,transcriber's ,note ,italic text is denoted by underscores and bold text by equal signs4 ,whole numbers with fractional parts are denoted as #g-c_/d4 ,every ,boy's ,mechanical ,library ,illustration ,,motors ,every ,boy's ,mechanical ,library ,by ,j4 ,s4 ,,zerbe1 ,m4,e4 ,price1 per volume1 #fj cents1 ,net4 ,postage extra4 ,,automobiles ,this is a subject in which every boy is interested4 ,while few mechanics have the opportunity to actually build an automobile1 it is the knowledge which he must acquire about every particular device used1 that enables him to repair and put such machines in order4 ,the aim of this book is to make the boy acquainted with each element1 so that he may understand why it is made in that special way1 and what the advantages and disadvantages are of the different types4 ,to that end each structure is shown in detail as much as possible1 and the parts separated so as to give a clear insight of the different functions1 all of which are explained by original drawings specially prepared to aid the reader4 ,,motors ,to the boy who wants to know the theory and the practical working of the different kinds of motors1 told in language which he can understand1 and illustrated with clear and explicit drawings1 this volume will be appreciated4 ,it sets forth the groundwork on which power is based1 and includes steam generators1 and engines1 as well as wind and water motors1 and thoroughly describes the ,internal ,combustion ,engine4 ,it has special chapters on ,carbureters1 ,ignition1 and ,electrical systems used1 and particularly points out the parts and fittings required with all devices needed in enginery4 ,it explains the value of compounding1 condensing1 pre-heating and expansion1 together with the methods used to calculate and transmit power4 ,numerous original illustrations4 ,,aeroplanes ,this work is not intended to set forth the exploits of aviators nor to give a history of the ,art4 ,it is a book of instructions intended to point out the theories of flying1 as given by the pioneers1 the practical application of power to the various flying structures2 how they are built2 the different methods of controlling them2 the advantages and disadvantages of the types now in use2 and suggestions as to the directions in which improvements are required4 ,it distinctly points out wherein mechanical flight differs from bird flight1 and what are the relations of shape1 form1 size and weight4 ,it treats of kites1 gliders and model aeroplanes1 and has an interesting chapter on the aeroplane and its uses in the great war4 ,all the illustrations have been specially prepared for the work4 ,,cupples ,,leon ,,co41 ,publishers1 ,,new ,,york ,illustration ,every ,boy's ,mechanical ,library ,,motors ,,by ,j4 ,s4 ,,zerbe1 ,m4,e4 ,author of ,aeroplanes--,automobiles ,,illustrated ,,new ,,york ,,cupples ,,leon ,,company ,copyright1 #aiae1 by ,,cupples ,,leon ,,company ,,contents ,,page ,introductory #a ,the ,subject4 ,the ,inquisitive ,trait4 ,the ,reasons for ,doing ,things4 ,the ,mystery of ,mechanism4 ,curiosity which prompts ,investigation4 ,the ,sum of ,knowledge4 ,chapter ,i4 ,motors and ,motive ,power #e-ba ,the ,water ,fall4 ,water moves in ,one ,direction only4 ,what is ,energy4 ,stored or ,potential ,energy4 ,kinetic ,energy4 ,friction4 ,resistance4 ,inertia4 ,the ,law of ,bodies4 ,internal and ,external ,resistance4 ,momentum4 ,energy ,indestructible4 ,wind ,power4 ,rectilinear ,motion4 ,oscillating ,motion4 ,movements in ,nature4 ,how ,man ,utilizes the ,various ,movements4 ,kinds of ,potential ,energy4 ,the ,power in ,heat4 ,energy in ,steam4 ,energy from the ,sun4 ,power from ,water4 ,the ,turbine4 ,calculating ,power of a ,turbine4 ,horse ,power4 ,foot ,pounds4 ,power and ,time4 ,gravitation4 ,utilizing the pull of ,gravity4 ,taking ,advantages of ,forces4 ,pitting ,forces ,against each ,other4 ,centripetal and ,centrifugal ,forces4 ,power not ,created4 ,developing the ,power of ,motors4 ,experimenting4 ,chapter ,,ii4 ,the ,steam ,generator #bb-ca ,water as an absorbent of ,heat4 ,classification of ,boilers4 ,mode of applying ,heat4 ,the ,cylindrical ,boiler4 ,the ,cornish ,boiler4 ,the ,water ,tube ,boiler4 ,various ,boiler ,types4 ,compound ,steam ,boiler4 ,locomotive ,steam ,boiler4 ,vertical ,steam ,boiler4 ,chapter ,,iii4 ,steam ,engines #cb-ei ,the ,original ,turbine ,engine4 ,the ,reciprocating ,engine4 ,atmospheric ,engine4 ,the ,piston4 ,importance of the ,valve4 ,expanding the ,steam4 ,balanced ,valve4 ,rotary ,valve4 ,engine ,accessories4 ,efficiency of ,engines4 ,how ,steam acts in a ,cylinder4 ,indicating the ,engine4 ,mean ,efficiency4 ,calculating ,horse ,power4 ,condensation4 ,atmospheric ,pressure4 ,the ,condenser4 ,pre-heating4 ,superheaters4 ,compounding4 ,triple and ,quadruple ,expansion ,engines4 ,the ,steam ,turbine4 ,pressure and ,velocity4 ,form of ,blades4 ,compounding the ,jet4 ,chapter ,,iv4 ,fuels and ,combustion #fj-fg ,solid ,fuels4 ,liquid ,fuels4 ,combustion4 ,oxidation4 ,the ,hydro-,carbon ,gases4 ,oxygen and the ,atmosphere4 ,internal ,combustion4 ,vaporizing ,fuel4 ,explosion by ,heat ,compression4 ,how ,compression ,heats4 ,elasticity of ,gases4 ,advantages of ,compression4 ,the ,necessity of ,compression4 ,chapter ,v4 ,the ,internal ,combustion ,engine #fh-hb ,fixed ,gases4 ,gas ,engines4 ,energy of ,carbon and ,hydrogen4 ,the ,two-,cycle ,type4 ,advantages of the ,two-,cycle ,engine4 ,the ,four-,cycle ,engine4 ,the ,four ,cycles4 ,ignition ,point4 ,advantages of the ,four-,cycle ,type4 ,the ,loss in ,power4 ,engine ,construction4 ,valve ,grinding4 ,the ,crank ,shaft4 ,the ,cams4 ,chapter ,,vi4 ,carbureters #hc-aja ,functions of a ,carbureter4 ,rich ,mixtures4 ,lean ,mixtures4 ,types of ,carbureters4 ,the ,sprayer4 ,the ,surface ,type4 ,governing a ,carbureter4 ,primary ,air4 ,needle ,valve4 ,secondary ,air4 ,requirements in a ,carbureter4 ,size of a ,carbureter4 ,rule for ,size of ,carbureters4 ,the ,throttle4 ,flooding4 ,adjustability4 ,surface ,carbureters4 ,float ,chamber4 ,chapter ,,vii4 ,ignition1 ,low ,tension ,system #ajb-abj ,electricity4 ,magnetism4 ,the ,armature4 ,characteristics of ,electricity4 ,make and ,break ,system4 ,voltage4 ,high and ,low ,voltage4 ,low ,tension method4 ,disadvantages of ,make and ,break4 ,amperes4 ,resistance4 ,direct ,current4 ,alternating ,current4 ,induction4 ,generating ,electricity4 ,primary ,battery4 ,making a ,dry ,cell4 ,energy in a cell4 ,wiring ,methods4 ,series ,connection4 ,multiple ,connection4 ,series ,multiple4 ,watts4 ,testing a ,cell4 ,testing with ,instruments4 ,simple ,battery ,make and ,brake ,system4 ,to ,advance the ,spark4 ,the ,magneto in the ,circuit4 ,magneto ,spark ,plug4 ,chapter ,,viii4 ,ignition1 ,high ,tension #aba-adj ,magnetos4 ,alternating ,current4 ,cutting ,lines of ,force4 ,plurality of ,loops4 ,the ,electro ,magnet4 ,the ,dynamo ,form4 ,the ,magneto ,form4 ,advantages of the ,magneto4 ,induction ,coil4 ,changing the ,current4 ,construction of a ,coil4 ,primary ,coil4 ,secondary ,coil4 ,contact ,maker4 ,high ,tension with ,battery and ,coil4 ,metallic ,core for ,induction ,coil4 ,the ,condenser4 ,operations of a ,vibrator ,coil4 ,the ,distributor4 ,circuiting with ,distributor4 ,chapter ,,ix4 ,mechanical ,devices ,utilized in ,power #ada-aeg ,the ,unit of ,time4 ,horse ,power4 ,proney ,brake4 ,reversing ,mechanism4 ,double ,eccentric ,reversing ,gear4 ,balanced ,slide ,valve4 ,balanced ,throttle ,valve4 ,engine ,governors4 ,injectors4 ,feed ,water ,heaters4 ,chapter ,x4 ,valves and ,valve ,fittings #aeh-aga ,check ,valve4 ,gate ,valve4 ,globe ,valve4 ,the ,corliss ,valve4 ,corliss ,valve-operating ,mechanism4 ,angle ,valve4 ,rotary ,valves4 ,rotable ,engine ,valves4 ,throttle ,valves4 ,blow-off ,valves4 ,pop-,safety ,valves4 ,chapter ,,xi4 ,cams and ,eccentrics #agb-agh ,simple ,cams4 ,wiper ,wheels4 ,cylindrical ,cam ,motion4 ,eccentrics4 ,triangularly-formed ,eccentrics4 ,chapter ,,xii4 ,gears and ,gearing #agi-aij ,racks and ,pinions4 ,mangle ,rack4 ,controlling the ,pinion4 ,dead ,center4 ,crank ,motion ,substitute4 ,mangle ,wheels4 ,quick ,return ,motion4 ,accelerated ,motion4 ,quick-return ,gearing4 ,scroll ,gearing4 ,chapter ,,xiii4 ,special ,types of ,engines #aia-bja ,temperatures4 ,artificial ,heat4 ,zero4 ,liquids and ,gases4 ,refrigeration4 ,rotary ,engines4 ,caloric ,engines4 ,adhesion ,engines4 ,chapter ,,xiv4 ,enginery in the ,development of the ,human ,race #bjb-bjg ,power in ,transportation4 ,power vs4 ,education and the ,arts4 ,lack of ,power in the ,ancient ,world4 ,the ,early ,days of the ,republic4 ,lack of ,cohesiveness in ,countries ,without ,power4 ,the ,railroad as a ,factor in ,civilization4 ,the ,wonderful ,effects of ,power4 ,england as a ,user of ,power4 ,the ,automobile4 ,high ,character of ,motor ,study4 ,the ,unlimited ,field of ,power4 ,chapter ,,xv4 ,the ,energy of the ,sun1 and ,how ,heat is ,measured #bjh-baf ,fuel ,economy4 ,direct ,conversion4 ,the ,measurement of ,heat4 ,caloric4 ,material ,theory4 ,heat ,transmitted in ,three ,ways4 ,conduction4 ,convection4 ,radiation4 ,glossary #bag ,,list ,,of ,,illustrations ,,fig4 ,,page #a4 ,undershot ,wheel #ac #b4 ,overshot ,wheel #ad #c4 ,primitive ,boiler #bd #d4 ,return ,tubular ,boiler #be #e4 ,cornish1 or ,scotch ,boiler #be #f4 ,water ,tube ,boiler4 ,end view #bg #g4 ,water ,tube ,boiler4 ,side view #bi #h4 ,the ,original ,engine #cc #i4 ,horizontal ,section of ,tube #cc #aj4 ,steam-,atmospheric ,engine #ce #aa4 ,simple ,valve ,motion4 ,first position #ch #ab4 ,simple ,valve ,motion4 ,second position #ch #ac4 ,effective pressure in a ,cylinder #db #ad4 ,indicating pressure line #dd #ae4 ,indicating the ,engine #de #af4 ,compound ,engine #ec #af;a4 ,relative ,piston ,pressures #ed #ag4 ,changing ,pressure into ,velocity #ee #ah4 ,reaction against ,air #ef #ai4 ,reaction against ,surface #ef #bj4 ,turbine4 ,straight ,blades #eg #ba4 ,curved ,blades #eh #bb4 ,compound ,turbine #eh #bc4 ,two-,cycle ,engine4 ,first position #ga #bd4 ,two-,cycle ,engine4 ,second position #gc #be4 ,two-,cycle ,engine4 ,third position #gc #bf4 ,four-,cycle ,engine4 ,first position #ge #bg4 ,four-,cycle ,engine4 ,second position #ge #bh4 ,four-,cycle ,engine4 ,third position #gf #bi4 ,four-,cycle ,engine4 ,fourth position #gf #cj4 ,valve ,grinding #ha #ca4 ,carbureter #hg #cb4 ,carbureter #ie #cc4 ,surface ,carbureter #ih #cd4 ,dry ,cell #ajh #ce4 ,series ,connection #aji #cf4 ,multiple1 or ,parallel ,connection #aaj #cg4 ,series-,multiple ,connection #aaa #ch4 ,circuit ,testing #aac #ci4 ,make and ,break1 with ,battery #aad #dj4 ,make and ,break1 with ,magneto #aag #da4 ,magneto ,spark ,plug #aai #db4 ,illustrating ,alternating ,current #abb #dc4 ,alternating ,current4 ,second position #abb #dd4 ,alternating ,current4 ,third position #abc #de4 ,alternating ,current4 ,fourth position #abd #df4 ,making the ,circuit #abe #dg4 ,the ,dynamo #abf #dh4 ,the ,magneto #abf #di4 ,current by ,induction #abh #ej4 ,induction ,coil #abi #ea4 ,typical ,induction ,coil #acj #eb4 ,contact ,maker #aca #ec4 ,typical ,circuiting1 ,jump spark ,ignition #acb #ed4 ,metallic ,core1 ,induction ,coil #acc #ee4 ,condenser #acd #ef4 ,vibrator ,coil and ,connections #ace #eg4 ,the ,distributer #acg #eh4 ,circuiting with ,distributer #ach #ei4 ,illustrating the ,unit of ,time #adb #fj4 ,the ,proney ,brake #adc #fa4 ,double ,eccentric ,reversing ,gear #adf #fb4 ,reversing ,gear1 ,neutral #adf #fc4 ,reversing ,gear1 ,reversed #adg #fd4 ,single ,eccentric ,reversing ,gear #adg #fe4 ,balanced ,slide ,valve #adh #ff4 ,valve ,chest4 ,double ,port ,exhaust #adi #fg4 ,balanced ,throttle-,valve #aej #fh4 ,watt's ,governor #aea #fi4 ,the ,original ,injector #aeb #gj4 ,injector with movable ,combining ,tube #aed #ga4 ,feed ,water ,heater #aef #gb4 ,check ,valve #aeh #gc4 ,gate ,valve #aei #gd4 ,globe ,valve #afj #ge4 ,corliss ,valve #afb #gf4 ,corliss ,valve-operating ,mechanism #afc #gg4 ,angle ,valve #afd #gh4 ,rotary-,valve #afe #gi4 ,two-way ,rotary #afe #hj4 ,rotary ,type #aff #ha4 ,two-,way ,rotary ,type #aff #hb4 ,butterfly ,throttle #afg #hc4 ,angle ,throttle #afg #hd4 ,slide ,throttle #afh #he4 ,two-slide ,throttle #afh #hf4 ,blow-off ,valve #afi #hg4 ,safety ,pop ,valve #agj #hh4 ,heart ,shaped #agc #hi4 ,elliptic #agc #ij4 ,double ,elliptic #agc #ia4 ,single ,wiper #agd #ib4 ,double ,wiper #agd #ic4 ,tilting ,cam #agd #id4 ,cam ,sector #age #ie4 ,grooved ,cam #age #if4 ,reciprocating ,motion #age #ig4 ,pivoted ,follower for ,cam #agf #ih4 ,eccentric #agg #ii4 ,eccentric ,cam #agg #ajj4 ,triangularly-formed ,eccentric #agh #aja4 ,rack and ,pinion #ahj #ajb4 ,rack ,motion #ahj #ajc4 ,plain ,mangle ,rack #aha #ajd4 ,mangle ,rack ,motion #aha #aje4 ,alternate ,circular ,motion #aha #ajf4 ,controlling ,pinion for ,mangle ,rack #ahb #ajg4 ,illustrating ,crank-pin ,movement #ahc #ajh4 ,the ,dead ,center #ahd #aji4 ,crank ,motion ,substitute #ahd #aaj4 ,mangle ,wheel #ahe #aaa4 ,quick ,return ,motion #ahf #aab4 ,accelerated ,circular ,motion #ahg #aac4 ,quick ,return ,gearing #ahh #aad4 ,scroll ,gearing #ahi #aae4 ,simple ,rotary ,engine #aif #aaf4 ,double-feed ,rotary ,engine #aih #aag4 ,adhesion ,motor #bjj ,,introductory ,the motor is the great dominating factor in the world of industry4 ,every wheel and spindle2 every shaft and loom1 and every piece of mechanism which has motion1 derives it from some sort of motor4 ,the term motor has a wider significance than any other word4 ,a steam engine is a motor1 and so1 also1 is a dynamo1 a water wheel or a wind mill4 ,it would be just as descriptive to call a wind mill a wind motor1 or a steam engine a steam motor1 as to adhere to the old terms2 and1 on the other hand1 since it would be out of place to call a dynamo or a wind mill an engine1 the word motor seems best adapted to express the meaning of every type of mechanism which transforms energy into motion4 ,in considering the subject ,i shall proceed on the theory that the boy knows nothing whatsoever of the subject1 nor the terms used to designate the various phases1 subjects and elements4 ,it must be elementary in its character1 and wholly devoid of technical terms or sentences4 ,while it is necessary to give information in a book of this character1 on the methods for figuring out power1 it must be done without resorting to the formulas usually employed in engineering works1 as they are of such a nature that the boy must have some knowledge of the higher mathematics to follow out the calculations employed4 ,indeed1 every phase should be brought within the mental view of the boy1 and to do this may occasionally necessitate what might appear to be long drawn out explanations1 all of which1 it is hoped1 will be the means of more clearly presenting the subject4 ,the opening chapters1 which treat of the fundamentals1 will be as nearly complete as possible1 and thus lay a foundation for the work we shall be called upon to perform1 when we treat of the structures of the different parts and devices in the various types of motors4 ,the object is to explain power in its various phases1 how derived1 and the manner in which advantage is taken of the elements1 and substances with which we are brought into contact4 ,the reasons for