;foot flue1 by reason of the suction of the wind1 blowing #g miles per hour is equal to the same flue working by gravity with a temperature difference of #bj4 ,with a wind velocity of #g miles per hour and a temperature as given1 the capacity of the flue is doubled4 ,it is easy1 therefore1 to understand why the rate at which fires burn is so greatly increased by high winds4 ,at the time of very high winds1 a chimney flue will carry away three and even four times the volume discharged at the time of atmospheric calm4 ,cost of ,ventilation4--,the cost of good ventilation is often looked upon as prohibitive1 because of the expense in heat necessary to keep the inside atmosphere at standard purity4 ,cost of ventilation is determined by analysis of the known conditions and calculations made of the amount of extra heat necessary to warm the greater volume of air4 ,the common practice of estimating the quantity of heat used in any form of heating or ventilation is by reference to the ,b4t4u4 used in producing the desired condition4 ,this unit1 as has already been stated1 is the amount of heat necessary to change a pound of water1 #a;,f4 ,in considering the cost of heating the air for ventilation1 it must be borne in mind that the heat used in raising the temperature of the air contained in an enclosure is only a part of that necessary for warming the building4 ,most of the heat used goes to keep up the loss due to radiation and conduction which goes on from the windows1 the walls and other parts of the building that are exposed to the outside cold4 ,the material of which the building is composed must be heated and in turn radiates its heat to the colder outside air4 ,the quantity of heat necessary to change the temperature of a definite amount of air is easy of calculation4 ,the problem is that of determining the number of heat units required to warm the necessary air to suit the average condition of weather4 ,we will assume that the house is heated to the normal temperature #gj1 and that the additional cost of heating the air for ventilation over the amount thus expended is the cost of ventilation4 ,assuming that the house is so constructed that it is possible to supply air at the rate of #ajjj cubic feet per hour to each person of a family of five1 this condition will necessitate #ejjj cubic feet of air per hour or #abj1jjj cubic feet of air per day4 ,the house is such that #aj tons of coal are required per year1 at a cost of #aj per ton4 ,the period of winter weather will be considered #e months of #cj days each4 ,this will be #aej days1 during which the fuel for heating the house will cost #ff-b_/c cents per day4 ,the average temperature of the outdoor air during the entire period will be assumed to be #bj;,f41 thus requiring the air for ventilation to be changed #ej in order to raise it to the normal temperature1 #gj4 ,the weight of a cubic foot of air at #gj is practically #j4jge pound4 ,the #abj1jjj cubic feet of air used per day will1 therefore1 weigh #j4jge #abj1jjj #ijjj pounds which must be raised #ej in temperature4 ,in order to express in ,b4t4u4 the necessary heat required to produce the change of air temperature1 the quantity of air is best stated in an equivalent amount of water4 ,the specific heat of air is #j4bcg2 that is1 the amount of heat necessary to change a pound of air #a is #j4bcg of the amount used in changing #a pound of water #a4 ,the #ijjj pounds of air expressed as an equivalent amount of water will then be3 #ijjj #j4bcg #bacc pounds of water4 ,this amount of water raised #a is equivalent to raising #abj1jjj cubic feet of air #a4 ,now the average change in the temperature of the air is #ej1 so that #ej #bacc will be the number of heat units used4 #ej #bacc #ajf1fej ,b4t4u4 ,that is1 #ajf1fej ,b4t4u4 will be required to heat the air for ventilation one day4 ,in order to express this amount of heat in terms of fuel consumed1 it will be assumed that the coal contained #ad1jjj ,b4t4u4 per pound1 this being a fair valuation of good coal4 ,the average house-heating furnace will turn into available heat about #ej per cent4 of the fuel burned4 ,this value is taken from house-heating fuel tests made at the ,iowa ,state ,college4 ,the available heat in each pound of coal then will be #gjjj ,b4t4u4 #ajf1fej #gjjj #ae4b pounds of coal4 ,that is1 #ae4b pounds of coal per day must be burned in order to furnish #ajjj cubic feet of air per person each hour at the desired temperature4 ,at #aj a ton of #bjjj pounds1 the fuel costs #a_/b cent per pound4 ,the cost of ventilation is1 therefore1 #a_/b #ae4b #g4fj cents a day1 not an extravagant amount for good air4 ,it is evident that with the use of hot-air furnaces which take their entire amount of air from outdoors1 the extra amount of heat necessary for this improved quality of atmosphere is very well expended4 ,the use of ventilating devices adds only a relatively small amount to the total cost of heating and provides for the well-being of the occupants of the house--in the form of good air--an amount of healthfulness impossible of calculation4 ,the best ventilation is attained where a constant supply of fresh air is admitted to the house at points from which the best circulation may be secured and equal quantities of vitiated air are removed from the different apartments4 ,it is understood that in the process of natural ventilation the desired condition can only be approximated and that the permissible ventilation appliances are so placed as to give results such as to permit the air to follow the natural laws that must prevail4 ,if the house is heated by stoves1 the outside air is best admitted near the ceiling1 so that the cold air on entering may come into contact and mingle with the warmest air in the room4 ,the circulation will by this method be effected by gravity4 ,in the use of the hot-air furnace1 the air supply--as has already been explained in the figures on pages #ee and #eh--;is brought from the outside1 where after being heated it enters the rooms through the registers placed near the floor4 ,being warmer than the air in the room1 it tends to quickly rise4 ,the currents set up by its motion help to produce a uniform temperature and to diffuse the new air through the entire space4 ,the more evenly the air is distributed the more uniform will be the condition of temperature of the room4 ,in hot-water and steam heating1 the direct method of heating in ,fig4 #bi and the indirect method of ,fig4 #cj show two forms of apparatus for admitting air to buildings that are quite generally employed for ventilation of dwellings4 ,in the use of all such devices for ventilation purposes1 there should be provided means of escape of air corresponding in amount to the fresh air admitted4 ,the exhaust air vent should be located near the floor to bring about the best results4 ,the degree of success attending the use of such apparatus will depend on the amount of care taken1 to suit the position of the dampers to the prevailing weather4 ,illustration3 ,,fig4 #afe4--,the ,wolpert air tester2 an instrument used to determine the quality of air4 ,the ,wolpert ,air ,tester4--,the purity of air is expressed by quantity of carbonic acid gas included in its composition4 ,in order to determine the degree of purity of any atmosphere the amount of contained gas must be determined4 ,this is accomplished by use of simple apparatus that may be successfully operated by those who are unacquainted with chemical analytical methods4 ,the process is due to chemical action but the manipulation of the required apparatus is purely mechanical4 ,fig4 #afe shows the ,wolpert air tester which is a form of this apparatus that has given general satisfaction4 ,the results attained by its use are approximate but sufficiently exact for all practical purposes4 ,the apparatus consists of a graduated glass tube in which fits a rubber piston mounted on a hollow glass rod1 through which the sample of air is admitted to the tube4 ,the chemicals used for absorbing the carbonic acid gas are furnished with the instrument but may be replenished without difficulty4 ,directions for its use are furnished with the tester that may be readily followed after a trial4 ,the results obtained are read directly from the side of the tube4 ,the tester may be obtained from any dealer in chemical or physical apparatus4 ,illustration3 ,,fig4 #aff4--,thermostat regulator and motor-valve attached to a radiator4 ,pneumatic ,temperature ,regulation4--,pneumatic temperature regulation is very generally used in large and complicated heating systems1 because of its positive action and completeness of heat control4 ,this method of heat regulation utilizes the energy of compressed air1 with which to open and close the valves of the radiators4 ,it may be adapted to any mode of heating and can be used with any size of plant1 but is particularly suited to extended systems4 ,the radiators1 providing heat for any particular space1 are under control of separate thermostats1 which by means of motor valves admit heat only as required4 ,a motor1 operated by compressed air1 is attached directly to each radiator valve4 ,any change in temperature of the room causes the thermostat to correct in the radiator the required amount of heat4 ,with this method of regulation the temperature-controlling element of the thermostat1 like that of the electro-thermostatic system1 is a sensitive part1 which by expanding and contracting with the heat and cold directly controls the heat in any part of the building4 ,the motive power for opening and closing the valves of steam or hot-water radiators or for operating the dampers in a hot-air system is supplied by compressed air4 ,the air supply is furnished by an air compressor which automatically stores air under pressure in a pressure tank1 from which is drawn the necessary energy1 as occasion demands4 ,the air is conducted to the motors through small pipes which are connected with the regulating elements and also with the motors4 ,the function of the thermostat is to so govern the air which enters the motor as to correct any change in the temperature of the rooms4 ,this it does by opening and closing the valves as occasion demands4 ,in ,fig4 #aff is shown the arrangement of the thermostat ,t as it appears on the wall4 ,air from the supply tank is conveyed by the pipe ,a through the thermostat ,t to the motor valve ,v attached to the radiator4 ,the function of the thermostat is that of so controlling the radiator valve by means of the motor ,v that the radiator will give out just sufficient heat to keep the room at the desired temperature4 ,a closer view of the thermostat is given in ,fig4 #afg4 ,illustration3 ,,fig4 #afg4--,outside view of thermostat as it appears in use4 ,the thermostat illustrated in ,fig4 #afg is that employed by the ,national ,regulator ,co4 ,the drawing shows the exterior and interior construction of the parts enclosed in the previous illustration4 ,the pipe ,c at the right and opening ,p at the left are the same as ,a in ,fig4 #afi2 likewise1 the pipe ,d connects at the opening ,m of the motor valve in ,fig4 #afi4 ,referring again to ,fig4 #afh1 the sensitive part consists of a tube ,a of vulcanized rubber4 ,it is the dark-shaded part in the left-hand drawing4 ,any change in the air temperature influences the length of this tube4 ,the changing length of the tube effects the air supply to close the radiator valve when the temperature rises above the desired amount and to reopen it when more heat is required4 ,a finely threaded screw passes through the plug ,h at the top and to this is secured the indicating disc ,x4 ,the bottom of this screw is cupped to receive the point of the rod ,k1 which connects with the piece ,l4 ,any change in length of the sensitive tube moves the valve lever ,o1 and thus opens or closes the air port ,g4 ,air under pressure is supplied by the pipe ,c1 connected to the air supply1 flowing into the thermostat through the filter ,p1 the restriction ,s1 the passage ,t1 and the port ,g4 ,the adjustment of the thermostat for different temperatures is provided for by the screw ,j through the top plug ,h1 and the indicating disc ,x4 ,the screw ,r in the connector ,q at the base of the thermostat is a needle valve which opens or closes the connection with the air supply1 and is used as an air shut-off valve when it is desired to remove the thermostat4 ,the screw ,s is a restriction valve which controls the supply of air to the thermostat1 and this screw is set so as to allow the air to pass in a restricted quantity4 ,illustration3 ,,fig4 #afh4--;,internal construction of the ,national ,regulator ,co4's thermostatic regulator4 ,when the temperature of the apartment has risen so as to expand the thermostatic element ,a1 the pressure on ,k and ,l is relieved and the spring ,n closes the port ,g4 ,the air admitted through the restriction screw ,s1 since it cannot escape through the port ,g1 accumulates in the passage ,y and pipe ,d1 filling the diaphragm and moving the valve into the position to decrease the supply of heat4 ,when the temperature of the apartment has decreased so as to produce pressure on the connecting rod ,k1 through the contraction of the thermostatic element ,a1 the port ,g will be opened by the valve lever ,o1 allowing the air in the pipe ,d1 together with that which flows through the restriction ,s1 to escape through the passage ,w to the atmosphere1 allowing no air to accumulate in the pipe ,d1 and thus permitting the spring at the diaphragm to actuate the damper or valve for more heat4 ,the amount of air released through the port ,g by the valve lever ,o varies the pressure accumulated in the pipe ,d and produces the graduated or intermediate action desired4 ,illustration3 ,,fig4 #afi4--;,cross-section of pneumatic radiator valve showing its internal construction4 ,illustration3 ,,fig4 #agj4--,pneumatic motor valve for automatic control of dampers1 etc4 ,a further application of air pressure in temperature regulation is that of the type of motor shown in ,fig4 #agj4 ,this device is intended to open and close dampers such as are used in the automatic regulation of temperature where heated air is used to warm the buildings4 ,the operation of the motor is the same as that which controls the steam valve4 ,the pressure exerted by the diaphragm is applied at ,a and the attachment to the damper is made at ,b4 ,the motors indicated at ,v and ,n in ,fig4 #agd and ,d in ,fig4 #age are examples of its application4 ,mechanical ,ventilation4--,draft ventilation produced by open windows1 flues and chimneys is influenced by extremes of temperature and by the force and changing direction of the wind2 it is1 therefore1 but imperfectly controlled4 ,the superiority of mechanical ventilation is generally recognized because the amount of entering air may be regulated to suit any circumstance and its temperature and humidity varied to conform to any desired atmospheric conditions4 ,mechanical ventilating plants are seldom employed in any but the more pretentious dwellings1 but their use has extended to a degree that they are occasionally installed in apartment buildings and their further application is likely to grow4 ,neither the cost of installation nor the expense of operation is prohibitive in dwellings of the better types4 ,mechanical ventilation is quite generally employed in school buildings1 auditoriums1 hospitals1 public buildings and others where means will permit1 and there is a universal recognition of the effects of the agreeably conditioned air4 ,mechanical ventilation may be accomplished by power-driven fans1 either by exhausting the air from the building or by forcing air into it1 and under some conditions a combination of the two methods is used4 ,illustration3 ,,fig4 #aga4--;,exhaust fan for induced ventilation4 ,illustration3 ,,fig4 #agb4--,ventilation apparatus in which is included the heater coils1 the fan and the motor4 ,the exhaust method of ventilation is that in which air is blown out of the building by a fan2 and the supply1 to replenish that taken away1 is conducted into the building through ducts prepared for the purpose4 ,in some cases the induced air supply leaks into the rooms through the joints in the doors and windows1 and through the accidental crevices4 ,in ,fig4 #aga is shown a simple exhaust fan installed to produce such a change of air4 ,it is suitable for kitchens and other places where it is desired to eliminate smoke or gases rather than to produce a supply of air4 ,with this apparatus the air of the room is blown out by the rotating fan and new air to take the place of that exhausted is drawn in at any convenient opening4 ,the ,plenum ,method4--,that form of mechanical ventilation by means of which air is forced into the rooms is known as the plenum method4 ,it is the most positive means of air supply because its action is attended by a slight pressure above the outside air2 it is continuous in action and the amount of entering air is under control4 ,the escape of the expelled air is made through vent flues especially constructed for the purpose4 ,ventilation ,apparatus4--,fig4 #agb illustrates the form of apparatus used for ventilating buildings where no attempt is made at washing or humidifying the air4 ,enclosed in a sheet-iron case ,c is a fan which is driven by the electric motor ,m4 ,the capacity of the fan1 for the delivery of air1 is made to suit the requirements of the building4 ,in this case the fan is secured to an extension of the armature shaft of the motor4 ,connecting with the case which encloses the fan is another sheet-iron box ,h1 containg coils of heating pipe4 ,the heating apparatus is designed to change the temperature of the entering air to suit the requirements of the building4 ,this represents the draw-through or induced-draft type of ventilation apparatus4 ,the air delivered by the fan induces a flow of outside air which is drawn through the heating coils and discharged through the opening ,e4 ,at this point it enters the main ventilation duct from which it is distributed by branch conduits throughout the building4 ,the temperature of the air sent out from the fan is regulated by the steam valves of the heater coils to suit the prevailing conditions4 ,under some installations of this character the ventilating air is made to furnish the heat necessary to warm the building as well as to provide its air supply4 ,as ordinarily used1 however1 the temperature of the ventilating air is the same as that of the room4 ,the method of conveying air to the various apartments depends entirely on local conditions4 ,the conduits may be made of sheet iron1 placed to suit the existing conditions2 but when a building is constructed with a ventilating plant in view as a part of the building equipment1 it is customary to make the ducts part of the partitions4 ,in brick buildings the ducts are constructed1 so far as it is practicable1 in the walls4 ,these ducts are made in size and arrangement to suit the amount of air required for each room4 ,when the plant is put into operation each duct is tested with an anemometer which indicates the velocity of the entering air4 ,the calculated amount of air1 determined by the velocity and area of the entering column1 when compared with the necessary quantity demanded for good ventilation1 gives the efficiency of the system4 ,air ,conditioning4--,in addition to the possibility of a constant supply of air1 a combination of the exhaust and plenum methods admits of air purification4 ,with such a plant1 the air may be washed free from all suspended dust or gases and moistened to any degree of humidity4 ,the process of washing and humidifying air is known as air conditioning4 ,apparatus for air conditioning is made in a variety of forms to produce any desired extent of air purification and any degree of humidity4 ,the plant may be regulated by hand or it may be made entirely automatic in its action4 ,air-conditioning plants may be arranged to produce air that is purified1 humidified and warmed during winter weather and in summer the hot humid atmosphere may be cooled and dehumidified to a temperature and percentage of moisture that is most agreeable4 ,conditioned air is often used in manufactories1 not for the purpose of supplying good air to the employees but because of the effect of the atmospheric air on the products4 ,the manufacture of textile fabrics often demands a constant atmospheric humidity in order that the material produced may be uniform in grade2 this is particularly true in the making of silks4 ,various manufactories require an atmosphere free from lint and dust in order that the best quality of material may be produced4 ,the air for ventilation in such places is washed free from all suspended matter before being sent into the building4 ,in ,fig4 #agc is indicated an application of apparatus similar in construction to that just described4 ,the arrangement of the parts is such as to produce a ,plenum hot-air system of ventilation and temperature regulation4 ,the plant occupies a room in the basement and the drawing shows the method of heating1 together with the plan of distribution4 ,the air duct leading to the room above furnishes an example of the manner of admitting the warmed air to the rooms4 ,the dampers ,c1 ,c1 etc41 are controlled by separate motors4 ,the motor ,m is under the control of the thermostat ,t in the room above4 ,any change of temperature in the room is corrected by the damper to admit cold or warm air as is desired4 ,illustration3 ,,fig4 #agc4--,plenum hot-blast heating system with temperature regulation4 ,the power-driven fan ,f draws in outdoor air from an opening ,a1 through a set of heater coils ,h1 in which it is raised considerably in temperature4 ,the heater in this case is a coil of steam pipes4 ,the air--after being warmed--is taken into the fan and from it may be sent through a second set of coils ,h1 to receive additional heat1 or if already sufficiently warmed the air from the fan may pass under the second set of coils and receive no heat from them4 ,under the first heater coil is also a bypass which may be opened by the motor ,n to admit cold air that is drawn directly into the fan4 ,the movement of the air through these bypasses is under control of the thermostat1 which causes the motor ,n to open or close the bypass to suit the temperature of the room4 ,when the bypass is opened the steam is shut off from the heater coils4 ,examination of the drawing will show that the air from the fan may pass through a second heater ,h1 to the place marked warm air1 or it may pass under the heater to the compartment marked cold air4 ,the amount of warm and cold air which enters the duct is regulated by the position of the dampers ,c4 ,the position of the dampers ,c1 which is controlled by the motors ,m1 is made to take amounts of cold or warm air to produce the desired temperature in the rooms4 ,the motors ,c1 etc41 are under control of the thermostat in each room4 ,any change of temperature in the room will immediately affect the thermostat4 ,the effect on the thermostat will so change the air pressure in the motor that the valve ,c is moved to correct the difference in room temperature4 ,if warm air is demanded1 the motor changes the damper ,c to close the cold-air supply and take air that must pass through the heater coils ,h4 ,if only cold air is desired the damper will turn to shut off the course through the heaters and admit air directly from outdoors4 ,humidifying ,plants4--,mechanical ventilation plants that are intended for washing the air may be made up of parts similar to that of ,fig4 #agc1 but in addition to the apparatus shown provision is made for the air to pass through a chamber filled with a spray of water4 ,the air in passing through this spray is washed free of dust and at the same time absorbs water necessary for its desired humidity4 ,the humidity of air may be increased by the addition of moisture or decreased 7dehumidified7 by raising its temperature1 thereby increasing its capacity for containing moisture4 ,suppose that air at #ej is saturated with moisture2 it will contain practically #d grains of water per cubic foot4 ,if now the temperature of the air is raised to #gj1 the same amount of air is capable of containing #h grains of water and is1 therefore1 only #ej per cent4 saturated4 ,humidification is accomplished in air-conditioning plants through one of two general methods3 by the evaporation type of apparatus1 in which the passing air absorbs moisture from contact with a large area of water2 or the spray method1 in which the water is broken into a very fine spray by a specially devised nozzle and thus rendered easy of absorption by the air to be moistened4 ,a third method is sometimes employed1 in which steam is introduced into the air supply4 ,steam is already vaporized water and immediately becomes a part of the air without further change4 ,the steam type of humidifying plant possesses features that limit its application1 in that the steam in some cases may possess objectionable odor or includes the vapor of grease1 either of which would materially effect its use4 ,further1 the heat of vaporization liberated by the condensing steam is also a factor that influences the temperature of the air and in case of direct humidification must receive special attention4 ,vaporization as a ,cooling ,agent4--,the evaporation of water has a distinct value aside from humidifying the air1 in that the cooling effect is in direct proportion to the added moisture4 ,in the process of evaporation the heat necessary to change the water into vapor is taken from the surrounding air and the temperature is thus materially lowered4 ,in practical air-conditioning apparatus1 of the evaporative or spray types1 the process consists of drawing the outside air into a chamber filled with falling water that is broken up into drops like rain or spray4 ,in passing1 every particle of the air comes into contact with the water drops2 the almost invisible particles of dust adhere to the water and are carried away leaving the air washed clean4 ,in addition to freeing the air from dust1 the intimate mixture of the air permits of a ready absorption of the water1 which is taken up to any per cent4 of saturation4 ,after leaving the spray chamber1 the moisture-laden air passes through an eliminator in which any unabsorbed moisture is extracted4 ,it is possible for air to become not only completely saturated with water under the conditions encountered in a humidifying plant1 but in addition1 the movement of the air may carry along unabsorbed particles that are precipitated directly after leaving the spray chamber4 ,for this reason the air is passed through an eliminator4 ,the eliminator is composed of a series of irregular sheet-metal surfaces so arranged that the air is required to abruptly change its direction several times in its passage of a short distance4 ,the impact of the air against the surfaces and the centrifugal force exerted by the sudden changes of direction throw out the excess moisture and any remaining suspended matter the air may contain4 ,the saturated air from the eliminator passes through a heater where the temperature is raised to that of the rooms4 ,in the rise of temperature the air which is saturated is rendered capable of absorbing more moisture1 and hence has been dehumidified4 ,the rise of temperature and the corresponding decrease in relative humidity is intended to be such as to leave in the finished air the desired percentage of moisture4 ,air-cooling ,plants4--,the use of air-washing and humidifying plants so far mentioned has been confined to elimination of dust and the addition of moisture to air1 under winter conditions4 ,the same type of apparatus1 used in summer1 becomes a cooling plant1 and by observance of the necessary requirements may be used to produce agreeable atmospheric conditions during hot weather4 ,when used for such purpose the air is washed1 by passing it through falling water which frees it from dust and reduces its temperature4 ,it is then further cooled by passing over cold surfaces that take the place of the heaters used in cold weather4 ,the cooling surfaces are pipe coils kept cold by the contained water which comes from the water supply or from a refrigerating plant4 ,the temperature and humidity are thus changed to suit the requirements of the conditioned air4 ,during the hot weather of summer the most disagreeable atmospheric condition is that caused by humidity near saturation1 at a time of relatively high temperature4 ,under such conditions the cooling plant not only cools the air1 but causes a precipitation of the moisture on the cold surfaces which are kept below the dew-point4 ,the air is cooled and dehumidified to a point such that the conditioned air produces an agreeable atmosphere4 ,the regulation of the degree to which the air is cooled is accomplished by the same general methods as are used in heating4 ,humidity ,control4--,the method of regulating atmospheric humidity in a humidifying plant will be determined by the conditions under which it is intended to work4 ,there are a variety of means employed that may be used to bring about the same effects1 each of which is particularly suited to certain requirements4 ,the present object is to describe the essential features of airconditioning plants1 by use of illustrations representing each of the three methods mentioned above4 ,that of the ventilation of a school building under winter conditions will be taken as an example4 ,in ,fig4 #agd is shown a heating and ventilating system in which the air conditioning is accomplished by automatic regulators for both temperature and humidity4 ,the plant occupies a room in the basement1 and a room directly above illustrates the conditions that prevail in all of the other rooms of the building4 ,the principal features of the plant are the fan ,g1 which supplies the air2 the hot-air furnace ,h1 which furnishes the heat2 and the water spray ,s1 which provides the moisture with which the air is humidified4 ,illustration3 ,,fig4 #agd4--;,furnace blast system of heating1 with temperature regulation and humidity control4 ,the air is drawn in at ,a to a room in which a motor-driven fan ,g forces the supply through the heating apparatus into the building4 ,the air after leaving the fan passes through a cold-air duct ,c to the heating surfaces ,h to be warmed4 ,the air in passing over the heating surfaces is raised to a degree considerably above the temperature of the rooms4 ,the hot air leaving the heater ,h enters the tempered air chamber ,t through the passage ,k4 ,a damper ,m provides means for also admitting cold air to the chamber ,t directly from the fan4 ,the thermostat1 located at ,o1 is connected with a pneumatic motor ,v 7similar to ,fig4 #agj7 which regulates the supply of cold and hot air from ,k and ,m to suit the desired temperature of the air supply for the rooms above4 ,the arm of the motor ,v is so arranged that an upward movement opens the cold-air and closes the hot-air passages2 the downward movement produces the opposite effect4 ,the motor ,v thus controls the temperature of the air4 ,in this system the air is humidified by a direct water spray marked ,s in the drawing4 ,a part of the hot air from the heater ,h may escape through the damper ,w and absorb water on its way to the duct ,d1 which takes the air to the room above1 where it enters through the register ,e4 ,this air as it comes from the heater1 being hot1 will absorb a larger amount of water than the air could hold when cooled to room temperature2 for this reason only a part of the air supply is humidified4 ,the supply of the hot humid air is admitted to the duct ,d in such quantity as will produce the desired degree of humidity in the rooms4 ,the degree of room temperature is governed by the thermostat1 in the room1 which1 by means of the motor ,n1 controls the damper ,f4 ,this damper admits hot humid air and the tempered air from the chamber ,t in proper proportion4 ,at any time the humidity of the air in the room reaches the maximum amount for which it is set1 the humidostat1 through its motor1 closes the valve ,r1 which controls the water supply to the spray nozzle1 and the moisture in the air is reduced until a further amount is demanded4 ,with apparatus of this kind the temperature and humidity may be kept practically constant4 ,illustration3 ,,fig4 #age4--;,direct steam heating system with mechanical fan-blast ventilation1 temperature regulation and humidity control4 ,fig4 #age shows another arrangement of a similarly controlled plant in which steam is used for humidifying the air4 ,the air is admitted at ,a1 from whence it passes through a steam-heating coil ,s1 which raises it to a predetermined temperature4 ,the steam jets are arranged at ,h1 for providing the necessary moisture4 ,the humidostat through a motor valve ,v governs the amount of steam that is permitted to enter the humidifying chamber4 ,a thermostat located in the air duct at ,b controls the temperature of the air sent to the rooms by regulating the amount of heat given out by the steam coils ,s4 ,this control is made still more sensitive by use of a cold-air bypass4 ,the damper ,d is opened by a motor valve to admit cold air at the same time the steam is shut off from the heater coils4 ,in this plant the ventilating air is not intended to supply all of the heat to the rooms4 ,a thermostat on the wall controls the room temperature by regulating the amount of steam admitted to the radiators4 ,in the ventilating plant previously described1 all of the heat for the building is supplied through the ventilating system2 in the plant shown in ,fig4 #age1 the heating apparatus which warms the building is entirely separate and may be used when the ventilating system is inoperative4 ,the humidity is controlled by admitting saturated air to the warmer air of the rooms in such quantity as will produce the desired mixture4 ,the humidostat1 on the left-hand wall1 regulates the quantity of moisture by opening or closing the steam valve ,v as occasion requires4 ,another example of air-conditioning plant similar in principle to that just described is often called the dew-point system4 ,it depends for its action on a definite dew-point temperature at which the air is saturated with moisture1 before being heated to room temperature4 ,the air to be conditioned is first warmed1 by passing through a set of tempering coils1 to a degree at which it will contain the necessary moisture when saturated4 ,after saturation the temperature is raised by a second set of heating coils to the room temperature1 the moisture contained being right to give the desired humidity4 ,to illustrate1 suppose that it is desired to maintain a constant humidity of #ej per cent4 saturation at #gj;,f4 in the building4 ,the temperature at which the air must be saturated1 to contain #d grains of moisture per cubic foot1 is found in the table on page #aii to be #dh;,f4 ,the entering air must first be raised to that temperature by the tempering coils4 ,the air then enters the spray chamber where it absorbs moisture to saturation1 by contact with a multitude of water particles4 ,this saturated air now passes through a second set of heated coils and takes up heat sufficient to raise it to the finished temperature4 ,the dew-point temperature at which the air enters the spray chamber and the final temperature are kept constant by motor-operated valves which supply the heating coils with the necessary heat in the form of steam4 ,the motors are controlled by thermostats1 placed to measure the temperature of the air as it enters the saturator and the finished air as it enters the rooms4 ,if these conditions are now kept constant1 the finished air will be constantly #ej per cent4 saturated4 ,illustration3 ,,fig4 #agf4--,school building section showing a complete air-conditioning plant4 ,a plant of this character is illustrated in ,fig4 #agf4 ,the figure shows the exterior of the casings which enclose the tempering coils and saturator at ,a1 the eliminator at ,b1 and the heating coils at ,c4 ,this is another draw-through type of plant where a fan1 enclosed in ,d1 draws the air through the conditioning apparatus and forces it through the sheet-iron ducts ,e4 ,the passages in the walls--as indicated by the arrows--conduct the air through the register ,r1 into the room4 ,the register ,s represents the discharge duct through which the vitiated air is forced from the room4 ,in this system of air conditioning1 all of the ventilating air is to be saturated with moisture at a temperature such that when raised to room temperature will contain the desired percentage of humidity4 ,the saturator occupies the space between ,a and ,b4 ,a number of spray jets are arranged to fill the entire space with water drops that are moving in every direction4 ,the air1 as it passes1 must come into contact with the drops again and again1 until by repeated impact each particle is completely saturated and at the same time washed free from dust4 ,it has already been explained that the movement of the saturated air through a mass of spray will carry with it a considerable amount of unabsorbed water that must be taken out by an eliminator4 ,a section of the casing is broken out at ,b1 showing the eliminator plates4 ,the irregular surfaces of these plates repeatedly change the direction of the passing air1 and the suspended water or remaining solid matter is thrown against the surfaces where they adhere4 ,the moisture accumulates in drops of water that run down the plates to the bottom of the enclosure and finally into the sewer4 ,from the eliminator the air passes through the heating coils enclosed in ,c1 where it is heated to the necessary temperature for admission to the rooms4 ,the regulation of the temperature of the tempering coils and heating coils is accomplished as in the other plants described4 ,the thermostats with their motors operate the valves of the heaters to admit steam sufficient to keep constant temperatures at the different parts4 ,the humidity is maintained at a constant amount by saturating the air at a constant temperature and therefore no humidostat is required4 ,,chapter ,,xii ,,gaseous ,,and ,,liquid ,,fuels ,gaseous and ,liquid ,fuels4--,gaseous and liquid fuels used for domestic illumination and heating may be divided into three general classes--coal gas1 including carburetted water gas and producer gas and their various mixtures2 oil gas1 acetylene and gasoline gas4 ,of these the first is the most important as an illuminating gas1 while for industrial and domestic purposes producer gas is of no importance as a fuel gas4 ,gasoline1 acetylene and oil gases are generated and used to a remarkable extent in isolated dwellings as fuel and for illumination4 ,the value of any gas for domestic purposes will depend on the amount of heat that is produced when it is burned4 ,in the earlier days of its use coal gas was employed entirely as an illuminant and its value was expressed in illuminating power2 at the present time the standard often prescribed by regulation is that of its illuminating capability and is stated in candlepower4 ,there is1 however1 a tendency to establish the more consistent standard of expressing the value of gas by its heat value4 ,the reasons for this is the general use of mantle gas burners which depend on the heating value alone for their efficiency and the fact that coal gas is very extensively used for domestic fuel4 ,coal ,gas4--,coal gas is derived from the solid hydrocarbons of coal transformed