each step are plainly set forth with the view of teaching the boy what power means1 rather than to instruct him how to make some particular part of the machinery4 ,the ,inquisitive ,trait4--,my experience has impressed me with the universality of one trait in boys1 namely1 that of inquisitiveness4 ,put a machine before a boy and allow him to dissect it1 and his curiosity will prompt him to question the motive for the particular construction of each part of its make-up4 ,the ,reasons for ,doing ,things4--,he is interested in knowing the reason why4 ,every boy has the spirit of the true investigator1--that quality which seeks to go behind or delve down deeply4 ,this is a natural instinct4 ,the ,mystery of ,mechanism4--,if this taste is gratified1 and he thereby learns the mystery of the machine1 what a wonderful world is opened to him6 ,the value of the lesson will depend1 in a large measure1 on the things which he has found out for himself4 ,it is that which counts1 because he never forgets that which he has dug out and discovered4 ,curiosity ,which ,prompts ,investigation4--,i recall a farmer's boy whose curiosity led him to investigate the binding mechanism of a reaper4 ,it was a marvel to him1 as it has been to many others4 ,he studied it day after day1 and finally1 unaided mastered the art4 ,that was something which could not be taken away from him4 ,it was a pleasure to hear him explain its operation to a group of boys1 and men1 too1 in which he used the knot itself to explain how the various fingers and levers coperated to perform their functions4 ,it was an open book to him1 but there was not one in the group of listeners who could repeat the explanation4 ,the ,sum of ,knowledge4--,it is the self-taught boy who becomes the expert4 ,the great inventors did not depend on explanations4 ,a book of this character has a field of usefulness if it merely sets forth1 as far as possible1 the sum of useful knowledge which has been gained by others1 so as to enable the boy to go forward from that point1 and thus gain immensely in time4 ,there is so much that has been developed in the past1 with reference to the properties of matter1 or concerning the utility of movements1 and facts in the realm of weights1 measures1 and values of elements which he must deal with1 that1 as he studies the mechanical problems1 the book becomes a sort of cyclopedia1 more than a work designed to guide him in the building of special engines or motors4 ,the ,author4 ,,motors ,,chapter ,i ,,motors ,,and ,,motive ,,power ,what makes the wheels turn round8 ,this simple question is asked over and over again4 ,to reply means pages of answers and volumes of explanations4 ,the ,water ,fall4--,go with me to the little stream ,i have in mind1 and stand on the crest of the hill where we can see the water pouring down over the falls1 and watch it whirling away over the rocks below4 ,the world was very1 very old1 before man thought of using the water of the falls1 or the rushing stream below1 to grind his corn or to render him other service4 ,water ,moves in ,one ,direction ,only4--,what the original man saw was a body of water moving in one direction only4 ,when he wanted to grind corn he put it in the hollow of a rock1 and then beat it with a stone1 which he raised by hand at each stroke4 ,in doing so two motions were required in opposite directions1 and it took thousands of years for him to learn that the water rushing along in one direction1 could be made to move the stone1 or the pestle of his primitive grinding mill1 in two directions4 ,it took him thousands of years more to learn another thing1 namely1 that the water could be made to turn the stone round1 or rotate it1 and thus cause one stone1 when turning on another1 to crush and grind the grain between them4 ,now1 as we go along with the unfolding of the great question of motors1 we must learn something of the terms which are employed1 to designate the different things we shall deal with1 and we ought to have some understanding of the sources of power4 ,what ,is ,energy8--,the running1 as well as the falling water represent energy4 ,this is something which is in the thing1 the element1 or the substance itself4 ,it does not come from without4 ,it is not imparted to it by anything4 ,stored or ,potential ,energy4--,at the top of the falls1 look at that immense rock4 ,it has been there for centuries4 ,it1 also1 has energy4 ,there is stored within it a tremendous power4 ,you smile6 ,yes1 the power has been there for ages1 and now by a slight push it is sent crashing down the precipice4 ,the power developed by that fall was thousands of times greater than the push which dislodged it4 ,but1 you say1 the push against the stone represented an external force1 and such being the case1 why do you say that power is within the thing itself8 ,the answer is1 that not one iota of the power required to push the stone off its seat was added to the power of the stone when it fell4 ,furthermore1 the power required to dislodge the stone came from within me1 and not from any outside source4 ,here we have two different forms of energy1 but both represent a moving force4 ,the power derived from them is the same4 ,kinetic ,energy4--,the energy of the falling water or stone is called ,kinetic energy4 ,in both cases the power developed came from within themselves and not from any exterior source4 ,the difference between ,potential and ,kinetic ,energy is therefore that ,potential ,energy represents the capacity to do work1 while ,kinetic ,energy is the actual performance of work4 ,friction4--,in every form of energy there is always something to detract from it or take away a portion of its full force1 called friction4 ,when a shaft turns1 it rubs against the bearings1 and more or less power is absorbed4 ,when a wheel travels over the ground friction is ever present4 ,the dislodging of the stone required ten pounds of energy1 but a thousand pounds was developed by the fall4 ,the water rushing along its rocky bed has friction all along its path4 ,resistance4--,this friction is a resistance to the movement of a body1 and is ever present4 ,it is necessary to go back and examine the reason for this4 ,as long as the stone was poised at the top of the precipice it had latent or potential energy1 which might be termed power at rest4 ,when it fell it had power in motion4 ,in both cases gravity acted upon the stone1 and in like manner on the water pouring over the falls4 ,inertia4--,inertia or momentum is inherent in all things and represents the resistance of any body or matter1 to change its condition of rest or standing still into motion1 and is then called ,inertia of ,rest1 or the resistance it offers to increase or decrease its speed when moving1 and is then called ,inertia of ,motion4 ,inertia or momentum is composed by the weight of the body and its speed and is measured by multiplying its weight by its speed4 ,the law is1 that when a body is at rest it will remain at rest eternally1 and when in motion it will continue in motion forever1 unless acted on by some external force or resistance4 ,an object lying on the ground has the frictional resistance of the earth to prevent its moving4 ,when the object is flying through space it meets the air and has also the downward pull of gravity1 which seek to bring it to rest4 ,these resisting forces are less in water1 and still less in gases1 and there is1 therefore1 a state of mobility in them which is not found in solids4 ,internal and ,external ,resistance4--,all bodies are subject to internal1 as well as external resistance4 ,the stone on the cliff resisted the movement to push it over4 ,weight was the resisting internal force1 but when the stone was moving through the air1 the friction with the air created external resistance4 ,energy ,indestructible4--,there is another thing which should be understood1 and that is the absolute indestructibility of energy4 ,matter may be changed in form1 or in the direction of its motion1 by the change of kinetic into potential energy1 or vice versa1 but the sum total of the energy in the world is unalterable or constant4 ,the tremendous power developed by the stone when it plunged through space and struck the rocks below1 developed a heat at its impact4 ,thus the moving force which was a motion in one direction was converted into another form of energy1 heat4 ,the expansion of the material exposed to the heat also represented energy4 ,when powder explodes and absolutely changes the form of the substance1 its volume of expansion1 if it should be retained within a vessel1 would perform a certain amount of work1 and the energy is thus transferred from one form to another without ceasing4 ,wind ,power4--,primitive man also saw and felt the winds4 ,he noted its tremendous power1 but he could not see how a force moving in one direction only could be utilized by him4 ,rectilinear ,motion4--,this movement of the wind in one direction1 like the water flowing along the bed of the river1 is called rectilinear motion4 ,it required invention to convert rectilinear into circular motion4 ,oscillating ,motion4--,when he threshed his grain and winnowed it by shaking it to and fro1 to rid it of the chaff1 the idea of using the wind to produce an oscillating motion did not occur to him4 ,after circular motion was produced1 the crank was formed and thus the oscillating movement was brought about4 ,movements in ,nature4--,all movements in nature are simple ones1 of which the following are illustrations3 #a4 ,rectilinear1 which1 as stated1 means in a straight line4 #b4 ,circular1 like the motion of the earth on its axis1 once every twenty-four hours4 #c4 ,oscillatory1 like a to and fro movement1 the swaying branches of trees1 or the swinging of a pendulum4 ,how ,man ,utilizes the ,various ,movements4--,what man has done is to utilize the great natural forces in nature in such a way as to produce these movements at will1 in either direction1 with greater or less speed1 at regular or irregular intervals1 and at such amplitudes as are required to perform the necessary work4 ,kinds of ,potential ,energy4--,now1 materials have within themselves potential energy of various kinds4 ,thus1 powder1 if ignited1 will burn1 and in burning will expand1 or explode1 as we term it4 ,this is true also of oils and gases4 ,the expansion pressure produced from such substances depends on the speed at which they will burn1 and in so confining the burning substances that a great pressure is produced4 ,the ,power in ,heat4--,the pressure of all such substances against the confining medium depends on heat4 ,any gas which has #ebc degrees of heat imparted to it will expand double its volume4 ,if one cubic inch of water is converted into steam the latter will occupy one cubic foot of space under atmospheric pressure1--that is1 it will expand over #agjj times4 ,energy in ,steam4--,if the steam thus generated is now subjected to #ebc degrees of heat additional1 it will occupy over #cdjj cubic inches of space4 ,it will thus be seen why steam1 gas1 and gasoline engines are called heat engines1 or heat motors4 ,energy ,from the ,sun4--,many attempts have been made to utilize the heat of the sun1 to turn machinery1 but the difficulty has been to secure sufficient heat1 on the one hand1 and on the other to properly cool down the heated gases1 so that the various liquid and solid fuels are required to make the heat transformations4 ,power ,from ,water4--,in the use of water two forms are available1 one where the water is moving along or falling in a constant open stream2 and the other where the flowing water is confined and where its flow can be regulated and controlled4 ,the latter is more available for two reasons3 ,first3 ,economy in the use of water4 ,second3 ,ability to control the speed or movement of the motor4 ,with running or falling streams a large surface is required1 and the wheels turn slowly4 ,two well-recognized forms of wheels have been employed1 one called the undershot1 or breast wheel1 shown in ,fig4 #a1 and the other the overshot1 illustrated in ,fig4 #b4 ,illustration3 ,fig4 #a4 ,undershot ,wheel4 ,in both types it is difficult to so arrange them as to shut off the power or water pressure when required1 or to regulate the speed4 ,the ,turbine4--,wheels which depend on the controllable pressure of the water are of the turbine type4 ,the word is derived from the ,latin word turbo1 meaning to whirl1 like a top4 ,this is a type of wheel mounted on the lower end of a vertical or horizontal shaft1 within1 or at the bottom1 of a penstock4 ,the perimeter of the wheel has blades1 and the whole is enclosed within a drum1 so that water from the penstock will rush through the tangentially-formed conduit into the drum1 and strike the blades of the wheel4 ,illustration3 ,fig4 #b4 ,overshot ,wheel4 ,a column of water one inch square and twenty-eight inches high weighs one pound1--or1 to express it in another way1 the pressure at the bottom of such a column is one pound1 and it is a pound for each additional #bh inches4 ,if there should be a head or height of water column of seven feet1 the pressure on each square inch of water at the bottom of the penstock would be three pounds to the square inch4 ,assuming the opening or duct leading to the wheel blades should be #ab #ab inches1 and also the blades be #ab #ab inches1 the area would be equal to #add square inches1 and this multiplied by three pounds would equal #dcb pounds pressure against the blades4 ,calculating ,power of a ,turbine ,wheel4--,the power of such a wheel depends principally on two things4 ,first1 the arrangement of the blades with reference to the inflowing water2 and1 second1 the discharge port1 or ability of the water to free itself from the wheel casing4 ,let us assume that the diameter of the wheel at the center of the blades is two feet1 which would1 roughly estimating1 give a circumference of six feet1 or a travel of each particular blade that distance at each turn of the wheel4 ,if the wheel turns one hundred times a minute1 and this is multiplied by the circumference of the wheel 7six feet71 the result is #fjj feet4 ,this1 again1 multiplied by #dcb pounds 7which represents the pressure of the water on the entire discharge opening71 and we have a product of #bei1bjj1 which represents foot pounds4 ,this means the same work as if #bei1bjj pounds would have been lifted through a space of one foot in one minute of time4 ,to ascertain how much power has been developed we must know how many foot pounds there are in a horse power4 ,horse ,power4--,it is determined in this way3 any force which is capable of raising #eej pounds one foot in one second of time1 is developing one horse power4 ,a man might have sufficient strength to raise such a weight once1 twice1 or a dozen times in succession1 but if he should try to do it sixty times a minute he would find it a trying1 if not impossible task4 ,foot ,pounds4--,if he should be able to lift #eej pounds sixty times within a minute1 he would have lifted #cc1jjj pounds one foot in one minute of time 7#eej #fj71 and thus have developed one horse power4 ,as the water wheel1 in our calculations above1 raised #bei1bjj pounds in that period of time1 this figure divided by #cc1jjj shows that a little more than #g-c_/d horse power was developed1 assuming1 of course1 that we have not taken into account any waste1 or loss by friction1 or otherwise4 ,this method of determining one horse power should be carefully studied4 ,always keep in mind the main factor1 #cc1jjj pounds1 and this multiplied by one foot1 the result will be #cc1jjj foot pounds1--that is1 one horse power4 ,it would be just the same1 however1 if it were possible to raise one pound #eej times in one second1 or one pound #cc1jjj times within a minute4 ,power and ,time4--,you are thus brought face to face with another thing which is just as important1 namely1 that1 in considering power1 time1 as well as energy1 must be considered4 ,if a man1 by superior strength1 could be able to raise #eej pounds once within a second1 then skip a few seconds1 take another hold1 and again raise it that distance1 he would not be developing one horse power for a minute1 but only for one second while he lifted the weight4 ,for the whole minute he would only develop a certain number of foot pounds1 and less than #cc1jjj foot pounds4 ,if1 within a minute1 he succeeded in raising it one foot for six times1 this would be six times #eej1 equal to #c1cjj foot pounds1 or just one-tenth of one horse power for one minute2 so time is just as important as the amount lifted at each effort4 ,gravitation4--,now1 let us examine power from another standpoint4 ,every attempt which man makes to produce motion is an effort to overcome some resistance4 ,in many cases this is weight or gravity4 ,while humanity unceasingly antagonizes the force of gravity it is constantly utilizing the laws of gravitation4 ,utilizing the ,pull of ,gravity4--,the boy laboriously drags his sled to the top of the hill against gravity1 and then depends on that force to carry him down4 ,we have learned to set up one force in nature against the other4 ,the running stream2 the moving winds2 the tides2 the expansive force of all materials under heat1 are brought into play to counteract the great prevailing agency which seeks to hold everything down to mother earth4 ,utilizing ,forces4--,the ,bible says3 ,blessed is he who maketh two blades of grass grow where one grew before4 ,to do that means the utilization of forces4 ,improved machinery is enabling man to make many blades grow where one grew before4 ,new methods to force the plow through the soil2 to dig it deeper2 to fertilize it2 and to harvest it2 all require power4 ,pitting ,forces ,against ,each ,other4--,man has discovered how to pit the forces of nature against each other1 and the laws which regulate them4 ,centripetal and ,centrifugal ,forces4--,gravity1 that action which seeks to draw all matter toward the center of the earth1 is termed centripetal force4 ,but as the earth rotates on its axis another force is exerted which tends to throw substances outwardly1 like dirt flying from the rim of a wheel4 ,this is called centrifugal force4 ,man utilizes this force in many ways1 one of which is illustrated in the engine governor1 where the revolving balls raise the arms on which they swing1 and by that means the engine valve is regulated4 ,power ,not ,created4--,in taking up the study of this subject start with a correct understanding of the source of all power4 ,it is inherent in all things4 ,all we can do is to liberate it1 or to put the various materials in such condition1 that they will exert their forces for our uses4 7,see ,page nine1 ,energy ,indestructible47 ,a ton of coal1 when burned1 produces a certain amount of heat1 which1 if allowed to escape1 will not turn a wheel4 ,but if confined1 it expands the air1 or it may convert water into steam which will turn ponderous machinery4 ,niagara ,falls has sent its great volume into the chasm for untold centuries1 but it has never been utilized until within the last twenty years4 ,the energy has been there1 nevertheless2 and so it is with every substance of which we have knowledge4 ,the successive steps1 wherein the experimenter and the inventor have greatly improved on the original inventions1 will be detailed as we go along through the different types of motors4 ,developing the ,power of ,motors4--,this development in the art is a most fascinating study4 ,it is like the explorer1 forcing his way through a primeval forest4 ,he knows not what is beyond4 ,often1 like the traveler1 he has met serious obstructions1 and has had to deviate from his course1 only to learn that he took the wrong direction and had to retrace his steps4 ,the study of motors and motive power is one which calls for the highest engineering qualities4 ,in this1 as in every other of the mechanical arts1 theory1 while it has an important function1 occupies second place4 ,experimenting4--,the great improvements have been made by building and testing2 the advance has been step by step4 ,sometimes a most important invention will loom up as a striking example to show how a valuable feature lies hidden and undeveloped4 ,an illustration of this may be cited with respect to the valve of the steam engine4 ,for four hundred years there was no striking improvement in the valve4 ,the various types of sliding and rocking valves were modified and refined until it was assumed that they typified perfection4 ,at one stroke the ,corliss valve made such an immense improvement that the marvel was as much in its simplicity as in its performance4 ,the reasons and the explanations will be set forth in the section which analyzes valve motion4 ,in this1 as in other matters1 it shall be our aim to explain why the different improvements were regarded as epochs in the production of motors4 ,,chapter ,,ii ,,the ,,steam ,,generator ,the most widely known and utilized source of power is the steam engine4 ,before its discovery wind and water were the only available means1 except the muscular power of man1 horses and other animals1 which was used with the crudest sort of contrivances4 ,in primitive days men did not value their time1 so they laboriously performed the work which machinery now does for us4 ,the steam engine1 like everything else which man has devised1 was a growth1 and1 singular as it may seem1 the boiler1 that vital part of the organism1 was1 really1 the last to receive due consideration and improvement4 ,as the boiler is depended upon to produce the steam pressure1 and since the pressure depends on the rapid and economical evaporation of water1 the importance of the subject will be understood in treating of the steam engine4 ,water as an ,absorbent of ,heat4--,water has the capacity to absorb a greater amount of heat than any other substance4 ,a pewter pot1 which melts at #ejj degrees1 will resist #bjjj degrees of heat if it is filled with water1 since the latter absorbs the heat so rapidly that the temperature of the metal is kept near the boiling point of water1 which is #bab degrees4 ,notwithstanding the great heat-absorbing qualities of water1 a large portion of the heat of the fuel passes through the flues and escapes from the stack4 ,this fact has caused inventors to devise various forms of boilers1 the object being to present as large an area of water as possible to the heat of the burning fuel4 ,how that was accomplished we shall try to make plain4 ,classification of ,boilers4--,numerous types of boilers have been devised1 the object being1 in all cases to evaporate the largest amount of water with the minimum quantity of fuel4 ,all boilers may be put under two general heads1 namely1 those which contain a large quantity of water1 and those which are intended to carry only a small charge4 ,in the first division the boilers are designed to carry a comparatively small pressure1 and in the latter high pressures are available4 ,mode of ,applying ,heat4--,the most important thing to fully understand is the manner in which heat is applied to the boiler1 and the different types which have been adapted to meet this requirement4 ,the ,cylindrical ,boiler4--,the most primitive type of boiler is a plain cylindrical shell ,a1 shown in ,fig4 #c1 in which the furnace ,b is placed below1 so that the surface of the water in contact with the fire area is exceedingly limited4 ,illustration3 ,fig4 #c4 ,primitive ,boiler4 ,in such a type of boiler it would be impossible for water to extract more than quarter the heat of the fuel4 ,usually it was much less4 ,the next step was to make what is called a return tubular type in which the heat of the burning gases is conveyed to the rear end of the boiler1 and then returned to the front end through tubes4 ,fig4 #d shows this construction4 ,the head of the shell holds the ends of a plurality of tubes1 and the products of combustion pass through the conduit1 below the boiler to the rear end1 and are conducted upwardly to the tubes4 ,as all the tubes are surrounded by water1 it will absorb a large amount of the heat as the gases move through1 and before passing out of the stack4 ,illustration3 ,fig4 #d4 ,return ,tubular ,boiler4 ,illustration3 ,fig4 #e4 ,cornish1 or ,scotch ,boiler4 ,the ,cornish ,boiler4--,one of the most important inventions in the generation of steam was the ,cornish boiler1 which for many years was the recognized type for marine purposes4 ,it had the advantage that a large amount of water could be carried and be subjected to heat at all times4 ,aside from that it sought to avoid the great loss due to radiation4 ,it will be seen from an examination of ,fig4 #e that the shell is made very large1 and its length does not exceed its diametrical measurement4 ,two1 and sometimes three1 fire tubes are placed within the shell1 these tubes being secured to the heads4 ,surrounding these fire tubes1 are numerous small tubes1 through which the products of combustion pass after leaving the rear ends of the fire tubes4 ,in these boilers the tubes are the combustion chambers1 and are provided with a grating for receiving the coal1 and the rear ends of the tubes are provided with bridge walls1 to arrest1 in a measure1 the free exit of the heated gases4 ,these boilers would be very efficient1 if they could be made of sufficient length to permit the water to absorb the heat of the fuel1 but it will be seen that it would be difficult to make them of very great length4 ,if made too small diametrically the diameter of the fire boxes would be reduced to such an extent that there would not be sufficient grate surface4 ,it is obvious1 however1 that this form of boiler adds greatly to the area of the water surface contact1 and in that particular is a great improvement4 ,illustration3 ,fig4 #f4 ,water ,tube ,boiler3 ,end ,view4 ,the ,water ,tube ,boiler4--,in the early days of the development of boilers1 the universal practice was to have the products of combustion pass through the flues or the tubes4 ,but quick generation of steam1 and high pressures1 necessitated a new type4 ,this was accomplished by connecting an upper1 or steam drum1 with a lower1 or water drum1 by a plurality of small tubes1 and causing the burning fuel to surround these tubes1 so that the water1 in passing upwardly1 would thus be subjected to the action of the fuel4 ,this form of boiler had two distinct advantages4 ,first1 an immense surface of water could be provided for2 and1 second1 the water and steam drums could be made very small1 diametrically1 and thus permit of very high pressures4 ,in ,fig4 #f1 which is designed to show a well known type of this structure1 ,a ,a1 represent the water drums and ,b1 the steam drum4 ,the water drums are separated from each other1 so as to provide for the grate bars ,c1 and each water drum is connected with the steam drum by a plurality of tubes ,d4 ,it will thus be seen that a fire box1 or combustion chamber1 is formed between the two sets of tubes ,d1 and to retain the heat1 or confine it as closely as possible to the tubes1 a jacket ,e is placed around the entire structure4 ,the ends of the water and steam drums are connected by means of tubes ,f1 shown in side view1 ,fig4 #g1 for the return or downward flow of the water4 ,the diagrams are made as simple as possible1 to show the principal features only4 ,the structure illustrated has been modified in many ways1 principally in simplifying the construction1 and in providing means whereby the products of combustion may be brought into more intimate contact with the water during its passage through the structure4 ,illustration3 ,fig4 #g4 ,water ,tube ,boiler3 ,side ,view4 ,as heretofore stated1 this type of boiler is designed to carry only a small quantity of water1 so that it is necessary to have practically a constant inflow of feed water1 and to economize in this respect the exhaust of the steam engine is used to initially heat up the water1 and thus1 in a measure1 start the water well on its way to the evaporation point before it reaches the boiler4 ,various ,boiler ,types4--,the different uses have brought forth many kinds of boilers1 in order to adapt them for some particular need4 ,it would be needless to illustrate them1 but to show the diversity of structures1 we may refer to some of them by their characteristics4 ,compound ,steam-,boiler4--,this is a battery of boilers having their steam and water spaces connected1 and acting together to supply steam to a heating apparatus or a steam engine4 ,these are also made by combining two or more boilers and using them as a feed water heater or a superheater1 for facilitating the production of steam1 or to be used for superheating steam4 ,the terms feed water heater and super heater are explained in chapter ,,iii4 ,locomotive ,steam-,boiler4--,this is a tubular boiler which has a contained furnace and ash pit1 and in which the gases of combustion pass from the furnace directly into the horizontal interior tubes1 and after passing through the tubes are conveyed directly into the smoke box at the opposite ends of the tubes4 ,the name is derived from the use of such boilers on locomotive engines1 but it is typical in its application to all boilers having the construction described1 and used for generating steam4 ,vertical ,steam-,boiler4--,this is a form of construction in which the shell1 or both the shell and the tubes1 are vertical1 and the tubes themselves may be used to convey the products of combustion1 or serve as the means for conveying water through them1 as in the well known water tube type4 ,this form of boiler is frequently used to good advantage where it is desired to utilize ground space1 and where there is sufficient head room4 ,properly constructed1 it is economical as a steam generator4 ,from the foregoing it will be seen that the structural features of all boilers are so arranged as to provide for the exposure of the largest possible area of water to a heated surface so that the greatest amount of heat from the fuel may be absorbed4 ,,chapter ,,iii ,,steam ,,engines ,the first steam engine was an exceedingly simple affair4 ,it had neither eccentric1 cylinder1 crank1 nor valves1 and it did not depend upon the pressure of the steam acting against a piston to drive it back and forth1 because it had no piston4 ,it is one of the remarkable things in the history and development of mechanism1 that in this day of