into the more convenient1 gaseous form of fuel by means of distillation4 ,coal gas was first made by distilling coal from an iron pot over a fire and to some extent this is still the principle of the present practice4 ,the gas as it comes from the retort is subjected to a refining process of washing and scrubbing to remove the undesirable properties when it is stored in a large gasometer for distribution through pipes to its places of use4 ,coal gas is now used largely for fuel as well as for lighting4 ,unless the heating value of gas is regulated by law in any community and determinations of its quality are made regularly by some competent official1 the amount of heat contained in coal gas is entirely at the option of the manufacturer and manager's conscience4 ,the value as given in the table on page #beb is the number of ,b4t4u4 coal gas should contain4 ,the heating value of any gas is determined by burning the gas in a calorimeter made expressly for the measurement of the heat of combustion for each foot of the gas consumed4 ,all-oil ,water ,gas4--,in places where an abundant supply of cheap oil is available1 all-oil water gas has met with a great deal of favor4 ,it is made by atomizing crude oil by a blast of steam in a heated chamber where a combination of the vaporized oil and steam form a gas4 ,in general the gas resembles coal gas and as given in the table on page #beb is slightly higher in heating value4 ,pintsch ,gas4--,one of the commercial adaptations of oil gas is that of the ,pintsch process of compressing the gas in tanks for transportation4 ,in the ,pintsch process1 the gas is subjected to a pressure of #aj atmospheres--about #aej pounds4 ,this condensation permits a sufficiently large volume of gas to be stored in tanks as to make possible the lighting of railroad trains1 etc41 by gaslight4 ,the pressure of the gas is reduced by an automatic regulating valve to that required by the burner4 ,the flame is very much the same as that produced by coal gas4 ,blau ,gas4--,another commercial adaptation of oil gas is that known as ,blau gas4 ,in this process of storage the gas is subjected to #ajj atmospheres of pressure--about #aejj pounds4 ,this pressure is sufficient to liquefy the gas and as a result a large amount can be transported in a relatively small space4 ,according to ,fulweiler #a gallon of the liquefied gas will yield about #bh cubic feet of the expanded gas and there will remain a residue that may run up to #i per cent4 ,water ,gas4--,when the vapor of water is brought into contact with incandescent carbon1 the water is decomposed and sufficient carbon is absorbed to produce a fuel gas4 ,its manufacture depends on the decomposition that takes place when steam is blown into a bed of incandescent coal4 ,the gas made by this reaction is a water gas1 but due to the fact that when burned it gives a blue flame1 it is known as 8blue gas40 ,it has a heating value of about #cjj ,b4t4u4 per cubic foot1 and as compared with coal gas which gives #fbb ,b4t4u4 per cubic foot1 would be reckoned at about one-half its value as a heating agent4 ,blue gas may be rendered luminous by the addition of some hydrocarbon that will liberate free carbon in the flame when burned4 ,this is accomplished in the process of manufacture by the addition of vaporized oil4 ,the following table as stated by ,fulweiler gives the heating values of the gases commonly used for domestic purposes in ,british thermal units per cubic foot4 ,coal gas4 #fbb ,b4t4u4 ,carburetted water gas #fdc ,b4t4u4 ,pintsch gas4 #a1bgf ,b4t4u4 ,blau gas4 #a1gjd ,b4t4u4 ,all-oil water gas #fhj ,b4t4u4 ,acetylene gas #a1cej ,b4t4u4 ,gasoline gas4 #ead ,b4t4u4 ,oil gas #a1cbj ,b4t4u4 ,blue water gas #cjj ,b4t4u4 ,the cost and calorific values as computed by ,dr4 ,willard of the ,state ,agricultural ,college of ,kansas1 given below1 shows the relative values of various kinds of domestic fuels4 ,cost per ,cal4 per ,cal4 for pound ,gram #a cent cents ,wood1 #bj per cent4 ,h4,o4 #e4jj per cord #j4afg #b4c #g1fbj ,bitu4 coal #d4be per ton4 #j4bac #g4e #af1jji ,ant4 coal #ab4ej per ton #j4fbe #f4j #d1ced ,gasoline1 sp4 gr4 #fh #j4ad per gallon1 #e pounds4 #b4dgj #aj4j #a1hdf ,kerosene1 sp4 gr4 #hj #j4aa per gallon1 #f pounds4 #a4fej #aj4j #b1gec ,coal gas1 #a4ej per #ajjj cubic feet4 #c4ajj #bj4j #b1ibg ,alcohol1 #ij per cent41 #ej per gallon1 #g4adj #f4d #djd #g pounds ,electricity1 #j4ae per kilowatt-hour #eg4d ,the relatively high heat value of ,blau gas 7#agjd ,b4t4u47 and the fact that it may be reduced to a liquid form for transportation has resulted in the manufacture of small lighting plants that may be used in places where other forms of liquid or gaseous fuel are not desirable4 ,for transportation the gas is compressed in seamless1 steel bottles that contain about #bj pounds of liquid4 ,the charged bottles are shipped to the consumer and when empty are returned to the manufacturers to be refilled4 ,the entire plant--ready to be attached to the distributing pipes in the house--is contained in a steel cabinet4 ,the charged tanks are attached to a larger tank into which the liquid gas is first expanded4 ,this expansion is accomplished by an automatic valve that maintains a constant pressure in the large tank4 ,with this plant the lamps and burners of the stoves are operated as with city gas--no generating or preliminary preparation being necessary4 ,as soon as the bottles are exhausted they are replaced by others and the empty bottles are shipped to the factory to be refilled4 ,measurement of ,gas4--,when gas of any kind is purchased from a manufacturing company1 the amount used is measured by a gas meter1 located at the point where the gas main enters the building4 ,the readings of the meter are taken by the company at stated intervals and the amount registered is charged to the account of the consumer4 ,gas is sold in cubic feet and is so registered by the meter4 ,the price is quoted by the manufacturers at a definite rate per thousand cubic feet4 ,the difference between the last two readings of the meter furnishes the amount from which the gas bill is reckoned4 ,the occupants of a building are responsible for all gas registered by the meter and1 therefore1 should be acquainted with the conditions under which the gas is sold4 ,gas bills are often the subject of dispute because of failure to understand the period of time covered by the amount claimed2 again1 the varying length of days due to the season of the year has a pronounced effect on the amount of gas consumed4 ,lack of care in the economical use of gas is probably the most prolific cause of disputed bills4 ,the amount due for gas may at any time be checked by the consumer who keeps a record of the meter readings4 ,at any time the correctness of a meter is doubted1 arrangement may be made with the gas company to have it tested for accuracy4 ,this is done in the office of the company1 by attaching the meter to a measuring device--called a meter prover--in which a definite measured amount of gas is passed through the meter and comparison made with meter registration4 ,if it is found that the meter does not register correctly1 the gas company is in duty bound to make good the difference4 ,if1 however1 the meter is found to be correct1 it is customary to charge for the services of proving the meter4 ,gas ,meters4--,the gas meter as ordinarily used is shown in ,fig4 #agg4 ,in ,fig4 #agh the same meter is shown with the top and front exposed4 ,illustration3 ,,fig4 #agg4--;,gas meter4 ,illustration3 ,,fig4 #agh4--;,gas meter showing internal mechanism4 ,the meter is operated by the pressure of the gas which enters at the inlet pipe on the left-hand side of the meter as you face the index4 ,the gas from this pipe comes into the valve chamber and passes alternately into the diaphragms and their chambers1 as the valve ports ,v are opened and closed by the action of the meter4 ,the movement of the valve in opening the port which admits gas to the diaphragm closes the port to the chamber which has filled4 ,the gas entering the diaphragm expands it like a bellows and forces the gas out of the chamber1 through the middle part of the valve into the outlet pipe ,f4 ,while this action is going on1 the gas is entering the case compartment on the opposite side of the meter and also forcing the gas from its diaphragm through the opening ,f4 ,while the meter is in operation1 one of the diaphragms and one of the case compartments are filling while the others are emptying4 ,the movement of the diaphragm discs is transformed to the recording dial by the connecting levers shown at the top of the figure4 ,the movement of these levers is such as to produce a rotary motion to a tangent which is attached to a shaft that operates the recording dial4 ,the tangent is carried around in a circle by the action of the arms and its movement is registered on the index of each cycle of the diaphragms4 ,the measurement is accomplished by the displacement of a definite amount of gas with each movement of the discs2 first1 from the chamber and then from the diaphragms4 ,,how ,,to ,,read ,,the ,,index ,the index of a gas meter looks quite complicated1 but it is really a very simple contrivance4 ,the small circle on the top in ,fig4 #agg is for testing purposes only and need not be considered4 ,the dial of ,fig4 #agg is shown in ,fig4 #agg;,a4 ,the first circle1 marked #a thousand1 registers #ajj feet for each figure1 #ajjj feet for the entire circle4 ,if the pointer stood on #i it would mean #ijj cubic feet4 ,the second circle registers #ajjj for each figure1 or #aj1jjj for the entire circle4 ,when the pointer of the first circle has been around once1 it reaches #j on that circle1 but the hand on the second has moved to figure #a1 showing #ajjj feet used4 ,the process goes on until the pointer of the second circle has traveled around and stands at zero4 ,the pointer on the third circle1 however1 has moved to #a1 indicating #aj1jjj4 ,this explanation shows the general plan of the index4 ,a few minutes study of it will render the index as easy to read as the face of a clock4 ,of course1 the pointers do not always stand exactly on the figures as they move from figure to figure as the gas is used4 ,suppose your index stood like this3 ,illustration3 ,,fig4 #agg;,a4--,gas-meter dial4 ,it reads #chfjj cubic feet4 ,take the figure #c on the #ajj thousand circle1 the figure #h on the #aj thousand1 and the figure #f on the #a thousand1 and you have #cj1jjj1 #hjjj1 and #fjj1 or #ch1fjj feet4 ,to ascertain the quantity of gas used in the time elapsing between the readings of the meter1 subtract the quantity registered at the previous reading4 ,thus1 if the previous reading was #ch1fjj feet1 and the next reading #dj1ajj feet1 the pointers standing thus3 ,illustration3 ,,fig4 #agg;,b4--,gas-meter dial4 ,it reads #djajj cubic feet4 ,you have #dj1ajj ,subtract your last reading #ch1fjj and you find ------ that your bill should be for #a1ejj feet ,when #ajj1jjj feet have been passed1 the index is at zero2 that is1 all the pointers stand at #j1 and the registration begins all over again4 ,prepayment ,meters4--,in many places it is desirable to sell gas in small quantities and to prepay the amount for a given supply of gas4 ,this is accomplished by a meter such as that of ,fig4 #agi4 ,the meter is constructed much the same as the former but provided with a mechanism such that when a coin--usually #be cents--is deposited1 according to the printed directions in the instrument1 an amount of gas representing the proportional current rate is allowed to pass the meter4 ,the supply is cut off as soon as the amount paid for is used2 when in order to receive more gas1 another coin must be deposited as before4 ,illustration3 ,,fig4 #agi4--,the prepayment gas meter4 ,gas-service ,rules4--,the rules for the regulation of gas service are in many ,states under the control of a board or commission whose duty it is to form codes prescribing the measurement and sale of all public utilities4 ,the following form1 ,general ,order ,no4 #bj1 ,state ,public ,utilities ,commission of ,illinois1 gives an idea of the requirements in that ,state for the sale of coal gas4 ,,rule #c4 ,,request ,,tests4--,each utility furnishing metered service shall make a test of the accuracy of any meter1 upon written request by a consumer3 ,provided1 first1 that the meter in question has not been tested by the utility or by the commission within #f months previous to such request2 and second1 that the consumer will agree to accept the result of the test made by the utility as determining the basis for settling the difference claimed4 ,no charge shall be made to the consumer for any such test4 ,a report1 giving the result of every such test1 shall be made to the consumer4 ,,rule #d4 ,,adjustment ,,of ,,bills ,,for ,,meter ,,error4--,if on any test of a service meter1 either by the utility or by the commission1 such meter shall be found to have a percentage of error greater than that allowed in ,rule #aa 7see below7 for gas meters1 the following provisions for the adjustment of bills shall be observed4 7a7 ,fast ,meters4--,if the meter is faster than allowable1 the utility shall refund to the consumer a percentage of the amount of his bills for the #f months previous to the test or for the time the meter was installed1 not exceeding #f months1 corresponding to the percentage of error of the meter4 ,no part of a minimum1 service or demand charge need be refunded4 7b7 ,slow ,meters4--,if the meter is found not to register or to run slow1 the utility may render a bill to the consumer for the estimated consumption during the preceding #f months1 not covered by bills previously rendered1 but such action shall be taken only in cases of substantial importance where the utility is not at fault for allowing the incorrect meter to be in service4 ,,rule #aa4 ,,gas-,,meter ,,accuracy4--7a7 ,method of ,testing4--,all tests to determine the accuracy of registration of a gas service meter shall be made with a suitable meter prover4 ,at least two test runs shall be made on each meter1 the results of which shall agree with each other within one-half per cent4 7#a_/b74 7c7 ,allowable ,error4--,whenever a meter is tested to determine the accuracy with which it has been registering in service1 it may be considered as correct if found not more than two per cent4 7#b7 in error1 and no adjustment of charges shall be entailed unless the error is greater than this amount4 ,,rule #ae4 ,,heating ,,value4--,each utility furnishing manufactured gas shall supply gas which at any point at least #a mile from the plant1 and tested in the place where it is consumed1 shall have a monthly average total heating value of not less than #efe ,b4t4u4 per cubic foot1 and at no time shall the total heating value of the gas at such point be less than #ecj ,b4t4u4 per cubic foot4 ,to arrive at the monthly average total heating value1 the results of all tests made on any one day shall be averaged and the average of all such daily averages shall be taken as the monthly average4 ,,rule #h4 ,,railroad ,,commission ,,of ,,wisconsin4--,each utility furnishing gas service must supply gas giving a monthly average of not less than #fjj ,b4t4u4 total heating value per cubic foot1 as referred to standard conditions of temperature and pressure4 ,the minimum heating value shall never fall below #eej4 ,the tests to determine the heating value of the gas shall be made anywhere within a #a-mile radius of the center of distribution4 ,gas ,ranges4--,gas ranges and all other heaters using gas as a fuel are constructed to utilize the principle of the ,bunsen burner4 ,fig4 #ahj illustrates the type of burner used in the ,jewel gas range4 ,this represents the form adapted to the top burners for all direct-contact cooking or heating4 ,the burners are of different sizes and arranged as they appear in ,fig4 #aha4 ,this picture shows the top of the range as seen from above1 looking directly downward4 ,the gas supply pipe and individual valves for each burner are in position as they appear in front of the range4 ,illustration3 ,,fig4 #ahj4--;,detroit ,jewel one-piece1 star-shaped burner4 ,illustration3 ,,fig4 #aha4 ,,fig4 #ahb4 ,,fig4 #aha4--,showing top burners and valve attachment of a gas stove4 ,,fig4 #ahb4--,section showing arrangement of oven burners and lighter of a gas oven4 ,in operation1 the nozzles of the gas valves stand directly in front of the opening ,g1 in ,fig4 #ahj4 ,the stream of gas in passing into the burner induces a flow of air through the opening ,a4 ,the mixture of gas and air is such as will burn with the characteristic ,bunsen flame without smoke4 ,the oven burners are different in form but the individual flames are the same as those of the top burners4 ,they extend across the oven as shown in ,fig4 #ahb4 ,in this the top of the oven is removed and burners as seen are viewed from above4 ,the top burners are lighted by direct application of a burning match but the oven burners must be lighted by first igniting a special torch or 8pilot lighter40 ,the middle gas valve of ,fig4 #ahb is turned and the torch lighted1 then the other valves are opened and the jets are instantly ignited4 ,as soon as they are burning the pilot lighter is extinguished by turning its valve4 ,the reason for this special lighter is because of the possibility of explosion at the time of lighting4 ,the gas from the jets is mixed with air at the proper proportion to be violently explosive and if by chance the gas should be turned on a sufficient time to fill the oven with this explosive mixture and then lighted1 an explosion would be certain1 with every possibility of disastrous consequences4 ,all gas ovens should be lighted in a manner similar to that described4 ,lighting and ,heating with ,gasoline4--,the remarkable growth of modern cities1 the building of small towns in the west1 and the improvement in suburban and rural homes has created a demand for efficient means of illumination in the form of small household lighting plants4 ,the development and improvement in electric lighting has induced an equal1 if not greater1 improvement in gas lighting4 ,up to the year #ahge1 the open-flame gas jet represented the most improved form of city lighting4 ,then came electricity1 which for a time bade fair to supplant all other forms of illumination2 but the relative high cost of electric lighting1 even with the advantages it afforded1 was a stimulus to improvement in less expensive forms of illuminants4 ,the invention of the incandescent-mantle gas burner enormously increased the opportunities for gas lighting and opened an inviting field of endeavor4 ,in a relatively short time1 three distinct types of gasoline lighting plants for household illumination came into common use1 with a great number of different systems in each type4 ,as a means of economical illumination the only rival of any consequence to the small gasoline-gas plant of today is acetylene4 ,the dangers attending the use of these agents of illumination have been rapidly eliminated1 until today--when intelligently managed--they are fully as safe as any other means of artificial lighting4 ,gasoline plants are now in common use in cities where competition with all other forms of illumination require excellence in service to hold an established place4 ,in order that any mechanical appliance may be used with the best results1 its principle of operation and mechanism must be thoroughly understood4 ,in the case of gasoline plants1 not only familiarity with the mechanism should be acquired but an intimate knowledge of gasoline and its characteristic properties should be gained1 that the peculiarities of the plant may be more fully comprehended4 ,gasoline is the first distillate of crude petroleum2 that is1 in the process of separation1 the crude petroleum is distilled from a retort and the condensed vapors at different degrees of temperature form the various grades of gasoline1 kerosene1 lubricating oil1 paraffin1 etc4 ,the crude oil is placed in the still and heated2 the distillate that first comes from the condenser1 at the lowest temperature of the still1 is gasoline of a light spiritous nature4 ,as the process of distillation continues1 this part of the petroleum is entirely driven off and it is necessary to raise the temperature of the still in order to vaporize an additional portion of the oil4 ,there is no distinct line of separation between the gasoline that first comes from the condenser and that which comes over after the temperature is raised1 except that it is less of a spiritous nature and contains more oily matter4 ,as the temperature of the retort is gradually raised1 the distillate contains less and less of the spiritous and constantly more of the oily matter4 ,in order to grade gasoline for the market1 the standard adopted was that of relative density4 ,the distillations produced at various temperatures are mixed to produce various densities which form definite grades of gasoline4 ,the ,beaum hydrometer is a scale of relative specific gravities in which the different densities are expressed in degrees4 ,the highest grade of gasoline produced by the first distillation is #ij;,b42 that is1 the hydrometer will sink in the gasoline to #ij on the scale4 ,as the temperature of the retort is gradually raised1 the distillate becomes heavier and the next commercial grade is #hf gasoline4 ,the #hf gasoline contains a greater proportion of oily matter and a less amount of that of a spiritous nature4 ,the next commercial grade that is produced1 as the temperature is raised1 is #gf gasoline1 a still highly volatile spirit but containing more oil than the last4 ,this process is kept up until there is an amount of oil in the distillate that can no longer be termed gasoline1 when kerosene is distilled from the retort4 ,the following descriptions of gasoline and kerosene by ,b4 ,l4 ,smith1 ,state ,oil ,inspection ,chemist of ,north ,dakota1 gives a definite idea of their properties and the requirements of the law in their regulation and sale4 8,gasoline is formed by the condensation of vapor that passes off at comparatively low temperatures during the distillation of crude petroleum4 ,it has been common practice among refiners to collect as #8straight' gasoline all that distillate having a specific gravity above #fj;,b4 ,at present1 the name applies broadly to all the lighter products of petroleum above #ej;,b4 in gravity1 including products obtained from the #8casing-head' gases of oil wells1 by methods of compression and cooling1 and also the #8cracked' gasoline formed by the decomposition of heavier oils when subjected to high temperature and pressure4 8,it has been the custom to grade and sell gasoline according to #8high' or #8low' gravity test4 ,recent study and investigation has shown that specific gravity in itself is of very little value in determining the quality of a gasoline4 ,it may be taken as an index of other properties1 particularly its volatility1 if information as to its source and method of production are at hand2 but under present market conditions a specific-gravity determination is entirely inadequate4 ,the specific-gravity test alone may give a high rating to a poor gasoline and a low rating to a good one4 ,it has been discarded as a standard of comparison by the ,u4 ,s4 ,bureau of ,mines4 ,it indicates nothing definite about the quality of a gasoline and in many cases it does not even approximate relative values4 ,volatility1 that is1 the ease with which it vaporizes1 is the fundamental property that determines the grade1 quality1 and usefulness of gasoline4 ,the ,beaum test1 however1 must remain the standard for grading gasolene until a more definite measure is adopted4 8,the ,oil ,inspection ,law 7#aiag7 for the ,state of ,north ,dakota1 states1 that3 #8all gasolines1 sold or offered for sale in this ,state for household use1 shall1 when one hundred cubic centimeters are subjected to a distillation in a flask--as described for distilling of oil--show not less than three 7#c7 per cent4 distilling at one hundred and fifty-eight 7#aeh7 degrees ,fahrenheit1 and there shall not be more than six 7#f7 per cent4 residue at two hundred and eighty-four 7#bhd7 degrees ,fahrenheit1 which shall be known as the chemical test for gasoline sold or offered for sale in this ,state for domestic purposes4' 8,gasoline for household purposes1 as for use in cold-process lighting systems should contain not more than a very slight amount of constituents that do not vaporize readily4 ,it is obvious that a gasoline for cleaning or drying purpose should contain no oily or kerosene distillate4 ,on the other hand1 the gasoline for use in a gasoline stove or other generator1 where heat is employed in its vaporization1 may contain a considerable amount of the less volatile oils4 ,the amount of gasoline sold for household use is in very minor proportion to the immense quantity used for motor purposes4 8,no hard and fast line differentiates good motor gasoline from bad4 ,in fact standards of quality seem to be varying with advances in engine design1 so that what once was poor gasoline can now be successfully used4 ,improvement in carburetors seem to be keeping pace with the ever increasing amount of kerosene in the ordinary motor gasoline4 8,gravity test cannot be relied upon as indicating the kerosene content4 ,in the laboratories of the ,oil ,inspection ,department for the ,state of ,north ,dakota1 there have been examined two gasolines of the same gravity1 #ef4b;,b4 at #fj;,f41 but which contains #ca per cent4 and #fb per cent4 of kerosene respectively1 and their distillation range is quite different4 ,on the other hand1 there are other gasolines whose boiling range is nearly parallel and similar1 yet whose gravities are #ej4b;,b4 and #ei4b;,b4 respectively4 ,also a gasoline and a kerosene having a difference in gravity of but #a;,b4 and a difference of nearly #ajj;,f4 in the temperature at which they begin to boil and a difference at #bjj;,f4 in the temperature at which all had distilled over4 ,the so-called #8low'-test gasolines average between #ce per cent4 and #dj per cent4 kerosene4 ,the chief element of advantage in the so-called #8high'-test gasolines seems to be that they yield a maximum efficiency over a larger range of engine conditions4 8,we have a sample of gasoline sold as #8high'-test gasoline which contains #bi per cent4 of kerosene4 ,indeed it has a high ,beaum gravity 7#fc4gj7 compared to the average low-gravity gasolines on the market1 and it also contains a large amount 7#ad per cent47 of very easily volatile constituents4 ,such a product seems to be a blend of very light #8casing-head' stock with kerosene of low boiling range to give the #8high' gravity4 8,it is desirable that a gasoline should contain a certain percentage of very low-boiling constituents1 so that engines may start more readily1 especially in unfavorable conditions of weather or climate2 but a large proportion would be undesirable because of loss through evaporation and the liability of accidental ignition and explosion4 ,a reasonable amount of light volatile material would probably be about #c-a_/b per cent4 ,again a reasonably low percentage of the very less volatile constituents is desirable to insure complete vaporization at a not too high temperature1 say not more than #aj per cent42 but such a gasoline would be expensive4 ,the producers and refiners claim that the present immense demand necessitates the mixture of low-boiling kerosene constituents with the true gasoline fraction4 8,kerosene4--,the character of this fuel is best understood by comparing it with gasoline1 which it in general resembles1 except that it is much less volatile4 ,it is obtained from crude petroleum at a temperature just above that 7#cjj;,f47 at which gasoline passes off4 ,its chief use is as an illuminant in lamps4 ,it is also increasingly used as a fuel in cooking stoves1 small portable heaters1 and as a motor fuel for engines and tractors4 8,the laws of most ,states stipulate certain tests which kerosene must meet in order to be approved for general sale4 ,these tests include color1 flash point1 fire test1 sulphur determination1 and candlepower tests4 ,the ,north ,dakota ,oil ,inspection ,law 7#aiag7 specifies that the color shall be water-white when viewed by transmitted light through a layer of oil #d inches deep4 ,it shall not give a flash test below #ajj;,f4 and shall not have a fire test below #abe;,f4 ,such illuminating oils shall not contain water or tar-like matter1 nor shall they contain more than a trace of any sulphur compound4 ,the photometric test1 when burning under normal conditions1 shall not show a fall of more than #be per cent4 in candlepower in a burning test of not less than #f hours nor more than #h hours' duration1 consuming #ie per cent4 of the oil4 8,the flash point of an oil is the lowest temperature at which vapors arising therefrom ignite1 without setting fire to the oil itself1 when a small test flame is quickly approached near the surface in a test cup and quickly removed4 8,the fire test of an oil is the lowest temperature at which the oil itself ignites from its vapors and continues to burn when a test flame is quickly approached near its surface and quickly removed4 8,when oils containing sulphur are burned1 the sulphur is thrown off in the form of gaseous sulphur compounds4 ,because of their poisonous nature and their bleaching and disintegrating action on clothing1 hangings1 wall coverings1 etc41 it is obvious that to safeguard the health and preserve the furnishings of the home1 illuminating oils should contain not more than a trace of sulphur compounds1 and that their flash and fire limits should be high enough to insure safety in ordinary use in lamps and stoves4 8,the law further specifies as to the boiling limits of kerosene3 #8,it shall be the duty of the ,state ,oil ,inspector 444 to have chemical tests made 444 demonstrating whether or no such oils contain more than #d per cent4 residue after being distilled at a temperature of #egj;,f41 and shall not contain more than #f per cent4 of oil distilling at #caj;,f41 when one hundred cubic centimeters of the oil is distilled from a side-neck distilling flask' of certain specified dimensions4 8,this is to insure the kerosene against an excess of easily inflammable material of the gasoline range and thus render it dangerous to the user4 ,in addition it is to insure against an undue proportion of heavy constituent of lubricating oil distillate1 which would clog the wick and reduce the efficiency1 heating and illuminating value of the oil40 ,,lighting ,,and ,,heating ,,with ,,gasoline ,the extended use of gasoline as a lighting and heating agent1 has brought about the development of a great number of mechanical devices that are intended to furnish the house with an efficient source of illumination and at the same time provide the kitchen with a convenient and relatively inexpensive fuel4 ,these machines are generally simple in mechanical construction and so designed as to eliminate most of the dangers involved in the use of gasoline4 ,in operation1 they require a minimum amount of attention when suited to the purpose for which they are intended4 ,that the object of the plants is attained is attested by the great number in use and the degree of satisfaction afforded the users4 ,the three systems of gasoline lighting referred to above are known commercially by terms which are characteristic of the process involved3 #a4 ,the cold-process system1 in which the gasoline is vaporized1 at the temperature of an underground supply tank1 and after being mixed with the required amount of air is sent through the building in ordinary gas pipes exactly as in the case of city gas4 #b4 ,the hollow-wire system1 in which the gasoline is sent from the supply tank to the burners in a liquid form1 where it is vaporized by heat and the vapor mixed with the necessary air to afford complete combustion4 #c4 ,the central-generator or tube system1 in which the gasoline is sent to a central generator from a supply tank and there vaporized by heat1 at the same time being mixed with air in sufficient amounts to render it a completely combustible gas without further dilution4 ,,the ,,cold-,,process ,,gas ,,machine ,the gas machine of the cold-process type is so constructed that air is forced through a tank or carburetor1 containing gasoline and remains in its presence until saturated with gasoline vapor4 ,this saturated air is afterward diluted with additional air1 to produce a quality of gas that contains proportions of air and gasoline vapor which will produce complete combustion when burned with an open flame4 ,combustion is a rapid chemical change in which heat is evolved due to the union of carbon and oxygen4 ,if the carbon is completely oxidized1 the combination produces carbon dioxide 7,,co7 and the greatest amount of heat is evolved4 ,gasoline being a highly volatile liquid will vaporize at temperatures as low as -#aj;,f41 but as the temperature is higher vaporization will be more rapid4 ,in a confined space1 at relatively low temperature1 such as the carburetor of a gas machine1 the vaporization will at first be very rapid2 but after the more highly spiritous portion has been evaporated1 a considerable part1 even of the lighter grades1 will be vaporized very slowly4 ,in the cold-process machines1 only the lighter grades can be used with success and even then1 in inefficient machines1 a portion of the lesser volatile gasoline will have to be thrown away4 ,for this reason and for others that will appear later1 it is advisable to consider very closely the working properties of the entire plant4 ,in order to obtain gas that will always be of the same quality and at the same time use gasoline in an efficient manner1 the gas machine must be composed of three essential parts3 the blower1 the carburetor and the mixer4 ,the blower is that part of the machine which supplies air for absorbing the gasoline vapor and maintaining a constant pressure on the system4 ,it is usually made in the form of a rotary pump1 the motive power for which is a heavy weight4 ,the pump may1 however1 be driven by water pressure furnished by city water pipes or other water supply4 ,the carburetor is a tank which contains the supply of gasoline and is so constructed as to permit the air from the blower to most readily take up the gasoline vapor4 ,it should be so arranged that when the contained gasoline becomes old and less volatile1 the air may remain in its presence a sufficient time to become saturated by slow absorption4 ,the mixer is that part of the machine which regulates the amount of gasoline vapor contained in the gas entering the distributing pipes4 ,in order to satisfactorily perform its function1 it should be so arranged as to permit a constant amount of gasoline vapor to enter the mixture which composes the finished gas4 ,this amount should be such as to produce a bright clear flame in an open gas jet4 ,if the gas contains too great an amount of gasoline vapor1 the flame will smoke4 ,if too little gasoline vapor is present1 the flames will be pale and lacking in heat4 ,illustration3 #a ,carburator #b ,mixer #c ,blower #d ,weight #e ,gas ,range #f ,water ,heater #g ,water ,tank ,,fig4 #ahc4--;,cold-process system of gasoline lighting with kitchen range and water heater4 ,in ,fig4 #ahc1 the entire plant is shown in place4 ,it occupies a place inside the building1 usually in the basement4 ,in the figure the carburetor is marked #a2 the mixer #b stands at the end of the blower1 which is numbered #c4 ,the motive power of the blower is furnished by a heavy weight1 which is raised by a block and tackle1 the cord of which is attached to the drum and fastened to the shaft of the blower4 ,the force furnished by the weight #d drives the blower and maintains a constant pressure on the gas in the system4 ,the pipe #h conducts the air from the blower to the carburetor1 which is located underground1 below the frost line and #be or #cj feet away from the building4 ,illustration3 ,,fig4 #ahd4--;,carburetor for cold-process gasoline lighting plant4 ,the carburetor in this case is also the storage tank1 as shown in detail in ,fig4 #ahd4 ,the carburetor is divided laterally into two or more compartments1 depending on the size of the plant to be accommodated4 ,that shown in ,fig4 #ahd contains four compartments and is intended for a large plant4 ,the construction is such that the compartments are only partly filled with gasoline1 and arranged to permit the air from the blower1 which enters at the pipe marked air1 to pass through each compartment in succession1 beginning at the bottom1 in order that it may become completely saturated with gasoline vapor4 ,as an additional means of aiding the saturation of the passing air1 the compartments in this carburetor are provided with spiral passages through which the air must pass1 so that when it reaches the outlet pipe1 marked gas1 the air is completely filled with gasoline vapor4 ,the vapor-saturated air now leaves the carburetor by pipe #i1 in ,fig4 #ahc1 and enters the mixing chamber #b1 where it is mixed with the required amount of atmospheric air1 to make it completely combustible when burned at the burner4 ,the mixing chamber is shown in detail in ,fig4 #ahe4 ,the mixing is done automatically and the quality of the gas is uniform1 regardless of the varying conditions of the attending temperature and the quality of the gasoline in the carburetor4 ,the vitally important feature of any gas machine is1 that a constant amount of gasoline vapor be carried to the burners4 ,if the gas contains too great an amount of gasoline vapor1 a smoky flame will be the result2 if an insufficient amount of gasoline is present1 the flame will be pale and give out little light4 ,when freshly charged1 the gasoline in the carburetor will vaporize very readily1 and a large amount of air must be added to the gas to reduce it to the proper consistency2 but from old gasoline1 which has lost most of the highly volatile matter1 a smaller proportion of atmospheric air will be demanded4 ,for this reason1 a mixing regulator that will always deliver gas containing the same amount of gasoline vapor is necessary to give satisfactory service4 ,the mixer shown in ,fig4 #ahe accomplishes this office by reason of the specific gravity of the gas4 ,as the air in the carburetor takes up gasoline vapor1 its specific gravity is increased until the air is saturated2 and by adding the amount of atmospheric air necessary for complete combustion the weight is reduced to a definite amount which will be constant4 ,the required mixture will1 therefore1 always weigh the same amount4 ,the principle on which this mixer works is that described in physics as the principle of ,archimedes3 8that a body immersed in a fluid will lose in weight an amount equal to the liquid displaced40 ,in the application of the law1 the gas in the mixer is the fluid1 and the float--to be described--is the displacing body4 ,illustration3 ,,fig4 #ahe4--;,diagram illustrating the mixer of the ,detroit cold-process system of gasoline lighting4 ,the mixer in ,fig4 #ahe1 is shown cut across lengthwise4 ,the outside casing is indicated by the heavy black lines4 ,the gas which leaves the opening at the top--marked gas outlet--is a mixture of gasoline and air that may be used for exactly the same purpose and in the same manner as coal gas4 ,it may be used in open-flame gas jets or in the mantle gas lamps for lighting purposes and also as fuel gas