perfected steam engines1 the inventors of our time should go back and utilize the principles employed in the first recorded steam engine1 namely1 the turbine4 ,instead of pressure exerting a force against a piston1 as in the reciprocating engine1 the steam acted by impacting against a moving surface1 and by obtaining more or less reaction from air-resistance against a freely discharging steam jet or jets4 ,the original engine1 so far as we have any knowledge1 had but one moving part1 namely1 a vertical tubular stem1 to which was attached a cross or a horizontal tube4 ,the ,original ,engine4--,figure #h is a side view of the original engine4 ,the vertical stem ,a is pivoted to a frame ,b1 and has a bore ,c which leads up to a cross tube ,d4 ,the ends of the tube ,d are bent in opposite directions1 as shown in the horizontal section1 ,fig4 #i4 ,illustration3 ,fig4 #h4 ,the ,original ,engine4 ,illustration3 ,fig4 #i4 ,horizontal ,section of ,tube4 ,steam enters the vertical stem by means of a pipe1 and as it rushes up and out through the lateral tubes ,d1 it strikes the angles ,e at the discharge ends1 so that an impulse is given which drives the ends of the tube in opposite directions4 ,as the fluid emerges from the ends of the tubes1 it expands1 and on contacting with the air1 the latter1 to a certain extent1 resists the expansion1 and this reacts on the tube4 ,thus1 both forces1 namely1 impact and reaction1 serve to give a turning motion to the turbine4 ,the ,reciprocating ,engine4--,the invention of this type of engine is wrapped in mystery4 ,it has been attributed to several4 ,the ,english maintain that it was the invention of the ,marquis of ,worcester1 who published an account of such an engine about #afej4 ,the ,french claim is that ,papin discovered and applied the principle before the year #afhj4 ,in fact1 the first actual working steam engine was invented and constructed by an ,englishman1 ,captain ,savery1 who obtained a patent for it in #afih4 ,this engine was so constructed as to raise water by the expansion and condensation of steam1 and most engines of early times were devoted solely to the task of raising water1 or were employed in mines4 ,atmospheric ,engines4--,when we examine them it is difficult to see how we can designate them as steam engines4 ,the steam did not do the actual work1 but a vacuum was depended on for the energy developed by the atmospheric pressure4 ,a diagram is given1 ,fig4 #aj1 showing how engines of this character were made and operated4 ,a working beam ,a was mounted on a standard ,b1 and one end had a chain ,c on which was placed heavy weights ,d4 ,near this end was also attached the upper end of a rod ,e1 which extended down to a pump4 ,illustration3 ,fig4 #aj4 ,steam-,atmospheric ,engine4 ,the other end of the working beam had a chain ,f1 which supported a piston ,g working within a vertically-disposed cylinder ,h4 ,this cylinder was located directly above a boiler ,i1 and a pipe ,j1 with a valve therein1 was designed to supply steam to the lower end of the cylinder4 ,a water tank ,k was also mounted at a point above the cylinder1 and this was supplied with water from the pump through a pipe ,l4 ,another pipe ,m from the tank conducted water from the tank to the bottom of the cylinder4 ,the operation of the mechanism was as follows3 ,the steam cock ,n1 in the short pipe ,j1 was opened to admit steam to the cylinder1 below the piston4 ,the stem of the steam cock also turned the cock in the water pipe ,m1 so that during the time the steam was admitted the water was shut off4 ,when the steam was admitted so that it filled the space below the piston1 the cock ,n was turned to shut off the steam1 and in shutting off the steam1 water was also admitted4 ,the injection of water at once condensed the steam within the cylinder so a partial vacuum was formed4 ,it will be remembered that as steam expanded #agjj times1 the condensation back into water made a very rarified area within the cylinder1 and the result was that the piston was drawn down1 thus raising both the weight ,d and also the pump rod ,e4 ,this operation was repeated over and over1 so long as the cock ,n was turned4 ,the turning of the stem of this cock was performed manually1--that is1 it had to be done by hand1 and boys were usually employed for doing this4 ,when1 later on1 some bright genius discovered that the valve could be turned by the machinery itself1 it was regarded as a most wonderful advance4 ,the discovery of this useful function has been attributed to ,watt4 ,of this there is no conclusive proof4 ,the great addition and improvements made by ,watt1 and which so greatly simplified and perfected the engine1 were through the addition of a separate condenser and air pump1 and on these improvements his fame rests4 ,from the foregoing it will be seen that the weight ,d caused the piston to travel upwardly1 and not the force of the steam1 and the suction produced by the vacuum within the cylinder did the work of actuating the pump piston1 so that it drew up the water4 ,the ,piston4--,from this crude attempt to use steam came the next step1 in which the steam was actually used to move the piston back and forth and thus actually do the work4 ,in doing so the ponderous walking beam was dispensed with1 and while1 for a long period the pistons were vertically-placed1 in time a single cylinder was used1 and a crank employed to convert the reciprocating into a circular motion4 ,fig4 #aa shows a simple diagram of a steam engine1 so arranged that the operation of the valves may be readily understood4 ,the cylinder ,a has a steam chest ,b1 which contains therein a slide valve ,c to cover the ports at the ends of the cylinder4 ,this figure shows the crank turning to the right1 and the eccentric ,d on the engine shaft is so placed1 that while the crank ,e is turning past the dead center1 from #a to #b1 the slide valve ,c is moved to the position shown in ,fig4 #ab1 thereby covering port ,f and opening port ,g4 ,illustration3 ,fig4 #aa4 ,simple ,valve ,motion4 ,first position4 ,illustration3 ,fig4 #ab4 ,simple ,valve ,motion4 ,second position4 ,it will be seen that the slide valve is hollowed within1 as at ,h1 and that the exhaust port ,i leads from this hollowed portion while the live steam from the boiler enters through pipe ,j and fills the space ,k of the chest4 ,in ,fig4 #aa live steam has been entering port ,f1 thus driving the piston to the right4 ,at the same time the exhaust steam at the right side of the piston is discharging through the port ,g and entering the hollow space within the slide valve4 ,in ,fig4 #ab the conditions are reversed1 and now live steam enters port ,g1 and the exhaust passes out through port ,f4 ,when the engine crank reaches the point #c1 which is directly opposite #a1 the reverse action takes place with the slide valve1 and it is again moved to its original position1 shown in ,fig4 #ab4 ,importance of the ,valve4--,every improvement which has been made in the engine has been directed to the valve4 ,the importance of this should be fully understood4 ,as the eccentric is constantly turning it is a difficult matter to so arrange the valve as to open or close it at the correct time1 absolutely1 and many devices have been resorted to to accomplish this4 ,expanding the ,steam4--,as all improvements were in the direction of economizing the use of steam1 it was early appreciated that it would be a waste to permit the steam to enter the cylinder during the entire period that the engine traveled from end to end1 so that the valve had to be constructed in such a way that while it would cut off the admission of steam at half or three-quarters stroke1 the exhaust would remain on until the entire stroke was completed4 ,some engines do this with a fair degree of accuracy1 but many of them were too complicated for general use4 ,in the form of slide valve shown the pressure of the steam on the upper side1 which is constant at all times1 produces a great wearing action on its seat4 ,this necessitated the designing of a type of valve which would have a firm bearing and be steam tight without grinding4 ,balanced ,valve4--,one of the inventions for this purpose is a valve so balanced by the steam pressure that but little wear results4 ,this has been the subject of many patents4 ,another type also largely used in engines is known as the oscillating valve1 which is cylindrical or conical in its structure1 and which revolves through less than a complete revolution in opening and closing the ports4 ,rotary ,valve4--,the rotary valve1 which constantly turns1 is employed where low pressures are used1 but it is not effectual with high pressures4 ,this is also cylindrical in its structure1 and has one or more ports through it1 which coincide with the ports through the walls of the engine1 as it turns1 and thus opens the port for admitting live steam and closing the discharge port at the same time or at a later period in its rotation4 ,engine ,accessories4--,while the steam engine is merely a device for utilizing the expansive force of steam1 and thus push a cylinder back and forth1 its successful operation1 from the standpoint of economy1 depends on a number of things1 which are rarely ever heard of except by users and engineers4 ,many of these devices are understood only by those who have given the matter thorough study and application4 ,to the layman1 or the ordinary user1 they are1 apparently1 worth but little consideration4 ,they are the things1 however1 which have more than doubled the value of the steam engine as a motor4 ,efficiency of ,engines4--,when it is understood that with all the refinements referred to the actual efficiency of a steam engine is less than #cj per cent4 some idea may be gained of the value which the various improvements have added to the motor4 ,efficiency refers to the relative amount of power which is obtained from the burning fuel4 ,for instance1 in burning petroleum about #ad1jjj heat units are developed from each pound4 ,if this is used to evaporate water1 and the steam therefrom drives an engine1 less than #dbjj heat units are actually utilized1 the remaining #ihjj heat units being lost in the transformation from the fuel to power4 ,illustration3 ,fig4 #ac4 ,effective pressure in a ,cylinder4 ,the value of considering and providing for condensation1 compression1 superheating1 re-heating1 compounding1 and radiation1 and to properly arrange the clearance spaces1 the steam jackets1 the valve adjustments1 the sizes of the ports and passages1 and the governor1 all form parts of the knowledge which must be gained and utilized4 ,how ,steam ,acts in a ,cylinder4--,reference has been made to the practice of cutting off steam before the piston has made a full stroke1 and permitting the expansive power of the steam to drive the piston the rest of the way1 needs some explanation4 ,as stated in a preceding chapter the work done is estimated in foot pounds4 ,for the purpose of more easily comprehending the manner in which the steam acts1 and the value obtained by expansion1 let us take a cylinder1 such as is shown in ,fig4 #ac1 and assume that it has a stroke of four feet4 ,let the cylinder have a diameter of a little less than one foot1 so that by using steam at fifty pounds pressure on every square inch of surface1 we shall have a pressure of about #ejjj pounds on the piston with live steam from the boiler4 ,in the diagram the piston moves forwardly to the right from #j to #a1 which represents a distance of one foot1 so that the full pressure of the steam of the boiler1 representing #ejjj pounds1 is exerted on the piston4 ,at #a the steam is cut off1 and the piston is now permitted to continue the stroke through the remaining three feet by the action of the steam within the cylinder1 the expansive force alone being depended on4 ,as the pressure of the steam within the cylinder is now much less and decreases as the piston moves along1 we have taken a theoretical indication of the combined pressure at each six inch of the travel of the piston4 ,the result is that we have the following figures1 namely1 #djjj1 #bgjj1 #agej1 #ajjj1 #dej and #ajj4 ,the sum of these figures is #aj1jjj pounds4 ,the piston1 in moving from #j to #a1 moved one foot1 we will say1 in one second of time1 hence the work done by the direct boiler pressure was #ejjj foot pounds2 and since the piston was moved three feet more by the expansion of the steam only1 after the steam pressure was shut off1 the work done in the three seconds required to move the piston1 was an additional #ejjj foot pounds1 making a total of #aj1jjj foot pounds for four seconds1 #aej1jjj foot pounds per minute1 or about #de horse power4 ,illustration3 ,fig4 #ad4 ,indicating pressure ,line4 ,this movement of the piston to the right1 represented only a half revolution of the crank1 and the same thing occurs when the piston moves back1 to complete the entire revolution4 ,indicating the ,engine4--,we now come to the important part of engine testing1 namely1 to ascertain how much power we have obtained from the engine4 ,to do this an indicator card must be furnished4 ,a card to indicate the pressure1 as we have shown it in the foregoing diagram would look like ,fig4 #ad4 ,the essential thing1 however1 is to learn how to take a card from a steam engine cylinder1 and we shall attempt to make this plain1 by a diagram of the mechanism so simplified as to be readily understood4 ,illustration3 ,fig4 #ae4 ,indicating the ,engine4 ,in ,fig4 #ae we have shown a cylinder ,a1 having within a piston ,b1 and a steam inlet pipe ,c4 ,above the cylinder is a drum ,d1 mounted on a vertical axis1 and so geared up with the engine shaft that it makes one complete turn with each shaft revolution4 ,a sheet of paper ,e1 ruled with cross lines1 is fixed around the drum4 ,the cylinder ,a has a small vertical cylinder ,f connected therewith by a pipe ,a1 and in this cylinder is a piston ,h1 the stem ,i of which extends up alongside of the drum1 and has a pointed or pencil ,j which presses against the paper ,e4 ,now1 when the engine is set in motion the drum turns in unison with the engine shaft1 and the pressure of the steam in the cylinder ,a1 as it pushes piston ,b along1 also pushes the piston ,h upwardly1 so that the pencil point ,j traces a line on the ruled paper4 ,it will be understood that a spring is arranged on the stem ,i in such a manner that it will always force the piston ,h downwardly against the pressure of the steam4 ,mean ,efficiency4--,we must now use a term which expresses the thing that is at the bottom of all calculations in determining how much power is developed4 ,you will note that the pressure on the piston during the first foot of its movement was #aj1jjj pounds1 but that from the point #a1 ,fig4 #ac1 to the end of the cylinder1 the pressure constantly decreased1 so that the pressure was not a uniform one1 but varied4 ,suppose we divide the cylinder into six inch spaces1 as shown in ,fig4 #ac1 then the pressure of the steam at the end of each six inches will be the figures given at bottom of diagram1 the sum total of which is #cj1jjj1 and the figures at the lower side show that there are eight factors4 ,the figure #aj1jjj represents1 of course1 two six inch spaces in the first foot of travel4 ,the result is1 that1 if we divide the sum total of the pressures at the eight points by #h1 we will get #cgej1 as the mean pressure of the steam on the piston during the full stroke of the piston4 ,in referring to the foot pounds in a previous paragraph1 it was assumed that the piston moved along each foot in one second of time4 ,that was done to simplify the statement concerning the use of foot pounds1 and not to indicate the time that the piston actually travels4 ,calculating ,horse ,power4--,we now have the first and most important factor in the problem1--that is1 how much pressure is exerted against the piston at every half revolution of the crank shaft4 ,the next factor to be determined is the distance that the piston travels in one minute of time4 ,this must be calculated in feet4 ,let us assume that the engine turns the crank shaft at a speed of #ej revolutions a minute4 ,as the piston travels #h feet at each revolution1 the total distance traveled is #djj feet4 ,if1 now1 we have a constant pressure of #cgej pounds on the piston1 and it moves along at the rate of #djj feet per minute1 it is obvious that by multiplying these two together1 we will get the figure which will indicate how many pounds the steam has lifted in that time4 ,this figure is found to be #a1ejj1jjj1 which means foot pounds1 as we have by this means measured pressure by feet1 or pounds lifted at each foot of the movement of the piston4 ,as heretofore stated1 we must now use the value of a horse power1 so that we may measure the foot pounds by it4 ,if we had a lot of wheat in bulk1 and we wanted to determine how much we had1 a bushel measure would be used4 ,so with power4 ,the measure1 as we have explained1 is #cc1jjj1 and #a1ejj1jjj foot pounds should give as a result a little over #de horse power4 ,condensation4--,we now come to the refinements in engine construction1--that which adds so greatly to the economy of operation4 ,the first of these is condensation4 ,the first reciprocating engine depended on this to do the actual work4 ,in this age it is depended upon simply as an aid4 ,the first thing however that the engineer tries to do is to prevent condensation4 ,this is done by jacketing the outside of the cylinder with some material which will prevent radiation of heat1 or protect the steam within from being turned back into water by the cool air striking the outside of the cylinder4 ,atmospheric ,pressure4--,on the other hand1 there is a time when condensation can be made available4 ,the pressure of air on every square inch of surface is #ad-c_/d pounds4 ,when a piston moves along and steam is being exhausted from the cylinder1 it must act against a pressure of #ad-c_/d pounds on every square inch of its surface4 ,the problem now is to get rid of that back pressure1 and the old type engines give a hint how it may be done4 ,why not condense the steam discharged from the engine cylinder8 ,in doing so a vacuum is produced on the exhaust side of the piston1 at the same time a pressure is exerted on its other side4 ,the ,condenser4--,thus the condenser is brought into existence1 as an aid4 ,by jacketing condensation is prevented2 it is fought as an enemy4 ,it is also utilized as a friend4 ,it is so with many of the forces of nature1 where man for years vainly fought some principle1 only to find1 later on1 that a friend is more valuable than a foe1 and to utilize a material agency in nature is more economical than to fight it4 ,pre-heating4--,the condenser does two things1 both of which are of great value to the economical operation of the engine4 ,for the purpose of rapidly converting the steam back into water as it issues from the engine cylinder1 water is used4 ,the steam from the cylinder has a temperature of #bab degrees and upwards1 dependent on its pressure4 ,water1 ordinarily1 has a temperature of #gj degrees1 or less1 so that when the steam strikes a surface which is cooled down by the water1 it is converted back into liquid form1 but at a temperature less than boiling water4 ,the water thus converted back from the steam gives up part of its heat to the water which cools the condenser1 and the water from the condenser1 as well as the water used to cool the condenser1 are thus made available to be fed into the boiler1 and thus assist in again converting it into a steam4 ,the economy thus lies in helping the coal1 or other fuel1 do its work1 or1 to put it more specifically1 it conserves the heat previously put out by the coal1 and thus saves by using part of the heat over again4 ,superheaters4--,another refinement1 and one which goes to the very essence of a heat motor1 is the method of superheating the steam4 ,this is a device located between the boiler and the engine1 so that the steam1 in its transit from the boiler to the engine1 will be heated up to a high degree1 and in the doing of which the pressure may be doubled1 or wonderfully increased4 ,this may be done in an economical manner in various ways1 but the usual practice is to take advantage of the exhaust gases of the boiler1 in the doing of which none of the heat is taken from the water in the boiler4 ,the products of combustion escaping from the stacks of boilers vary4 ,sometimes the temperature will be #hjj degrees and over1 so that if pipes are placed within the path of the heated gases1 and the supply steam from the boiler permitted to pass through them a large amount of heat is imparted to the steam from a source which is of no further use to the water being generated in the boiler4 ,compounding4--,when reference was made to the condensation of steam as it issued from the boiler1 no allusion was made to the pressure at which it emerged4 ,if the cylinder was well jacketed1 so that the amount of condensation in the cylinder was small1 then the pressure would still be considerable at the exhaust4 ,or1 the steam might be cut off before the piston had traveled very far at each stroke1 in which case the exhaust would be very weak4 ,in practice it has been found to be most economical to provide a high boiler pressure1 and also to superheat the steam1 but where it is not superheated1 and a comparatively high boiler pressure is provided1 compounding is resorted to4 ,to compound steam means to use the exhaust to drive a piston4 ,in such a case two cylinders are placed side by side1 one1 called the high pressure cylinder1 being smaller than the low pressure cylinder1 which takes the exhaust from the high pressure4 ,the exhaust from the second1 or low pressure cylinder may then be supplied to a condenser1 and in that case the mechanism would be termed a compound condensing engine4 ,if a condenser is not used1 then it is simply a compound engine4 ,triple and ,quadruple ,expansion ,engines4--,instead of using two cylinders1 three1 or four1 are employed1 each succeeding cylinder being larger than the last4 ,as steam expands it loses its pressure1 or1 stated in another way1 whenever it loses pressure it increases in volume4 ,for that reason when steam enters the first cylinder at a pressure of say #bej pounds1 it may exhaust therefrom into the next cylinder at a pressure of #age pounds1 with a corresponding increase in volume4 ,to receive this increased volume1 without causing a sensible back pressure on the first cylinder1 the second cylinder must be larger in area than the first2 in like manner when it issues from the exhaust of the second cylinder at #abe pounds pressure1 there is again an increase in volume1 and so on4 ,illustration3 ,fig4 #af4 ,compound ,engine4 ,examine ,fig4 #af1 which shows a pair of cylinders1 ,a being the high1 and ,b the low pressure cylinders1 the exhausts of the high pressure being connected up with the inlets of the low pressure1 as indicated by the pipes1 ,c ,d4 ,the diagram does not show the valve operations in detail1 it being sufficient to explain that when the valve ,e in the pipe ,c is closed1 the valve ,f1 at the other end of the cylinders1 in the pipe ,d1 is closed4 ,the same principle is employed in the triple and quadruple expansion engines1 whereby the force of the steam at each exhaust is put to work immediately in the next cylinder1 until it reaches such a low pressure that condensation is more effective than its pressure4 ,the diagram1 as given1 is merely theoretical1 and it shows the following factors3 ,first3 ,the diameter of each piston4 ,second3 ,the area of each piston in square inches4 ,illustration3 ,fig4 #af;a4 ,relative ,piston ,pressures4 ,third3 ,the steam pressure in each cylinder4 ,fourth3 ,the piston pressure of each cylinder4 ,it will be seen that an engine so arranged is able to get substantially the same pressure in each of the second1 third and fourth cylinders1 as in the first 7see ,fig4 #af;a71 and by condensing the discharge from the fourth cylinder a most economical use of steam is provided for4 ,the ,steam ,turbine4--,we must now consider an entirely new use of steam as a motive power4 ,heretofore we have been considering steam as a matter of pressure only1 in the development of power4 ,it has been observed that when the pressure of steam decreases at the same temperature it is because it has a greater volume1 or a greater volume results4 ,illustration3 ,fig4 #ag4 ,changing ,pressure into ,velocity ,when steam issues from the end of a pipe its velocity depends on its pressure4 ,the higher the pressure the greater its velocity4 ,the elastic character of steam is shown by its action when ejected from the end of a pipe1 by the gradually enlarging area of the discharging column4 ,in a reciprocating engine the power is derived from the pressure of the steam2 in a turbine the power results from the impact force of the steam jet4 ,such being the case velocity in the movement of the steam is of first importance4 ,pressure and ,velocity4--,to show the effectiveness of velocity1 as compared with pressure1 examine ,fig4 #ag4 ,a is a pipe discharging steam at a pressure of #ajj pounds4 ,to hold the steam in the pipe would require a pressure of #ajj pounds against the disk ,b1 when held at #a1 the first position4 ,suppose1 now1 the disk is moved away from the end of the pipe to position #b4 ,the steam1 in issuing forth1 strikes the disk over a larger area1 and in escaping it expands1 with the result that its velocity from #a to #b is greater than the movement of the steam within the pipe that same distance4 ,illustration3 ,fig4 #ah4 ,reaction against ,air4 ,illustration3 ,fig4 #ai4 ,reaction against ,surface4 ,the disk is now moved successively to positions #c1 #d1 #e1 and so on4 ,if we had a measuring device to determine the push against the disk at the various positions1 it would be found that there is a point at some distance from the end of the pipe1 at which the steam has the greatest striking force1 which might be called the focal point4 ,a blow pipe exhibits this same phase2 the hottest point is not at the end of the pipe1 but at an area some distance away1 called the focal point of heat4 ,the first feature of value1 therefore1 is to understand that pressure can be converted into velocity1 and that to get a great impact force1 the steam must be made to strike the hardest and most effective blow4 ,when a jet of steam strikes a surface it is diverted or it glances in a direction opposite the angle at which it strikes the object4 ,in directing a jet against the blades of a turbine it is impossible to make it strike squarely against the surface4 ,illustration3 ,fig4 #bj4 ,turbine ,straight ,blades4 ,let us assume that a wheel ,a1 ,fig4 #bj1 has a set of blades ,b1 and a steam jet is directed against it by the pipe ,c4 ,it will be seen that after the first impact the steam is forced across the blades1 and no further force is transferred to them4 ,form of ,blades4--,the blades are therefore so curved1 that the steam after the first impact cannot freely pass along the blade1 as it does on a straight blade1 but imparts on every element of the curved-back blade1 thereby giving up continually part of its speed to the blade4 ,this is clearly shown in ,fig4 #ba1 where the pipe ,d ejects the stream of steam against the concaved blades ,e4 ,many modifications have been made in the shapes of these blades1 all designed to take advantage of this action4 ,illustration3 ,fig4 #ba4 ,curved ,blades4 ,illustration3 ,fig4 #bb4 ,compound ,turbine4 ,compounding the ,jet4--,we may extend the advantages gained by this form of blades1 and diverting the course of the jet1 so that it will be directed through a series of wheels1 each of which will get the benefit of the moving mass from the pipes4 ,such a structure is shown in ,fig4 #bb1 in which three bladed wheels ,a1 ,b1 ,c1 are caused to rotate1 a set of stationary blades ,d1 ,e1 being placed between the three moving wheels1 but the stationary blades are disposed in reverse directions4 ,when the steam from pipes ,f1 ,f1 impinges against the blades of the first wheel ,a1 it is directed by the stationary blade ,d to the next wheel ,b1 and from the stationary blade ,e to the blades of the next wheel ,c1 thus1 in a manner somewhat similar to the compounding effect of the steam engine1 utilizes the pressure which is not used at the first impulse4 ,,chapter ,,iv ,,fuels ,,and ,,combustion ,all fuels must be put into a gaseous state before they will burn4 ,this is true of coal as well as of hydro-carbon oils4 ,neither coal nor petroleum will burn in its native state1 without the addition of oxygen4 ,this is absolutely necessary to support combustion4 ,burning is caused by the chemical union of oxygen with such substances as will burn4 ,this burning process may be slow1 and extend over a period of years1 or it may be instantaneous1 in which latter case the expansion of the heated gases is so great as to cause an explosion4 ,when a sufficient amount of oxygen has been mixed with a fuel to permit it to burn1 a high temperature is necessary to cause the immediate burning of the entire mass4 ,if such a temperature is not present the course of combustion is not arrested1 but it will1 on its own account1 start to oxydize1 and eventually be reduced to the same condition that would take place if exploded by means of a flame4 ,solid ,fuels4--,the great fuels in nature are carbon and hydrogen1 carbon being the substance most widely known and depended upon4 ,hard coal1 for instance1 is composed almost wholly of carbon2 whereas soft coal has a considerable quantity of hydrogen4 ,as coal was formed by wood1 which1 through long process of time became carbonized1 it contains considerable foreign matter which will not burn1 forming ash4 ,liquid ,fuels4--,the volatile oils1 however1 have very little non-combustible matter4 ,ordinary petroleum contains about #hj per cent1 of carbon1 and from #ab to #ae per cent4 of hydrogen1 the residue being foreign matter1 all more or less susceptible of being consumed at high temperatures4 ,combustion4--,the term combustion1 in its general sense1 means the act of burning2 but in a larger and more correct application it refers to that change which takes place in matter when oxygen unites with it4 ,oxygen is a wonderful element1 and will unite with all known substances1 unlike all other elements in this respect4 ,it may take years for it to form a complete unity4 ,thus1 wood1 in time1 will crumble1 or rot1 as it is called4 ,this is a slow process of combustion1 brought about without applying heat to it1 the change taking place in a gradual way1 because oxygen unites with only a small portion of the wood4 ,oxidation4--,iron will rust4 ,this is another instance of combustion1 called oxidation4 ,when oxygen unites with a substance it may produce an acid1 or an alkali1 or a neutral compound4 ,when wood is burned it produces an ash1 and this ash contains a large amount of potash1 or lye1 which is an alkali1 or a salt4 ,so when other substances are burnt the result may be an acid1 like sulphur1 or it may be unlike either acid or the alkali4 ,the unity of oxygen with the food in the body is another instance of oxidation1 which produces and maintains the heat necessary for existence4 ,carbon or hydrogen1 as a fuel1 are inert without oxygen1 so that in considering the evolution of a force which is dependent on heat1 we should know something of its nature1 thereby enabling us to utilize it to the best advantage4 ,the ,hydro-carbon ,gases4--,if petroleum1 or gasoline1 should be put into the form of a gas1 and as such be confined in a receiver1 without adding any oxygen1 it would be impossible to ignite it4 ,the character of the material is such that it would instantaneously extinguish any flame4 ,now1 to make a burning mixture1 at least three parts of oxygen must be mixed with one of the hydro-carbon1 before it is combustible4 ,oxygen and ,atmosphere4--,the atmosphere is not oxygen4 ,only one-fifth of common air is oxygen1 the residue being1 principally1 nitrogen1 which is not a fuel4 ,to produce the proper aration1 therefore1 at least fifteen parts of air must be mixed with one part of hydro-carbon gas4 ,the term hydro-carbon is applied to petroleum1 and its products1 because the elements carbon and hydrogen make up the largest part of the oil1 whereas this is not the case with most of the other oils4 ,we are now dealing with a fuel such as is needed in ,internal ,combustion ,engines1 and it is well to know some of the problems involved in the use of the fuel1 as this will give a better understanding of the structure of the devices which handle and evolve the gases1 and properly burn them within the engine4 ,vaporizing ,fuel4--,as the pure liquid will not burn in that state the first essential is to put it into a gaseous form1 or to generate a vapor from it4 ,the vapor thus made is not a gas1 in the true sense of that term1 but it is composed of minute globules of finely-divided particles of oil4 ,nearly all liquids will vaporize if permitted to come into contact with air4 ,the greater the surface exposed to air the more rapidly will it turn into a vapor4 ,by forcibly ejecting the liquid from a pipe or spraying device1 and mingling air with it1 evaporation is facilitated1 and at the same time the proper admixture of air is provided to make a combustible substance the moment sufficient heat is brought into contact with it4 ,this is what actually takes place in a gasoline engine1 and all the mechanism is built with this end in view4 ,it has been the universal practice to make an explosive mixture of this character1 and then ignite it by means of an electric spark1 but it is now known that such a fuel can be exploded by pressure1 and this needs some explanation4 ,explosion by ,compression4--,the study of the compressibility of gases is an interesting one4 ,as we have previously stated1 the atoms1 comprising the gases1 are constantly moving among themselves with great rapidity1 so that they bombard the sides of the receiver in which they are confined1 and also contact with each other in their restless movements4 ,when compression takes place the speed of the movements of the atoms is greatly accelerated1 the friction of their movements is increased1 and heat is evolved4 ,as the pressure becomes greater the heat increases until it is of such intensity that the gas ignites1 and an explosion follows4 ,how ,compression ,heats4--,the theory of the compressibility of gases may be stated as follows3 ,let us assume that the temperature of the air is #gj degrees ,fahrenheit1 and we have a receiver which holds two cubic feet of this air4 ,if the contained air is now compressed to a volume of one cubic foot1 the temperature of two cubic feet is compressed into one cubic foot1 and there is now #adj degrees of heat within the receiver4 ,if this cubic foot of air is again compressed to half its volume1 the temperature is correspondingly increased4 ,while this it not absolutely true in practice1 owing to the immense loss caused by radiation1 still1 it will enable the mind to grasp the significance of compression1 when the subject of heat is concerned4 ,elasticity of ,gases4--,the great elasticity of gases1 and the perfected mechanical devices for compressing the same1 afford means whereby ten or twenty atmospheres can be forced into a receiver1 and thereby produce pressures of several hundred pounds1 which would mean sufficiently high temperatures to ignite oils having the higher flash point4 ,advantages of ,compression4--,the compression system permits of the introduction of a larger quantity of fuel than is usually drawn into the cylinder1 and thereby a greater and more efficient action is produced on the piston of the engine on account of quicker combustion and therefore higher gas pressures4 ,the compression1 however1 rarely if ever exceeds six atmospheres or about #ij pounds per square inch4 ,the ,necessity of ,compression4--,there are two reasons why compression is necessary before igniting it4 ,first1 because it is essential to put sufficient gas in the cylinder to make the engine efficient4 ,to illustrate3 ,suppose we have a cylinder capable of drawing in #aej cubic inches of gas1 and this is compressed down to #be cubic inches1 the space then occupied by the gas would represent what is called the clearance space at the head of the cylinder4 ,to compress it to a greater degree the clearance space might be made smaller1 which could be done in several ways1 but whether the gas thus drawn in should be compressed to #cj1 or #be1 or even #aj cubic inches1 it is obvious that there would be no more fuel in the cylinder in one case than in the other4 ,as however the mean effective pressure1 which determines the efficiency of the motor1 increases with the compression pressure1 the latter should be as high as possible1 but not so high that premature explosion takes place owing to the heat created by compression4 ,second3 ,the more perfect the mixture of the vaporized product with the air1 the more vigorous will be the explosion4 ,the downward movement of the piston draws in the charge of air and sprayed jet of gasoline1 and the only time for mixing it is during the period that it travels from the carbureter through the pipes and manifold to the cylinder4 ,having in mind the statement formerly made that compression causes a more rapid movement of the molecules of a gas1 it is obvious that the upward movement of the piston1 in the act of compressing the gas has a more positive action in causing an intimate mixture of the hydro-carbon gases than took place when the gases were traveling through the pipes on their way to the cylinder4 ,,chapter ,v ,,the ,,internal ,,combustion ,,engine ,it will be observed that in a steam engine the heat is developed outside of the cylinders and the latter used solely for the purpose of taking the steam and utilizing it1 by causing its expansion to push a piston to and fro4 ,we shall now consider that type of motor which creates the heat within the cylinder itself and causes an expansion which is at once used and discharged at the reciprocating motion of the piston4 ,the original method of utilizing what is called ,internal combustion ,motors1 was to employ a fixed gas4 ,a fixed gas is one which will remain permanently in that condition1 unlike a vapor made from gasoline4 ,the difference may be explained as follows3 ,fixed ,gases4--,if the vapor of gasoline1 or petroleum1 is subjected to a high heat1 upwards of #aejj degrees1 it is so changed chemically1 that it will not again return to a liquid state4 ,this is called fixing it4 ,gas is made in that way from the vapor of coal1 and fixed1 producing what is called illuminating gas4 ,although the temperature of fixing it is fully three times greater than is required to explode it1 the fact that it is heated in closed retorts1 and oxygen is prevented from mixing with it1 prevents it from burning1 or exploding4 ,gas ,engines4--,such a gas has been used for many years in engines which were usually of the horizontal type1 and were made exceedingly heavy and cumbrous1 and provided with enormous fly wheels4 ,gases thus made are not as rich as those generated direct from the hydro-carbon fuels1 because1 being usually made from coal they did not have a large percentage of hydrogen4 ,energy of ,carbon and ,hydrogen4--,when a pound of carbon is burned1 it develops #ad1ejj heat units1 and a pound of hydrogen over #eb1jjj heat units4 ,assuming that #he per cent4 of a pound of petroleum is carbon1 and #ae per cent4 is hydrogen1 the heat units of the carbon would be #ab1bbe1 and the heat units of the #ae per cent4 of hydrogen would be #ab1hjj4 ,the combined value is1 therefore1 #be1jbe1 which is almost double that of coal gas4 ,this fact makes the gasoline engine so much more efficient1 and for the same horse power the cylinders can be made smaller1 and the whole structure much lighter in every way4 ,gasoline motors are of two types1 one in which an explosion takes place at every revolution of the crank1 called the two-cycle1 and the other the four-cycle1 in which the explosion occurs at every other turn of the crank4 ,the terms two-cycle is derived from the movement of the piston1 as that moves downwardly during the period when the crank is making a half turn1 and returns in its upward stroke when the crank completes the turn1 or that two half turns of the crankshaft complete the cycle4 ,four-cycle engines have two such complete movements at each impulse1 or require four half turns of the crankshaft to complete the cycle4 ,the ,two-,cycle ,type4--,in order to clearly distinguish between this and the four-cycle1 it would be well to examine the diagram1 ,fig4 #bc4 ,for a clearer understanding the drawing is explained in detail4 ,the cylinder ,a1 within which the piston works1 has a removable cap ,b1 and at its lower end a removable crank case ,c4 ,the case is designed to entirely close the lower end of the cylinder so that it is air tight1 for reasons which will be explained4 ,the outer jacket1 or casing ,d1 at the upper end of the cylinder1 is designed to provide a space ,e1 for the circulation of water1 to cool the cylinder during its working period4 ,the crankshaft ,f passes through the crank case1 the latter having suitable bearings ,g for taking care of the wear4 ,illustration3 ,fig4 #bc4 ,two-cycle4 ,first ,position4 ,the piston ,h is connected up with the rod ,i1 the latter being hinged at a point within the piston1 as shown4 ,the crank case has an inlet port1 provided with a valve which opens inwardly1 so that when the piston moves upwardly the valve will open and air will be drawn into the crank case and space below the piston4 ,at one side is a vertical duct ,k1 which extends from a point directly above the crank case1 to such a position that when the piston is at its lowest point gas can be discharged into the space above the piston4 ,on the opposite side of the cylinder1 and a little above the inlet port of the duct ,k1 is a discharge port ,m4 ,the inlet port and the discharge port1 thus described1 are both above the lower end of the piston when it is at its highest point4 ,the spark plug is shown at ,n4 ,on the upper end of the piston1 and close to the side wall through which the inlet port ,k is formed1 is an upwardly-projecting deflecting plate ,o1 the uses of which will be explained in the description of its operation4 ,fig4 #bc shows the piston at its highest point1 and we will now assume that ignition takes place1 thus driving the piston downwardly until the upper end of the piston has fully uncovered the discharge port ,m1 as shown in ,fig4 #bd4 ,this permits the exhaust to commence1 and as the piston proceeds down still further1 so as to uncover the inlet port ,k1 the gas1 which at the down stroke has been compressed in the space below the piston1 rushes in1 and as it strikes the deflecting plate ,o1 is caused to flow upwardly1 and thus helps to drive out the burnt gases remaining at the upper end of the cylinder4 ,illustration3 ,two-cycle ,engine4 ,fig4 #bd4 ,second position4 ,fig4 #be4 ,third position4 ,this action is called scavenging the cylinder1 and the efficiency of this type of engine is largely due to the manner in which this is done4 ,it is obvious that more or less of the unburnt gases will remain1 or that some of the unburnt carbureted air will pass out at each discharge1 and thus1 in either case1 detract from the power of the subsequent explosion4 ,as the piston now moves upwardly to complete the cycle1 the piston closes both of the ports1 thus confining the gas which was previously partly compressed1 and as the piston proceeds the gas is still further compressed until the piston again reaches the upward limit of its motion4 ,advantages of the ,two-,cycle ,engine4--,this kind of engine has several distinct advantages4 ,it has less weight than the four-cycle2 it gives double the number of impulses for a given number of revolutions of the crankshaft2 and it dispenses with valves1 springs1 cam-shafts1 stems and push rods4 ,more or less danger1 however1 attends the operation of a two-cycle engine1 principally from the fact that an explosive mixture in a partially compressed condition is forced into the space which the instant before was occupied by a flame1 and it is only because the expansion of the burst gases at the previous charge has its temperature decreased so far below the explosion point1 that the fresh gas is not ignited1 although there have been occasions when explosions have taken place during the upstroke4 ,the ,four-,cycle ,engine4--,the most approved type is that which is known as the four-cycle4 ,this will also be fully diagrammed so as to enable us to point out the distinctive difference4 ,illustration3 ,four-cycle ,engine4 ,fig4 #bf4 ,first position4 ,fig4 #bg4 ,second position4 ,figs4 #bf and #bg show sections of a typical four-cycle engine1 in which the inlet and the exhaust valves are mechanically operated4 ,the cylinder ,a is either cast with or separate from the crank case ,b1 and has a removable head ,c4 ,the upper end of the cylinder has a water space formed by the jacket ,d4 ,the inlet port ,e and the discharge port ,f are both at the upper end of the cylinder4 ,the crank shaft ,g passes horizontally through the crank case1 and it is not necessary1 as in the case of the two-cycle-engine1 to have the case closed tight4 ,the piston ,h is attached to the connecting rod ,i1 which is coupled to the crank1 as shown4 ,the crank shaft has a small gear ,j1 which meshes with two gears of double size on opposite sides of the crank shaft1 one of the gears ,k1 being designed to carry the cam ,l for actuating the stem ,l1 which opens the valve ,m in the port that admits the carbureted air4 ,illustration3 ,four-cycle ,engine4 ,fig4 #bh4 ,third position4 ,fig4 #bi4 ,fourth position4 ,the other large gear ,n is mounted on a shaft which carries a cam ,o that engages the lower end of a push rod ,p1 to open the valve ,q in the discharge port ,f4 ,it should be observed that the stems ,l1 ,p1 are made in two parts1 with interposing springs ,r1 so the valves may be firmly seated when the stems drop from the cams4 ,the spark plug ,s is located in the head1 close to the inlet port4 ,the character of the igniting system is immaterial1 as the object of the present diagrams is to show the cycle and method of operating the engine at each explosion1 and to fully illustrate the manner in which it is distinguished from the two-cycle type4 ,a fly wheel is necessary in this as in the other type1 and in practice the two gear wheels1 ,k1 ,n1 are placed outside of the case ,b1 and only the small gear1 and the cam shafts1 on which the cams are mounted1 are within the case4 ,the operation is as follows3 ,in ,fig4 #bf the piston is shown in a position about to commence its downward movement1 and we will assume that the ignition has just taken place4 ,both valves ,m1 ,q1 are closed1 as it will be noticed that the cams ,l1 ,o1 are not in contact with the lower ends of the push rods4 ,the explosion drives the piston down to the position shown in ,fig4 #bg1 when the cam ,o begins to raise the stem ,p1 and thus opens the discharge valve ,q1 permitting the burnt gases to escape as the piston travels upwardly to the position shown in ,fig4 #bh4 ,at this position the valve ,q closes1 and the cam ,l opens the inlet valve ,m1 so that as the piston descends the second revolution1 the carbureted air is drawn in until the crank has just turned at its lowest limit of movement1 as shown in ,fig4 #bi4 ,the upward stroke of the piston now performs the work of compressing the carbureted air in the cylinder1 and it is ready for the ignition the moment it again reaches the position shown in ,fig4 #bf4 ,the ,four ,cycles4--,the four distinct operations thus performed are as follows3 ,first1 the explosion1 and downward movement of the piston4 ,second1 the upward movement of the piston1 and the discharge of the burnt gases4 ,third1 the down stroke of the piston1 and the indrawing of a fresh charge of carbureted air4 ,fourth1 the upward movement of the piston1 and the compression of the charge of carbureted air4 ,the order of the engine performance may be designated as follows3 #a4 ,impulse4 #b4 ,exhaust4 #c4 ,admission4 #d4 ,compression4 ,ignition ,point4--,while the point of ignition1 shown in the foregoing diagrams1 represents them as taking place after the crank has passed the dead center1 the firing1 in practice1 is so adjusted that the spark flashes before the crank turns past the dead center4 ,the reason for this will be apparent on a little reflection4 ,as the crank turns very rapidly the spark should be advanced1 as it is called1 because it takes an interval of time for the spark to take effect and start the explosion4 ,if the sparking did not take place until the crank had actually passed the dead center1 the full effect of the compression and subsequent explosion pressure would not be had4 ,advantage of the ,four-,cycle ,type4--,the most marked advantage in the four-cycle type is its efficiency4 ,as it has one full stroke within which to exhaust the burnt gases1 the cylinder is in a proper condition to receive a full value of the incoming charge1 and there is no liability of any of the unburnt gases escaping during the exhaust from the previous explosion4 ,the next important advantage of this type is in the fact that it can be operated at a higher speed than the two-cycle type1 and this is a great advantage1 notwithstanding the less number of impulses in the four-cycle type4 ,the ,loss in ,power4--,the great disadvantage in all engines of this class is the great loss resulting from their action4 ,the explosion which takes place raises the temperature to fully #bjjj degrees of heat1 and unless some provision is made to keep the cylinder down to a much lower temperature the engine would soon be useless4 ,high temperatures of this character absolutely prevent lubrication1 a thing which is necessary to insure proper working4 ,for this reason a water jacket is provided1 although there are engines which are cooled by the action of air4 ,in any event1 the heat imparted to the cylinder is carried away and cannot be used effectively1 so that fully one-half of the power is dissipated in this direction alone4 ,the next most serious loss is in the escape of heat through the burnt gases1 which amounts to seventeen per cent4 ,if the expansive force of the burnt gases at the time of ignition is #bej pounds per square inch1 and at the time of the discharge it is fifty pounds1 only four-fifths of its power is effectively used4 ,as1 however1 the discharge is against the air pressure of nearly fifteen pounds per square inch1 it is obvious that thirty-five pounds per inch is driven away and lost4 ,the third loss is by conduction and radiation1 which amounts to fifteen per cent4 or more1 so that the total loss from all sources is about eighty-four per cent41 leaving not more than sixteen per cent4 of the value of the fuel which is converted into power4 ,engine ,construction4--,in the construction of engines the utmost care should be exercised in making the various parts4 ,the particular features which require special care are the valves1 which should be ground to fit tightly1 the proper fitting of the piston rings1 crank shaft and connecting rod bearings as well as the accurate relining of these bearings4 ,illustration3 ,fig4 #cj4 ,valve ,grinding4 ,valve ,grinding4--,fig4 #cj shows a valve and valve seat4 ,the valve has usually a cross groove so that a screw driver in a drill stock may be used to turn it and to exert the proper pressure4 ,the finest emery powder and a first class quality of oil should be used4 ,the valve is seated and after the oil and emery powder are applied the drill stock is used to turn the valve4 ,after twenty or thirty turns1 wipe off the parts and examine the contact edges1 to see whether the entire surfaces are bright1 which will indicate that the valve fits true on its seat4 ,never overgrind4 ,this is entirely unnecessary4 ,it is better also to rock the crank of the drill stock back and forth1 instead of turning it in one direction only4 ,the ,crank ,shaft4--,the crank shaft is the most difficult part of the engine to build4 ,it is usually made of a single forging of special steel and the cranks and bearings are turned out of this1 requiring the utmost care4 ,formerly these were subject to breakage1 but improved methods have eliminated all danger in this direction4 ,the ,cams4--,notwithstanding the ends of the push rods are provided with rollers to make the contact with the cams1 the latter will wear1 and in doing so they will open the valves too late4 ,the slightest wear will make considerable difference in the inlet valve1 and it requires care and attention for this reason1 in properly designing the cams1 so that wear will be brought to a minimum4 ,,chapter ,,vi ,,carbureters ,a carbureter is a device which receives and mixes gasoline and air in proper proportions1 and in which a vapor is formed for gasoline engines4 ,the product of the carbureter is a mixture of gasoline vapor and air1 not a gas4 ,a gas1 as explained1 is of such a character that it remains fixed and will not stratify or condense4 ,functions of a ,carbureter4--,the function of a carbureter is to supply air and gasoline by means of its adjustable features so as to make the best mixture4 ,the proportions of air and gasoline will vary1 but generally the average is fifteen parts of air to one of gasoline vapor4 ,if there is too much gasoline1 proportionately1 a waste of fuel results1 as a great amount of soot is formed under those conditions4 ,if there is an excess of air the mixture1 when ignited1 will not have such a high temperature1 hence the expansive force is less1 and the result is a decrease of power4 ,while it is possible to get a rapid evaporation from gasoline by heating it1 experience has shown that it is more economical to keep the gasoline cool1 or at ordinary temperatures1 provided the carbureter is properly constructed1 because the vapor1 if heated1 when drawn into the engine1 will be unduly expanded1 and less fuel in that case is drawn in at each charge1 and less power results4 ,rich ,mixtures4--,there are conditions under which rich mixtures are advantageous4 ,this is a mixture in which there is a larger percentage of gasoline than is necessary for instantaneous combustion4 ,for ordinary uses such a mixture would not be economical4 ,at low speeds1 however1 or when carrying heavy loads1 it is desirable1 for the reasons that at a slow speed the combustion is slower4 ,rich mixtures are objectionable at high speeds because1 as the combustion is slow1 incomplete combustion within the power stroke results1 the temperature of the gas at the end of the stroke is very high1 and this will seriously affect the exhaust valves4 ,furthermore1 there is likelihood of the gas continuing to burn after it is discharged from the cylinder4 ,lean ,mixtures4--,such a mixture is one which has a less amount of gasoline than is necessary to make a perfectly explosive compound4 ,for high speeds a lean mixture is desirable1 principally because it burns more rapidly than a rich mixture4 ,types of ,carbureters4--,there are two distinct types of carbureters1 one which sprays the gasoline into a conduit through which air is passing1 and the other in which a large surface of gasoline is placed in the path of the moving air column1 which was originally used1 but has been absolutely replaced by the jet carbureters on account of their better control features4 ,it will be remembered that reference was made to the manner in which vaporization takes place1 this term being used to designate that tendency of all liquids to change into a gaseous state4 ,all carbureters are designed with the object of mechanically presenting the largest possible area of oil to the air1 so that the latter will become impregnated with the vapor4 ,the ,sprayer4--,the best known type depends on dividing up the gasoline into fine globules1 by ejecting it from a small pipe or jet4 ,the spray thus formed is caught by the air column produced by the suction of the engine pistons1 and during its passage through the throttle and the manifold1 is in condition where a fair mixture of air and vapor is formed1 which will readily ignite4 ,the ,surface ,type4--,this form of carbureter provides a pool of gasoline with a large surface1 within the shell1 so arranged that as the air is drawn past the pool it must come into contact with the oil1 and thus take up the necessary quantity of evaporated gasoline for charging the air4 ,the surface type has not been used to a large extent1 but the sprayer is universally used1 and of this kind there are many examples of construction1 each having some particular merit4 ,governing a ,carbureter4--,it is a curious thing that one carbureter will work admirably with one engine1 and be entirely useless in another4 ,this is due to several factors1 both in the engine design and in the carbureter itself4 ,the quality of mixture that an engine will take depends on its speed4 ,the suction of the pistons depends on the speed of the engine4 ,if1 at ordinary speed the carbureter gives a proper mixture1 the throats and passages through the pipes and manifold1 as well as the valve which discharges the gasoline1 may be in a prime condition to do good work2 but when the pistons work at double speed the inrush of air may not carry with it the proper amount of fuel2 or1 under those conditions1 the air may receive too great an amount of gasoline1 proportionally4 ,the latter is usually the case1 hence provision must be made for such a contingency1 and we shall therefore take up the various features essential in the construction of the carbureter1 so as to show what steps have been taken to meet the problems arising from varying speeds1 differences in the character of the fuel1 regulating the inflow and mixture of gasoline and air1 and adjustments4 ,illustration3 ,fig4 #ca4 ,carbureter4 ,so many different types of carbureters have been devised1 that it is difficult to select one which typifies all the best elements of construction4 ,in ,fig4 #ca we have shown a well known construction1 and which will illustrate the features of the sprayer type to good advantage4 ,the body of the device1 represented by ,a1 has a flange by means of which it is secured to the pipe which carries the carbureted air to the engine4 ,the lower end of this tubular body is contracted1 as shown at ,b1 so as to form what is called a venturi tube4 ,exteriorly this contracted tube is threaded1 as shown at ,c1 so as to receive thereon a threaded body ,d1 the lower end of the body having an enlarged disk-head ,e1 integral therewith1 and an upwardly-projecting annular flange ,f is formed around this disk to receive and hold a cylinder ,g1 which constitutes the float and fuel chamber4 ,the upper end of this cylinder rests against a seat cast with the body ,a1 and packing rings are placed at the ends of the cylinder to prevent the oil from leaking out4 ,within the tubular body ,d is a vertical tube ,h1 integral with the disk head ,e1 and oil is supplied to this tube through ducts ,i1 which communicate with the chamber within the reservoir ,g4 ,a drain cock is at the lower end of this tube1 and an adjustable cap ,k screws on the tubular stem of the drain tube1 around which air is admitted1 the air passing upwardly through vertical ducts ,l1 as shown1 and thus mixes with air at the contracted part of the venturi tube4 ,a ring-like float ,n is placed within the glass chamber1 and this is adapted to engage with the inner end of a lever ,n1 this lever being pivoted at ,o1 within a side extension ,p of the carbureter shell4 ,the inner end of this lever has a link hinged thereto1 the lower end of which serves as a needle valve to close the ejecting orifice of the tube ,l4 ,the outer end of the lever ,n engages a shoulder on a vertically-disposed needle valve ,q1 which has its point in the inlet opening of the pipe ,r1 through which gasoline is supplied to the glass chamber4 ,a spring ,t serves to keep the valve stem normally on its seat4 ,directly opposite this chambered extension ,p is another extension ,u1 also cast with the shell1 through which is a vertical stem ,v4 ,this stem carries a downwardly-opening valve ,w1 that seats against a plug1 and a spring ,x below the valve1 serves to keep it against its seat1 unless there should be an extraordinarily heavy pull or suction4 ,this is the auxiliary air inlet1 and the lower spring is actuated only when the engine is running at moderate speeds1 but when running at high speed and an additional quantity of air is required