for domestic heating4 ,the gas is distributed through the building in ordinary gas pipes which are installed as for any other kind of gas4 ,in ,fig4 #ahc the distributing pipes are indicated by the heavy lines4 ,the valve in the air inlet1 in the bottom of the mixer1 controls the amount of air to be admitted4 ,the entering gas from the carburetor being heavier than the desired mixture1 will raise the float and in so doing will open the air valve and allow the air from the blower to enter4 ,the float and valve are so adjusted that the desired mixture is attained when the balance beam is level4 ,any variation in the mixture will change its weight and the valve corrects the change whether it be too much or too little air4 ,the openings at the bottom1 marked gas inlet and air inlet1 are intended for the admission of the saturated vapor from the carburetor1 and the atmospheric air1 as required4 ,the float which fills the greater part of the inner space is a light sheet-metal drum1 that is tightly sealed and nicely balanced by a counterweight on the opposite end of the suspending bar4 ,the counterweight is made adjustable by the device marked movable adjusting weight--in the drawing--which permits the quantity of entering gas to be slightly changed as the gasoline in the carburetor grows old4 ,the adjustment of the counterweight to suit the gas given off from old gasoline in the carburetor1 and the occasional rewinding1 to elevate the blower weight1 is practically all the attention this plant requires4 ,it is a real gas plant which gives every service that may be obtained from coal gas4 ,,the ,,hollow-,,wire ,,system ,,of ,,gasoline ,,lighting ,,and ,,heating ,the hollow-wire system of gasoline lighting possesses the advantage of simplicity in construction and ease of installation that makes it attractive1 particularly for use in small dwellings4 ,the ease with which plants of this character are installed in buildings already constructed and its relatively low cost has made it a popular means of lighting4 ,the same principle as that used in the hollow-wire system is applied to portable gasoline lamps in which a remarkably convenient and brilliant lamp is made to take the place of the customary kerosene lamp4 ,small portable gasoline lamps are now extensively used for the same purpose as ordinary oil lanterns4 ,these lamps are convenient as a source of light1 make a handsome appearance and are relatively inexpensive to operate4 ,illustration3 ,,fig4 #ahf4--;,hollow-wire system of gasoline lighting with gravity feed4 ,the hollow-wire system as commonly employed is illustrated in ,figs4 #ahf and #ahg4 ,in the gravity type of the system as illustrated in ,fig4 #ahf1 the supply of gasoline is stored in the upper part of the house in a tank ,t and conducted to the burners below1 through a system of small copper tubes as indicated by the heavy lines in the drawing4 ,the same tank is used to supply the gasoline for the stove ,r in the kitchen and the lamps ,l in the different apartments4 ,the gasoline supply in this case1 is obtained entirely by gravity4 ,this type of plant is not approved by the ,national ,board of ,underwriters but its use is quite generally permitted4 ,the storage of gasoline in this form should be done with caution as carelessness or accident might lead to serious results4 ,with an arrangement of this kind the force of gravity gives the pressure which supplies the burners below but it would not be possible to use the lamps on the same floor with the tank4 ,illustration3 ,,fig4 #ahg4--;,hollow-wire system of gasoline lighting with pressure-tank feed4 ,where it is desired to use lamps on both floors1 a pressure tank is employed for supplying the gasoline to the lamps1 as indicated in ,fig4 #ahg4 ,in this plant the pressure tanks ,s1 ,t in the basement1 furnish the pressure which forces the supply of gasoline through the small tubes to the lamps ,l in the different rooms and also to the stove ,r in the kitchen4 ,the means of furnishing the pressure for supplying the gasoline to the burners may be a simple tank as that in ,fig4 #ahh1 or the more elaborate apparatus shown in the double tank of ,fig4 #ahi4 ,either style will give good results but the double tank requires the least attention in operation and is therefore more satisfactory in use4 ,the tank in ,fig4 #ahh is made of sheet metal of such weight as will safely withstand the pressure necessary in its use4 ,it is arranged with an opening ,e1 for filling with gasoline1 a pressure gage for indicating the air pressure to which the gasoline is subjected1 and two needle valves2 ,c1 for attaching an air pump and ,d1 to which the hollow wire is attached for distributing the gasoline to the places of use4 ,the tank is filled with gasoline to about the line ,a1 and then air pressure is applied with an ordinary air pump to say #bj pounds to the square inch4 ,this pressure will be much more than will be necessary to force the gasoline through the tubes but it is intended to last for a considerable length of time4 ,illustration3 ,,fig4 #ahh4--,simple gasoline pressure-tank4 ,,fig4 #ahi4--;,double-pressure tank for constant pressure service in gasoline lighting systems4 ,the principle of operation is that known in physics as ,boyle's law1 that 8the temperature being constant1 the pressure of a confined gas will be inversely as its volume40 ,that is1 if the tank is perfectly tight1 the pressure above the line ,a1 in the tank1 will gradually become less as the gasoline is used and when its level is at the line ,b1 where the volume is twice the original amount1 the pressure will be one-half what it was originally1 and will still be sufficient to force the gasoline through the tubes to the lamps4 ,it is evident that once the tank is charged and the air pressure applied it will require no further attention until a considerable part of the gasoline is consumed4 ,if at any time the pressure in the tank becomes too low to feed the lamps1 a few strokes of the pump will raise it to the required amount4 ,while the single tank does the required work1 its use is not perfect because the pressure is constantly varying4 ,if a lamp is set to burn at a definite pressure1 any decrease in the gasoline supply due to falling pressure will change the amount of light given by the lamp2 while the variation in the pressure of the single supply tank is not great1 a more perfect effect is attained in the double type of tank as that of ,fig4 #ahi4 ,the object attained in the use of two tanks differs with different manufacturers4 ,the tank shown in ,fig4 #ahc1 being intended to maintain a constant pressure on the gasoline1 is quite different from those described in ,fig4 #aig in use with the central-generator system of lighting1 to be described later4 ,in ,fig4 #ahi tank ,no4 #a is for air supply alone and tank ,no4 #b is the storage tank for gasoline4 ,between the two tanks is a pressure-regulating valve #f-g1 which keeps a constant pressure on tank ,no4 #b so long as the air pressure of the tank ,no4 #a is equal or greater than the other4 ,the gasoline in tank ,no4 #b will therefore be always under the same pressure and when the lamps are once burning the gasoline supply to each lamp will be a constant amount4 ,tank ,no4 #b is separated by the head #ac into two compartments1 marked #ah and #ai4 ,the connection between the two compartments is made by the valve #ae and the connection #af4 ,the gasoline supply for the lighting system is taken from the lower chamber at the valve marked #ag4 ,it is possible to refill this tank with gasoline while the system is working4 ,to accomplish this1 the air supply is cut off from tank ,no4 #a1 by closing valve #i and the valve #ae is closed to retain the pressure on the lower chamber of tank ,no4 #b4 ,the screw-plug is then taken from the tube #ab and the tank refilled4 ,the screw-plug is then returned to its place1 the valves #i and #ae are again opened and the regulating valve immediately restores the desired pressure4 ,the amount of pressure required on the system will depend on the height to which the gasoline is carried within the building4 ,the pressure is generally #a pound to each foot in height and to do the best work the pressure must be constant4 ,these plants may serve as a fuel supply for gasoline stove as indicated at ,r or any other source of domestic heating4 ,the usual gravity supply tank is replaced by the hollow wire through which is the gasoline from the tank in the basement4 ,mantle ,gas ,lamps4--,mantle lamps that are intended for using city gas are much the same in construction as those using the cold-process gasoline gas2 the styles of mechanism differ somewhat with manufacturers but all lamps of this kind possess the essential features that are common to all4 ,either of these gases may be used with open-flame burners1 such as ,fig4 #aic1 but since the introduction of mantle lamps1 the open-flame burners are rarely used for household illumination4 ,in the incandescent-mantle lamp1 the light is produced by heating to incandescence a filmy mantle of highly refractory material4 ,the higher the temperature to which the mantle of a lamp is raised1 the greater is the quantity of light produced4 ,the office of the burner is to produce a uniform heat throughout the mantle with the use of the least amount of gas4 ,as ordinarily furnished from the mains1 coal gas or gasoline gas is too rich in carbon to be used in mantle lamps without dilution4 ,when gas is burned in a mantle lamp1 it must contain sufficient oxygen--which is supplied by the air--to combine completely with the contained carbon and reduce it to carbon dioxide4 ,if insufficient air is supplied1 the lamp will smoke and the mantle will soon be filled with soot4 ,in the use of the various gases--made from coal1 gasoline1 kerosene1 alcohol1 etc4--as a fuel for the production of either heat or light1 the form of the burner in which the gas is consumed is the most important factor of the system4 ,without burners in which to generate a satisfactory supply of heat for the desired purposes1 mantle gas lamps would never have come into common use4 ,an understanding of the mechanism of the burners of a system is of first importance because of the possibility of the failure of the entire plant through an improper adjustment of the lamps4 ,if complete combustion of the gas is attained in the burner1 the greatest amount of heat will be evolved and the residue will be an odorless gas1 carbon dioxide 7,,co74 ,if the gas is not completely burned the odor of the gas is noticeable in the air4 ,incomplete combustion may be caused by an insufficient air supply1 which causes a smoky flame2 or if a larger flame is used than the burner is designed to carry1 some of the gas will escape unburned4 ,in either case the greatest amount of heat is not developed by the burner4 ,in most burners1 whether for heating or lighting--in which gas1 gasoline or alcohol is used as a fuel--the principle of operation is that of the ,bunsen tube4 ,one noticeable exception to this rule is the burners used with the central-generating systems where the ,bunsen tube is a part of the generator4 ,the gas generated from any hydrocarbon will burn completely1 only after being mixed with air or other incombustible gas1 in proportions such as will completely oxidize the carbon contained in the fuel4 ,in ,fig4 #aij the familiar laboratory ,bunsen burner affords an excellent illustration of the ,bunsen principle which forms a part of all burners using gas as a fuel4 ,the gas from the supply pipe issues from a small opening ,a into a tube ,b and by the force of its velocity the entering gas carries into the tube above it a quantity of air that may be regulated by the size of the opening4 ,if the gas is burned without being first mixed with air1 the flame will be dull and smoky but if air is admitted to mix with the gas1 an entirely different flame is produced1 the characteristic shape of which is shown in the figure4 ,illustration3 ,,fig4 #aij4--;,cross-section of ,bunsen burner showing characteristic ,bunsen flame4 ,the upper part of the flame ,c is known as the reducing flame2 it is blue in color and intensely hot4 ,the portion ,d is the oxidizing flame2 it is pale blue1 sometimes light green in color4 ,the lower part ,e is the gas before it begins to burn4 ,when burning in air1 the ,bunsen flame gives scarcely any light1 all of the energy being expended in heat4 ,in the gas stove where the burners are made up of a great number of small jets1 it will be seen that each jet shows the characteristic features of the ,bunsen flame4 ,the incandescent-mantle gaslight takes advantage of the heat generated by the ,bunsen flame and produces an incandescent light that has revolutionized gas lighting4 ,the flame of the ,bunsen tube is burned inside a mantle which is rendered incandescent by the heat4 ,the incandescent mantle was invented by ,dr4 ,auer von ,welsbach and was known for a long time as the ,welsbach light2 but improvements in the process of making the mantles1 brought other lamps of the same type on the market1 when it became known as the mantle lamp4 ,the first serviceable mantles were made in #ahia and from that time there has been a steady development in the gas-lighting industry4 ,the original mantles were made of knitted cotton yarn1 impregnated with rare earths and are still so made2 but the most durable mantles are now constructed from ramie or china grass4 ,after being knitted1 the mantles are impregnated with thorium nitrate1 with the addition of a small quantity of cerium nitrate1 and occasionally other nitrates4 ,the mantles are then shaped and mounted2 the fiber is burned out and the mantles are dipped in collodion to give them stability for transportation4 ,when placed in the lamp for use1 the collodion is first burned off and the remaining oxide of thorium forms the incandescent mantle4 ,one style of mantle is now being made in which the fiber is not burned out until it is placed in the lamp4 ,they are commonly used with gasoline lamps and give very good results4 ,illustration3 ,,fig4 #aia4--;,gas lamp with upright mantle4 ,the first incandescent-mantle gas lamps to be used were of the upright type1 such as is shown in ,fig4 #aia1 and for a long time they were the only mantle lamps in use4 ,while the upright mantle was a great improvement over the open-flame gas jet1 the lamp was not satisfactory because of the shadows cast by the fixture and from the fact that a large amount of the light was lost by being directed upward from the incandescent mantle4 ,with the development of the inverted type1 the mantle lamp was greatly improved4 ,in the use of lamps of any kind1 the desired position of the illumination is that in which the light is directed downward4 ,in the inverted type of mantle lamp this feature is accomplished and adds materially to the efficiency of the light1 because the rays are sent in the direction of greatest service4 ,the upright mantle lamps are still sold but by far the greater number offered for sale are of the inverted type4 ,the essential features of all gas lamps used under these conditions are shown in ,fig4 #aib1 which represents the common bracket type of lamp4 ,the gas-cock ,c1 connects the lamp with the gas supply ,g4 ,the gas escapes into the ,bunsen tube1 through an opening in the tip ,p1 which is so constructed that the amount of gas may be varied to suit the required conditions4 ,the brass screw nut ,n may be raised or lowered and thus increase or diminish the amount of escaping gas by reason of the position of the pin ,p4 ,if the nut is screwed completely down the pin closes the opening and the gas is entirely shut off4 ,when the lamp is put in place1 the burner is adjusted to admit the proper amount of gas and so long as the quality of the gas remains the same1 no further adjustment will be necessary4 ,any change to a richer or poorer gas will1 however1 require an adjustment of the burner to suit the mantle4 ,the amount of gas admitted is only that which will produce complete combustion in the mantle when combined with the required amount of air4 ,each burner must1 therefore1 be designed for the mantle in use4 ,illustration3 ,,fig4 #aib4--,mantle gas lamp showing details of ,bunsen tube4 ,as the gas leaves the opening above the pin ,p1 it enters the mixing chamber of the ,bunsen tube and air is drawn at the openings ,a-,a4 ,the mixture of the gas and air is accomplished in the tube leading to the mantle ,m1 where it is burned4 ,in all lamps of this kind1 there is a wire screen placed relatively as ,s1 the object of which is to prevent the mixture in the tube from exploding--in case of low pressure--and thus cause the gas to ignite and burn at the point of entrance to the tube4 ,at any time the pressure is insufficient to send a steady flow of gas into the tube1 the flame may 8flash back0 and ignite the gas at the point of entrance where it will continue to burn4 ,if1 however1 the screen is interposed between the gas supply and the burner1 the flame of explosion will not pass the screen4 ,in lighting the lamp1 the gas is turned on and a lighted match is held under the mantle1 the explosive mixture of gas and air fills the mantle and escapes into the globe1 in which it is usually inclosed4 ,as soon as ignition takes place the gas outside the mantle explodes with the effect that is startling but not necessarily dangerous4 ,the escaping gas continues to burn and heats the mantle to incandescence4 ,the amount of escaping gas is regulated by turning the gas-cock to produce the greatest brilliance with the least flame outside the mantle4 ,when used for household illumination1 the intensity of the light is such as to be objectionable1 when used directly2 but when surrounded by an opal glass globe to diffuse the light1 this is a highly satisfactory and economical means of lighting4 ,open-flame ,gas ,burners4--,gas jets of the open-flame type continue to be used to some extent but the more efficient mantle lamp has very largely supplanted lights of this kind4 ,in the past1 these gas lights were made in a great many styles and were known under a variety of trade names--the fish-tail burner1 the bats-wing burner and the ,argand burner--and were at times very generally used for gas lighting4 ,illustration3 ,,fig4 #aic4--,swing-bracket gas lamp with open-flame burner4 ,the common gas jet is illustrated in ,fig4 #aic4 ,the figure shows a bracket fixture which is generally fastened to a pipe in the wall4 ,a swing-joint at ,a permits the flame ,f to be moved into different positions4 ,the annular opening ,a permits the gas to pass to the jet in any position to which the light is moved4 ,the gas-cock ,c is a cone-shaped plug1 which has been ground to perfectly fit its socket4 ,it should move with perfect freedom1 and yet prevent the escape of the gas4 ,a slotted screw ,n permits the joint to be readjusted1 should the plug become loose in the socket4 ,the gas-tips ,t are made of a number of different kinds of materials and are commonly termed lava-tips but tips for gas and gasoline are frequently made of metal4 ,the bottom of the tip is cone-shaped1 which permits it to be forced into place in the end of the tube with a pair of pliers4 ,in size the tips are graded by the amount of gas which they will allow to escape in cubic feet per hour4 ,for example--a #d-;foot tip will use approximately #d cubic feet of gas per hour4 ,they are made in a number of sizes to suit the varying requirements4 ,the ,inverted-mantle ,gasoline ,lamp4--,the inverted-mantle gasoline-gas lamp shown in ,fig4 #aid1 furnishes a good example of mechanism and principle of operation1 when used with the hollow-wire system4 ,this is the bracket style of lamp but the same mechanism is used in other forms of fixtures4 ,lamps of similar construction are suspended from the ceiling1 either singly or in clusters2 they are also used in portable form4 ,illustration3 ,,fig4 #aid4--,sectional view of hollow-wire mantle gasoline lamp4 ,in ,fig4 #aid the lamp consists of a bracket ,h1 which is secured to the wall and through the stem of which the gasoline is conducted to the generator by the pipe ,w4 ,the arrows show the course of the gasoline and its vapor as it passes through the lamp4 ,on entering the generator the gasoline first passes1 the percolation1 through an asbestos wick ,b1 the object of which is to prevent the vapor pressure from acting directly on the gasoline in the supply tube4 ,the gasoline passes through the wick ,b1 largely by capillary action1 as it must enter the generator against a pressure greater than that afforded by the pressure tank4 ,the vaporization of the gasoline takes place in the tube above the mantle ,t1 from the flame of which it receives the necessary heat4 ,in lighting the lamp an asbestos torch saturated with alcohol is ignited and hung on the frame1 so that the flame may heat the generating casting ,n4 ,this process usually requires less than a minute1 generally about #dj or #ej seconds4 ,the torch supplies heat sufficient to generate the vapor for lighting the lamp1 but as soon as lighted the heat from the glowing mantle keeps the generator at the required temperature for continuous supply of vapor4 ,when the generator is sufficiently heated by the generating torch1 the needle valve ,n is opened by pulling the chain ,p4 ,this allows the gasoline vapor from the generating tube to escape at ,g into the induction tube ,r4 ,as the vapor enters the induction tube at a high velocity1 it carries with it the atmospheric air in quantity sufficient to render it completely combustible4 ,the opening ,g and the tube together form a ,bunsen burner4 ,the lamp is so proportioned as to give a mixture of gasoline vapor and air that will produce complete combustion in the mantle ,t4 ,the portion of the burner ,z1 through which the gas enters the mantle1 is a brass tip1 filled with a fluted strip of ,german silver1 so arranged that the gas on entering the mantle will be uniformly distributed and that the heat generated will render the entire mantle uniformly brilliant4 ,one feature of the lamp that requires special attention is the opening ,g1 through which the vapor from the generator is discharged into the induction tube4 ,this is a very small opening and occasionally becomes stopped or partly closed4 ,when this occurs the lamp fails to receive the necessary amount of gas1 and the light is unsatisfactory4 ,in this lamp1 the cleaning needle ,q is provided for removing the stoppage4 ,the needle is simply screwed into the opening and forces out the obstruction2 when it is withdrawn1 the opening is left free4 ,a more convenient device for accomplishing the same purpose is described in the portable lamp1 ,figs4 #aie and #aif4 ,portable ,gasoline ,lamps4--,the portable form of desk and reading lamps for the use of gasoline is made in a great variety of styles4 ,they are sometimes constructed to feed by gravity1 but by far the greater number are operated by the pressure method4 ,the portable lamp must be a complete gas plant1 with storage tank for the gasoline1 pipe system for conducting the gasoline to the lamp1 generator and burner4 ,to give satisfactory results1 the lamp must be capable of being lighted with the least degree of trouble and operated with the least amount of care4 ,the immense number of lamps of this kind that are sold shows that they meet all of these requirements and have proven satisfactory in operation4 ,their greatest attractiveness is their capability of giving a very large amount of light at relatively low cost4 ,fig4 #aie illustrates a portable gasoline lamp in which a convenient and efficient form of generating mechanism is combined with an attractively proportioned exterior4 ,the lamp works on the principle of the hollow-wire system1 the base serving as a storage and pressure tank1 the frame of the lamp acting as the tube for supplying the lamp with gasoline1 and the canopy containing the generating mechanism4 ,illustration3 ,,fig4 #aie4--,portable gasoline mantle lamp4 ,the tank in the base is filled with gasoline at the opening ,e1 which is made air-tight by a screw-plug4 ,the plug also contains an attachment piece for the air pump1 which furnishes the pressure to the gasoline4 ,the hollow standard reaches to the bottom of the tank and through it the gasoline is forced to the point marked ,a1 where the gasoline enters the generating mechanism4 ,this part of the lamp1 which is entirely concealed by the lamp canopy1 is shown in detail in ,fig4 #aif4 ,the reference letters in ,fig4 #aie apply to the same parts in the detail drawing4 ,the gasoline enters an asbestos-packed tube ,f at the point ,a1 and after percolating through the tube1 reaches the regulating valve at the point ,g4 ,the hand-wheel ,b opens and closes the valve1 and thus controls the entrance of the gasoline to the generating tube ,h1 where it is converted into the vapor4 ,the vapor now needs only the addition of air to make it the desired gas for illuminating the mantle4 ,the vapor from the generating tube escapes at the small hole ,k1 located directly under the mixing chamber ,m4 ,the supply of air is received through the tube ,c1 provided with a regulator1 which is readily accessible from the outside of the lamp4 ,the mixture of gasoline vapor and air is accomplished as in the other lamps described1 through the ,bunsen tube ,n4 ,in this case1 the ,bunsen tube is extended and increased in size to produce a mixing chamber of considerable volume4 ,the mantle is attached to the tip ,o4 ,the tip1 like the one already described1 is made of ,german silver and constructed to produce a flame that will entirely fill the mantle4 ,this lamp is provided with a special means of keeping the opening ,k free from accumulations4 ,the opening ,k1 through which the gasoline vapor escapes from the generator1 is very small and a slight stoppage will materially interfere with the flow of the vapor and thus impair the illuminating effect of the light4 ,a lever ,d operates an eccentric which engages the piece ,p1 to which is attached a pin that readily enters an opening ,k1 when the lever is turned4 ,any accumulation which may lodge in the opening is instantly removed and the needle returned to its place by a turn of the lever ,d4 ,illustration3 ,,fig4 #aif4--,sectional view of the generator for the ,american hollow-wire gasoline lamp4 ,central-generator ,plants4--,the central-generator or tube system of lighting with gasoline1 differs from the other methods described1 in the manner of generating and distributing the supply of gas to the lamps4 ,in the hollow-wire system each lamp generates its own gas supply4 ,with the central-generator system the gas for all of the lamps is generated and properly mixed with air in a central generator1 and the finished gas distributed through tubes to the different burners and there burned in incandescent mantles4 ,the gas as it leaves the generator requires no further mixing with air and therefore the burners are not of the ,bunsen type4 ,central-generator gas machines are made in a number of different forms by different manufacturers1 all of which are intended to perform the same work but differ in the mechanism employed4 ,the machines are simple in construction and as in the hollow-wire system are capable of using lower grades of gasoline than can be used with the cold-process plants4 ,the gas from a central generator may be used for all purposes for which gasoline gas is employed1 either for lighting or heating4 ,one difficulty in the use of the machine is the lack of flexibility when required for only a few lamps or varying number of lights4 ,although these plants are sometimes used for lighting and heating dwellings1 their use is limited1 for the reason that variation of the number of lights requires the generator to be regulated to suit the change in the gas supply4 ,the plants cannot be conveniently cut down to one light4 ,their most general use is that of lighting churches1 stores1 halls1 auditoriums1 etc41 where a variable amount of light is not demanded4 ,plants of this character are quite generally used for street lighting and for other outside illumination4 ,an efficient and simple plant of the central-generator type is shown in ,fig4 #aig4 ,the supply of gasoline is stored in a tank similar to that used with the hollow-wire system and placed in any convenient location4 ,the gasoline is conducted to the generator ,g1 through a hollow wire marked ,w4 ,the generator is inclosed in a sheet-iron box1 which is located at any convenient place in the building4 ,from the generator the gas is conducted through the tube to the lamps ,l4 ,in ,fig4 #aih is shown a diagram of the generator1 cut through the middle lengthwise1 in which all of the working parts are shown in their relative positions4 ,the reference figures designate the same parts of the generator in ,figs4 #aig and #aih4 ,in the process of generation the tank is filled with gasoline and pressure applied with the air pump4 ,the tanks described in ,fig4 #ahi might be used to advantage with this plant but the one shown in ,fig4 #aig is so constructed that the larger tank is used for storage of gasoline4 ,the gasoline is pumped directly into the smaller tank which alone is kept under pressure4 ,the pump ,p is enclosed in the large tank2 at any time it is desired to replenish the supply of gasoline1 it is only necessary to open the valve ,v and pump the necessary supply into the small tank4 ,this transfer may be done at any time without danger from escaping gasoline vapor4 ,illustration3 ,,fig4 #aig4--;,diagram of central-generator tube system of gasoline lighting4 ,the process of generating the gas is best understood by reference to ,fig4 #aih1 which shows the internal construction of the generator4 ,the liquid gasoline is admitted at the bottom through the small pipe ,w1 and then enters the space #d1 where it is vaporized4 ,the initial flow of gas is generated by heating the generator with an alcohol flame from the iron cup #a1 which surrounds the generator4 ,when the generator is heated the gasoline admitted to the generator is immediately vaporized2 when1 by turning the handle #f1 the needle valve #e opens a small orifice through which the heated gasoline vapor escapes into the tube #g1 above4 ,the blast of vapor issuing from the orifice carries with it air of sufficient volume to render the gasoline vapor an explosive mixture that when burned in the mantle will be reduced to ,,co gas4 ,when the initial heating by the alcohol flame is exhausted1 sufficient gas has been generated so that part of it may be used as a sub-flame in the gas burner #i1 to keep the generator heated4 ,the gas is conducted to the burner from the main tube #aa1 through the pipe #ab-ad1 as indicated by the arrows4 ,the burner #i surrounds the generator and the size of the flame is regulated by the valve #ae1 which is opened an amount sufficient to admit the necessary gas to the burner4 ,to start the generator1 the cup #a is filled with alcohol and ignited4 ,the needle valve #b is now opened by turning the hand-wheel #c1 admitting gasoline into the generator chamber #d1 where the vaporization of the gasoline takes place4 ,the flame from the burning alcohol will heat the generator in about a minute4 ,when the generator is hot1 the needle valve #e is opened slightly1 by turning the lever #f1 and the gasoline vapor under high pressure blows into the tube #g4 ,as the gasoline vapor is blown into the tube #g1 air is drawn in through the opening #h1 as indicated by the arrows4 ,the generator is practically a large ,bunsen tube from which the mixture of gasoline vapor and air is conducted to the burners by a connecting pipe4 ,illustration3 ,,fig4 #aih4--;,cross-section of the generator for the tube system of gasoline lighting4 ,gas machines operated on this principle are made to accommodate a definite number of lamps4 ,after the lamps are lighted1 the amount of gas is regulated to suit the number in use4 ,if at any time it is desired to reduce the number of lamps in operation1 the gas supply must be regulated to suit the lights left burning4 ,as an illustration1 suppose that a plant of ten lamps had been burning and that it was desired to reduce the number to six2 four of the lamps are extinguished by turning the levers ,c1 which control the gas-cocks4 ,the generator which had been supplying sufficient gas for ten lights will continue to produce the same amount until the lever #f is turned to reduce the supply of gasoline to the required amount for six lamps4 ,this is done by gradually closing the valve #e until the lamps again burn brightly4 ,in small plants the least number of lamps that will work satisfactorily at one time is three4 ,automatic regulators are made for plants of considerable size but do not satisfactorily control the gas when the lamps are reduced below three in number4 ,the gas from these plants may readily be used in kitchen ranges1 water heaters and other domestic purposes4 ,individual plants for operating ranges in restaurants and hotels are in common use4 ,the plants are subject to minor derangements that require correcting as they occur1 but as soon as the mechanism and characteristic properties of the plant are known1 the correction of any difficulty that may present itself is easily accomplished4 ,illustration3 ,,fig4 #aii4--;,gas lamp for use with the central-generator or tube system of gasoline lighting4 ,central-generator ,gas ,lamps4--,fig4 #aii shows the general construction and arrangement of the parts of the inverted-mantle lamp used with the central-generator system4 ,in outward appearance the lamp is much like any other inverted-mantle gas lamp1 but in arrangement of parts it is markedly different4 ,the gas-cock ,c is larger than that used with the ordinary fixture1 because the opening ,o must carry a larger volume of gas than that for supplying gas to lamps using the ,bunsen tube4 ,in the use of lamps with the ,bunsen tube1 the gas from the mains is mixed with approximately twenty times its volume of air2 with a lamp like that of ,fig4 #aii1 where the mixture has already been made in the generator1 the conducting tubes and the gas-cock must be relatively very large4 ,the screen ,s1 which corresponds to the screen ,s in ,fig4 #aib1 is quite as necessary as in the other lamp4 ,it not only assures a uniform distribution of the gas in the tube but it prevents the mantle from being broken when the burner is lighted4 ,if this screen is punctured1 the explosion which takes place when the burner is lighted will be sufficient to blow out the bottom of the mantle4 ,the burner tip ,t is practically the same as that used with other mantle lamps4 ,boulevard ,lamps4--,gasoline lamps for outside illumination may be constructed to operate with any of the systems described1 but the hollow-wire and the generator systems are most conveniently used1 because each post may be arranged as an independent plant4 ,for illuminating private grounds or public thoroughfares1 lamps such as are illustrated in ,figs4 #bjj and #bja are very generally used4 ,the lamp shown in ,fig4 #bjj is of the central generator type in which the storage tank and generator mechanism are located in the base of the post4 ,these lamps are also sometimes constructed with a time attachment in the base of the post1 arranged with a clock mechanism so that the light may be automatically extinguished at any desired time4 ,illustration3 ,,fig4 #bjj4--;,boulevard lamp with generator in the base of the lamp post4 ,illustration3 ,,fig4 #bja4--;,boulevard lamp operated by the hollow-wire method of lighting4 ,in ,fig4 #bja the lamp is of the hollow-wire type and as in the case of the other1 the supply tank is in the base of the post4 ,with this system it would be possible to supply several lamps from a common supply tank1 provided the hollow wire was protected against damage4 ,the lamps arranged to work on either system1 require the same amount of attention and are subject to the same derangements as those for inside service4 ,burners for gasoline stoves are made in a great variety of forms1 each having some special points of excellence that are used to recommend the sale of the stove4 ,the most essential feature of a gasoline stove is the burner1 since on its successful performance will depend the satisfaction given by the stove4 ,many self-generating burners have been devised which have met with a great deal of favor1 but the type of burner most widely used and the first to be devised for the purpose is the generating burner similar in principle to the generating gasoline lamp4 ,the burner is first heated from an outside source1 in order to generate sufficient gas to start the flame1 after which the heat from the burner will develop the gas supply4 ,with gasoline stoves of this kind1 the supply tank is elevated1 in order that the force of gravity may give sufficient pressure to send the gasoline into the generator while the flame is burning4 ,in the hollow-wire system the same type of burner is used1 but the gasoline is forced into the burner by the pressure in the tank4 ,illustration3 ,,fig4 #bjb4--,sectional view of the generator and burner of a gasoline stove4 ,in ,fig4 #bjb is shown a sectional view of the burner as it appears in the stove4 ,the supply tank1 or hollow wire from the pressure tank1 sends the gasoline into the tube ,a at the bottom of the stove1 to which several burners may be attached4 ,the tube ,b1 through which the gasoline percolates on its way to the generator1 is filled with moderately coarse sand1 or other material that is intended to prevent the gasoline from being forced out of the pipe by the pressure that is developed in the generator4 ,the pieces ,c-,c are perforated metal plugs that prevent the escape of the particles of which ,b is composed4 ,the generator is a brass casting ,d-,d which is firmly screwed to the top of the tube ,b4 ,a needle-valve ,e governs the discharge of the gasoline vapor at ,g1 where the vapor enters the tube ,h1 as indicated at ,k-,k4 ,the gasoline vapor enters the open ,bunsen tube ,h1 and with it is carried the air necessary to produce the required gas for complete combustion4 ,the piece ,n is the generating cup in which is burned the generating fluid--either gasoline or alcohol4 ,the gasoline from the pipe ,a percolates through the material in ,b and flows into the generator4 ,the needle-valve being closed1 the space ,d-,d fills with gasoline4 ,to light the burner1 the hand-wheel ,j is turned1 opening the needle-valve a sufficient length of time to allow the gasoline to fill the cup ,n with fuel for generating the initial volume of vapor4 ,a still better way is to fill the cup with alcohol1 because the burning alcohol does not fill the air with smoke and odors1 as in the case of gasoline1 when used for generating purposes4 ,the generating material having been ignited and burned out1 the generator is hot and filled with vapor4 ,the heated generator vaporizes a portion of the contained gasoline and forms sufficient pressure to force the remaining gasoline back through ,b into the supply tank4 ,the material of the tube ,b permits only a slow movement of the gasoline and prevents the possibility of surging in the generator4 ,the initial supply of vapor being generated1 the needle-valve may be opened and the gas lighted above the burner ,i-,i1 where it should burn in little jets at each opening with the characteristic ,bunsen flame4 ,it sometimes happens that the generator is not heated sufficiently1 by the generating flame1 to vaporize the necessary gasoline for starting the burner2 in this case liquid gasoline will be forced from the opening ,g1 and the burner will flare up intermittently in a red smoky flame4 ,when this occurs the burners must be regenerated4 ,gasoline ,sad ,irons4--,the use of gaseous or liquid fuel is always attended by an element of danger1 because of the possibility of accidental explosion4 ,the use of gasoline1 the most highly volatile of all liquid fuels1 has1 however1 come to be very generally used as a source of heat for domestic purposes4 ,the danger of accident in the use of gasoline as a fuel for heating sad irons is largely due to ignorance of the involved mechanism or carelessness in manipulation4 ,a knowledge of the principle included in their operation1 together with an observance of the possible cause of accident1 will reduce the element of danger to a negligible quantity4 ,the use of gasoline sad irons has come into favor because of their convenience and economy in operation4 ,these irons1 in common with the use of gasoline in its other applications of heating and lighting1 are made in a great many forms but the principle of operation is confined to two types4 ,illustration3 ,,fig4 #bjc4--;,gasoline flat-iron operated by a heated fuel tank4 ,illustration3 ,,fig4 #bjd4--;,gasoline flat-iron showing the position of the cover while initial charge of gas is being generated4 ,first1 those in which the gasoline is forced into the generator by the vapor pressure1 from the heated supply tank2 and second those in which the pressure is caused by pumping air into the supply tank after the manner of the hollow-wire system of lighting4 ,the first type of iron is illustrated in ,fig4 #bjc4 ,the same iron is shown in ,fig4 #bjd1 with the top in position for generating vapor pressure necessary to start the burner4 ,the body of the iron ,a is a hollow casting1 designed to receive the generator and burner in such position that the bottom portion of the iron may be uniformly heated4 ,the generator and burner are shown in detail in ,fig4 #bje1 in which a sectional view is given of the parts1 cut across lengthwise of the iron4 ,in starting the burner for use1 the tank is first filled--not quite full--of strained gasoline4 ,the precaution of straining the gasoline should be taken1 to prevent putting into the tank anything that will possibly choke the needle-valve4 ,alcohol is used for generating the vapor supply1 because the flame does not black the iron and fill the room with smoke as in the case when gasoline is used for the purpose4 ,when the alcohol is ignited1 the cover is placed in position as shown in ,fig4 #bjd1 so that the flame may heat not only the generator but also the tank4 ,the object of heating the tank is that the heated gasoline may furnish pressure with which to force the gasoline into the generator4 ,when the alcohol used for generating is almost burned out1 the valve ,f is slightly opened and the burner lighted4 ,illustration3 ,,fig4 #bje4--,sectional view of gasoline flat-iron generator and burner4 ,as shown in ,fig4 #bje1 the generator ,g is a brass tube1 inclosing the valve-stem ,g1 which terminates in the needle-valve ,v4 ,this valve regulates the supply of gas admitted to the burner and is operated by the hand-wheel ,f4 ,when the gasoline in the tank has been heated the necessary amount1 the vapor in ,g is allowed to escape through the valve ,v4 ,the vapor is discharged into the ,bunsen tube1 and with it the air is carried in through the openings ,e1 from both sides of the iron4 ,the burner is a brass tube1 slotted as shown at ,h1 through which the gas escapes1 forming a short flame of large area close to the part of the iron to be heated4 ,the size of the flame is regulated by the hand-wheel ,f4 ,the tank is entirely closed1 the plug ,p being provided with a lead washer to insure a tight joint4 ,the plug is further provided with a soft metal center which acts as a 8safety-plug0 in case of overheating4 ,should the iron at any time become too hot1 the soft metal center will melt and the released pressure in the tank will put out the burner flame4 ,the soft metal center may be renewed with a drop of solder4 ,in case the safety-plug at any time is melted1 the hot gasoline will spurt from the opening and immediately vaporize4 ,this of course would1 in a short time1 produce an explosive atmosphere which if ignited would be dangerous4 ,in case of accident the iron should be carried to the open air and the flame smothered with a cloth4 ,alcohol ,sad ,irons4--,irons of the same style are also made in which alcohol is used as a fuel4 ,the alcohol irons differ in construction from those using gasoline only in the amount of air that is mixed with the vapor4 ,in general appearance the two styles look very much alike1 but in the alcohol iron one of the intakes ,e is entirely closed and the other opening is partially closed4 ,illustration3 ,,fig4 #bjf4--;,gasoline flat-iron operated by an air-pressure fuel tank4 ,the operation of these irons is identical to those using gasoline1 but they are preferred by those who fear the use of that fuel4 ,in reality there is little difference in the danger attending the use of the two liquids4 ,it is only fair to say1 however1 that the use of any highly volatile fuel is attended with some danger when used carelessly1 but with a reasonable amount of care and a knowledge of the mechanism of the machine in use the danger is of minor consequence4 ,in ,fig4 #bjf is illustrated another style of gasoline sad iron1 the working principle of which is the same as those already described but the supply tank is not heated to give pressure to the gasoline in the tank4 ,in this iron the tank is located at one side of the iron and pressure is applied with an air pump as in the hollow-wire system of lighting4 ,the burner is generated after the manner of the others and operated in exactly the same manner4 ,the chief difference is that the possibility of excessive pressure through overheating is eliminated4 ,alcohol ,table ,stoves4--,in the ,united ,states the use of alcohol as a fuel has never been extensively employed because of the duty imposed on its manufacture by the ,federal ,government4 ,in #ahif this duty was removed from denatured alcohol and the cost was sufficiently reduced to permit a great extension in its use as a fuel4 ,denatured alcohol is any alcohol to which has been added any of the list of prescribed volatile fluids that will render the alcohol unfit for use in beverages and not materially change its heating value4 ,denatured alcohol is sold at a price that will permit its use in small flat-irons1 table stoves and other forms of burners where small amounts of heat are generated for convenience4 ,at the price of denatured alcohol as generally sold1 it cannot compete with gasoline and kerosene as a fuel4 ,in ,fig4 #bjg is shown a convenient and inexpensive form of table stove1 in which the vapor of alcohol is burned in practically the same manner as the vapor of gasoline in the burners already described4 ,the supply of alcohol is stored in a tank ,a1 and fed by gravity to the burner ,b1 the flame from which resembles that of the ordinary gasoline burner4 ,the generator ,g with the other essential parts are shown in detail in ,fig4 #bjh4 ,the reference letters indicate the same parts in the detail drawing as in ,fig4 #bjg4 ,illustration3 ,,fig4 #bjg4--;,alcohol vapor stove4 ,illustration3 ,,fig4 #bjh4--,sectional view of the generator and burner of the alcohol vapor stove4 ,the alcohol flows from the supply tank through the pipe ,c to the generator ,g1 which is a brass tube filled with copper wires4 ,the vapor for starting the burner is generated by opening the valve ,v and allowing a small amount of alcohol to flow through the orifice ,c into the pan ,p directly below the generator4 ,the valve is then closed and the alcohol ignited4 ,when the generating flame has burned out1 the valve ,v is again opened and the vapor which has generated in the tube escapes at the orifice ,c and enters the ,bunsen tube ,t1 7,fig4 #bjg7 carrying with it the proper amount of air to produce the ,bunsen flame at each of the holes of the burner4 ,as in the case of the gasoline burners the orifice ,c sometimes becomes clogged and it is necessary to insert a small wire to clear the opening4 ,with the stove is provided a tool for this purpose4 ,with stoves of this kind1 the supply tank must not be tightly closed1 because any pressure in the tank would cause it to become dangerous4 ,the alcohol is fed to the generator entirely by gravity4 ,the stopper of the tank contains a small hole at the top which should be kept open to avoid the generation of pressure should the tank become accidentally heated4 ,stoves of this kind may be conveniently used for a great variety of household purposes1 and when intelligently handled are relatively free from danger4 ,danger from ,gaseous and ,liquid ,fuels4--,all combustible gases or vapors1 when mixed within definite amounts1 are explosive4 ,the violence of the explosion will be in proportion to the volumes of the gas and the condition of confinement4 ,when gasoline or other volatile fuel is vaporized in a closed room1 there is danger of an explosion1 should the mixture of the vapor and air reach explosive proportions4 ,it is dangerous to enter a room with a lighted match or open-flame lamp1 where gaseous odor is markedly noticeable4 ,in case of danger of this kind the windows and doors should be immediately opened to produce the most rapid ventilation4 ,in the act of igniting the flame in a gas or vapor stove1 the lighter should be made ready before the gas is turned on4 ,explosions in gas and vapor stoves are usually due to carelessness in igniting the fuel4 ,it should be kept constantly in mind that1 if a combustible gas is allowed to escape and mix with air in any space and then ignited1 an explosion of more or less violence is sure to occur4 ,gasoline and kerosene are lighter than water and will float on its surface4 ,the flames from these oils are aggravated when water is used in attempting to extinguish them4 ,the burning oil floating on the surface of the water increases the burning surface4 ,burning oil must be either removed to a place where danger will not result or the flames must be smothered4 ,in case of a small blaze1 the fire may be extinguished with a cloth1 preferably of wool1 or if circumstances will permit1 with ashes sand or earth4 ,alcohol dissolves in water and may1 therefore1 be diluted to a point where it will no longer burn4 ,,acetylene-,,gas ,,machines ,acetylene is a gas that is generated when water is absorbed by calcium carbide1 after the manner in which carbonic acid gas is evolved when lime slakes with water1 but with the liberation of a larger amount of the combustible gas4 ,calcium carbide is a product resulting from the union of lime and coke1 fused in an electric furnace to form a grayish-brown mass4 ,it is brittle and more or less crystalline in structure and looks much like stone4 ,it will not burn except when heated with oxygen4 ,a cubic foot of the crushed calcium carbide weighs #afj pounds4 ,calcium carbide--or carbide as it is ordinarily termed--may be preserved for any length of time if kept sealed from the air1 but the ordinary moisture of the atmosphere gradually slakes it and after exposure for a considerable time it changes into slaked lime4 ,the carbide itself has no odor1 but in the air it is always attended by the penetrating odor of acetylene1 because of the gas liberated by the moisture absorbed from the air4 ,if protected from moisture1 calcium carbide cannot take fire1 being like lime in this respect2 it is therefore a safe substance to store4 ,it is transported under the same classification as hardware1 and will keep indefinitely if properly sealed4 ,a pound of pure carbide yields #e-a_/b cubic feet of acetylene1 but in commercial form1 as rated by the ,national ,board of ,fire ,underwriters1 lump carbide is estimated at #d-a_/b cubic feet per pound4 ,in the generation of acetylene1 exact weights of carbide and water always enter into combination1 i4e41 #fd parts of carbide to #cd parts of water1 and a definite amount of heat is evolved for each part of carbide consumed4 ,uncontrolled1 the gas burns with a bright but not brilliant flame and with a great deal of smoke1 but when used in a burner suited for its combustion it burns with a clear brilliant flame of a quality approaching sunlight4 ,while carbide is not explosive nor inflammable1 it may1 if it finds access to water1 create a pressure such as to burst its container1 and it is not impossible that heat might be generated sufficient to ignite the gas under such conditions4 ,that such condition would often occur is not at all probable4 ,when water is sprinkled upon carbide1 in quantity such that it will all be taken up1 the resultant slaked lime is left dry and dusty1 and occupies more space than the original carbide4 ,when more than enough water is employed1 the remaining mixture of lime and water is whitewash4 ,chemically considered1 acetylene is ,c,h2 it is composed of carbon and hydrogen and belongs to a class of compounds known as hydrocarbons1 represented in nature by petroleum1 natural gas1 etc4 ,it is composed of #ib4c per cent4 carbon and #g4g per cent4 of hydrogen1 both combustible gases4 ,it is a non-poisonous1 colorless gas1 with a persistent and penetrating odor4 ,its presence in the air1 to the extent of #a part in #ajjj is distinctly perceptible4 ,when burning brightly in a jet1 there is no perceptible odor4 ,when completely burned it requires for its combustion #b-a_/b times its volume of oxygen4 ,all combustible gases1 when mixed with air and ignited1 produce more or less violent explosions4 ,acetylene is no exception to the rule1 and when allowed to escape into any enclosed space it will quickly produce a violently explosive mixture1 so that it is always dangerous to enter a room or basement with a lamp or flame of any kind where the odor of gas is perceptible4 ,this is quite true with a combustible gas of any kind1 but with acetylene all mixtures from #c to #cj per cent4 are capable of being exploded with greater or less violence4 ,the kindling point of acetylene is lower than coal gas or gasoline gas4 ,to ignite either of the latter gases1 a flame is necessary to start the combustion1 but a spark or a glowing cigar is sufficient to ignite acetylene4 ,it should therefore be borne in mind that acetylene is not only explosive when mixed with air but that it is very easy to ignite4 ,under ordinary pressures pure acetylene is not explosive1 but at pressure above #ae pounds to the square inch explosions sometimes occur where proper precautions are not observed4 ,at all pressures such as are required for household purposes acetylene is as safe for use as any other gas4 ,although acetylene is in danger of exploding when under pressure1 it is perfectly safe1 when the proper conditions are observed1 in tanks for a great many kinds of portable lights4 ,where acetylene is used in portable tanks under pressure1 advantage is taken of its solubility in acetone4 ,this is a product of the distillation of wood which possesses the property of absorbing acetylene to a remarkable degree4 ,in addition to this property is the more important one of rendering the acetylene non-explosive when under pressure4 ,the tanks for its storage are filled with asbestos or other absorbent material that is saturated with acetone4 ,the acetylene is then forced into the tanks under pressure and is absorbed by the acetone4 ,the safety of this means of storage lies in the degree of perfection to which the tanks are filled with the absorbent material4 ,there must be no space anywhere in the tank where undissolved acetylene can exist4 ,its freedom from danger under such conditions has been thoroughly demonstrated in its use for railroad and automobile lamps4 ,the use of acetylene as a fuel for cooking and for the various other purposes of domestic use is successfully accomplished in burners that give the blue flame desired for such purposes4 ,complete cooking ranges and various other heating and cooking devices are regularly sold by dealers in heating appliances1 while water-heaters1 hot-plates1 chafing-dish heaters1 etc41 are as much a possibility as with any other of gaseous fuel and in as reasonably an inexpensive way4 ,coal gas1 containing as it does sufficient carbon monoxide to render it poisonous1 will cause death when inhaled for any length of time1 but acetylene under the same conditions will have no deleterious effect4 ,types of ,acetylene ,generators4--,there are two general methods of generating acetylene for domestic illuminating and heating purposes3 that of adding carbide to water1 and that in which the water is mixed with carbide4 ,the two types are illustrated in the diagrams shown in ,figs4 #bji and #baj4 ,the first method1 that in which the carbide is dropped into water1 is shown in ,fig4 #bji4 ,the tank ,a is the generator and ,b is the receiver or gas-holder4 ,the tank ,a holds a considerable quantity of water and is provided with a container ,c for holding the supply of carbide4 ,the tank ,a is connected with the gas-holders by a pipe which extends above the water line in the tank ,b1 where the gas is allowed to collect in the gas-holder ,g4 ,a charge of carbide1 sufficient to fill the holder with gas1 is pushed into the tank ,a by raising the lever ,h4 ,immediately the water begins to combine with the carbide and the bubbles of gas pass up through the water and are conducted into the tank ,b4 ,the holder ,g is lifted by the gas and its weight furnishes the pressure necessary to force the gas into the pipes1 which conduct it to the burners4 ,if this machine were provided with the proper mechanism to feed into the generator a supply of carbide whenever the gas in the holder is exhausted1 the machine would represent the modern 8carbide to water0 generator4 ,illustration3 ,,fig4 #bji4--;,diagram of a carbide-to-water acetylene-gas generator4 ,illustration3 ,,fig4 #baj4--;,diagram of a water-to-carbide acetylene-gas machine4 ,the 8water to carbide0 generator is shown diagrammatically in ,fig4 #baj4 ,as in the other figure1 ,a is the generator and ,b is the gas-holder4 ,a supply of carbide ,s is placed in the generator and water from a tank ,c is allowed to drip or spray onto the carbide4 ,the gas collects in the gas-holder as before4 ,this apparatus represents in principle the parts of a machine for generating acetylene by this process4 ,the actual machines are arranged to perform the functions necessary to make the machines automatic in their action4 ,whatever the type of the machine1 the object is to keep in the holders a sufficient amount of gas with which to supply the demand made on the plant4 ,machines representing each of the types described are to be obtained1 but the greater number of those manufactured are of the 8carbide to water0 form4 ,in the formative period of acetylene generators many accidents of serious consequence resulted from imperfect mechanism4 ,imperfections have been gradually eliminated until the machines which have survived are efficient in action and mechanically free from dangerous eccentricities4 ,the qualities demanded of a good generator are3 ,there must be no possibility of an explosive mixture in any of the parts2 it must insure a cool generation of gas2 it must be well-constructed and simple to operate2 it should create no pressure above a few ounces2 it should be provided with an indicator to show how low the charge of carbide has become in order that it may be recharged in due season1 and it must use up the carbide completely4 ,because of the fact that the greater number of acetylene-gas machines of today are of the 8carbide to water0 type1 in the description to follow that type of machine is used4 ,they are generally made in two parts1 one part containing the generating apparatus and the other acting as gasometer 7gas-holder71 but some machines are made in which one cell contains both the generator and gasometer4 ,in ,fig4 #baa is shown a two-part1 gravity-fed machine1 in which all of the internal working parts are exposed to view4 ,the tank 7a71 as in the diagram1 is the generator and the tank 7b7 contains the gasometer marked ,g4 ,each tank possesses a number of appliances which are necessary to make the machine automatic in its action4 ,the part ,c of the generator contains the supply of carbide1 broken into small pieces1 a portion of which is dropped into the water whenever additional gas is required4 ,the feed mechanism ,f is controlled by the gasometer bell ,g1 which is buoyed up by the gas it contains4 ,when the supply of gas becomes low1 the descending bell carries with it the end of the lever ,f1 which is attached to the feed valve2 this motion raises the feed valve and allows some of the carbide to fall into the water4 ,the gas that is immediately generated passes into the gasometer through the pipe ,p1 and as the bell is raised by the accumulating gas the valve ,v is closed4 ,the gas as it enters the gasometer passes through a hollow device ,w1 that looks like an inverted ,t1 the lower edge of which is tooth-shaped and extends below the surface of the water4 ,the gas1 in passing this irregular surface1 is broken up and comes through the water in little bubbles1 in order that it may be washed clean of dust4 ,this device also prevents the return of the gas to the generator tank during the process of charging4 ,illustration3 ,,fig4 #baa4--,sectional view of the ,colt acetylene-gas machine4 ,the gas escapes from the bell through the pipe ,s to the filter ,d1 where any dust that may have escaped the washing process is removed by a felt filter4 ,it finally leaves the machine by the pipe ,l1 at which point it enters the system through which it is conveyed to the different lighting fixtures4 ,it will be noticed that the tank 7b7 is divided into two compartments1 the upper portion containing the water in which the gasometer floats4 ,the lower compartment is also partly filled with water which acts as a safety valve to prevent any escape of gas into the room in which the generator is located4 ,the lower end of the pipes ,p and ,s are immersed in the water at the bottom chamber of the tank1 from which the gas could escape in case too much is generated and finally exit through the vent pipe ,u to the outside air4 ,the float ,a in the tank 7a7 is a safety device that prevents the introduction of carbide unless the tank contains a full supply of water4 ,the float is a hollow metal cylinder connected by a rod to a hinged cup under the bottom opening of the carbide holder4 ,when the water is withdrawn from the generator1 the float falls and the cup shuts off the carbide outlet4 ,illustration3 ,,fig4 #bab4--,sectional view of a house equipped with acetylene lights and domestic heating apparatus4 ,the accumulation of lime1 from the disintegrated carbide1 requires occasional removal from the tank 7a72 the valve ,k is provided for this purpose4 ,the lever ,s is used to stir up the lime which is deposited on the bottom of the tank1 that it may be carried out with the discharged water4 ,machines of this kind that are safeguarded against leakage of gas or the possibility of accumulated pressure are practically free from danger in the use of acetylene4 ,the accidental leakage of gas from defective pipes and fixtures produce only the element of risk that is assumed with the use of any other form of gas for illuminating purposes4 ,acetylene is distributed through the house in pipes in the same manner as for ordinary illuminating gas4 ,the sizes of the pipes to suit the varying conditions of use are regulated by rules provided by the ,national ,board of ,fire ,underwriters4 ,these rules state definitely the sizes of pipes required for machines of different capacities4 ,rules of this kind and others that specify all matters relating to the use of acetylene may be obtained from any fire insurance agent4 ,the general plan of piping is shown in ,fig4 #bab4 ,the generator ,g is in this case a 8water to carbide0 machine and is shown connected to the kitchen range1 as well as the pipe system which may be traced to the lamps in the different rooms1 to the porch lights and to the boulevard lamp in front of the building4 ,illustration3 ,,fig4 #bac4--;,acetylene gas burner4 ,illustration3 ,,fig4 #bad4--;,electric igniter for acetylene gas burners4 ,illustration3 ,,fig4 #bae4--;,electric igniter for acetylene gas burners4 ,the type of burner used in acetylene lamps is shown in ,fig4 #bac4 ,the gas issues from two openings to form the jet as it appears in the engraving4 ,these burners are made in sizes to consume #a_/d1 #a_/b1 #c_/d1 and #a foot per hour depending on the amount of light demanded4 ,gas ,lighters4--,the acetylene gas jets are lighted ordinarily with a match or taper but electric igniters are often used for that purpose4 ,electric lighters for acetylene lamps are practically the same as those used with ordinary gas lamps but they must be adapted to the type of burner on which they are used4 ,electric igniters that are intended to be used with lamps placed in inaccessible places are different in construction from those within reach4 ,in ,figs4 #bad and #bae are illustrated two forms of igniters that are intended to be used on bracket or pendent lamps4 ,they differ in mechanical construction to suit two different conditions4 ,fig4 #bad is an igniter in which is also included the gas-cock4 ,the gas is lighted by pulling a cord or chain attached to the lever ,l4 ,the movement of this lever turns on the gas and at the same time brings the piece ,c in contact with the wire ,a to complete an electric circuit4 ,as the contact between these two pieces is broken1 a spark is formed that ignites the gas escaping from the burner at ,b4 ,on releasing the lever a spring returns the piece ,c to its original position4 ,the light is extinguished by a second pull of the lever4 ,fig4 #bae illustrates a style of igniter which may be attached to an ordinary gas-cock4 ,it is attached to the stem of the burner by a clamp ,d4 ,the gas is turned on by the usual gas-cock and by pulling the chain at the left the jet is lighted4 ,in pulling the chain the arm ,a is raised and carries with it the arm ,b4 ,when the arms ,a and ,b touch1 an electric circuit is formed with a battery and spark coil4 ,when the desired position of the arms is reached1 the points separate to form an electric flash which lights the gas4 ,illustration3 ,,fig4 #baf4--;,diagram of electric igniters attached to gas burners4 ,fig4 #baf illustrates in ,a the method of installing electric igniters like those described4 ,a battery ,b and a spark coil ,s are joined in circuit as shown4 ,the gas pipe acts as one of the wires of the circuit4 ,a battery of four dry cells is commonly used for the purpose4 ,the spark coil is a simple coil of wire wound on a heavy iron core1 which serves to intensify the spark when the circuit is broken4 ,in using the igniter1 it is only necessary to see that the cells are joined in series with the coil and attached to the insulated part of the igniter4 ,as already explained the action of the igniter is to close the circuit and immediately break the contact at a point where the spark will ignite the gas4 ,on being released the igniter returns to its original position4 ,in the fixture shown at ,c is an igniter such as is used in places that cannot be conveniently reached4 ,to light the jet1 the circuit is completed by turning the switch at ,w4 ,as soon as the gas is lighted the switch is again turned to break the igniter-circuit4 ,in this device the current passes through a magnet coil in the igniter which acts to open and close the circuit with the same effect as in the others4 ,acetylene ,stoves4--,stoves in which acetylene is used as a fuel are quite similar in construction to those which burn coal gas4 ,the principle of operation is that of mixing the acetylene with air in proper proportion so as to produce complete combustion when burned4 ,,chapter ,,xiii ,,electricity ,the adaptability of electricity to household use for lighting1 heating and the generation of power has brought into use a host of mechanical devices that have found a permanent place in every community where electricity may be obtained at a reasonable rate1 or where it can be generated to advantage in small plants4 ,because of its cleanliness and convenience1 electricity is used in preference to other forms of lighting1 even though its cost is relatively high4 ,electric power for household purposes is constantly finding new applications and will continue to increase in favor because its use as compared with hand power is remarkably inexpensive4 ,small motors adapted to most of the ordinary household uses are made in convenient sizes and sold at prices that are conducive to their greater use4 ,human energy is far too precious to be expended in household drudgery where mechanical power can be used in its place and often to greater advantage4 ,electric heating devices compete favorably with many of the established forms of household heating appliances1 the electric flat-iron being a notable example4 ,in all applications where small amounts of heat are required for short periods of time1 electricity is used at a cost that permits its use1 in competition with other forms of heating4 ,the remarkable advance that has taken place in electric transmission in the past few years tends to an enormous increase in its use4 ,the constant increase in its use for lighting1 heating and power purposes is due in a great measure to the development of efficient electric generating plants from which this energy may be obtained at the least cost4 ,in those communities where hydro-electric generation is possible its field of application is almost without end4 ,incandescent ,electric ,lamps4--,anything made in the form of an illuminating device1 in which the lighting element is rendered incandescent by electricity1 may properly be called an incandescent lamp1 whether the medium is incandescent gas as in the ,moore lamp1 an incandescent vapor as the ,cooper ,hewitt mercury-vapor lamp1 or the incandescent filament of carbon or metal such as is universally used for lighting4 ,from the year #ahgi1 when ,mr4 ,edison announced the perfection of the incandescent electric lamp1 until #aijc1 when for a short period tantalum lamps were used1 very little improvement had been made in the carbon-filament lamp4 ,immediately following the introduction of the tantalum lamp came the tungsten lamp1 which because of its wonderfully increased capability for producing light has extended artificial illumination to a degree almost beyond comprehension4 ,the influence of the tungsten lamp has induced a new era of illumination that has affected the entire civilized world4 ,the development of the high-efficiency incandescent lamp has brought about a revolution in electric lighting4 ,its use is universal and its application is made in every form of electric illumination4 ,regardless of the immense number of tungsten lamps in use1 the carbon-filament lamp is still employed in great numbers and will probably continue in use for a long time to come4 ,in places where lamps are required for occasional use and for short intervals of time1 the carbon filament still finds efficient use4 ,in one form of manufacture the carbon filament is subjected to a metalizing process that materially increases its efficiency4 ,this form1 known commercially as the ,,gem lamp1 fills an important place in electric lighting4 ,of the rare-metal filament lamps1 those using tungsten and tantalum are in general use1 but the tungsten lamps give results so much superior in point of economy in current consumed that the future filament lamps will beyond doubt be of that type unless some other material is found that will give better results4 ,the filaments of the first tungsten lamps were very fragile and were so easily broken that their use was limited1 but in a very short time methods were found for producing filaments capable of withstanding general usage and having an average life of #ajjj hours of service4 ,these lamps give an efficiency of #a4a to #a4be watts per candlepower of light1 as will be later more fully explained4 ,this1 as compared with the carbon-filament lamps which average #c4a to #d4e watts per candlepower1 gives a remarkable advantage to the former4 ,the tungsten lamp has a useful life that for cost of light is practically one-third that of the carbon-filament lamp4 ,the metal tungsten1 from which the lamp filament is made1 was discovered in #ahga4 ,it is not found in the metallic state but occurs as tungstate of iron and manganese and as calcium tungstate4 ,up to #aijf it was known only in laboratories and on account of its rarity the price was very high4 ,as greater bodies of ore were found and the process of extraction became better known1 the price soon dropped to a point permitting its use for lamp filaments in a commercial scale4 ,pure tungsten is hard enough to scratch glass4 ,its fusing point is higher than any other known metal2 under ordinary conditions it is almost impossible to melt it and this property gives its value as an incandescent filament4 ,one of the laws that affect the lighting properties of incandescent lamps is3 8the higher the temperature of the glowing filament1 the greater will be the amount of light furnished for a given amount of current consumed40 ,the high melting point permits the tungsten filament to be used at a higher temperature than any other known material4 ,tungsten is not ductile1 and in ordinary form cannot be drawn into wire4 ,because of this fact1 the filaments of the first lamps were made by the 8paste0 process1 which consisted of mixing the powdered metal with a binding material1 in the form of gums1 until the mass acquired a consistency in which it might be squirted through a minute orifice in a diamond dye4 ,the resulting thread was dried1 after which it was heated1 and finally placed in an atmosphere of gases which attacked the binding material without affecting the metal4 ,when heated by electricity in this condition1 the particles of metal fused together to form a filament of tungsten4 ,while the 8paste0 filaments were never satisfactory in general use1 their efficiency as a light-producing agent inspired a greater diligence in the search for a more durable form4 ,although tungsten in ordinary condition is not at all ductile1 methods were soon found for making tungsten wire and the wire-filament lamps are now those of general use4 ,one process of producing the drawn wire is that of filling a molten mass of a ductile metal with powdered tungsten after which wire is drawn from the mixture in the usual way4 ,the enclosing metal is then removed by chemical means or volatilized by heat4 ,of the difficulties encountered in the use of metal-filament lamps that of the low resistance offered by the wire was overcome by using filaments very small in cross-section and of as great length as could be conveniently handled4 ,the long tungsten filament requires a method of support very different from the carbon lamp4 ,the characteristic form of tungsten lamps is shown in ,fig4 #bag1 in which the various parts of the lamp are named4 ,illustration3 ,,fig4 #bag4--;,an ,edison ,mazda lamp and its parts4 ,the filament of an incandescent lamp is heated because of the current which passes through it4 ,the electric pressure furnished by the voltage1 forces current through the filament in as great an amount as the resistance will permit4 ,a #af-;candlepower carbon lamp attached to a #aaj-volt circuit requires practically #a_/b ampere of current to render the filament incandescent2 the filament resistance must1 therefore1 allow the passage of #a_/b ampere4 ,with a given size of filament1 its length must be such as will produce the desired resistance4 ,a greater length of this filament would give more resistance and a correspondingly less amount of current would give a dim light because of its lower temperature4 ,likewise1 a shorter filament would allow more current to pass and a brighter light would result4 ,when the size and length of filament is once found that will permit the right amount of current to pass1 if the voltage is kept constant1 the filaments will always burn with the same brightness4 ,this is in accordance with ,ohm's law which as stated in a formula is ,e ,,rc that is ,e1 the electromotive force in volts1 is always equal to the product of the resistance ,r1 in ohms1 and the current ,c1 in amperes4 ,in the incandescent lamp1 if the electromotive force is #aaj volts and the current is #a_/b ampere1 the resistance will be #bbj ohms and as expressed by the law #aaj #bbj #j4e ,from this it is seen that any change in the voltage will produce a corresponding change in the current to keep an equality in the equation4 ,if the voltage increases1 the current also increases and the lamp burns brighter4 ,should the voltage decrease the current will decrease and the lamp will burn dim4 ,this dimming effect is noticeable in any lighting system whenever there occurs a change in voltage4 ,the quantity of electricity used up in such a lamp is expressed in watts1 which is the product of the volts and amperes of the circuit4 ,in the lamp described1 the product of the voltage 7#aaj7 by the amount of passing current 7#a_/b ampere7 is #ee watts4 ,with the above conditions the #af candlepower of light will require #c4dc watts in the production of each candlepower4 ,the best performance of carbon-filament lamps give a candlepower for each #c4a watts of energy4 ,the filament of the tungsten lamp must offer a resistance sufficient to prevent only enough current to pass as will raise its temperature to a point giving the greatest permissible amount of light1 and yet not destroy the wire4 ,the high fusing point and the low specific heat of tungsten permits the filament to be heated to a higher temperature than the carbon filament and with a less amount of electric energy4 ,these are the properties that give to the tungsten lamp its value over the carbon lamp4 ,the exact advantage of the tungsten lamp has been investigated with great care and its behavior under general working conditions is definitely known4 ,in light-giving properties where the carbon-filament lamp requires #c4a watts to produce a candlepower of light1 in the tungsten filament only #a4a watts are necessary to cause the same effect4 ,the tungsten lamp therefore gives almost three times as much light as the carbon lamp for the same energy expended4 ,the manufacturers aim to make lamps that give the greatest efficiency for a definite number of hours of service4 ,it has been agreed that #ajjj working hours shall be the life of the lamps and in that period the filament should give its greatest amount of light for the energy consumed4 ,the ,mazda ,lamp4--,the trade name for the lamp giving the greatest efficiency is ,mazda4 ,the term is taken as a symbol of efficiency in electric incandescent lighting4 ,at present the ,mazda is the tungsten-filament lamp1 but should there be found some other more efficient means of lighting1 which can take its place to greater advantage1 that will become the ,mazda lamp4 ,candlepower4--,the incandescent lamps are usually rated in light-giving properties by their value in horizontal candlepower4 ,this represents the mean value of the light of the lamp which comes from a horizontal plane passing through the center of illumination and perpendicular to the long axis of the lamp4 ,candlepower in this connection originally referred to the ,english standard candle which is made of spermaceti4 ,the standard candle is #j4i inch in diameter at the base1 #j4h inch in diameter at the top and #aj inches long4 ,it burns #abj grains of spermaceti and wick per hour4 ,this candle is not satisfactory as a standard because of the variable conditions that must surround its use4 ,the ,american or ,international standard is equal to #a4aa ,hefner candles4 ,the ,hefner candle 7which is the standard in continental ,europe and ,south ,american countries7 is produced by a lamp burning amylacetate4 ,this lamp consists of a reservoir and wick of standard dimensions which gives a constant quantity of light4 ,the light from this lamp has proven much more satisfactory as a means of measurement of light than the ,english standard and therefore its use has been very generally adopted4 ,the light given out by an incandescent lamp is not the same in all directions4 ,in making comparisons it is necessary to define the position from which the light of the lamps is taken4 ,the horizontal candlepower affords a fairly exact means of comparing lamps which have the same shape of filament1 but for different kinds of lamps it does not give a true comparison4 ,the spherical candlepower is used to compare lamps of different construction as this gives the mean value at all points of a sphere surrounding the lamp4 ,the candlepower is measured at various positions about the lamp with the use of a photometer1 and the mean of these values is taken as the mean spherical candlepower4 ,at their best1 carbon-filament lamps require in electricity #c4a w4p4c4 7watts per candlepower74 ,as the lamp grows old the number of watts per candle power increases1 until in very old lamps the amount of electricity used to produce a given amount of light may become excessively large4 ,according to a bulletin issued by the ,illinois ,engineering ,experiment ,station on the efficiency of carbon-filament incandescent lamps1 the amount of electrical energy per candlepower varied from #c4a w4p4c41 when new1 to #d4b w4p4c41 after burning #hjj hours4 ,a common practice in the use of carbon-filament lamps is to consider that the period of useful life ends at a point where the amount of electricity1 per candlepower1 reaches #bj per cent4 in excess of the original amount4 ,this point 7sometimes termed the smashing point7 would be reached after #hjj working hours1 according to the ,illinois ,station1 and at about #ajjj hours as stated by the bulletins of the ,general ,electric ,co4 ,if a carbon-filament lamp burns for an average period of #c hours a day for a year1 it ought to be replaced4 ,the ,edison screw base as shown in ,fig4 #bag is now generally used in all makes of incandescent lamps for attaching the lamp to the socket4 ,when screwed into place this base forms in the socket the connections with the supply wires1 to produce a circuit through the lamp4 ,one end of the filament is attached to the brass cap contact2 the opposite end connects with the brass screw shell of the base4 ,when the current is turned on1 the contact made in the switch is such as to form a complete circuit between the supply wires2 the voltage sending a constant current through the lamp produces a steady incandescence of the filament4 ,in ,fig4 #bah is shown a carbon-filament lamp attached to an ordinary socket4 ,the lamp base and socket are shown in section to expose all of the parts that comprise the mechanism4 ,the insulated wires of the lamp cord enter the top of the socket and the ends attach to the binding screws ,a and ,b1 which are insulated from each other and form the brass shell which encases the socket4 ,the lamp base is shown screwed into the socket1 the brass cap contact ,f making connection at ,g2 the screw shell joins the socket at ,d4 ,to the key ,s is attached a brass rod ,r1 on which is fastened ,e1 the contact-maker4 ,the rod ,r passes through a supportary frame which is secured to the lamp socket at ,g4 ,as shown in the figures the piece ,e makes contact with a brass spring attached to ,a1 and this completes a circuit through the filament4 ,the brass cap contact of the lamp base makes connection at one end of the filament ,h1 the other end of the filament ,k is attached to the brass screw shell of the base1 which in turn connects with the screw shell of the socket and this shell is connected with the piece containing the binding screw ,b by the rod ,c to complete the circuit4 ,when the key ,s turns1 the contact above ,e is broken and the lamp ceases to burn4 ,illustration3 ,,fig4 #bah4--,section of a lamp base and socket4 ,fig4 #aah shows the use of an adapter that is sometimes encountered in old electric fixtures1 the use of which requires explanation4 ,mention has already been made of the various forms of lamp sockets in use before the ,edison base became a standard4 ,in order to use an ,edison lamp in a socket intended for another form of base an adapter must be employed to suit the new base to the old socket4 ,in the figure the piece ,p1 is the adapter4 ,this is intended to adapt the standard lamp base to a socket that was formerly in use on the ,thompson-,houston system of electric lighting4 ,the adapter is joined to the old socket by the screw at ,g and the circuit formed as already described4 ,lamp ,labels4--,for many years all incandescent lamps were rated in candlepower and were made in sizes #h1 #af1 #cb1 etc41 candlepower4 ,on the label was printed the voltage at which the lamp was intended to operate1 and also the candlepower it was supposed to develop4 ,thus #aaj v41 #af cp4 indicated that when used on #aaj-volt circuit1 the lamp would give #af candlepower of light4 ,this label in no way indicated the amount of energy expended4 ,with the development of the more efficient filaments came a tendency to label lamps in the amount of energy consumed4 ,this has resulted in all lamps being labeled to show the voltage of the circuit suited to the lamp1 and the watts of electricity consumed when working at that voltage4 ,at present a lamp label may be marked #aaj v41 #dj w41 which indicates that it is intended to develop its best performance at #aaj volts and will consume #dj watts at that voltage4 ,commercial lamps are now manufactured in sizes of #aj1 #ae1 #be1 #dj1 #fj1 #ge1 and #ajj watts capacity for ordinary use4 ,of these the #dj-watt lamp probably fulfills the greatest number of conditions and is most commonly used4 ,besides these there are the high-efficiency lamps of the gas-filled variety that are made in larger sizes and the miniature lamps in great variety4 ,all are labeled to show the volts and the watts consumed4 ,illumination4--,the development of high-efficiency lamps has caused a radical change in the methods of illumination4 ,with cheaper light came the desire to more nearly approximate the effect of daylight in illumination4 ,this has brought into use indirect illumination1 in which the light from the lamp is diffused by reflection from the ceiling and walls of the room4 ,illuminating engineering is now a business that has to do with placing of lamps to the greatest advantage in lighting any desired space4 ,in large and complicated schemes of lighting professional services are necessary1 but in household lighting the required number of lamps for the various apartments are almost self-evident4 ,the lighting of large rooms1 however1 requires thoughtful consideration and in many cases the only definite solution of the problem is that of calculation4 ,the ,foot-candle4--,the amount of illumination produced over a given area depends not only on the number of lamps and their candlepower1 but upon their distribution and the color of the walls and furnishings4 ,in the calculation of problems in illumination1 units of measure are necessary to express the amount of light that will be furnished at any point from its source4 ,the units adopted for such purposes are the foot-candle and the lumen4 ,the ,lumen4--,a light giving #a candlepower1 placed in the center of a sphere of #a foot radius illuminates a sphere1 the area of which is #d #c4adaf or #ab4eg square feet4 ,the intensity of light on each square foot is denoted as a candle-foot4 ,the candle-foot is the standard of illumination on any surface4 ,the quantity of light used in illuminating each square foot of the sphere is called a lumen4 ,a light of #a candlepower will therefore produce an intensity of #a candle-foot over #ab4eg square feet and give #ab4eg lumens4 ,therefore1 if all of the light is effective on a plane to be illuminated1 a lamp rated at #djj lumens would light an area of #djj square feet to an average intensity of #a candle-foot4 ,to find the number of lamps required for lighting any space1 the area in square feet is multiplied by the required intensity in foot-candles1 to obtain the total necessary lumens1 and the amount thus obtained is divided by the effective lumens per lamp4 ,the bulletins of the ,columbia ,incandescent ,lamp ,works gives the following method of calculating the number of lamps required to light a given space3 ,number of lamps 7,s ,i7_/7,effective lumens per lamp7 ,s 7square feet7 ,i 7required illumination in foot-candles7 total lumens4 ,the total lumens divided by the number of effective lumens per lamp gives the number of lamps required4 ,in using the formula the effective lumens per lamp is taken from the following table3 ,watts per lamp #be #dj #fj #afj #aej #bej ,effective lumens per lamp #ie #afj #bej #dbj #fcj #ajij ,lumens per watt #c4h #d4j #d4b #d4b #d4b #d4c ,the size of the units is a matter of choice since six #djj-lumen units are equal to four #fjj-lumen units in illuminating power1 etc4 ,in deciding upon the proper size of lamps to use1 consideration must be taken of the outlets if the building is already wired4 ,in general the fewest units consistent with good distribution will be the most economical4 ,the table shows the lumens effective for ordinary lighting with ,mazda lamps and clear high-efficiency reflectors with dark walls and ceiling4 ,where both ceiling and walls are very light these figures may be increased by #be per cent4 ,to illustrate the use of the table1 take an average room #af by #bd to be lighted with ,mazda lamps to an intensity of #c4e foot-candles4 ,if clear ,holoplane reflectors are used1 the values for lumens effective on the plane may be increased #aj per cent4 due to reflection from fairly light walls4 ,the lamps in this case are to be of the #dj-watt type which in the table are rated at #afj lumens4 ,to this amount #aj per cent4 is added on account of the reflectors and walls4 ,this data applied to the formula gives3 s #af by #bd feet ,i #c4e ,lumens per lamp #afj 77#af #bd7 #c4e7_/agf eight #dj-watt lamps4 ,illustration3 ,,fig4 #bai4 ,reflectors4--,the character and form of reflectors have much to do with the effective distribution of the light produced by the lamp4 ,the most efficient form of reflectors are made of glass and designed to project the light in the desired direction4 ,the illustration in ,fig4 #bai1 marked open reflector1 shows the characteristic features of reflectors designed for special purposes4 ,they are made of prismatic glass fashioned into such form as will produce the desired effect and at the same time transmit and diffuse a part of the light to all parts of the space to be lighted4 ,the greater portion of the light is sent in the direction in which the highest illumination is desired4 ,the reflectors are made to concentrate the light on a small space or to spread it over a large area as is desired4 ,they are1 therefore1 designated as intensive or extensive reflectors and made in a variety of forms4 ,choice of ,reflector4--,where the light from a single lamp must spread over a relatively great area1 it is advisable to use an extensive form of reflector4 ,this reflector is applicable to general residence lighting1 also uniform lighting of large areas where low ceilings or widely spaced outlets demand a wide distribution of light4 ,where the area to be lighted by one lamp is smaller1 the intensive reflector is used4 ,such cases include brilliant local illumination1 as for reading tables1 single-unit lighting or rooms with high ceilings as pantries or halls4 ,where an intense light on a small area directly below the lamp is desired1 a focusing reflector is used4 ,the diameter of the circle thus intensely lighted is about one-half the height of the lamp above the plane considered4 ,focusing reflectors are used in vestibules or rooms of unusually high ceilings4 ,type ,height above plane to be lighted ,extensive #a_/b ,d ,intensive #d_/e ,d ,focusing #d_/c ,d ,d distance between sides of room to be illuminated4 ,the various other fixtures of ,fig4 #bai that are designated as reflectors are in some cases only a means of diffusion of light4 ,in the use of the high-efficiency gas-filled lamps the light is too bright to be used directly for ordinary illumination4 ,when these lamps are placed in opal screens of the indirect or the semi-indirect form the light produced for general illumination is very satisfactory4 ,considerable light is lost in passing through the translucent glass but this is compensated by the use of the high-efficiency lamps and the general satisfaction of light distribution4 ,lamp ,transformers4--,lamps of the ,mazda type1 constructed to work at the usual commercial voltages1 are made in low-power forms to consume as little as #aj watts2 but owing to the difficulty of arranging a suitable filament for the smaller sizes of lamps1 less voltage is required to insure successful operation4 ,the lamps for this purpose are of the type used in connection with batteries and require #a or more volts to produce the desired illumination4 ,when these little lamps are used on a commercial circuit1 the reduction of the voltage is accomplished by small transformers1 located in the lamp socket4 ,the operating principle and further use of the transformers will be explained later under doorbell transformers4 ,the lamp transformer1 although miniature in design1 is constructed as any other of its kind but designed to reduce the usual voltage of the circuit to #f volts of pressure4 ,the socket is that intended for the use of the ,mazda automobile lamp giving #b candlepower4 ,this lamp used with electricity at the average rate per kilowatt can be burned for #aj hours at less than half a cent4 ,in bedrooms1 sickrooms and other places where a small amount of light is necessary but where a considerable quantity is objectionable1 the miniature lamp transformer serves an admirable purpose in adapting the voltage of the commercial alternating circuit to that required for lamps of small illuminating power4 ,such a transformer is shown in ,fig4 #bbj4 ,illustration3 ,,fig4 #bbj4--,miniature lamp transformer complete and the parts of which it is composed4 ,the figure shows in ,a the assembled attachment with the lamp bulb in place4 ,the part ,b1 the transformer1 changes the line voltage to that of a battery lamp4 ,a line voltage of #aaj may be transformed to suit a #f-volt miniature lamp4 ,the parts ,c and ,d compose the screw base and the cover1 in which is fitted the transformer ,b4 ,units of ,electrical ,measurement4--,the general application of electricity has brought into common use the terms necessary in its measurement and units of quantity by which it is sold4 ,the volt1 ampere and ohm are terms that are used to express the conditions of the electric circuit2 the watt and the kilowatt are units that are employed in measuring its quantity in commercial usage4 ,the use of these units in actual problems is the most satisfactory method of appreciating their application4 ,as already explained the volt is the unit of electric pressure which causes current to be sent through any circuit4 ,the electric circuits of houses are intended to be under constant voltage--commonly #aaj or #bbj--;but the voltage may be any amount for which the generating system is designed4 ,independent lighting systems such as are used in house-lighting plants--to be described later--commonly employ #cb volts of electric pressure4 ,opposed to the effect of the volts of electromotive force is the resistance of the circuit1 which is measured in ohms4 ,resistance has been called electric friction2 it expresses itself as heat and tends to diminish the flow of current4 ,every circuit offers resistance depending on the length1 the kind and the size of wire used4 ,since the wires of commercial lighting systems are made of copper1 it can be said that the resistance of the circuit increases as the size of the conducting wire decreases4 ,in large wires the resistance is small but as the size of the wire is reduced the resistance is increased4 ,a long attachment cord of a flat-iron1 may offer sufficient resistance to prevent the iron from heating properly4 ,the ampere is the unit which measures the amount of current4 ,the amperes of current determine the rate at which the electricity is being used in any circuit4 ,the wires of a house must be of a size sufficient to carry the necessary current without heating4 ,any house wire which becomes noticeably warm is too small for the current it carries and should be replaced by one that is larger4 ,the watt is the unit of electric quantity4 ,the quantity of electricity being used in any circuit is the product of the volts of pressure and amperes of current flowing through the wires4 ,the amount of current--in amperes--sent through the circuit is the direct result of the volts of pressure2 the quantity of electricity is therefore the product of these two factors4 ,a #be-watt lamp on a circuit of #aaj volts uses #j4bbg ampere of current4 #be watts #aaj volts #j4bbg amperes4 ,ten such lamps use #aj #j4bbg amperes #b4bg amperes4 ,the product of #aaj volts and #b4bg amperes is #bej watts4 ,in order to express quantity of energy1 it is necessary to state the length of time the energy is to act and originally the watt represented the energy of a volt-ampere for one second4 ,for commercial purposes this quantity is too small for convenient use and the hour of time was taken instead4 ,the watt of commercial measurement is the watt-hour and in the purchase of electricity the watt is always understood as that quantity4 ,even as a watt-hour the measure is so small as to require a large number to express ordinary amounts and a still larger unit of #ajjj watt-hours or the kilowatt-hour was adopted and has become the accepted unit of commercial electric measurement4 ,just as a dollar in money conveniently represents #ajjj mills so does a kilowatt of electricity represent a convenient quantity4 ,in the purchase of electricity1 the consumer pays a definite amount1 say #aj cents per kilowatt4 ,this represents an exact quantity of energy1 that may be expended in light1 in heat1 or in the generation of power1 all of which may be expressed as definite quantities4 ,as light1 it indicates in the electric lamp the number of candle-power-hours that may be obtained for #aj cents4 ,at this rate a single watt costs #j4ja cent an hour4 ,a #be-watt electric lamp will therefore cost #j4be 7#a_/d7 cent for each hour of use2 a #fj-watt lamp costs #j4f cent per hour2 the ten #be-watt lamp mentioned above using #bej watts costs #b4e cents per hour4 ,as heat1 it is expressed in ,english-speaking countries as ,british thermal units1 #a kilowatt-hour representing #cdab ,b4t4u4 per hour4 ,one cent's worth of electricity at the rate given yields #cda4b ,b4t4u4 of heat4 ,as power1 it represents an exact amount of work4 ,so expressed1 a watt represents #a_/gdf horsepower2 therefore a kilowatt is represented in power as #ajjj_/gdf #a4c horsepower4 ,since the kilowatt purchased for #aj cents is a kilowatt-hour1 the equivalent horsepower is for the same length of time4 ,at the assumed rate1 #aj cents buys #a4c horsepower for one hour4 ,when used as work it represents #b1edd1jjj foot-pounds or #bee1djj foot-pounds of work for #a cent4 ,this work when expended in a motor1 to do the family washing or perform any other household drudgery1 represents the greatest value to be derived from its use4 ,a #a_/b-;horsepower motor is amply large to operate a family washing machine4 ,even though the motor is only #ej per cent4 efficient its cost of operation is less than #g cents per hour4 ,miniature ,lamps4--,miniature electric lamps include all that are not used for general illuminating purposes4 ,the term applies more particularly to the form of the base than to the voltage or candlepower of the filament4 ,there are three general classes of these lamps3 candelabra and decorative1 that operate on lighting circuits of #ajj to #acj volts and are usually intended for decorative purposes2 general battery lamps used for flash lights2 and lamps for automobiles and electric-vehicle service4 ,illustration3 ,candelabra screw base ,miniature screw base ,double-contact bayonet candelabra base ,single-contact bayonet candelabra base ,,fig4 #bba4--,miniature lamp bases4 ,the term miniature lamp applies more particularly to the base than to the voltage or candlepower4 ,the style of base is characteristic of the service for which the lamp is designed rather than the size or number of watts consumed4 ,there are two general styles of bases3 the screw type of the ,edison construction of which there are two sizes2 and the bayonet type of which there are two styles of construction4 ,bases for miniature lamps are made in form to suit the conditions of their use4 ,the styles at present are shown in ,fig4 #bba4 ,of these the screw bases at the left are those attached to small flash-lamp bulbs and others of the smaller sizes of lamps4 ,the two at the right of the figure are the bayonet style used under conditions not suited to the screw contact4 ,in the case of automobile lamps and in places where vibration will cause loss of contact the bayonet base is generally in use4 ,the lamp is held in place by the projecting lugs that engage with openings in the socket and kept in place by the pressure of a spring4 ,the contact with the lamp filament is made by two terminals that make connection directly with the terminals of the lamp filament4 ,the single contact base is kept in place similarly to that of the other but makes a single contact at the end of the socket while the other but makes a single contact at the end of the socket while the circuit is completed through the pressure exerted between the projecting lugs and the socket4 ,effect of ,voltage ,variations4--,voltage variation may be temporary1 due to changing load in the circuit1 or in constantly overloaded circuits the voltage may be constantly below normal4 ,the change in electric pressure affects in a considerable degree the amount of light given by the lamp4 ,as an example1 a #e per cent4 drop from the normal voltage will cause a decrease of #ca per cent4 in the amount of light given4 ,this means that if a lamp is working on a circuit of #aaj volts and the voltage from any cause were to drop to #ajd-a_/b volts1 the light would decrease #f4h1 almost #g candlepower4 ,drop in voltage may also be due to the resistance of wires that are too small for the service4 ,lamps attached to such a circuit will constantly burn dim4 ,turn-down ,electric ,lamps4--,the ordinary incandescent lamp lacks the flexibility of gas and oil lamp1 in that the amount of light cannot be varied at will4 ,this feature is attained in the electric turn-down lamp either by resistance added to the lamp circuit or by the use of two separate filaments in a single globe2 one of ordinary lamp size and the other of such size that it consumes only a fraction as much energy as the normal lamp4 ,illustration3 ,,fig4 #bbb4--,sectional view of a 8turn-down0 lamp socket4 ,turn-down lamps of the latter form are made in several styles1 the chief points of difference being in the method of changing the contact from the high-to the low-power filament4 ,in ,fig4 #bbb a sectional view shows the 8pull-string0 form of lamp in which the parts are exposed4 ,the long filament ,h and the smaller one ,l represent two individual lamps of different lighting power4 ,the change in light is made from one to the other by pulling the string which is attached to a switch in the socket and which changes the contact to send the current through the filament giving the desired amount of light4 ,the figure shows a carbon-filament lamp1 but tungsten lamps are made to accomplish the same purpose4 ,the difficulty of manufacturing a #a-;candlepower tungsten lamp for direct operation on a #aaj-volt circuit requires the filaments to work in series4 ,the figure is arranged on the same plan as for a tungsten lamp4 ,the lamp base when screwed into the socket makes contact with the two service wires of the circuit at ,a and at ,e1 which are part of the screw base4 ,to light the lamp the current is switched on as in any lamp4 ,the current enters at ,a and passes down the connecting piece to the contact ,b4 ,the piece ,b is moved by the cord to light either the large or the small filament4 ,in the position shown the current enters the small filament at ,c and in order to complete the circuit to ,e must traverse both the large and the small filament4 ,the resistance of the small filament is such that the passing current raises it to a temperature of incandescence but the large filament does not heat sufficiently to give an appreciable amount of light4 ,when the cord is pulled to light the large filament1 the contact is made at ,d and the current passes directly through the large filament to complete the circuit at ,e4 ,turn-down lamps are especially adapted to the home4 ,their use in a child's bedroom or sick chamber is a great convenience4 ,the lamps are often constructed with a long-distance cord extending from a fixture to the bedside4 ,by this means a dim or bright light is given as desired1 with the least inconvenience4 ,turn-down lamps are made in a variety of sizes4 ,the large filaments are arranged to give #h1 #af1 and #cb candlepower4 ,with the #h-;candlepower lamp the small filament gives #a_/b candlepower and with the #af-;and #cb-;candlepower the small filament gives #a candlepower4 ,with the lamps described1 the variation in amount of light is attained by changing the contacts1 to bring into action filaments of different resistances4 ,they admit of only two changes1 either the lamp burns at full capacity or at the least light the lamp will give4 ,the heat liberated by the large filament1 when the small light is in use1 takes place inside the lamp globe4 ,the ,dim-a-lite4--,in another form of turn-down lamp the change in amount of light is produced by external resistance in the circuit4 ,the resistance is furnished by a coil of wire which is enclosed in a special lamp socket4 ,it possesses the advantage as a turn-down lamp in a number of changes of light4 ,the added resistance in a socket decreases the flow of current and1 therefore1 the filament gives less light4 ,the resistance wire is divided into a number of sections and contact with the terminals of these sections decreases the light with each addition of resistance4 ,the heat generated in the resistance coils is dissipated by the brass covering of the socket4 ,illustration3 ,,fig4 #bbc4--,the resistance type of 8turn-down0 lamp4 ,an illustration of a turn-down lamp using a separate resistance is that of ,fig4 #bbc1 known commercially as the ,dim-a-lite1 which is an excellent example4 ,the ,dim-a-lite attachment is a lamp socket in which is enclosed a miniature rheostat or resistance unit4 ,the lamp1 when placed on the ,dim-a-lite1 makes electrical contact as in an ordinary socket but with the difference that in series with the lamp filament is the rheostat1 by means of which additional resistance may be added to change the current flowing in the lamp4 ,the rheostat is so arranged that contact may be made at four different points in the resistance coil1 through which the electricity may be varied from #ajj to #bj per cent4 of the normal quantity4 ,the resistance in any case permits current to pass through the filament in amounts of #gj1 #cj and #bj per cent4 of the normal amount4 ,in use1 the variation is made by pulling one string to add resistance and thus dim the light2 or by pulling the other string1 the resistance is decreased and more electricity passes through the filament to produce a brighter light4 ,the quantity of light given out by the filament does not vary in the ratio of the added resistance but a variable light is obtained at the expense of a small amount of electricity which is changed into heat4 ,when the light is burning at its dimmest only #bj per cent4 of the normal current is used4 ,under this condition the light given out by filament does not express the high efficiency attained when the lamp is burning at its full power but it does give a convenient form of light regulation with the minimum waste of energy4 ,gas-filled ,lamps4--,until #aiac the filaments of all ,mazda lamps operated in a vacuum4 ,the vacuum serving the purpose of preventing oxidation and at the same time it reduced the energy loss to the least amount4 ,it was found1 however1 under some conditions of construction that lamps filled with inert gas gave a higher efficiency and more satisfactory service than those of the vacuum type4 ,in this construction1 the filament is operated at a temperature much higher than that of the vacuum lamp and as a consequence gives light at a less cost per candlepower4 ,mazda vacuum lamps are now designated by the ,general ,electric ,co4 as ,mazda ,b lamps1 ,fig4 #bbd1 and those of the gas-filled variety1 ,fig4 #bbe1 are designated as ,mazda ,c lamps4 ,illustration3 ,,fig4 #bbd4--dj-watt ,mazda ,b lamp 7#a_/b scale74 ,illustration3 ,,fig4 #bbe4--gej-watt ,mazda ,c lamp 7#a_/d scale74 ,the filaments of the gas-filled lamps are intensely brilliant and where they come within the line of vision should be screened from the eyes4 ,the high efficiency of these lamps permit the use of opal shades to produce a desired illumination at a rate of cost that compares favorably with the unscreened light of the vacuum lamps4 ,daylight ,lamps4--,the color of the light from an incandescent electric lamp depends on the temperature of the filament4 ,in the case of the gas-filled ,mazda lamp the high filament temperature produces a light that differs markedly from the vacuum lamps in that it contains a greater amount of blue and green rays4 ,it is therefore possible to produce light that is the same as average daylight4 ,gas-filled lamps with globes colored to produce light of noonday quality are produced at an expenditure of #a4b watts per candlepower4 ,in the matching of colors1 it should be kept in mind that the tint of any color is influenced by the kind of light by which it is viewed4 ,colors matched by ordinary incandescent light containing a large percentage of red rays cannot produce the same effect when the same articles are seen in light of different quality4 ,the daylight lamps are therefore intended to be used under conditions that require daylight quality4 ,miniature ,tungsten ,lamps4--,the wonderful light-giving properties of tungsten has made possible the use of miniature incandescent lamps for an almost infinite variety of usages4 ,the miniature lamps are similar in action to other incandescent electric lamps except that they are operated on voltages lower than is used on commercial circuits4 ,when used on commercial circuits1 incandescent tungsten lamps of less than #aj watts capacity require filaments that are too delicate to withstand the conditions of ordinary use4 ,the properties of tungsten are such that the passage of only a small amount of current is required to render the filament incandescent4 ,in the case of a #aaj-volt circuit1 a #aj-watt lamp requires only #j4ji ampere to produce the desired incandescence4 ,it will be remembered that the watt is a volt-ampere and the #aj-watt lamp will then require #aaj volts #j4ji ampere #aj watts4 ,since #aj-watt lamps are the smallest units that may be used on #aaj-volt circuits1 their employment in smaller sizes must be such as will give more stable filaments4 ,this is possible when the lamps are used at lower voltage4 ,a #aj-watt lamp on a #aj-volt circuit will require an ampere of current4 #aj volts #a ampere #aj watts4 ,a filament suitable for an ampere of current is shorter and heavier than that of the #aaj-volt lamp and therefore furnishes a good form of construction4 ,still lower voltages may be used with filaments suited to the quantity of light desired4 ,in the case of battery lamps that are intended to operate on #a or more volts1 the filaments are made in size and length to suit the condition of action4 ,in all cases the product of the volts and amperes give the capacity of the lamp in watts4 ,miniature lamps are ordinarily marked to show the voltage on which they are intended to operate4 ,a #f-volt battery lamp is intended to be used with a primary battery of four to six cells depending on the condition of usage1 or three cells of storage battery1 each cell of which gives #b volts of pressure4 ,flash ,lights4--,these are portable electric lamps composed of a miniature incandescent bulb1 which with one or more dry cells are enclosed in a frame to suit the purpose of their use4 ,they are made in pocket sizes or in form to be conveniently carried in the hand and are convenient and efficient lamps wherever a small amount of light is required for a short time4 ,the electricity for operating the lamp is supplied by a battery of dry cells 7to be described later71 or by a single dry cell4 ,in each case the incandescent bulb is suited to the voltage of the battery4 ,in replacing the bulbs care must be taken to see that the voltage is that suited to the battery4 ,the voltage is usually stamped on the lamp base or marked on the bulb4 ,in case a lamp intended for a single cell is used with a battery of three or four cells1 the lamp filament will soon be destroyed4 ,the reverse will be true should a lamp intended for a battery be used with a single cell4 ,the single cell giving not much more than a volt of electromotive force will not send sufficient current through the lamp filament to render it incandescent4 ,the ,electric ,flat-iron4--,the changes that have been made in domestic appliances by the extended use of electricity have brought many innovations but none are more pronounced than the improvements made in the domestic flat-iron4 ,it was the first of the household heating devices to receive universal recognition and its place as a domestic utility is firmly established4 ,the relatively high cost of heat as generated through electric energy is in a great measure counterbalanced in the flat-iron by high efficiency in its use4 ,in the electric iron1 the heat is developed in the place where it can be used to the greatest advantage1 and transmitted to the face of the iron with but very little loss4 ,because of this direct application the cost of operation is but slightly in excess of the other methods of heating4 ,the electric flat-iron has now become a part of the equipment of every commercial laundry1 where electricity can be obtained at a reasonable rate4 ,the popularity of the electric iron is due to its cleanliness and to the increased amount of work that may be accomplished through its use4 ,because of the time saved in changing irons and the comfort of the room by reason of its lower temperature1 a sufficiently greater amount of work is accomplished to more than compensate for the greater cost of heat4 ,the electric current is conducted to the flat-iron from the house circuit by wires made into the form of a flexible cord4 ,the cord attaches to the electric-lamp fixture by a screw-plug and connects with the iron by a special attachment piece as indicated at ,p and ,r in ,fig4 #bbf4 ,connection is made to an incandescent lamp socket at any convenient place4 ,the only precaution necessary in attaching the iron is to see that the fuse and the wires1 which form the circuit1 are of size sufficient to transmit the amount of current the iron is rated to use4 ,as explained later1 the fuse which is a part of every electric house circuit1 and the conducting wires which form the heater circuit1 must be sufficient in size to transmit the necessary current without material heating4 ,illustration3 ,,fig4 #bbf4--;,electric flat-iron and its attachments4 ,the cord connects with the socket at ,p1 and the current turned on4 ,it is attached with the iron by a piece ,r1 made of non-conducting and heat-resisting material and arranged to make contact with the heater terminals by two brass plugs that are insulated from the body of the iron and afford easy means of making electric contact4 ,the contact plugs are shown in ,fig4 #bbg4 ,to make electric connection1 the contact piece is simply pushed over the plugs1 where it is held in place by friction4 ,instructions which accompany a flat-iron when purchased advise that the attachment piece be used in turning off the current4 ,the reason for this is because of the flash that accompanies the break in the circuit when disconnection is made in the socket4 ,this flash is really a small electric arc1 that forms as the circuit is broken and which burns away the switch at the point of disconnection4 ,the arc so formed burns away the contact pieces in the switch and it is soon destroyed4 ,the attachment piece will stand this wear more readily than the socket switch and hence is preferable for disconnecting4 ,the irons are frequently provided with a special switch for the service required in the flat-iron4 ,illustration3 ,,fig4 #bbg4--;,electric flat-iron showing position of the heating element and contact plugs4 ,a spiral spring connected to the attachment cord prevents it from kinking when in use and thus breaking the conducting wires4 ,the attachment cord is made of stranded wires to make it flexible4 ,the strands of fine copper wire are made to correspond to the gage numbers by which the various sizes of wire are designated4 ,in use the constant movement of the iron tends to kink the cord and thus breaks the strands4 ,this action is most pronounced at the point where the cord attaches to the iron4 ,for this reason a spiral spring wire encloses the cord for a short distance above the attachment piece4 ,after long usage the cord is apt to break in this vicinity4 ,it may usually be repaired by cutting off the ends of the cords and new connections made in the attachment piece4 ,when the iron is in use the slack portion of the cord is kept from interfering with the work by the coiled wire ,s1 which connects with the cord at any convenient place4 ,electric flat-irons are made in a variety of styles and forms1 the mechanism of each possessing some particular advantage1 but all are provided with the same essential parts1 chief of which is the heater with its electric attachment piece4 ,in ,fig4 #bbh is shown very clearly the construction of an example in which attention is called to the points of excellence that are required in a particularly serviceable iron4 ,the form of the heating element which is recognized in the iron is also shown in ,fig4 #bbh4 ,illustration3 ,,fig4 #bbh4--;,electric flat-iron heating element4 ,in the figure the heater is made of coils of resistance wire1 wound on a suitable frame of mica4 ,the heating element is insulated from the body of the iron with sheets of mica1 this being a material that makes an excellent insulator and is not materially affected by the heat to which it is subjected4 ,the resistance wire of which the element is composed is especially prepared to resist the corroding action common to metal when heated in air4 ,the form of the element is such as to permit the least movement of the turns of wire--in their constant heating and cooling--that will allow the different spires to make contact and thus change the resistance4 ,should the spires of wire come together1 the current would be shunted across the contact and the resistance of the element decreased4 ,the effect of such a reduction of resistance would be an increased flow of current and a corresponding increase of heat4 ,in this1 as in the electric lamp and all other electric circuits1 the current1 voltage and resistance follow the conditions of ,ohm's law4 ,different sizes of irons will1 of course1 require different amounts of current4 ,a #f-pound iron1 such as is commonly used for household work1 will take about #e amperes of current at #aaj volts pressure4 ,the amount of electricity the iron is intended to consume is generally stamped on the nameplate of the manufacturer4 ,this is specified by the number of volts and amperes of current the iron is rated to use4 ,as an example1 the iron may be marked1 ,volts #aje-aae1 ,amperes #b-c4 ,this indicates that the iron is intended to be used on circuits that carry electric pressure varying from #aje to #aae volts and that the heater will use from #b to #c amperes of current1 depending on the voltage4 ,to estimate the cost of operating such an iron1 it is necessary to determine the number of watts of electric energy consumed4 ,the number of watts of energy developed under any condition will be the product of the volts times the amperes4 ,suppose that in the above example the iron was used on a circuit of #aaj volts4 ,under this condition the current required to keep the iron hot would be #b4e amperes4 ,the product of these two qualities1 #aaj #b4e is #bge watts4 ,if the cost of electricity is #aj cents per kilowatt-hour 7#ajjj watts7 the cost of operating the iron would be #bge_/ajjj #aj cents #b-c_/d cents an hour4 ,since the electric iron requires a much larger amount of current than is usually required for ordinary lighting1 the circuit on which it is used should receive more than passing attention4 ,the wires should be of size amply large to carry without heating the current necessary for its operation4 ,this topic will be discussed later but it is well here to call attention to the necessity for a circuit suited to the required current4 ,if an iron requiring #e amperes of current is attached to a circuit that is intended to carry only #c amperes the conducting wires will be overheated and may be the cause of serious results4 ,the ,electric ,toaster4--,as shown in ,fig4 #bbi the toaster is made of a series of heating elements mounted on mica frames and supported on a porcelain base4 ,it is an example of heating by exposed wires and direct radiation4 ,the heaters ,h are coils of flat resistance wire that are wound on wedge-shaped pieces of mica4 ,they are supported on a wire frame that is formed to receive slices of bread on each side of the heaters4 ,the attachment piece ,a and the material of the heater is similar in construction to that of the flat-iron4 ,the electric circuit may be traced from the contacts at ,a and ,b in the attachment plug by the dotted lines which indicate the wires in the porcelain base4 ,the current traverses each coil in turn and connects with the next1 alternately at the top and bottom4 ,the resistance is such as will permit the voltage of the circuit to send through the coils current sufficient to raise the heaters to a red heat4 ,the added resistance of the hot wires decreases the flow of current to keep the temperature at the desired degree4 ,illustration3 ,,fig4 #bbi4--,the electric toaster4 ,in a heater of this kind the resistance of the wire may increase with age and the coils fail to glow with a sufficient brightness4 ,the reason for the lack of heat is that of decrease in current1 due to the increased resistance of the wires4 ,this condition may be corrected by the removal of a little of the heater coils4 ,if a turn or two of the heater wire is removed1 the resistance of the circuit is reduced and the effect of the increased current will produce a higher temperature in the heater4 ,motors4--,as a means of developing mechanical power in small units1 the electric motor has made possible its application in many household uses that were formerly performed entirely by manual labor4 ,as a domestic utility electrical power is generated at a cost that is the least expensive of all its applications4 ,as a means of lighting and heating electricity has had to compete with established methods and has won place because of the advantages it possesses over that of cost4 ,in the development of domestic power it has practically no opponent4 ,there is no other form of power that can be so successfully utilized in delivering mechanical work for the purposes required4 ,a kilowatt of electric energy1 for which #aj cents is a common price1 will furnish a surprising amount of manual labor4 ,theoretically1 #gdf watts is equal to #a horsepower4 ,the commercial kilowatt is rated at an hour of time1 and is1 therefore1 equal theoretically to #a-a_/c horsepower for one hour4 ,while motors cannot be expected to transform all of this energy into actual work without loss1 even at the low rate of efficiency attained by the small electric motor1 they furnish power at a relatively small cost4 ,the first applications of electric power were those for sewing machines1 fans1 washing machines1 etc4 ,its use has made possible the vacuum cleaner1 automatic pumping1 refrigeration1 ventilation1 and many other minor uses as the turning of ice-cream freezers1 churning and rocking the cradle4 ,electric motors are made in many sizes for power generation and in forms to suit any application4 ,they are made to develop #a_/cj horsepower and in other fractional sizes for both direct and alternating current4 ,in applying mechanical power to any particular purpose special appliances must be made to adopt electric motors to the required work4 ,this is accomplished in all household requirements4 ,the motors are made to run at a high rate of speed and must be reduced in motion by pulleys or gears to suit their condition of operation4 ,as in the case of electric lamps they must be suited to the voltage and type of current of the circuit on which they are to be used4 ,commercial electric circuits furnish electricity in two types1 direct current1 ordinarily termed ,d4,c41 and ,a4,c4 or alternating current4 ,the terms direct and alternating current apply to the direction of the electric impulses which constitute the transmitted energy4 ,in the electric dynamo1 the generation of the current is due to impulses that are induced in the wires of the dynamo armature as they pass through a magnetic field of great intensity4 ,these electric impulses are directed by the manner in which the wires cut across the lines of force which make up the magnetic field4 ,in the case of the direct current the impulses are always in the same direction through the circuit1 while in the other they are induced alternately to and fro and so produce alternating current4 ,the term electric current is used only for convenience of expressing a directed form of energy4 ,since nothing really passes through the wires but a wave of energy1 the effect is the same whether the electric impulses are in the same or in opposite directions4 ,an incandescent lamp will work equally well on an ,a4,c4 or a ,d4,c4 circuit of the proper voltage2 but in the case of motors the form of construction must be suited to the kind of current4 ,both ,a4,c4 and ,d4,c4 commercial circuits are in common use1 the units of measurement are the same for each but in ordering a motor it is necessary to state the type of current and the voltage1 in order that the dealer may supply the required machine4 ,in the case of an alternating motor it is further necessary to state the number of cycles of changes of direction made per second in the ,a4,c4 circuit4 ,all of this information may be obtained by inquiring of a local electrician or of the power station from which the current is obtained4 ,there is still another item of information necessary to be supplied with an order for a motor1 other than those of fractional horsepower4 ,with motors of a horsepower or more it is necessary to state the number of phases included in the circuit4 ,this information to be complete must state whether the motor is to operate on a single-phase1 two-phase1 or three-phase circuit4 ,these terms apply to a condition made possible in ,a4,c4 generation that permits one1 two1 or three complete impulses to be developed in a circuit at the same time4 ,these phases are transmitted by three wires1 any two of which will form a circuit and give a supply of energy at the same voltage4 ,either one phase or all may be used at the same time and for this reason the phase of an ,a4,c4 motor should be given in an order4 ,to make the information complete there should be included the number of cycles or complete electric impulses per second produced in the circuit4 ,suppose that a #a-;horsepower motor is required to work on an ,a4,c4 circuit of #aaj volts4 ,inquiry of the electric company reveals that the circuit is three-phase at #fj cycles per second4 ,the dealer on receiving this information will be able to send a motor to suit your conditions4 ,most ,a4,c4 motors of #a horsepower or less are of the single-phase variety4 ,in the case of ,d4,c4 motors it is necessary only to state the voltage of the circuit to make the required information complete4 ,fuse ,plugs4--,every electric circuit is liable to occurrences known as short-circuiting or 8shorting40 ,this is a technical term describing a condition where1 by accident or design1 the wires of a circuit are in any way connected by a low-resistance conductor or by coming directly into contact with each other4 ,in case of shorting1 the resistance is practically all removed and the amount of current which flows through the circuit is so great as to produce a dangerous amount of heat in the wires4 ,if the covering of a lamp cord becomes worn so as to permit the bare wire of the two strands to come together1 a 8short0 is produced4 ,immediately1 the reduced resistance permits the electric pressure to send an amount of current through the wires1 greater than they are intended to carry4 ,when this occurs an electric arc will form at the point of contact with the accompanying flash of vaporizing metal and the wire will finally burn off4 ,fires started from this cause are not uncommon4 ,to guard against accidents from short-circuiting1 every electric circuit should be provided with fuses which1 in cases of emergency1 are intended to melt and thus break the circuit4 ,fuses are made of lead-composition or aluminum and are used in the form of wire or ribbon-like strips1 of sizes that will carry a definite amount of current4 ,they are designated by their carrying capacity in amperes4 ,as an example3 a #b-;ampere fuse will carry #b amperes of current without noticeable heating1 but at a dangerous overload the fuse will melt and the circuit be broken4 ,should a short-circuit be formed at any time1 the rush of current through the fuse will cause it almost immediately to melt1 and stop the flow of current4 ,they are1 therefore1 the safeguard of the circuit against undue heating of the conducting wires4 ,when an open fuse blows 7melts71 the heat generated by the arc1 formed at the breaking circuit1 is so sudden that there is frequently an explosive effect that throws the melted metal in all directions1 and in case it comes into contact with combustible material a fire may result4 ,to do away with this danger1 fire insurance companies in their specifications of electric fixtures state what forms of fuses will be acceptable in the buildings to be insured4 ,these specifications are known as the ,underwriters ,rules and may be obtained from any fire insurance company4 ,the fuses1 or fuse plug1 as they are commonly called1 generally occupy a place in a cabinet or distributing panel1 near the point where the lead wires enter the building4 ,the cabinet contains the porcelain cutouts for sending the current through the different circuits2 the fuse plugs form a part of the cutouts1 one fuse to each wire4 ,the cabinet contains besides the cutouts a double-poled switch to be used for shutting off the current from the building when desired4 ,illustration3 ,,fig4 #bcj4--;,electric cabinets4 ,cabinets for this purpose are made in standard form of wood or steel to suit the condition of service4 ,these cabinets may be obtained from any dealers in electrical supplies or the cabinet may be made a part of the house since they are only small shallow closets4 ,fig4 #bcj represents such a cabinet as is used in the average dwelling4 ,it is made of a light wooden frame set between the studding of a partition at any convenient place4 ,the bottom of the cabinet is made sloping to prevent its being used as a place of storage for articles that might lead to trouble4 ,the cabinet is sometimes lined with asbestos paper as a prevention from fire but this is not necessary as the fuse plugs and their receptacles1 when of approved design1 are sufficient to prevent accident4 ,the main wires which supply the house with electricity--marked lead wires--are brought into the cabinet as shown in ,fig4 #bca and attached to the poles of the switch ,s4 ,in passing through the switch the lead wires each contain a mica-covered fuse plug ,f1 that will be described later4 ,the current at any time may be entirely cut off from the house by pulling the handle ,h1 which is connected by an insulating bar and the contacts ,n of the switch4 ,when the handle ,h is pulled to separate the contact pieces1 all electric connection is severed at that point4 ,illustration3 ,,fig4 #bca4--;,electric panel containing cutout blocks1 fuses and switch4 ,the wattmeter for measuring the current is placed at the points marked meter1 as a part of the main circuit4 ,the main wires in the cabinet terminate in the porcelain cutouts1 from which are taken off the various circuits of the house4 ,in the figure1 three such cutouts are shown making three circuits marked #a1 #b1 and #c4 ,in circuit ,no4 #a1 the fuses are marked ,f4 ,these wires are joined to the main wires at the points marked ,c and ,c4 ,the number of circuits the house will contain depends on the number of lights and the manner in which they are placed4 ,the circuits are intended to be arranged so that in case of a short1 no part of the house will be left entirely in darkness4 ,fuses for general use are made in two different types--the plug type and the cartridge type--each of which conforms to the rules of the ,underwriters ,association4 ,those most commonly used for house wiring are the plug type shown in ,fig4 #bcb and indicated in the figure just described4 ,these plugs are made of porcelain and provided with a screw base which permits their being screwed into place like an incandescent lamp4 ,the front of the plug is arranged with a mica window which allows inspection to be made in case of a short1 the blown fuse indicating the circuit in which the trouble is located4 ,another style of the same type of plug1 known as the re-fusable fuse plug1 permits the fuse to be replaced after the wire has been destroyed by a short4 ,illustration3 ,,fig4 #bcb4--,mica covered fuse plug4 ,illustration3 ,,fig4 #bcc4--;,cartridge fuse4 ,illustration3 ,,fig4 #bcd4--,plug receptacle for cartridge fuse4 ,the second type is commonly known as the cartridge fuse plug from its general appearance4 ,this fuse is shown in ,fig4 #bcc4 ,the fusable wire is enclosed in a composition fiber tube1 the ends of which are covered by brass caps which afford contact pieces in the fuse receptacle and to which are fastened the ends of the fuse wire4 ,these fuses are very generally employed in power circuits and others of large current capacity4 ,the small circle in the center of the label is the indicator4 ,when the fuse burns out1 a black spot will appear in the circle4 ,it is sometimes desirable to use the cartridge fuse plug in receptacles intended for the mica-covered type4 ,the use of the cartridge fuses under this condition is effected by use of a porcelain receptacle such as is shown in ,fig4 #bcd2 the cartridge fuse is simply inserted into the receptacle which is then screwed into the socket in place of the mica fuse4 ,in order to avoid any possible chance of overloading the wires of a circuit1 fuses are installed which are suited to the work to be performed4 ,suppose that there are ten #dj-watt lamps that may be used on a circuit1 each lamp of which requires #d_/aa ampere of current4 #aaj ,c #dj watts ,c #dj_/aaj #d_/aa ampere per lamp4 ,ten such lamps require ten times #d_/aa ampere or #dj_/aa #c4g amperes to supply the lamps4 ,a fuse that will carry #c4g amperes of current will supply the circuit but a #e-;ampere fuse will permit an increase in the size of the lamp and will fulfill all the necessary conditions4 ,if1 however1 an electric heater requiring #g amperes were attached to the circuit1 the fuse being intended for only #e amperes would soon burn out4 ,when a fuse burns out it must be replaced either with an entirely new receptacle or the fuse wire must be replaced4 ,it sometimes happens that in case of a blown fuse there is no extra part at hand and a wire of much greater carrying capacity is used in its place4 ,it should be remembered that in this practice of 8coppering0 a blown fuse1 has taken away the protection against short-circuiting with its possibility of mischief4 ,when a short occurs1 the cause should be sought for4 ,it cannot be located and on being replaced a second fuse blows1 the services of an electrician should be secured4 ,electric ,heaters4--,all electric heating devices--whether in the form of hot plates1 ovens1 stoves or other domestic heating apparatus-possess heating elements somewhat similar to the flat-iron or the toaster4 ,the construction of the heating element will depend on the use for which the heater is intended and the temperature to be maintained4 ,hot plates similar to that of ,fig4 #bce are made singly or two or more in combination4 ,when the heat is to be transmitted directly by radiation the heating coils are open1 as with the toaster4 ,under other conditions the coils are embedded in enamel that is fused to a metal plate4 ,in elements of this kind the heat is transmitted to the plate entirely by conduction from which it is utilized in any manner requiring a heated surface4 ,the form of the heating element will1 therefore1 depend on the application of the heat1 whether it is by direct radiation or by a combination of radiation and conduction4 ,electric ovens are constructed to utilize electric heat in an insulated enclosure4 ,heat derived from electricity is more expensive than from other sources but when used in insulated ovens it may be made to conveniently perform the service of that derived from other fuels4 ,in electric ovens the heaters are attached to inside walls4 ,as in other heating elements they are arranged to suit the conditions for which the oven is to be used4 ,the heaters are usually so divided as to permit either all of the heaters to be used at the same time to quickly produce a high temperature1 or only a portion of the heat to be used in keeping up the temperature lost by radiation4 ,ovens of this kind may be provided with regulators by means of which the heat may be automatically kept at any desired temperature4 ,such heating and temperature regulation may be used to produce any desired condition1 but in practice the cost of the heat is the factor which determines its use4 ,unless electric heat is conserved by insulation it cannot become a competitor with other forms of heating4 ,illustration3 ,,fig4 #bce4--;,electric three-burner hot plate4 ,electric hot plate4 ,electric cooking stoves and ranges are made for every form of domestic and culinary service4 ,they fulfill many purposes that may be obtained in no other way4 ,as conveniences1 the cost of heat becomes of secondary consideration and their use is constantly increasing4 ,in ,fig4 #bcf is an example of a time-controlled and automatically regulated electric range4 ,in the picture is shown separately all of the heaters for the ovens and stove top4 ,the part ,s shows the switches attached to the heaters of the stove top1 which is raised to show the connecting wires4 ,in the larger oven there are two heaters of #ajjj watts each1 and in the smaller oven one heater of #hej watts4 ,each heater may be controlled separately with a switch giving three regulations of heat--high1 medium and low4 ,the advantage of this arrangement lies in the fact that one can set the two heaters in the oven at different temperatures which will permit either a slow or quick heat1 but when the predetermined temperature is reached the current will be automatically cut off by the circuit-breakers4 ,such flexibility of heat control in the ovens permits the operator to apply heat at both top and bottom for baking and roasting at just the desired temperature4 ,this arrangement also avoids the danger of scorching food from concentration of heat1 and warping utensils or the linings of the oven4 ,all oven heaters on the automatic ranges are further controlled and mastered by the circuit-breakers4 ,illustration3 ,fig4 #bcf4--;,electric range4 ,showing how all parts can be removed for cleaning and replacement4 ,intercommunicating ,telephones4--,this form of telephone is used over short distances such as from room to room in buildings or for connecting the house with the stable1 garage1 etc4 ,it is complete1 in that it possesses the same features as any other telephone but the signal is an electric call-bell instead of the polarized electric bell used in commercial telephone service4 ,any telephone is made to perform two functions3 7#a7 that of a signal with which to call attention2 and 7#b7 the apparatus required to transmit spoken words4 ,in the intercommunicating telephone or interphone1 the signal is made like any call-bell and parts are similar to those described under electric signals4 ,the bell-ringing mechanism is included in the box with the transmitting apparatus and the signal is made by pressing a push button4 ,it is not suitable for connecting with public telephones4 ,telephone companies1 as a rule1 do not permit connection with their lines any apparatus which they do not control4 ,the interphone of ,fig4 #bcg shows the instrument complete except the battery4 ,this form of instrument is inexpensive1 easy to put in1 simple to operate and supplies a most excellent means of intercommunication4 ,complete directions for installation are supplied with the phones by the manufacturers4 ,illustration3 ,,fig4 #bcg4--,the intercommunicating telephone4 ,electric ,signals4--,electrical signaling devices for household use1 in the form of bells and buzzers1 are made in a great variety of forms and sizes to suit every condition of requirement4 ,the vibrating mechanism of the doorbell is used in all other household signals except that of the magneto telephone4 ,it is an application of the electromagnet1 in which the magnetism is applied to vibrate a tapper against the rim of a bell4 ,a bell system consists of the gong with its mechanism for vibrating the armature1 an electric battery or ,a4,c4 transformer connected to the magnet coils to form an electric circuit and a push button which serves to close the circuit whenever the bell is to be sounded4 ,the bell system is an open-circuit form of apparatus2 that is1 the circuit is not complete except during the time the bell is ringing4 ,by pressing the push button the circuit is closed and the electric current from the battery flows through the magnet and causes the tapper to vibrate4 ,when the push button is released the circuit is broken and the circuit stands open until the bell is to be again used4 ,the parts of the bell mechanism are shown in ,fig4 #bch where with the battery1 the push button and the connecting wires is shown a complete doorbell outfit4 ,these parts may be placed in different parts of the building and connected by wires as shown in the ,fig4 #bci4 ,the bell is located at ,r1 in the kitchen4 ,the battery is placed in the closet at ,b1 the connecting wires are indicated by the heavy lines2 they are secured to any convenient part of the wall and extend into the basement and are fastened to the joists4 ,the wires terminate in the push button ,p1 where they pass through the frame of the front door4 ,the wires are secured by staples to keep them in place4 ,each wire is fastened separately to avoid the danger of short-circuiting4 ,if both wires are secured with a single staple there is a possibility of the insulation being cut and a short produced across the staple4 ,illustration3 ,,fig4 #bch4--;,diagram showing the parts of an electric doorbell4 ,the battery ,b1 in ,fig4 #bch1 is a single dry cell but more commonly it is composed of two dry cells joined in series4 ,it is connected1 as shown in the figure1 to the binding posts ,p and ,p of the vibrating mechanism1 the push button ,,pb serving to make contact when the circuit is to be closed4 ,when the button is pressed the circuit is complete from the pole of the battery cell through the binding post ,p1 across the contact ,f1 through the spring ,a1 through the magnet coils ,m1 across the binding post ,p and push button to the-pole of the cell4 ,the vibration of the tapper is caused by the magnetized cores of the coils ,m4 ,when the electric current flows through the coils of wire1 the iron cores become temporary magnets4 ,this magnetism attracts the iron armature attached to the spring ,a1 and it is suddenly pulled forward with energy sufficient to cause the tapper to strike the gong4 ,as the armature moves forward1 the spring contact at ,f is broken and the current stops flowing through the magnet coils4 ,when the current ceases to flow in the magnet coils1 the cores are demagnetized and the armature is drawn back by the spring ,a to the original position4 ,as soon as the contact is restored at ,f a new impulse is received only to be broken as before4 ,in this manner the bell continues ringing so long as the push button makes contact4 ,the screw at ,f is adjusted to suit the contact with the spring attached to the armature4 ,the motion of the armature may be regulated to a considerable degree by this adjustment4 ,when properly set the screw is locked in place by a nut and should require no further attention4 ,illustration3 ,,fig4 #bci4--;,example of an electric doorbell installation4 ,electric bells vary in price according to design and workmanship4 ,a bell outfit may be purchased complete for #a but it is advisable to install a bell of better construction1 as few pieces of household mechanism repay their cost in service so often as a well-made bell4 ,the bell should be rigid1 well-constructed1 and the contact piece ,f should be adjustable4 ,this part ,f1 being the most important of the moving parts of the bell1 is shown separately in ,fig4 #bdj4 ,only the ends of the magnet coils with their cores are shown in the figure4 ,the contact is made at ,a1 by the pressure of the spring against the end of the adjustable screw ,d4 ,when the screw is properly adjusted it is locked securely in place by the nut ,g4 ,the screw ,d is held with a screw-driver and the nut ,g forced into position to prevent any movement4 ,if the screw is moved1 so that contact is lost at ,a1 the bell will not ring4 ,in the better class of bells the point of the screw and its contact at ,a are made of platinum to insure long life4 ,with each movement of the armature a spark forms at the contact which wears away the point1 so that to insure good service these points must be made of refractory material4 ,illustration3 ,,fig4 #bdj4--;,diagram of the vibrating mechanism used in buzzers and doorbells4 ,buzzers4--,electric bells are often objectionable as signal calls because of their clamor1 but with the removal of the bell the vibrating armature serves equally well as a signal but without the undesirable noise4 ,with the bell and tapper removed the operating mechanism of such a device works with a sound that has given to them the name of buzzers4 ,fig4 #bda illustrates the form of an iron-cased buzzer for ordinary duty4 ,the working parts are enclosed by a stamped steel cover that may be easily removed4 ,the mechanism is quite similar to that already described in the doorbell and ,fig4 #bdj shows in detail the working parts4 ,the noise1 from which the device takes its name1 is produced by the armature and spring in making and breaking contact4 ,burglar ,alarms4--,a burglar alarm is any device that will give notice of the attempted entrance of an intruder4 ,it is usually in the form of a bell or buzzer placed in circuit with a battery1 as a doorbell system1 in which the contact piece is placed to detect the opening of a door or window4 ,the contact is arranged to start the alarm whenever the window or door is opened beyond a certain point4 ,the attachment shown in ,fig4 #bdb is intended to form the contact for a window4 ,it is set in the window frame so that the lug ,c will be depressed and close the alarm circuit in case the sash is raised sufficiently to admit a man4 ,each window may be furnished with a similar device and the doors provided with suitable contacts which together form a system to operate in a single alarm4 ,during the time when the alarm is not needed it is disconnected by a switch4 ,the windows and doors are sometimes connected with an annunciator which will indicate the place from which an alarm is given4 ,an annunciator used for this purpose designates the exact point at which the contact is made and removes the necessity of searching for the place of attempted entrance4 ,illustration3 ,,fig4 #bda4--,the electric buzzer4 ,,fig4 #bdb4--;,contact for a window burglar alarm4 ,,fig4 #bdc4--,trip contact which announces the opening of a door4 ,,fig4 #bdd4--;,contact for a door alarm4 ,,fig4 #bde4--;,doorway or hall matting with contacts for electric alarm4 ,in ,fig4 #bdc is illustrated one form of door trip which may be used on a door to announce its opening4 ,this trip makes electric connection in the alarm circuit when the opening door comes into contact with the swinging piece ,t1 but no contact is made as the door closes4 ,the trip is fastened with screws at ,d to the frame above the door4 ,the opening door comes into contact with ,t and moves it forward until the electric circuit is formed at ,c2 after the door has passed1 a spring returns it to place4 ,as the door is closed1 the part ,t is moved aside without making electric contact4 ,fig4 #bdd is another form of door alarm that makes contact when the door is opened and remains in contact until the door is closed4 ,the part ,p is set into the door frame of the door in such position that the contact at ,c is held open when the door is closed4 ,when the door is opened a spring in ,c closes the contact and causes the alarm to sound4 ,it continues to sound until the door is closed and the contact is broken4 ,when the use of the alarm is not required1 the contact-maker is turned to one side and the contact is held open by a catch4 ,it is put out of use by pressing the plunger to one side4 ,the matting shown in ,fig4 #bde is provided with spring contacts so placed that no part may be stepped upon without sounding the alarm4 ,when placed in a doorway and properly connected with a signal1 no person can enter without starting an alarm4 ,the matting is attached to the alarm by the wires ,c and contacts are set at close intervals so that a footstep on the mat must close at least one contact4 ,annunciators4--,it is often convenient for a bell or buzzer to serve two or more push buttons placed in different parts of the house4 ,in order that there may be means of designating the push button used--when the bell is rung--an annunciator is provided4 ,this is a box arranged with an electric bell and the required number of pointers and fingers corresponding to the push buttons4 ,in ,fig4 #bdf is shown an annunciator with which two push buttons are served by the single bell4 ,the annunciator is placed at the most convenient place of observation1 usually in the kitchen4 ,when the bell rings the pointer indicates the push button that has last been used4 ,in hotels or apartment houses an annunciator with a single bell may thus serve any number of push buttons4 ,in a burglar-alarm system the annunciator numbers are arranged to indicate the windows and other openings at which entrance might be made4 ,when the alarm sounds the annunciator indicates the place from which the alarm is made4 ,table ,pushes4--,call bells to be rung from the dining-room table are connected with an annunciator or to a separate bell4 ,the table pushes may be temporarily clamped on the edge of the table and connected by a cord to an attachment set in the floor or the connection may be made by a foot plate set on the floor4 ,in ,fig4 #bdg is shown a form of push ,p which is intended to be clamped to the edge of the table under the cloth4 ,the plate ,f forms the floor connection4 ,it is set permanently with the upper edge flush with the surface of the floor4 ,the part ,s1 in which the connecting cord terminates1 when inserted in the floor plate1 makes contact at the points ,c to form an electric circuit with the battery4 ,the foot plate shown in ,fig4 #bdh is only an enlarged push button which is set under the table in convenient positions to be pressed with the foot4 ,its connection might be made as indicated or with the same floor connection as that of the preceding figure4 ,fig4 #bdi is a simpler form of floor push in which a metallic plug is inserted in the floor plate4 ,when the plug ,r is pressed1 contact is made at the points ,c to form the circuit with the battery and bell4 ,illustration3 ,,fig4 #bdf4--;,a kitchen annunciator4 ,,fig4 #bdg4--,plug attachment and table push for a dining table4 ,,fig4 #bdh4--;,foot plate and contact for table bell4 ,,fig4 #bdi4--;,call bell attachment with detachable contact piece4 ,bell-ringing ,transformers4--,the general employment of alternating electricity for all commercial service requiring distant transmission is because of the possibility of changing the voltage to suit any condition4 ,the energy transmitted is determined by the amperes of current carried by the wires and the volts of pressure by which it is impelled4 ,the product of these two factors determines the watts of energy transmitted4 #aaj volts #a ampere #aaj watts4 ,if the voltage is raised to say ten times the original intensity with the same current1 the quantity of energy is ten times the original amount4 #aajj volts #a ampere #aajj watts4 ,the carrying capacity of wires is determined by the amperes of current that can be transmitted without heating4 ,the cost of copper wire is such that the expense of large wires for carrying a large current is unnecessary where by raising the voltage a small wire will perform the same service2 therefore1 it is desirable to transmit electric energy at a high voltage and then transform it to suit the condition of usage4 ,alternating current may be transformed to a higher or a lower voltage to suit any condition by using step-up or step-down transformers4 ,a transformer is a simple device composed of two coils of wire wound on a closed core of iron4 ,the coil into which is sent the inducing current is the primary4 ,that in which the current is induced is the secondary coil4 ,the change in voltage between primary and secondary coils vary as the number of turns of wire which compose the coils4 ,the house circuit may be stepped down from the customary #aaj volts to a voltage such as is furnished by a single dry cell1 or a battery of cells4 ,in principle1 the action of the transformer is the same as that of the induction coil1 a detailed explanation of which will be found in any text-book of physics4 ,each impulse of current in the primary coil of the transformer magnetizes its core and the magnetism thus excited induces a corresponding current in the secondary coil4 ,since alternating current in the primary coil constantly changes the polarity of the core1 each change of magnetism induces current in the secondary coil4 ,small transformers are frequently used for operating doorbells1 annunciators1 etc41 in place of primary batteries4 ,these transformers are also used to supply current for lighting low-power tungsten lamps that cannot be used with the ordinary voltages employed in house lighting4 ,the primary wires of the transformer are attached to the service wires in the house and from the secondary wires voltages are taken to suit the desired purposes4 ,illustration3 ,,fig4 #bej4--;,doorbell transformer4 ,illustration3 ,,fig4 #bea4--;,details of doorbell transformer4 ,fig4 #bej shows such a transformer with the cover partly broken away to expose the interior construction4 ,the wires from house mains ,,mm lead the current to the primary coil ,p which is a large number of turns of fine wire wound about a soft-iron core4 ,the induced current in the secondary coil ,s is taken from the contact points #a1 #b1 #c and #d4 ,the construction of the transformer coils shown in ,fig4 #bej indicates the primary wires at ,,ll of ,fig4 #bea4 ,the wires of the primary coil are permanently attached to house wires4 ,the reactive effect of the magnetism in the coil permits only enough current to flow as will keep the core excited4 ,this is a step-down transformer and the secondary coil contains fewer turns of wire than the primary coil4 ,since the voltage induced in the secondary coil is determined by the number of turns of wire in action1 this coil is so arranged that circuits formed by attachment with different contacts give a variety of voltages4 ,the numbers on the front of ,fig4 #bej correspond to those of ,fig4 #bea4 ,the coils between contact #a and the others #b1 #c and #d1 represent different number of turns of wire and in them is induced voltages corresponding with the number of turns of wire in each4 ,the ,recording ,wattmeter4--,to determine the amount of electricity used by consumers1 each circuit is provided with some form of wattmeter4 ,these meters might be more correctly called watt-hour meters since they register the watt-hours of electrical energy that pass through the circuit4 ,illustration3 ,,fig4 #beb4--,recording watt meter4 ,in the common type of meter1 the recording apparatus in composed of a motor and a registering dial4 ,the motor is intended to rotate at a rate that is proportional to the amount of passing current4 ,an example of this device is the ,thompson induction meter of ,fig4 #beb4 ,the motion of the aluminum disc seen through the window in front indicates at any time the rate at which electricity is being used4 ,this constitutes the rotating part of the motor4 ,it is propelled by the magnetism1 created by the passing current1 and is sensitive to every change that takes place in the electric circuit4 ,each lamp1 heater or motor that is brought into use or turned off produces a change of current in the conducting wires and this change is indicated by the rate of rotation of the disc4 ,each rotation of the disc represents the passage of a definite amount of electricity that is recorded on the registering dials4 ,the shaft on which the disc is mounted is connected with the recording mechanism by a screw which engages with the first of a train of gears4 ,these gears have1 to each other1 a ratio of #aj to #a2 that is1 ten rotations of any right-hand gear1 causes one rotation of the gear next to the left4 ,the pointers on the dial are attached to the gear spindles4 ,one rotation of the right-hand dial will move the pointer next to the left one division on its dial4 ,each dial in succession will move in like ratio4 ,the meters are carefully calibrated and usually record with truthfulness the amount of electricity used4 ,they are1 however1 subject to derangement that produces incorrect registration4 ,to ,read the ,meter4--,first1 note carefully the unit in which the dial of the meter reads4 ,the figures above the dial circle indicate the value of one complete revolution of the pointer in that circle4 ,therefore1 each division indicates one-tenth of the amount marked above or below the circle4 ,second1 in reading1 note the direction of rotation of the pointers4 ,commencing at the right1 the first pointer rotates in the direction of the hands of a clock 7clockwise72 the second rotates counter-clockwise2 the third1 clockwise2 etc41 alternately4 ,the direction of rotation of any one pointer may easily be determined by noting the direction of the sequence of figures placed around each division4 ,the arrows 7shown above7 indicate the direction of rotation of the pointers when the meter is in operation4 ,third1 read the figures indicated by the pointers from right to left1 setting down the figures as they are read1 i4e41 in a position relative to the position of the pointers4 ,,note3 ,one revolution of the first or right-hand pointer makes one-tenth of a revolution of the pointer next to it on the left4 ,one revolution of this second pointer makes one-tenth of a revolution of the pointer next to it on the left1 etc4 ,therefore1 if1 when reading the dial1 it is found that the second pointer rests very nearly over one of the tenth divisions and it is doubtful as to whether it has passed that mark1 it is only necessary to refer to the pointer next to it on the right4 ,if this pointer on the right has not completed its revolution1 it shows that the second pointer has not yet reached the division in question4 ,if it has completed its revolution1 that is1 passed the zero1 it indicates that the second pointer has reached the division and the figure corresponding is to be set down for the reading4 ,illustration3 ,,fig4 #bec;a4--,this dial reads #idhd kilowatt hours4 ,the foregoing also applies to the remaining pointers4 ,when it is desired to know whether a pointer has passed a tenth division mark1 it is necessary to refer only to the next pointer to the right of it4 ,fourth1 see if the register is direct-reading1 i4e41 has no multiplying constant4 ,some registers are not direct-reading in that they require multiplying the dial reading by a constant such as #aj or #ajj in order to obtain the true reading4 ,if the register bears some notation such as 8,multiply by #ajj10 the reading as indicated by the pointers should be multiplied by #aj or #ajj as the case may be to determine the true amount of energy consumed4 ,some of the earlier forms of meters were equipped with what is known as a 8non-direct-reading register40 ,in this case1 the reading must be multiplied by the figure appearing on the dial as just explained1 but the dial differs from those just described in that the multiplying constant is generally a fraction such as #a_/b1 etc41 and the dial has five pointers4 ,this older style of register reads in 8watt-hours0 of 8kilowatt-hours40 ,fifth1 the reading of the dial does not necessarily show the watt-hours used during the past month4 ,in other words1 the pointers do not always start from zero4 ,to determine the number of watt-hours used during a certain period it is necessary to read the dial at the beginning of a period and again at the end of that period4 ,by subtracting the first reading from the second1 the number of watt-hours or kilowatt-hours used during the period is obtained4 ,the meter man1 having in his possession a record of the readings of each customer's meter for the preceding months1 is thus able to determine the amount of energy consumed monthly4 ,,examples ,,of ,,meter ,,readings ,fig4 #bec;a shows an example of an ordinary dial reading4 ,commencing at the first right-hand pointer1 ,fig4 #bec;c1 it is noted that the last figure passed over by the pointer is #a4 ,the next circle to the left shows the figure last passed to be #b1 bearing in mind that the direction of the rotation of this pointer is counter-clockwise4 ,the last figure passed by the next pointer to the left is #a1 while that passed by the last pointer to the left is obviously #i4 ,the reading to be set down1 therefore1 is #iaba4 ,illustration3 ,,fig4 #bec;b4--,this dial reads #iig kilowatt hours4 ,illustration3 ,,fig4 #bec;c4--,this dial reads #iaba kilowatt hours4 ,in a similar manner the dial shown in ,fig4 #bec;b may be read4 ,in this case1 however1 three of the pointers rest nearly over the divisions and care must be used to follow the direction to avoid error4 ,commencing at the right1 the first pointer indicates #g4 ,the second pointer has passed #i and is approaching #j4 ,the third pointer appears to rest directly over #j1 but since the second pointer reads but #i1 the third cannot have completed its revolution and hence the figure last passed is set down which in this case is #i4 ,similarly1 the fourth or left-hand pointer appears to rest directly over #a but by referring to the pointer next to it on the right1 we find that its indication is #i as just explained4 ,therefore1 the fourth pointer cannot have reached #a1 and so the figure last passed which is #j is set down1 which in this case is #i4 ,similarly1 the fourth or left-hand pointer appears to rest directly over #a1 but by referring to the pointer next to it on the right we find that its indication is #i as just explained4 ,therefore1 the fourth pointer cannot have reached #a1 and so we set down the figure last passed which is #j4 ,the figures as they have been set down1 therefore1 are #jiig1 which indicates that #iig kilowatt-hours of electricity have been used4 ,if1 for example1 the reading of this meter for the preceding month was #igf kilowatt-hours1 the number of kilowatt-hours used during that month would be #iig-igf #ba kilowatt-hours4 ,state ,regulation of ,meter ,service4--,electric wattmeters are subject to errors that may cause them to run either fast or slow4 ,complaints made of inaccurate records or readings are usually rectified by the electric company4 ,in many ,states all public utilities are governed by laws that are formulated by public utilities commissions or other bodies from which may be obtained bulletins fully describing the conditions required of public service corporations or owners of public utilities4 ,the following quotation from ,bulletin ,no4 ,v41 #bcc of the ,railroad ,commission of ,wisconsin1 will give an illustration of the requirement in that ,state4 ,,rule #ad4--;,,creeping ,,meters4--,no electric meter which registers upon 8no load0 shall be placed in service or allowed to remain in service4 ,this means that when no electricity is being used in the system the motor disc should remain stationary and if it shows any motion under such condition it is not recording accurately4 ,,periodic ,,tests ,,rule #ag4--;,each watt-hour meter shall be tested according to the following schedule and adjusted whenever it is found to be in error more than #a per cent41 the tests both before and after adjustment being made at approximately three-quarters and one-tenth of the rated capacity of the meter4 ,meters operated at low power-factor shall also be tested at approximately the minimum power-factor under which they will be required to operate4 ,the tests shall be made by comparing the meter1 while connected in its permanent position1 on the consumer's premises with approved1 suitable standards1 making at least two test runs at each load1 of at least #cj seconds each1 which agree within #a per cent4 ,single-phase1 induction-type meters having current capacities not exceeding #ej amperes shall be tested at least once every #d months and as much oftener as the results obtained shall warrant4 ,all single-phase induction-type meters having current capacities exceeding #ej amperes and all polyphase and commutator-type meters having voltage ratings not exceeding #bej volts and current capacities not exceeding #ej amperes shall be tested at least once every #ab months4 ,all other watt-hour meters shall be tested at least once every #f months4 ,,rule #bj4--,,request ,,tests4--,each utility furnishing metered electric service shall make a test of the accuracy of any electricity meter upon request of the consumer1 provided the consumer does not request such test more frequently than once in #f months4 ,a report giving the results of each request test shall be made to the consumer and the complete1 original record kept on file in the office of the utility4 ,electric ,batteries4--,electric batteries are composed of electric cells that are made in two general types3 the primary cell1 in which electricity is generated by the decomposition of zinc2 and the secondary cell or storage cell in which electricity from a dynamo may be accumulated and thus stored4 ,electric cells are the elements of which electric batteries are made2 a single electric cell is often called a battery but the battery is really two or more cells combined to produce effects that cannot be attained by a single element4 ,both primary and secondary batteries form a part of the household equipment but the work of the secondary battery is used more particularly for electric lighting1 the operation of small motors and for other purposes where continuous current is required4 ,it will1 therefore1 be considered in another place4 ,primary batteries are used to operate call-bells1 table pushes1 buzzers1 night latches and various other forms of electric alarms besides which they are used in gas lighters1 thermostat motors and for many special forms1 all of which form an important part in the affairs of everyday life4 ,primary battery cells for household use are made to be used in the wet and dry form1 but the dry cell is now more extensively used than any other kind and for most purposes has supplanted the wet form4 ,formerly all primary cells were made of zinc and copper plates placed in a solution called an electrolite1 that dissolved the zinc and thus generated electricity1 the electrolite acting as a conductor of the electricity to the opposite plate4 ,in later electric cells the copper was replaced by plates of carbon and from the zinc and carbon cell was finally evolved the present-day dry cell4 ,when the use of electric cells reached a point where portable batteries were required1 a form was demanded from which the solution could not be lost accidentally4 ,the first electric cells in which the electrolite was not fluid was1 therefore1 called a dry cell4 ,these cells are not completely dry4 ,the electrolite is made in the form of a paste that acts in the same manner as the fluid electrolite and is only dry in that it is not fluid4 ,illustration3 ,,fig4 #bed4--;,electric dry cell4 ,illustration3 ,,fig4 #bee4--;,details of electric dry cell4 ,in construction the dry cell is shown in ,figs4 #bed and #bee1 the former showing its exterior and the latter exposing its internal construction4 ,the container is a zinc can which is lined with porous paper to prevent the filler from coming into contact with the zinc4 ,the zinc further is the active electrode1 the chemical destruction of which generates the electricity4 ,the parts enclosed in the container are3 a carbon rod1 which acts as the positive pole2 and the filler1 composed of finely divided carbon mixed with manganese dioxide and wet with a solution of salammoniac4 ,the composition plug1 made of coal-tar products and rosin1 is intended to keep the contents of the can in place and prevent the evaporation of the moisture4 ,binding posts attached to the carbon rod and soldered to the can furnish the and-poles4 ,in the action of cell1 the salammoniac attacks the zinc in which chemical action electricity is evolved4 ,the electricity is conducted to the carbon pole through the carbon and the salammoniac solution which in this case is the electrolite4 ,in the dissolution of the zinc1 hydrogen gas is liberated which adds to the resistance of the cell and thus reduces the current4 ,the presence of the hydrogen is increased when the action of the cell is rapid and the decrease in current is said to be due to polarization4 ,the manganese dioxide is mixed with the filler in order that the free hydrogen may combine with the oxide and thus reduce the resistance4 ,this process is known as depolarization4 ,the combination between the hydrogen and the oxide is slow and for this reason the depolarization of batteries sometimes require several hours4 ,dry cells are usually contained in paper cartons to prevent the surfaces from coming into contact and thus destroying their electrical action4 ,the best cell is that which gives the greatest amount of current for the longest time4 ,under any condition the working value of a cell is determined by the number of amperes of current it can furnish4 ,the current is measured by a battery tester such as ,fig4 #beg4 ,the connection of the tester is placed in contact with the pole of the cell or battery and the other connection placed on the-pole4 ,the pointer will immediately indicate the current given out by the battery4 ,a new dry cell will give #bj or more amperes of current for a short time but if used continuously the quantity of current will be reduced by polarizing until but a very small amount is generated4 ,a cell that indicates less than #e amperes should be replaced4 ,if short-circuited1 that is if the poles are connected without any intervening resistance1 a large amount of current will be given but the cell will soon wear out and possibly be ruined4 ,a cell should1 therefore1 never be allowed to become short-circuited4 ,the voltage of a cell is practically continuous and should be from #a4e to #a volt4 ,it is quite possible that a cell may possess its normal voltage and yet deliver little current2 the voltage of a cell does not indicate its working property4 ,in order to be assured of active cells they should be tested at the time of purchase with an ammeter4 ,the moisture in the paste of a cell is that which forms the circuit between the zinc and the carbon elements4 ,if the paste has dried out its resistance is increased and the cell generates little current4 ,the voltage of such a cell may be normal while the amperage is very low4 ,cells in this condition may be revived by adding moisture to the paste as a temporary remedy4 ,this may be accomplished by puncturing the can with a nail and adding water4 ,a solution of salammoniac may be used instead of water and the cell soaked to accomplish the same purpose2 this1 however1 is only a temporary expedient4 ,temperature influences the working properties of an electric cell in pronounced manner4 ,the moisture contained in the cell is composed of ammonium chloride and zinc chloride and consequently the resistance of the cell increases with the fall of temperature2 the effect of the resistance thus added is a decrease in the flow of current4 ,batteries should be kept in a temperature as nearly as possible that of #gj;,f4 ,the battery regains its normal rate of discharge when the temperature is restored4 ,the normal voltage and amperage for a given make of cell is practically the same for all4 ,the size of the cell does not in any way influence the voltage4 ,small cells and large cells are the same4 ,the large cells are advantageous only in that they give out a greater number of ampere-hours of energy4 ,all batteries are rated in the number of ampere-hours of current they are capable of furnishing4 ,the ampere-hour represents an ampere of current for one hour4 ,on this basis all batteries are rated for the total amount of energy they are capable of producing4 ,if the battery is worked at a high current1 its life is short2 if however1 it is discharged at a low rate1 its life should be long4 ,in all cases the product of the number of amperes and the number of hours constitute the ampere-hours of energy produced4 ,battery ,formation4--,for ordinary household work as that of operating doorbells1 etc41 the cells which form a battery are joined in series1 that is the positive or carbon pole of one cell is joined to the zinc or negative pole of the next4 ,the cells so connected are placed in circuit with the bell and push button4 ,if by accident the two cells of a battery are joined with both carbon poles or both zinc poles together the battery will give out no current because the voltage is opposed4 ,illustration3 ,,fig4 #bef4--;,battery combinations4 ,in the use of batteries for ignition as for gasoline engines1 automobiles1 etc41 the arrangement of the cells has frequently a decided influence on the effect produced4 ,in ,fig4 #bef ,a is represented four cells joined in series1 that is the carbon or poles are joined with the zinc or-poles1 alternately4 ,connected in this manner if each cell gives #a4e volts the battery will give #d #a4e #f volts2 the current1 however1 will remain as that of a single cell4 ,if the cells singly give #bj amperes1 the battery will give #bj amperes4 ,when cells are connected in this form the current passes through each cell in turn and is as much a part of the circuit as the wires4 ,should one of the cells be 8dead0--that is delivering no current--it will act as additional resistance and the current is reduced4 ,when joined in multiple or parallel connection as in ,fig4 #bef ,b1 in which all similar binding posts are connected1 the effect is decidedly different4 ,in the multiple connection all of the zincs are joined to act as a single zinc and all of the carbons are likewise joined and act as a single carbon4 ,in such a combination the voltage will be that of a single cell #a4e volts1 but the amperage will be four times that of a single cell or #hj amperes4 ,the diagrams and following descriptions of possible combinations were taken from a bulletin on battery connections issued by the ,french ,battery and ,carbon ,co4 ,by combining the series and multiple connections1 as shown in ,fig4 ,c1 both the voltage and current can be increased over that delivered by one cell4 ,referring to the figure1 it is seen that in each of the two rows of four cells the cells are connected in series4 ,this would produce #f volts and #bj amperes for the series of four which may now be assumed as a unit1 so that the two rows can be imagined as two large cells1 each of which has a normal output of #bj amperes at #f volts4 ,now by connecting the similar poles of two such large cells they are in multiple and we get an increased current or #dj amperes and #f volts1 which is the capacity of the eight cells connected as shown in the figure4 ,this is commonly designated as a multiple-series battery4 ,fig4 #bef ,d illustrates a multiple-series connection made in a different manner1 but which produces the same voltage and current as the above mentioned4 ,in ,fig4 ,d1 two cells at a time are connected in multiple1 and these sets are then connected in series4 ,the capacity of each set of two is #dj amperes at #a-a_/b volts1 and as these four sets are connected in series the total output of the eight cells combined is #f volts and #dj amperes1 the same as that produced by the connections shown in ,fig4 ,c4 ,fig4 ,e shows the multiple-series connection illustrated in ,fig4 ,d1 applied to twelve cells in which four sets of three cells each are wired in series1 the three cells of a set being in multiple so that the capacity of a set is #a-a_/b volts and #fj amperes4 ,by connecting the four sets in series as shown1 the total capacity will be #fj amperes at #f volts4 ,the use of the series-multiple connection is a distinct step forward in dry-cell use4 ,the arrangement of cells shown in ,figs4 ,c or ,d is better than the arrangement in ,fig4 ,a1 in just the same way that a team of horses is better than a single horse4 ,one horse pulling a load of #b tons may become exhausted in one hour1 but two horses pulling that same load may work continuously for six hours4 ,it is true that in ,fig4 ,c there are twice as many cells used as in ,fig4 ,a1 but the eight cells in ,fig4 ,c will do from three to four times as much work as the four cells in ,fig4 ,a4 ,in other words1 while more cells are used in the multiple-series arrangement1 the amount of service per cell is greater and the service is1 therefore1 cheaper in the multiple-series arrangement4 ,some battery manufacturers sell their batteries put up in boxes1 the cells being connected up in multiple-series and surrounded by pitch or tar to keep out the moisture4 ,this has certain advantages as well as certain disadvantages4 ,one of the objections to this method of putting up dry cells is that if by any chance one cell out of the eight or twelve which are buried in the pitch is defective it will run all of the cells down1 and being buried offers no means of detection or removal4 ,it is not possible to guarantee absolutely that a weak cell will not be occasionally included in a large number1 so dry cells may be expected to vary to some degree among themselves4 ,it is interesting to know the effect of one weak cell on a series-multiple arrangement4 ,if1 for example1 in ,fig4 ,c or ,fig4 ,d1 the dotted line connecting 7a7 and 7b7 be used to indicate a cell which is partly short-circuited by internal weakness or external defect the result is as follows3 ,in the arrangement shown in ,fig4 ,c1 where one cell of the upper four is short-circuited1 the lower four will discharge through the upper four even though the external circuit is not closed2 that is1 one short-circuited cell will cause a run-down in all of the cells4 ,in ,fig4 ,d1 however1 one short-circuited cell will influence not the entire set but the other one to which it is directly connected4 ,there is thus seen to be an advantage in the arrangement of ,fig4 ,d and ,fig4 ,e1 over the arrangement in ,fig4 ,c4 ,in making connections between cells insulated wire should be used1 or special battery connectors are preferably employed4 ,the ends of the wires or connectors and the binding posts must be scraped clean so that good electrical connection can be made between the two1 and the knurled nuts should be screwed tight into place4 ,care must also be taken that the pasteboard covering around the battery is not torn4 ,this would allow contact between the zinc containers1 and thus short-circuit the cells4 ,the batteries should be placed so that the zinc cans and the binding posts of any cell do not come into contact with any other cell4 ,vibration might cause enough motion for the brass terminal to wear through the pasteboard of the neighboring cell and make contact with the zinc can4 ,different classes of work require different amounts of current at different voltages and by choosing the proper combination of series1 multiple1 or series-multiple connections practically every requirement can be fulfilled4 ,for electric bells1 telegraph instruments1 miniature lights1 toy motors with fine wire windings1 etc41 series connection is recommended for the reason that the resistance of the external circuit is high and a large voltage is necessary4 ,for spark coils1 magnets and toy motors with large wire windings1 multiple or series-multiple connection of batteries should be used as a high voltage is not required4 ,for some work1 gas-engine ignition especially1 it is economical to have two complete sets of batteries1 either of which can be thrown into the circuit at will1 so that while one set is delivering current the other is recuperating4 ,it has been estimated that by using two sets of batteries1 properly connected to give the desired current1 the life of each set is increased about four times4 ,thus it is seen that a saving of #ej per cent4 is effected in the cost of the batteries4 ,battery ,testers4--,the 8strength0 of a cell is determined by the amperes of current it is capable of producing2 therefore1 a meter that will indicate the amount of current being produced is used to test the current strength of the cell4 ,battery testers are made to indicate voltage or amperage and sometimes the instrument is made to indicate both volts and amperes4 ,as explained above1 the voltage of a cell is not a true indicator of its strength4 ,the ampere meter or ammeter1 as it is termed1 is the proper indicator of the strength of the cell4 ,illustration3 ,,fig4 #beg4--;,battery tester4 ,the common battery tester does not always give the exact number of amperes of current1 but it indicates the relative strength which is really the thing desired4 ,when the current from an active cell is once shown on the dial of the tester1 any other cell of the same intensity will be indicated in like amount4 ,electric ,conductors4--,covered wire for carrying electricity is made in a great variety of forms and designated by names that have been suggested by their use4 ,these wires are made of a single strand or in cables1 where several wires are collected1 insulated and formed into a single piece4 ,cables may contain any number of insulated wires4 ,the sizes of wires are determined by a wire gage4 ,in the ,united ,states the ,b4 ,s4 gage is used as the standard for all wires and sheet metal4 ,the gage originated with the ,brown ,sharp ,mfg4 ,co4 of ,providence1 ,r4 ,i41 and has become a national standard by common consent4 ,the numbers range from ,no4 #jjjj to ,no4 #fj4 ,the size of wire for household electrical service ranges from ,no4 #ah which is #j4jd inch in diameter to ,no4 #h which is #j4abh inch across4 ,the carrying capacities in amperes of wires1 as given by the ,underwriters' table of sizes from ,no4 #h to ,no4 #ah1 are as follows3 -------------------------------- ,wire ,rubber ,other gage insulation1 insulation1 ,no4 amperes amperes -------------------------------- #h #ce #ej #aj #be #cj #ab #bj #be #ad #ae #bj #af #f #aj #ah #c #e -------------------------------- ,lamp ,cord4--,the flexible cord used for drop lights1 connectors1 portable lamps1 extensions1 etc41 is made of two cords twisted together or two cords laid parallel and covered with braided silk or cotton4 ,the conductors consist of a number of ,no4 #cj ,b4 ,s4 gage1 unannealed copper wires twisted into a cable of required capacity4 ,the conductor is wound with fine cotton thread over which is a layer of seamless rubber1 and the whole is covered with braided cotton or silk4 ,lamp cord is sold in three grades1 old code1 new code1 and commercial1 which vary only in the thickness and quality of rubber which encloses the conductor4 ,the new code lamp cord is identical with the old code form except that it is required by the ,national ,board of ,fire ,underwriters to be covered with a higher quality of rubber insulation than was used in the old form4 ,the commercial cord is not recognized by the ,national ,board of ,underwriters4 ,it is practically the same as that described but does not conform to the tests prescribed for the new code cord4 ,the sizes of the conductors enclosed in the lamp cord are made equal in carrying capacity to the standard wire gage numbers4 ,the sizes ordinarily used are ,no4 #ah and #bj gage but they are made in sizes from ,no4 #aj to ,no4 #bb of the ,brown ,sharp gage4 ,portable ,cord4--,this is a term used to designate reinforced lamp cord4 ,the wires are laid parallel and are covered as with a supplementary insulation of rubber4 ,the additional insulation and the braided covering assumes a cylindrical form4 ,the covering is saturated with weatherproof compound1 waxed and polished4 ,annunciator ,wire4--,this wire is made in the usual sizes and covered with two layers of cotton thread saturated with a special wax and highly polished4 ,as the name implies it is used for annunciators1 door bells and other purposes of like importance4 ,private ,electric ,generating ,plants4--,the conveniences to be derived from the use of electricity were for many years available only by those who lived in distributing areas covered by commercial electrical generating plants4 ,except in towns of sufficient size to warrant the erection of expensive light and power systems or along the lines of electric power transmission1 current for domestic purposes was not obtainable4 ,within a comparatively few years there have been developed a number of small electric generating systems that are suitable for supplying the average household with the electric energy for all domestic conveniences4 ,the combination of the gasoline engine1 the electric dynamo and the storage battery have made possible generating apparatus that is operated with the minimum of difficulty and which supplies all of the electric appliances that were formerly served only from commercial electric circuits4 ,an electric generating system is commonly termed an electric plant4 ,it consists of an engine for the development of power1 a dynamo for changing the power into electricity and--to be of the greatest service--a storage battery for the accumulation of a supply of energy to be used at such times as are not convenient to keep the dynamo in active operation4 ,such a combination1 each part comprised of mechanism with which the average householder is unfamiliar1 seems at first too great a complication to put into successful practice4 ,such1 however1 is not the case4 ,the operation of small electric generating plants is no longer an experiment4 ,their general use testifies to their successful service4 ,the working principles are in most cases those of elementary physics combined with mechanism1 the management of which is not difficult to comprehend4 ,such plants are made to suit every condition of application and at a cost that is condusive to general employment4 ,in a brief space it is not possible to enter into a detailed discussion of the gasoline engine1 the electric dynamo1 and the storage battery with the various appliances necessary for their operation2 it is1 therefore1 intended to give only a general description of the leading features of each4 ,the manufacturers of such plants furnish to their customers and to others who are interested detailed information with explicit instructions for their successful management4 ,the first private lighting plants were made up of parts built by different manufacturers and assembled to form generating systems with little regard to their adaptability4 ,a gasoline engine belted to a dynamo of the proper generating capacity supplied the electricity4 ,neither the engines nor the dynamos were particularly suited to the work to be performed1 yet these combinations were sufficiently successful to command a ready sale4 ,the energy thus generated was accumulated in a storage battery from which was taken the current for a lighting and heating device4 ,besides the generating and storage apparatus there is required in such a system1 a switchboard1 to which are attached the necessary meters and switches that are required to measure and direct the current to the various electric circuits4 ,foresighted manufacturers1 comprehending the probable future demand1 began the construction of the various parts1 suited to the work and the conditions under which they were to be employed4 ,the manufacture of apparatus1 designed for the special service and composed of the fewest possible parts1 has reduced the operating difficulty to a point of relative simplicity4 ,experience in the use of a large number of these plants has revealed to the maker the course of many minor difficulties of operation and the means of their correction4 ,the mechanism has been improved to prevent possible derangement and to simplify the means of control1 until the private electric plant is successfully employed by those who have had no former experience with power-generating machines4 ,illustration3 ,,fig4 #beh4--;,household electric generating plant4 ,as an example of the private electric plant ,fig4 #beh shows the apparatus included in a combined engine1 dynamo and switchboard1 connected with a storage battery4 ,the relative size of the machine is shown by comparison with the girl in the act of starting the motor4 ,this plant is of capacity suitable for supplying an average home with electricity for all ordinary domestic uses4 ,a nearer view of the generating apparatus is given in ,fig4 #bei in which all of the exterior parts are named4 ,an interior view of the generating apparatus is given in ,fig4 #bfj1 in which is exposed all of the working parts4 ,the right-hand side of the picture shows all of the parts of the gasoline engine that furnishes the power for driving the generator4 ,this is an example of an air-cooled gasoline engine in which the excess heat developed in the cylinder is carried away by a drought of air4 ,the air draft is induced by the flywheel of the engine1 which is constructed as a fan4 ,the blades of the fan1 when in motion1 are so set as to draw air into the top of the engine casing and exhaust it from the rim of the wheel4 ,the air in passing takes up the heat in excess of that necessary for the proper cylinder temperature4 ,this form of cylinder cooling takes the place of the customary water circulation and thus eliminates its attending sources of trouble4 ,in principle the engine is the same as is employed in automobiles and other power generation4 ,illustration3 ,,fig4 #bei4--;,combined motor1 electric generator and switchboard4 ,on the left-hand side is seen the dynamo and switchboard4 ,the dynamo armature is attached to the crankshaft of the engine by which it is rotated in a magnetic field to produce the desired amount of electricity4 ,the brushes1 in contact with the commutator1 conduct the electricity as it is generated in the armature1 which after passing through the switchboard is made available from the two wires at the top of the board marked 8light and power wires40 ,these wires are connected with the storage battery and also to the house circuits through which the current is to be sent4 ,illustration3 ,,fig4 #bfj4--;,details of motor1 electric generator and switchboard4 ,referring to the switchboard of ,fig4 #bei1 the three switches and the ammeter comprise the necessary accessories4 ,the starting switch is so arranged that by pressing the lever a current of electricity from the storage battery is sent through the dynamo4 ,the dynamo acting as a motor starts the engine4 ,when the engine has attained its proper speed its function as a dynamo overcomes the current pressure from the battery and sends electricity into the cells to restore the expended energy1 or if so desired the current may be used directly from the dynamo for any household purpose4 ,the box enclosing the switch contains a magnetic circuit-breaker so constructed that when the battery is completely charged the switch automatically releases its contact and stops the engine4 ,the 8stopping switch0 at the right of the board and the 8switch for light and circuit0 on the left are used respectively for stopping the engine and for opening and closing the house circuits4 ,the meter performs a multiple function1 in that it shows at any time the condition of charge in the storage battery1 the rate at which current is entering or leaving the battery and also acts to stop the engine when the battery is charged4 ,at any time the pointer reaches the mark indicated in the picture1 the ignition circuit is automatically broken and the engine stops4 ,the fuses on the board in this case perform the same function as those already described4 ,storage ,batteries4--,these batteries have already been mentioned as secondary batteries4 ,they are sometimes called electric accumulators4 ,the electricity is stored or accumulated1 not by reason of the destruction of an electrode as in the primary cell but by the chemical change that takes place in the plates as the charging current is sent through the cell4 ,when the battery is discharged1 the current from the dynamo is sent through the battery circuit in the reverse direction to that of the discharge and the plates are restored to their original condition4 ,the action that takes place in charging and discharging is due to chemical changes that take place in the plates and also in the solution or electrolyte in which the plates are immersed4 ,there are two types of storage batteries1 those made of lead plates immersed in an acid electrolyte and the ,edison battery which is composed of iron-nickel cells immersed in a caustic potash electrolyte4 ,the former type is most commonly used and is the one to be described4 ,the lead-plate cell illustrated in ,fig4 #bfb shows all of the parts of a working element4 ,the plates are made in the form of lead grids which when filled to suit the requirements of their action1 form the positive and negative electrodes4 ,the negative plates are filled with finely divided metallic lead which when charged are slate gray in color4 ,the positive plates are filled with lead oxide4 ,when charged they are chocolate brown in color4 ,in the figure there are three positive and four negative plates which together form the element1 then with their separators are placed in a solution of sulphuric acid electrolyte4 ,the separators are thin pieces of wood and perforated rubber plates that keep the positive and negative plates from touching each other and keep in place the disintegration produced by the electro-chemical action of the cell4 ,the unit of electric capacity in batteries is the ampere-hour4 ,the cell illustrated will accumulate #hj ampere-hours of energy4 ,it will discharge an ampere of current for #hj hours4 ,if desired it may be discharged at the rate of two amperes for #dj hours1 or four amperes for #bj hours1 or at any other rate of amperes and hours1 the product of which is #hj4 ,the number of ampere-hours a cell will accumulate will depend on the area of the positive and negative plates2 large cells will store a greater number of ampere-hours than those of small size4 ,the cells1 no matter what size1 give an average electric pressure of #b volts4 ,the plates are joined by heavy plate-straps connecting all of the positives on one end and all of the negative kind on the opposite end4 ,to insure rigidity the two sets are secured to the rubber cover by locknuts4 ,in this cell the plates are suspended from the cover4 ,the plate terminals are made of heavy lead connectors that when formed into a battery are joined together with lead bolts and nuts4 ,illustration3 ,,fig4 #bfa4--;,hydrometer for testing storage battery electrolyte4 ,the electrolyte is a solution of pure sulphuric acid in distilled water and on its purity depends1 in a great measure1 its action and length of life4 ,the electrolyte is made of a definite density which is expressed as its specific gravity4 ,when fully charged the electrolyte will test #abbj by the hydrometer4 ,that is1 it will be #a4bbj heavier than water4 ,when discharged it will test by the hydrometer #aahe4 ,this means that in discharging the density has been reduced to #a4ahe that of water4 ,the chemical change in the electrolyte is1 therefore1 an important part of the charge and discharge of the cell4 ,the density of an electrolyte may be determined by a hydrometer such as ,fig4 #bfa4 ,this is an ordinary glass hydrometer such as is used for determining the density of fluids1 enclosed in a glass tube1 to which is attached a rubber bulb4 ,the point of the tube is inserted into the opening at the top of the cell and the electrolyte drawn into the tube by the reopening of the collapsed bulb4 ,the density is then read from the stem of the hydrometer4 ,the ,pilot ,cell4--,in order to make apparent this density of the electrolyte without the necessity of its measurement with a hydrometer1 one cell of the battery is provided with a gage as that of ,fig4 #bfb4 ,this is an enlargement of the end of the jar in which floats a hollow glass ball of such weight that it will at any time indicate by its position the relative density of the solution4 ,when the cell is charged the ball stands at the top of the gage and indicates a density #abbj2 when discharged it is at the bottom and expressed by its position a density of #aahe4 ,the electrolyte densities are the indicators of the conditions of charge4 ,the ball by its position shows at a glance the quantity of electricity in the battery4 ,the voltage usually employed in household electric plants is that of a battery composed of #af cells4 ,since the normal voltage of a storage cell is #b volts such a battery joined in series is #cb volts4 ,this voltage for the purpose fulfills all ordinary conditions and is generally employed4 ,a battery of #af cells1 of #hj-;ampere-hour capacity1 will deliver current of #a ampere for #hj hours at #cb volts intensity4 ,a #bj-watt lamp on a #cb-volt circuit requires #b_/c ampere for its operation4 ,the battery will1 therefore1 keep lighted one such lamp for #if hours1 or four #bj-watt lamps may be lighted continuously for #bd hours1 or eight lamps for #ab hours1 before recharging4 ,aside from its ability to supply the required light for the average home1 it furnishes energy sufficient for heating a flat-iron or other heating apparatus1 to operate motors for pumping water1 driving a washing machine or any other of the domestic requirements4 ,such plants are made in sizes to suit any condition of requirement4 ,in large establishments a larger motor generator and battery will be necessary with which to generate and store the required electricity but in any case suitable apparatus is to be obtained to meet any requirement of light1 heat or power developed4 ,illustration3 ,,fig4 #bfb4--;,electric storage cell4 ,national ,electrical ,code4--,the details governing the size1 the manner of placing and securing wires in buildings is included in the regulations published by the ,national ,board of ,fire ,underwriters as the ,national ,electric ,code4 ,likewise the mechanical construction of all apparatus dealing with electric distribution is definitely specified so that manufacturers furnish reliable materials for all requirements4 ,in the specifications for furnishing buildings with the use of electricity1 descriptions are made of the desired types and styles of the switches and various other fixtures to suit the requirements4 ,electric ,light ,wiring4--,in the equipment of a house for the use of electricity1 the wiring1 together with distributing panel1 the various outlets1 receptacles1 switches1 and other appliances that make up the system1 is of more than passing consequence4 ,in the construction of the electric system it is important that the wires and their installation be done in a manner to meet every contingency4 ,the following descriptions for electric house wiring were taken from a set of specifications published by the ,bryant ,electric ,co4 as applying to buildings of wood frame construction4 ,the specifications serve as explanations for the appliances required in an ordinary dwelling4 ,the specifications are for the least expensive form of good practice in wiring for frame buildings4 ,they would not be permitted in large cities where further protection from fire is required and where more rigid rules are demanded by the ,board of ,fire ,underwriters4 #a4 ,,system4--,the circuit wiring shall be installed as a two-wire direct current or alternating system4 ,not more than #af outlets or a maximum of #ffj watts shall be placed on any one circuit1 allowing #aaj watts for each baseboard plug connection or extension outlet and #ee watts for each #af candlepower lamp indicated at the various wall and ceiling outlets on plans4 ,all wiring shall be installed as a concealed knob-and-tube system4 ,the type of wiring is designated as a two-wire direct or alternating current system in order that there shall be no doubt as to the method of wiring to be used4 ,there are other methods that might be employed that need not be discussed here4 ,the #af outlets mentioned are intended to cover all lamps or plug attachments that are to be used for heaters1 fans1 motors1 or any other electric device4 ,the #ffj watts at #aaj volts pressure will require #f amperes in the main wires of the circuit1 which is the maximum current the wires are intended to carry4 ,this does not mean that #aaj-watt lamps might not be used but that no single circuit shall carry lamps that will aggregate more than #ffj watts4 ,the concealed knob-and-tube system mentioned is illustrated in ,figs4 #bfc and #bfd1 in which the wires which pass through joists and studding are to be insulated by porcelain tubes and those wires which lay parallel to these members are to be fastened to porcelain knobs which are secured by screws to the wood pieces to prevent any possibility of coming into contact with electric conducting materials4 ,illustration3 ,,fig4 #bfc4--,manner of securing wires by the knob-and-tube system for ceiling outlets4 #b4 ,,outlets4--,at each and every switch1 wall1 ceiling1 receptacle or other outlet shown on plans1 install a metal outlet box of a style most suitable for the purpose of the outlet4 ,all outlet boxes must be rigidly secured in place by approved method and those intended for fixtures shall be provided with a fixture stud1 or in the case of large fixtures1 a hanger to furnish support independent of the outlet box4 ,outlet ,boxes4--,for the safe and convenient accommodation of switches1 receptacles or other connections in the walls and ceilings of a building1 outlet boxes are used as a means of securing the wire terminals to the receptacles4 ,these boxes are made in a number of forms for general application4 ,one style is shown in ,fig4 #bfe4 ,the boxes are made of sheet steel and arranged to be secured in place with screws4 ,the box is further provided with screw fastenings to which the switch or receptacle may be firmly attached4 ,illustration3 ,,fig4 #bfd4--,this shows the knob-and-tube system of securing the wires in partitions and the manner of fastening metal 8cut out0 boxes2 for switch1 attachments1 plugs1 etc4 #c4 ,,installation ,,of ,,wires1 ,,etc4--,all wires shall be rigidly supported on porcelain insulators which separate the wire at least #a inch from the surface wired over4 ,wires passing through floors1 studding1 etc41 shall be protected with porcelain tubes1 and where wires pass vertically through bottom plates1 bridging1 etc41 of partitions1 an extra tube shall be used to protect wires from plaster droppings4 ,wires must be supported at least every #d feet and where near gas or water pipes extra supports shall be used4 ,all porcelain material shall be non-absorptive and broken or damaged pieces must be replaced4 ,tubes shall be of sufficient length to bush entire length of hole4 ,at outlets the wires shall be protected by flexible tubing1 the same to be continuous from nearest wire support to inside of outlet box4 ,wires installed in masonry work shall be protected by approved rigid iron conduit which shall be continuous from outlet to outlet4 ,the method and reasons for supporting the wires described above are as have already been mentioned under item #a4 ,the reason for extra supports near gas pipes and water pipes is as a precaution against the possibility of short-circuiting4 ,illustration3 ,,fig4 #bfe4--,outlet box4 #d4 ,,conductors4--,conductors shall be continuous from outlet to outlet and no splices shall be made except in outlet boxes4 ,no wire smaller than ,no4 #ad ,b4 ,s4 gage shall be used and for all circuits of #ajj feet or longer1 ,no4 #ab1 ,b4 ,s4 gage or larger shall be used4 ,all conductors of ,no4 #h ,b4 ,s4 gage or larger shall be stranded4 ,wires shall be of sufficient length at outlets to make connection to apparatus without straining connections4 ,splices shall be made both mechanically and electrically perfect1 and the proper thickness of rubber and friction tape shall be then applied4 ,continuous conductors are required because of the possibility of defects in the joints of spliced wire4 #e4 ,,position ,,of ,,outlets4--,unless otherwise indicated or directed1 plug receptacles shall be located just above baseboard2 wall brackets1 #e feet above finished floor in bedrooms1 and #e feet #f inches in all other rooms2 wall switches1 #d feet above finished floors4 ,all outlets shall be centered with regard to panelling1 furring1 trim1 etc41 and any outlet which is improperly located on account of above conditions must be corrected at the contractor's expense4 ,all outlets must be set plumb and extend to finish of wall1 ceiling or floor1 as the case may be1 without projecting beyond same4 #f4 ,,materials4--,all materials used in carrying out these specifications shall be acceptable to the ,national ,board of ,fire ,underwriters and to the local department having jurisdiction4 ,where the make or brand is specified or where the expression 8equal to0 is used1 the contractor must notify the architect of the make or brand to be used and receive his approval before any of said material is installed4 ,where a particular brand or make is distinctly specified1 no substitution will be permitted4 #g4 ,,grade ,,of ,,wire4--,the insulation of all conductors shall be rubber1 with protecting braids1 which shall be ,n4,e4,c4 ,standard 7,national ,electrical ,code ,standard74 #h4 ,,outlet ,,boxes4--,outlet boxes shall be standard pressed steel1 knock-out type and shall be enameled4 #i4 ,,local ,,switches4--,local wall switches shall be two-button flush type completely enclosed in a box of non-breakable insulating material with brass beveled-edge cover plate finished to match surrounding hardware4 ,fig4 #bfi shows the various forms and grades of switches that there are on the market4 ,the screws which attach the plate to the switch enter bushings that are under spring tension thereby preventing defacement of the plate by overtightening of the screws4 ,single-pole is to be used where the load will not be in excess of #ffj watts2 double-pole to be used where the load is more then #ffj watts or where for any other reason it is desirable to break the current at both wires4 ,three-point switches are to be used when a light or group of lights is to be controlled1 as hall lights that may be lighted or extinguished1 from either the top or at the bottom of a stairway4 ,four-point switches are to be used between and two1 three-point switches to control additional lights4 ,where two or more switches are placed together an approved gang plate is to be provided which designates the use of each switch4 ,where indicated on the plan1 clothes closets shall be equipped with automatic door switch to connect the light when the door is open4 #aj4 ,,pilot ,,lights4--,switches controlling cellar1 attic and porch lights shall have pilot lamp in parallel on the load side of the switch4 ,the switch in ,fig4 #c requires for its installation a two-gang outlet box4 ,the ruby bull's-eye which covers the lamp is practically flush1 extending from the wall no further than the buttons of the switch4 ,pilot lights are intended to indicate the operation of other lights or apparatus that cannot be directly observed4 ,the term bull's-eye applies to a colored-glass button covering a miniature lamp which burns whenever a light is used which is apt to be forgotten and allowed to burn for a longer time than necessary4 #aa4 ,,plug ,,receptacles4--,plug receptacles shall be of the disappearing-door type1 with beveled-edge brass cover plate finished to match surrounding hardware 7see ,fig4 #bff74 ,in this receptacle the doors are pushed inward by the insertion of the plug and upon its withdrawal close automatically1 effectually excluding dirt and concealing the live terminals4 ,it is the latest and best plug receptacle obtainable4 ,plug receptacles are the attachments for the terminal pieces of plugs1 which temporarily connect portable lamps1 electric fans or other devices1 they are made in many forms4 #ab4 ,,wall ,,and ,,ceiling ,,sockets4--,one-light ceiling receptacles shall be of a type to fit standard #c-a_/d-;inch or #d-;inch outlet boxes4 ,wall sockets shall be of the insulated base type4 ,sockets in cellars shall be made entirely of porcelain and of the pull type4 ,all lamp sockets used in fulfilling these specifications shall have an approved rating of #ffj watts1 #bej volts4 #ac4 ,,drop ,,lights4--,drop lights shall consist of the necessary length of reinforced cord supported by an insulated rosette with brass base and cover2 the latter to cover #d-;inch outlet box1 and furnished with a key socket complete with a #b-a_/d-;inch shade-holder4 ,each drop cord shall have an adjuster4 #ad4 ,,heater ,,switch1 ,,pilot ,,and ,,receptacle4--,heating device outlets shall be equipped with combination of switch1 pilot light and receptacle with plug and spare pilot lamp4 #ae4 ,,service ,,switch4--,the service-entrance switch shall be #cj amperes1 porcelain base with connections for plug fuses4 ,,installation ,,of ,,service ,,switch4--,service switch shall be installed in a moisture-proof metal box with hinged door4 ,,panel ,,cabinet4--,the distributing panel cabinet shall be of steel not less than ,no4 #ab gage reinforced with angle iron frames1 which shall be securely riveted in place4 ,cabinet shall be larger than panel to give at least #d-;inch wire space around panel and shall be given at least two coats of moisture-repellant paint4 ,,distributing ,,panel4--,the distributing panel shall consist of two-wire #abe-volt branch cutouts1 two-wire #abe-volt porcelain-base panel-board units1 two-wire #abe-volt porcelain-base deadfront panel-board units4 ,the distributing panel shall be surrounded with an ebony asbestos or slate partition #a_/b inch thick which will form a wire space around panel4 ,,fuses4--,all fuses for branch circuits shall be not more than #aj amperes capacity4 ,the contractor shall furnish the owner with #aej per cent4 of required number of #abe-volt plug-type fuses for complete installation4 ,,panel ,,trim ,,and ,,door4--,the panel trim and door shall be of steel1 with brass cylinder lock and concealed hinges1 all furnished under this contract4 ,a directory of circuits and outlets served by panel shall be enclosed in glass with metal frame1 mounted on inside of panel door4 ,,hardware4--,all hardware furnished under this contract shall match in quality and finish other adjacent hardware4 ,,three-,,way ,,control4--,the nearest outlet at top and bottom of all stairs and in entrance hall shall be controlled by three-way switches located on separate floors where directed4 ,,electrolier ,,control4--,wherever there are ceiling outlets for fixtures having three or more sockets controlled by wall switches three wires shall be run between the switch box and the outlet to permit the use of electrolier switches4 ,,dining-,,room ,,circuit4--,furnish and install in dining-room1 where indicated on plans1 an approved floor box containing an approved #be-;ampere plug receptacle4 ,the wires connecting this receptacle to the center of distribution shall be ,no4 #aj ,b4 ,s4 gage4 ,furnish and deliver to whom directed an approved multiple-connection block consisting of three individually fused plug receptacles4 ,the connection between the plug receptacle and this block shall be made by means of #aj feet of ,no4 #aj ,b4 ,s4 approved silk-covered portable cord with an approved #bj-;ampere cord connector #b feet from the multiple block4 ,,house ,,feeders4--,the size of the feeder from the service switch to the panel board shall be figured in accordance with the ,national ,code rules for carrying capacity1 allowing for all circuits being fully loaded4 ,the feeder shall be of sufficient size1 however1 to confine the drop in voltage with all lights in circuit to #a per cent4 of the line voltage4 ,,service ,,connection4--,make extension of house feeder overhead to lighting company's mains and make all connections complete to the satisfaction of the light company and the architect4 ,furnish and install the necessary frame or backboard for meter4 ,,call ,,bells4--,the contractor shall furnish1 install and connect all push buttons1 bells1 buzzers and annunciators1 as shown on plans or therein described4 ,all wiring shall be cleated in joists1 studs1 etc41 with insulated staples4 ,damp places1 metal pipes of all descriptions1 flues1 etc41 must be avoided and wire fastenings must be applied in such a way that insulation is not damaged4 ,no splices shall be made where same will not be accessible at any time after completion of building4 ,wires shall not be smaller than ,no4 #ah ,b4 ,s4 gage and shall be damp-proof insulated4 ,bells1 buzzers1 buttons1 etc41 shall be of approved make4 ,push button for main entrance door shall be provided with ornamental place with approved finish4 ,push button in dining-room shall consist of combination floor push1 with necessary length of flexible cord and approved portable foot push4 ,furnish and install where directed three cells of carbon cylinder battery in a substantial cabinet4 ,,burglar ,,alarm4--,furnish and install complete burglar alarm system consisting of the necessary wires1 window springs1 door springs1 night latch cutout for front door1 bell1 batteries1 cabinet1 interconnection strip1 etc41 and everything required for a complete open-circuit system4 ,each window sash and door throughout the building shall be equipped with contact spring of approved make and all springs on same side of building on each floor shall be wired on one circuit and terminated on single-pole knife switch on interconnection strip4 ,the interconnection strip shall be located as directed and shall have cutout switches for each circuit as well as a double-pole battery switch4 ,the battery shall consist of at least three dry cells in suitable cabinet placed where directed and both positive and negative leads shall be carried direct to interconnection strip4 ,the burglar-alarm wires shall be not less than ,no4 #af ,b4 ,s4 gage1 insulated and installed as specified for call bells4 ,,intercommunicating ,,telephones4--,furnish and install an intercommunicating telephone system complete with all telephone sets1 wiring1 batteries1 etc4 ,all wires to be cables containing one pair of ,no4 #bb ,b4 ,s4 gage conductors for each station and a pair of ,no4 #af ,b4 ,s4 gage conductors for talking and ringing battery respectively4 ,each pair of wires shall be twisted and all pairs shall be twisted around each other to eliminate cross talk and inductive noises4 ,the wires shall be silk insulated1 with a moisture repellent of beeswax or varnish and the whole covered with a lead sheath at least #a_/fd inch in thickness4 ,where cables terminate in outlet boxes they shall be fanned out and laced in an orderly manner and secured to connecting terminals1 one of which shall be provided for each wire4 ,install where directed in an approved cabinet at least four cells of dry battery each1 for talking and ringing purposes4 ,,installation ,,of ,,interphone ,,cable4--,intercommunicating cables shall be supported with pipe straps and liberal clearance shall be observed where near steam or other pipes4 ,automatic ,door ,switch4--,where indicated on the plan1 clothes closets shall be equipped with automatic door switch to connect the light when the door is open4 ,fig4 #bff is placed in the door frame in such position that electric contact is made by release of the projecting pin as the door is opened4 ,when the door is closed1 the pin is depressed and the light is extinguished ,plug ,receptacles4--,plug receptacles shall be selected from the styles shown in ,figs4 #bfg1;a1 b1 c or d4 ,illustration3 ,,fig4 #bff4--;,automatic door switch4 ,fig4 #bfg1;a is the disappearing-door type with beveled-edge brass cover plate finished to match surrounding hardware4 ,in this receptacle the doors are pushed inward by the insertion of the plug and upon its withdrawal close automatically1 effectually excluding dirt and concealing the live terminals4 ,it is the latest and best plug receptacle obtainable4 ,fig4 #bfg1;b is of the ,chapman type with beveled-edge brass cover plate finished to match surrounding hardware4 ,in this receptacle the doors open outward but are flush whether the plug is in or out4 ,illustration3 ,,fig4 #bfg4--,styles of plug receptacles4 ,illustration3 ,,fig4 #bfh4--;,heating-device receptacles4 ,fig4 #bfg1;c is of the screw-plug type with beveled-edge brass cover plate finished to match surrounding hardware4 ,by many this is preferred for apartment use as it will receive any style of ,edison attachment plug4 ,illustration3 ,,fig4 #bfi4--,service switches4 ,fig4 #bfg1;d is of the removable-mechanism type with beveled-edge brass cover plate finished to match surrounding hardware4 ,the mechanism of this receptacle is exchangeable with the mechanism of the double-pole switch as shown in ,fig4 #bgj1;c4 ,heater ,switch1 ,pilot and ,receptacle4--,heating-device outlets shall be equipped with combination of switch1 pilot light and receptacle with plug and spare pilot lamp4 ,figs4 #bfh1;a1 b1 c and d1 represent various forms from which selection may be made4 ,all are adapted for the same purpose and differ only in mechanical arrangement4 ,illustration3 ,,fig4 #bgj4--,local wall switches4 ,service ,switch4--,the service entrance switch may be selected from the three styles shown in ,figs4 #bfi1;a1 b1 and c4 ,illustration3 ,,fig4 #bga4--,pilot lights4 ,illustration3 ,,fig4 #bgb4--,wall and ceiling sockets4 ,fig4 #bfi1;a is composed of a #cj-;ampere porcelain base with connections for plug fuses4 ,fig4 #bfi1;b is a slate base with connections for cartridge fuses4 ,fig4 #bfi1;c is a slate base with connections for open-link fuses ,local ,switches4--,local wall switches may be selected from the various styles shown in ,figs4 #bgj1;a1 b1 c1 d and e4 ,fig4 #bgj1;a is the two-button flush type completely enclosed in a box of non-breakable insulating material with brass beveled cover plate finished to match surrounding hardware4 ,illustration3 ,,fig4 #bgc4--;,drop-light attachments and lamp bases4 ,fig4 #bgj1;b is a two-button flush type with brass beveled-edge cover plate finished to match surrounding hardware4 ,fig4 #bgj1;c is of the removable-mechanism type with brass beveled-edge cover plate finished to match surrounding hardware4 ,fig4 #bgj1;d is the single-button flush type with brass beveled-edge cover plate finished to match surrounding hardware4 ,fig4 #bgj1;e is the rotary-flush type with brass beveled-edge cover plate finished to match surrounding hardware4 ,pilot ,lights4--,switches controlling cellar1 attic and porch lights may be either ,fig4 #bgj1;a or b4 ,fig4 #bgj1;a requires for its installation a two-gang outlet box4 ,the ruby bull's-eye which covers the lamp is practically flush1 extending from the wall no further than the buttons of the switch4 ,fig4 #bgj1;b is installed in a single-gang box4 ,the lamp extends through the plate and is protected by a perforated cage which extends about an inch from the plate4 ,wall and ,ceiling ,sockets4--,one-light ceiling receptacles may be selected from the types shown in ,figs4 #bgb1;a1 b1 c1 d and e4 ,fig4 #bgb1;a is of a type to fit standard #c-a_/d-;inch or #d-;inch outlet boxes4 ,fig4 #bgb1;b is of the small concealed-base type4 ,fig4 #bgb1;c is of the large concealed-base type4 ,fig4 #bgb1;d is of the insulated-base type4 ,fig4 #bgb1;e is of the porcelain-base type4 ,sockets in cellars shall be made entirely of porcelain4 ,those in bathrooms shall be entirely of porcelain and of the pull type4 ,drop ,lights4--,drop lights shall consist of the necessary length of reinforced cord supported by either brass or porcelain bases4 ,each drop cord to have an adjuster4 ,figs4 #bgc1;a1 b1 c1 d1 e1 f1 g1 illustrate the various styles4 ,fig4 #bgc1;h is a shade holder to be used with the drop lights4 ,,index ,a ,acetylene1 gas burner1 #cjb gas machine1 the ,colt1 #cjj machines1 #bie generators1 types of1 #big stoves1 #cjd ,air conditioning1 #bdj cooling plants1 #bdd discharged by a flue1 #bbe eliminators1 #ce1 #cf properties of1 table1 #aii tester1 the ,wolpert1 #bcc valves1 #ai ,alcohol1 sad irons1 #bhi table stoves1 #bic ,annunciators1 #cdf ,anthracite1 graphitic1 #ahf ,atmospheric humidity1 #aif ,b ,backventing1 of plumbing1 #aje ,bathroom1 #ig ,bathtubs1 #ih fixtures for1 #ajj ,bibb1 compression flange1 #hi flange1 #hi ,fuller1 #hi hose1 #hi lever handle1 #ij screw1 #hi self-closing1 #ij solder1 #hi wash-tray1 #ia ,boiler1 at end of season1 #gi cast-iron1 #ai1 #bj1 #ch cylindrical form of1 #ch house heating1 #ai1 #bd rules for management of1 #gg sheet-metal1 #ai ,boiler1 steam1 rules for management of1 #gh the house-heating steam1 #ai ,boyle's law1 definition1 #afa1 #bgb ,briquettes1 #ahi ,british thermal units1 #d for one cent1 #aij ,b4t4u41 #b1 #cb1 #ahb1 #ahe ,burglar alarms1 #cdd ,buzzers1 #cdd ,c ,candle1 foot1 #cac ,hefner1 #caj power1 #caj horizontal1 #caj spherical1 #caa ,cellar drain1 #hd ,cell1 ,pilot1 storage battery1 #cgj ,cesspools1 #afi ,charcoal1 #ahh ,check-draft damper1 #bd ,chimney flue1 the right1 #gi ,chimneys1 8smokey10 #hj1 #ha ,cisterns1 filters for1 #aeb1 #aec galvanized iron tanks as1 #aeb rain-water1 #aea wooden1 #aeb ,clinkers1 #gb1 #gc ,close-nipples1 #bh ,coal1 #ahb anthracite or hard1 #ahc1 #aic bituminous or soft1 #ahd burning soft1 #ge calorific value of typical ,american1 #aib1 #aic cannel1 #ahf coking1 #ahd comparative value of1 #ahi free burning1 #ge ,coal1 fusing-coking1 #ge grades of soft1 #ahd pea size1 #gf price of1 #aij1 #aia semi-bituminous1 #ahf1 #aic ,cocks1 basin1 #ib bibb1 #hh corporation1 #hg curb1 #hg ,fuller1 #ia bibb1 #hi repairs for1 #ia pantry1 #ic sill1 #ic stop and drain1 #hh stop and waste1 #hg ,code1 national electric1 #cga ,coke1 #gf1 #ahh gas1 #ahh ,column1 the water1 #bb ,condensation1 water of1 #f1 #aj1 #aa1 #ae1 #ce ,conductors1 #cgd ,cord1 lamp1 #cfc portable1 #cfc ,current1 alternating1 #ccb direct1 #ccb ,d ,damper1 ash-pit1 #ei check-draft1 #bd1 #fg1 #fi1 #gj direct-draft1 #ei1 #fa1 #fg regulator1 #ei1 #fj combined thermostat and1 #fg for hot-water furnaces1 #fa1 #fb for steam boiler1 #fj1 #gh ,design1 heating plant1 #dd ,devining rod1 #acg ,dew-point1 #bji to determine the1 #bab ,dim-a-lite1 #cbc ,door bells1 #cdb ,draft1 economy of good furnace1 #gj hand1 regulation1 #ei induced1 #fi ,drip-cock1 #bc ,dry cells1 #ced ,e ,electric annunciators1 #cdf batteries1 #ced battery formation1 #ceh testers1 #cfj burglar alarms1 #cdd buzzers1 #cdd conductors1 #cfb door bell1 #cdb dry cell1 #cee flat-iron1 #cbf fuse plugs1 #ccd1 #ccg generating plants1 #cfc heaters1 #cch heating devices1 #cje lamp cord1 #cfb lamps1 ,gem1 #cjf incandescent1 #cjf motors1 #ccb panel1 #ccf range1 #cdj signals1 #cda stoves1 #cci table pushes1 #cdf toaster1 #ccj ,electrical measurements1 units of1 #cag ,electricity1 #cje ,eliminator1 air1 #ce1 #cf ,evaporation as a cooling agent1 #bdc ,f ,filaments1 carbon1 #cjh incandescent lamp1 #cjf1 #cjg tungsten1 #cjg ,fire-box1 #ai1 #bj1 #ed ,firing1 first day1 #gc in moderate weather1 #gd in severe weather1 #gd night1 #gb ,fixtures1 bathroom1 #aje kitchen and laundry1 #id ,flat-iron1 electric1 #cbf ,flues1 furnace1 #ee ,flush tanks1 #aaj details of construction1 #aab1 #aac low down1 #aaa ,foot-candle1 #cac ,frost prediction1 #bab ,fuels1 comparative value of coal to other1 #ahi danger from gaseous and liquid1 #bid heating values of domestic1 #beb moisture in1 #aid ,furnace1 cast-iron1 #ed firing1 general rules for1 #gj times of day for1 #gb location of1 #ed the hot-air1 #ea1 #eb construction of1 #eb ,furnace-gas leaks1 #ed ,fuse plugs1 #ccd ,g ,gage1 ,bourdon type of1 #bc electrified ,bourdon spring pressure1 #cf glass1 #bb1 #dj1 #afa1 #afb steam1 #bb water1 #bb ,gas1 acetylene1 machines1 #bie all-oil water1 #bea ,blau1 #bea burner1 ,bunsen1 #bge open-flame1 #bgh coal1 #bej lamps1 mantle1 #bgd1 #bgf1 #bgg lighters1 #cjb measurements of1 #bec meter dials1 reading of1 #bee1 #bef meters1 #bed prepayment1 #bef ,pintsch1 #bea service rules1 #bef1 #beg ranges1 #beh water1 #bea ,gases1 heating values of1 #beb ,gasoline1 #bej ,beaum test of1 #bfa ,gasoline1 boulevard lamp1 #bhg central generator plants for use of1 #bhb cold process system of lighting with1 #bfd1 #bfe gas lamps1 #bhf gravity test of1 #bfb hollow-wire system of lighting and heating with1 #bfi lamps1 inverted mantle1 #bgi portable1 #bhj1 #bha lighting and heating with1 #bei1 #bfd regulation and sale of1 #bfa sad irons1 #bhi stoves1 burners for1 #bhh ,gate valve1 #id ,globe valve1 #ic angle1 #id ,grate surface1 #ec ,gravity system1 low pressure1 #f1 #ae ,h ,heaters1 combination hot-air and hot-water1 #ef direct and indirect1 #bh furnace hot-water1 #abb instantaneous1 #abc tank1 #aba wash boilers1 #if ,heating1 ,c4 ,a4 ,dunham's system of vapor1 #cd1 #ce direct indirect1 #cj hot-water1 #bf indirect method of1 #bi1 #cj low pressure system of1 #e1 #f overhead or drop system of steam1 #ad system of hot water1 #dd plants1 management of1 #gj separate return system of steam1 #ac single pipe system of steam1 #f1 #ab1 #ae steam1 #bf surface of furnaces1 #ef ,heating1 radiators1 #bf two pipe system of steam1 #f1 #aj1 #aa1 #ae ,heat1 of vaporization1 #b specific1 #cg ,hot-air furnace1 #fa ,hot-water heaters1 #ch ,house drain1 #hb ,humidifying apparatus1 #bae plants1 #bdb ,humidity1 absolute1 #aif atmospheric1 #aif control1 #bdd of the air1 #aif relative1 #aig1 #bjd ,hydraulic ram1 #aed double acting1 #aeg single acting1 #aee ,hydrometer1 storage battery1 #cfh ,hygrodeik1 #bjf ,hygrometer1 #bjd dial1 #bjh ,i ,illumination1 #cac intensity of1 #cad quantity of1 #cad ,k ,kerosene1 #bfc legal tests for1 #bfc ,l ,lamp1 base1 the ,edison1 #caa cord1 #cfc labels1 #cab ,lamps1 boulevard1 #bhg carbon filament1 #caa central-generator gas1 #bhf daylight1 electric1 #cbd gas-filled electric1 #cbd incandescent electric1 #cjf mantle1 #bgf inverted-mantle gasoline1 #bgi ,lamps1 ,mazda1 #caj miniature electric1 #cbj1 #cbe portable1 gasoline1 #bhj tantalum1 #cjf tungsten-filament1 #cjf turn-down electric1 #cba ,lights1 drop1 #chc flash1 #cbf pilot1 #chc ,lignite1 #ahf ,lumen1 #cac ,o ,outlet boxes1 #cgc ,overflow pipe1 #de ,overheated water1 #dg ,p ,peat1 #ahg ,pilot light1 #cge ,pipes1 covering1 #cc eliminator1 #cf flow1 #eg openings stopped1 #aac overflow1 #dj1 #da return1 #f1 #aj1 #eg supply1 #f1 #aj ,plant1 hot-water heating1 #cg steam heating1 #a1 #e ,plug receptacles1 #cgh ,plumbers friend1 #aac ,plumbing1 #ha rough1 #hb ,pneumatic motor valve1 #bcg radiator valve1 #bcg ,polluted water1 #acd ,pollution of wells1 #acd ,pressure1 absolute1 #d gage1 #d tank1 #afb vapor1 #ce1 #cf ,properties of steam1 #c ,psychrometer1 #bjg ,pump1 force1 the1 #adf lift1 the1 #add tank1 #adf ,pumps1 #add chain1 #aea deep well1 #aej for driven wells1 #aej priming of1 #ade well1 #adh wooden1 #adh ,r ,radiating surface1 #a1 #ba1 #bb1 #bg ,radiators1 air vent on1 #gg connections1 #aj1 #dg corner1 #bh finishings1 #ca forms of1 #bf hot-water1 #bh1 #di rules for proportioning1 #bd1 #be single column1 #bh pipe1 #aj1 #ae three column1 #bh to control1 #gi wall1 #bh water-filled1 #ae ,range boilers1 #aae blow-off cock1 #aah double heater connections for1 #aai excessive pressure in1 #aag horizontal1 #aai location1 #aah ,reflectors1 #cae choice of1 #caf focusing1 #caf holoplane1 #cae intensive1 #caf ,registers1 rules for proportioning1 #ee ,regulator1 combined thermostat and damper1 #fg damper1 #ei1 #fj1 #fg draft1 #bd temperature1 #ei1 #fg ,riser1 #f1 #aj ,s ,sad irons1 alcohol1 #bib gasoline1 #bhi ,safety valve1 #bd1 #dd1 #dg1 #fg ,septic tank1 #agj and anaerobic filter1 #agd automatic siphon for1 #agf concrete1 #agi limit of efficiency of1 #agh ,universal ,portland ,cement ,co41 #agi with sand-bed filter1 #aga ,sewage1 #afh disposal1 #afh purification1 #afh ,sewer1 #hb1 #he gas1#aad ,short circuiting1 #ccd ,sitz bath1 #ih ,slicing bar1 #gb ,slugging1 #ae ,soil pipe1 #hd1 #ajg ,soot pocket1 #hj ,stand pipe eliminator1 #cf ,steam temperatures1 #d ,stop-cock1 #df ,stove1 acetylene1 #bib gasoline1 #bhh putty1 #ed ,surface1 grate1 #ec air-heating1 #ec ,surging1 #ae ,switch1 automatic door1 #cgh heater1 #chj local1 #chb service1 #cha ,system1 high-pressure hot-water1 #da low-pressure gravity1 #f hot-water1 #ch overhead or drop1 #ad separate return1 #ac single pipe1 #h two pipe1 #aj ,t ,table1 air discharged from flues1 #bbi required for ventilation1 #bbj calorific value of ,american coals1 #aib ,table1 dew-point1 #baj1 #baa frost prediction1 #bad heating values of coals1 #ic gases1 #beb wood1 #ahg1 #ahh hot-air furnaces1 #ea registers1 #ea lumens per watt1 #cad prices of fuels1 #aia properties of air1 #aii steam1 #c radiators1 sizes of1 #bg record of evaporation from hot-air furnace1 #bag relative heating values of domestic fuel1 #beb humidity1 #bjb1 #bjc sizes of hard coal1 #ahc heating mains1 #bf hot-air furnaces1 #ea soft coal1 #ahd thermal units for one cent1 #aij ,table pushes1 #cdf ,tank heaters1 #aba expansion1 #ch1 #dj1 #da1 #de1 #df1 #dg ,telephones1 intercommunicating1 #cdj ,temperature regulation1 #ei hand1 #ei pneumatic1 #bcd ,thermostats1 #fb1 #fg controllers1 #fb1 #fc electric1 #fb motor1 #fd ,national ,regulator ,co41 #bce1 #bcf pneumatic1 #fb time attachment1 #fc ,transformers1 bell-ringing1 #cdg lamp1 #caf ,traps1 ,bower1 #ajc clean sweep1 #ajc drum1 #ajc1 #aje for bathroom fixture1 #ajb1 #ajc inside1 #hc non-siphoning1 #aje outside1 #hc sewer for house drains1 #hb siphoning1 #ajf ,s1 #ajc1 #ajd ,try-cocks1 #bb1 #bc ,tungsten1 #cjg ,u ,union joint1 #ah ,v ,vacuum1 #e ,valve1 air1 #gi angle1 #ah check1 #db1 #dc definition of1 #hh1 #ic disc1 #ai globe1 #ic hot-water radiator1 #di ,ohio hot-water1 #di on cellar mains1 #gh safety1 #bd1 #dd1 #dg steam radiator1 #ah stem1 #ai ,valves1 definition of1 #ic globe1 #ic ,vaporization1 heat of1 #b ,ventilation1 #bai apparatus1 #bci by direct method of heating1 #ca by indirect method of heating1 #ca cost of1 #bcj ,de ,chaumont standard of1 #bai mechanical1 #bcg of dwellings1 #bbb1 #bbc1 #bbd ,plenum method of1 #bci quantity of air required for1 #bbj ,vents1 air1 #af1 #de1 #dh1 #di automatic air1 #af hot-water air1 #ej ,monash ,no4 #af air1 #af pipe1 #hc radiator1 #af sewer1 #he the ,allen float1 #af ,voltage variation1 effect of1 #cba ,w ,wash stands and lavatories1 #aja ,waste stack1 #hd1 #he ,water1 ammonia in1 #acj analyses1 #abf artesian1 #abh back1 #aae chlorine in1 #acc closets1 #ajh siphon-jet1 #ajh washdown1 #aji washout1 #ajh frost1 #aae hammer1 #i1 #ae hardness in1 #aca iron in1 #aca lift1 #afe medical1 #abh of condensation1 #aa organic matter in1 #acj overheated1 #aba ,pokegama1 #abg polluted1 #acc river1 #abg seal1 #hc softening with hydrated silicates1 #acb supply1 #hg1 #abe electric power1 #afd plants1 domestic1 #aeh gravity1 #aeh power1 #afc pressure tank system of1 #afj wind power1 #afd table1 #acg ,wattmeter1 periodic tests of1 #ced readings1 #ceb recording1 #cej state regulation of1 #cec to read the1 #cej ,well1 the ideal1 #adj ,wells1 artesian1 #adj bored1 #ada breathing1 #adc cleaning of1 #adb concrete coverings for1 #adj construction of1 #ach curbing of1 #acf1 #adj cylinders for tubular1 #aea driven1 #ada dug1 #aci flowing1 #ach freezing1 #add gases in1 #adb open1 #aci peculiarities of1 #adc safe distance in the location of1 #ace selection of the type of1 #ach surface pollution of1 #ace ,wiped joints1 #ajg ,wire annunciator1 #cec ,wiring1 electric light1 #cgb ,wood1 #ahg heating value of1 #ahg ,transcriber's note3 ,minor punctuation errors e4g4 missing 4 in ,fig4 have been corrected4 ,inconsistent hyphenation and use of ligatures has been left e4g4 cast-iron and cast iron4 7,often the difference is between the hyphenation in the text1 that used in captions to illustrations and that used in the index47 ,both gasolene and gasoline are used in the text ,both carburator and carburetor are used in the text ,many of the table values have errors which can be shown by graphing the results1 these have been left as printed but are noted here3 p4#e4 ,absolute ,pressure #e1 ,latent heat of #ieh4cj should be #ief4cj p4#aii4 ,air temperature #cc deg,f4 ,weight of cu4 ft4 air #eff4d should be #efj4d ,air temperature #dc deg,f4 ,weight of cu4 ft4 air #edh4d should be #edb4d ,air temperature #di deg,f4 ,weight of cu4 ft4 air #edb4e should be #eda4e ,air temperature #eh deg,f4 ,weight of cu4 ft4 air #ecd4i should be #ecj4i ,air temperature #fc deg,f4 ,weight of vapor_/cu4 ft4 air should be #f4de p4#bjc4 ,air ,temp4 #ajf1 #b deg4 depression of wet-bulb thermometer #ie should be #ic p4#baa4 ,dew point4 #fi1 #ab deg4 depression of wet-bulb thermometer #hd should be #dh p4#bad4 ,dry-bulb temp4 #ci1 #ab deg4 depression of wet-bulb thermometer #bc should be -#bc ,dry-bulb temp4 #ch #i deg4 depression of wet-bulb thermometer -#f should be #f p4#cad4 ,column heading should read ,watts per lamp #be #dj #fj #ajj #aej #bej ,other errors found3 ,page ,original ,corrected number text text ---------------------------------------- ---------------------------- #cc asbestus plaster ,asbetos is used elsewhere but this could be a trade name so it has been left as printed4 #ee two layers of asbestus paper ,as above4 #ef heating the house ,the us in house was upside-down4 #ic pipe to which ,a is attached ,a should be in italics4 #ajj bath tubs1 avatories bath tubs1 lavatories #acc drinking porposes drinking purposes #acc elementary tract alimentary tract #acg ,it is flatest ,it is flattest #afa ,boyles ,boyle's #afb wtih the pump with the pump #ahj its legnth its length #aha hould should #ahh ,as given by ,suplees ,as given by ,suplee's #baf hydrodeik hygrodeik #bbj ,cubic feet or pure air ,cubic feet of pure air #bci containg coils containing coils #bdc sheet-met a surfaces sheet-metal surfaces #bei and explosion an explosion #bfh ,the vitally improtant ,the vitally important #bfi end of the supending bar end of the suspending bar #bfi gasoline in the caburetor gasoline in the carburetor #bgj gasoline for the stove ,s gasoline for the stove ,r #bgb ,boyles law ,boyle's law #bgi ,inverted-mantel ,gasoline ,lamp,inverted-mantle ,gasoline ,lamp #bha percolating trough the tube percolating through the tube #cje elect ic transmission electric transmission #cji the electrotromotive force electromotive force #cai #ajjj #gdf #a4c horsepower #ajjj_/gdf #a4c horsepower #cbj ,minature screw base ,miniature screw base #cbi also shown in ,fig4 #bhh also shown in ,fig4 #bbh #cdc the contact peice the contact piece #cde window burgler alarm window burglar alarm #cdg inserted in the floor place inserted in the floor plate #ceb at the begining at the beginning #cef require severals hours require several hours #ceg ,the amper-hour ,the ampere-hour #ceh ,if the cells singly give ,if the cells singly give #bj volts1 the battery will #bj amperes1 the battery will give #bj volts give #bj amperes #che ,boyles' law1 definition ,boyle's law1 definition #chg blau1 #bea ,blau1 #bea #cij ,de,chaumont ,de ,chaumont 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