the upper spring ,y is compressed1 and thus a much greater quantity of air is allowed to pass in and mingle with the spray at the throttle valve ,z4 ,the throttle valve is mounted in the discharge opening1 and is controlled by a lever on the outside of the carbureter4 ,the device operates as follows3 ,primary air enters the opening between the cup ,k and the disk-head ,e1 passing up into the space around the oil tube ,h4 ,as the spring ,t1 around the needle valve ,q1 draws up the valve from its seat1 oil is permitted to flow in through the duct ,r and fill the chamber1 until the float engages with the inner end of the lever ,n1 and raises it1 thus uncovering the ejecting end of the tube ,h1 and at the same time closing the inlet tube ,r4 ,the suction from the engine then draws air through the primary duct1 as stated1 and also an additional quantity through the secondary source1 by way of the valve ,w1 this valve being so regulated as to supply the requisite quantity4 ,the auxiliary air source serves the purpose that means should be provided to supply more than the ordinary amount of air1 when running at high speeds4 ,from the foregoing it will be observed that a carbureter must be so constructed that it will perform a variety of work4 ,these are3 ,first1 ,automatic means for filling the float chamber when the gasoline goes below a certain level4 ,second1 ,cutting off the supply of gasoline4 ,third1 ,providing a primary supply of gasoline for spraying purposes4 ,fourth1 ,furnishing an auxiliary air supply4 ,fifth1 ,throttling means in the discharge opening4 ,it is thus a most wonderful contrivance1 and considering that all the elements necessary to make it work satisfactorily are provided with adjustable devices1 it may be seen that to make it perform correctly requires a perfect understanding of its various features4 ,requirements in a ,carbureter4--,in view of the foregoing it might be well to know how to select a carbureter that is ideal in its operation4 ,first4 ,the adjustment of the auxiliary valve should be of such a character that at the slowest speed the valve should not be lifted from its seat4 ,second4 ,it must be so arranged that it is not difficult to change the relative amount of air and gasoline4 ,third4 ,the floating chamber should be so arranged that the float will act on the lever which lifts the valve of the injecting pipe1 even though the carbureter body should be tilted at an angle4 ,this is particularly important when the carbureter is used in automobiles4 ,fourth4 ,the valves should be in such position that they are readily accessible for cleaning or for examination4 ,fifth4 ,the float should be so arranged that it is adjustable with reference to the lever that it contacts with4 ,sixth4 ,a gauze strainer should be placed at the gasoline inlet1 and it is also advisable to have a similar strainer above the mixing chamber1 beyond the throttle4 ,seventh4 ,there should be no pockets at any point in the body to hold the gasoline which might condense4 ,eighth4 ,the body of the carbureter should be so constructed that every part is easily accessible1 and draining means provided so that every particle of gasoline can be withdrawn4 ,ninth4 ,means for heating it1 in case of cold weather4 ,size of the ,carbureter4--,the proper size of a carbureter for an engine has been the subject of considerable discussion and experimenting4 ,if its passages are too large1 difficulty will be experienced in starting the engine1 because the pulling draft through the primary will not be sufficient to make a spray that will unite with the air4 ,a carbureter too large will only waste fuel1 even after the engine has been cranked up so it will start4 ,if the carbureter is too small the engine will not develop its required output of power4 ,while it might work satisfactorily at low speeds it would be entirely inefficient at high speeds4 ,rule for ,size of ,carbureter4--,in all cases the valve opening and cylinder capacity in the engine should determine this4 ,the size of the opening of the carbureter outlet should be the same as that of the engine valve1 which is also the case where the carbureter supplies a multi-cylinder1 as there is only one valve open at the same time4 ,it was formerly the custom to use a carbureter for each cylinder but the practice has been abandoned1 because it is obvious that a single carbureter will1 owing to the continuous suction1 supply a mixture of more nearly uniform character than two or more1 even though they should supply the mixture to a common manifold4 ,the ,throttle4--,much of the economy in running an engine depends on the manipulation of the throttle4 ,as an example1 with a certain motor and carbureter it will be found that for maximum speed the throttle should be open about one-eighth of the way4 ,the proper way1 in starting the engine1 is to open the throttle fully half way1 and to retard the spark4 ,as soon as the engine begins to run properly1 the spark is advanced and the throttle closed down to the required point4 ,the engine speed may always be maintained by the throttle under a constant varying load1 by adjusting the throttle valve4 ,a rich mixture may be obtained by throttling the primary air supply4 ,the throttle may also be a most effective means of economizing fuel when the engine has a first class sparking device1 as in that case the throttle can be closed down to provide a very small opening4 ,flooding4--,one of the most prevalent troubles in carbureters is the liability to flood4 ,this is usually caused by foreign matter getting under or in the float valve1 so that it will not properly seat4 ,sometimes the mere moving of the float will dislodge the particle4 ,another cause of flooding is due1 frequently1 to an improperly-arranged float1 which1 when the engine is inclined1 will prevent improper seating of the valve1 and flooding follows4 ,the greatest care should be exercised in seeing that the gasoline supply is free from all impurities when it is poured into the tank4 ,to strain it is the best precaution1 and it pays to be particular in this respect4 ,it is surprising to see the smallest speck1 either stop the flow entirely1 or produce an overflow1 either of which will cause a world of trouble4 ,water is another element which has no place in a carbureter4 ,an indication of this is the irregular movement of the engine4 ,the only remedy is to stop and drain the carbureter4 ,a few drops may cause all the trouble4 ,illustration3 ,fig4 #cb4 ,carbureter4 ,types of ,carbureters4--,in ,fig4 #cb we show another type of carbureter1 which is simple in construction1 and has many desirable features4 ,the cylindrical body of the carbureter1 ,a1 has a downwardly-projecting globular extension ,b1 at one side of which is a flange ,c to secure it to the pipe1 and through this is the discharge opening ,d4 ,this globular extension serves as the mixing chamber4 ,within the cylindrical shell is an upwardly-projecting circularly-formed extension ,e1 and the top or cap ,f of the cylindrical body ,a has a downwardly-projecting cylindrical rim ,g which overlaps the lower circular extension ,e1 and it is so constructed that a very thin annular slit ,h is thus formed between the two parts1 through which fuel oil flows from the float chamber ,i into the space around the central tube ,j which passes down through the two circular extensions ,e1 ,g4 ,this central tube ,j is designed for the auxiliary air supply4 ,it extends down to the globular base ,b1 and has a valve ,k seated against its end4 ,the stem ,l of the valve is vertically-movable within an adjustable stem ,m1 and a helical spring ,n1 capable of having its tension adjusted by the stem ,m1 bears upwardly against the valve so as to keep it normally against the lower end of the tube ,j4 ,the auxiliary air1 therefore1 passes down centrally through the tube ,j1 while the primary air supply passes through openings ,o1 surrounding the tube ,j1 downwardly past the slitted opening ,h1 and thence to the discharge port ,d4 ,surrounding the tubular projections ,e1 ,g1 and within the float chamber ,i1 is the float ,p4 ,this is designed to strike the bifurcated ends of a lever ,q1 which is hinged near its outer end1 as at ,r1 and has its short projecting end resting beneath the collar of a vertical needle valve ,s4 ,this needle valve is vertically placed within a chambered extension ,t at the side of the shell ,a1 and its lower end rests within the opening of the inlet ,u which supplies the gasoline to the chamber ,i4 ,the upper end of the valve stem passes through a plug ,v1 through which is a vent hole ,w4 ,a spring ,x is used between the plug and the collar on the lower end of the needle valve1 so that the valve is kept on its seat thereby1 unless the gasoline in the chamber should fall so low as to cause the float to rest on the inner end of the lever ,q1 when the needle valve would be unseated thereby4 ,all the parts of this device seem to be accessible1 and it is presented as an example of construction that seems to meet pretty nearly all of the ideal requirements of a device for furnishing a perfect admixture4 ,surface ,carbureter4--,this type of carbureter also requires a float but does not have secondary air inlet mechanism4 ,it has one striking advantage over the sprayer system1 in the particular that the suction of the engine is not depended upon to draw the gasoline from the float chamber4 ,it is much more sensitive to adjustment in the float level and needle valve than the other type4 ,illustration3 ,fig4 #cc4 ,surface ,carbureter4 ,the diagram1 ,fig4 #cc1 shows a body ,a1 somewhat bowl-shaped1 with a chambered extension1 ,b1 at one side1 at the lower side of which is the fuel inlet duct ,c4 ,directly above this duct the upper wall of the extension has a plug ,d1 the lower end of which carries therein the upper end of a vertically-movable needle valve1 ,e1 the lower end of the valve resting within the duct ,c4 ,a float ,f within the bowl-shaped body is secured at one side to a lever ,g1 which is hinged at a point near the needle valve ,e1 and the short end of this lever connects with this needle valve in such a manner that as the float moves upwardly the valve is seated1 and when the level of the fuel oil falls below a certain point the needle is lifted from its seat1 and oil is permitted to flow into the float chamber4 ,the cap ,h of the float chamber has cast therewith a ,u-shaped tube1 the inlet end ,i being horizontally-disposed1 while the discharge end ,j is vertical4 ,directly above the lowest part of the bend in this tube1 the vertical dimension of the tube is contracted by a downwardly-projecting wall ,k1 so as to form a narrow throat ,l4 ,below this contracted point1 the ,u-shaped tube has integral therewith a downwardly-projecting stem ,m1 the lower end of which passes through an opening in the float chamber1 and is threaded1 so as to receive a nut1 by means of which the cap ,h may be firmly fixed to the float chamber4 ,this stem ,m has a vertical duct ,n1 which communicates with the float chamber1 and is provided with a drain plug ,o4 ,alongside of this duct is a tube ,p which extends up into the ,u-shaped tube and is open at its lower end so that the level of the gasoline within the bent tube cannot extend above the end of this drain tube ,p4 ,an adjustable valve stem ,q passes through one side of the bent tube1 the lower end being pointed and adapted to regulate the inflow of gasoline through the duct ,n1 and into the ,u-shaped tube4 ,a throttle valve ,r is placed in the discharge end of the ,u-shaped tube1 which is susceptible of regulation by means of a lever ,s4 ,the diagram shows the gasoline within the ,u-shaped tube1 so that it is on a level with the gasoline in the float chamber4 ,in operation a sufficient amount of gasoline is permitted to enter the float chamber so that a pool is formed in the bottom of the ,u-shaped tube4 ,when suction takes place the air rushes through the tube1 at ,i1 down beneath the wall ,k1 and in doing so it sweeps past the surface of the pool at that point1 absorbing a greater or less amount of the vapor4 ,in order to adjust the device so that a smaller amount of the liquid fuel will be exposed1 the carbureter is adjusted so it will close the needle valve before the level of the liquid is so high1 and thereby a less surface of oil is formed within the ,u-shaped tube4 ,it is obvious that this type of carbureter1 owing to the absence of the secondary air-supply mechanism1 can be readily regulated and all adjustments made while running1 while for automobile uses the lever ,s1 which controls the throttle1 can be connected up with a dash-board control4 ,,chapter ,,vii ,,ignition4 ,,low ,,tension ,,system ,electricity1 that subtle force1 which manifests itself in so many ways1 is nevertheless beyond the power of man to see4 ,the only way in which we know of its presence is by the results produced by its movements1 because it can make itself known to our senses only by some form of motion4 ,the authorities regard light1 heat and electricity as merely different forms of motion4 ,the most that can be done with such a force is to learn the laws governing it4 ,magnetism4--,this is a form of electricity4 ,in fact1 it is one of the most universal manifestations1 for without it electricity would be useless4 ,when the first permanent magnet was found at ,magnesia1 it was not considered electricity4 ,the sciences had not arrived at that point where they were able to classify it as belonging to lightning and other manifestations of that kind which we now know to be electricity4 ,the ,armature4--,but magnetism can no more be seen than electricity flowing through a wire4 ,if a piece of metal has magnetism it will attract a piece of iron or steel placed in close proximity1 and thus we are permitted to see the action4 ,the lightning in the upper atmosphere burns the gases in its path4 ,this enables us to see1 not the current1 but its action1--the result produced by its power4 ,the electric current has many peculiar manifestations1 the causes of some of them being known and utilized4 ,in the use of this medium for igniting the fuel gas1 many of the phases of electrical phenomena are brought into play1 and it is necessary1 therefore1 to know something of the fundamentals of the science to enable us to apply it4 ,characteristics of ,electricity4--,when a current passes along a wire1 it does not describe a straight path1 but it moves around the conductor in the form of circles4 ,the current is not confined wholly to the wire itself1 but it extends out a certain distance from it at all points4 ,magnetic ,field4--,every part of a wire which is carrying a current of electricity has1 surrounding it1 a magnetic field1 of the same character1 and to all intents and purposes1 of the same nature as the magnetic field at the ends of a magnet4 ,elasticity4--,this current has also something akin to elasticity4 ,that is1 it surges to and fro1 particularly when a current is interrupted in the circuit4 ,at the instant of breaking a current in an electric light circuit there is a momentary flash which is much brighter than the normal light1 which is due to the regular flow of the current4 ,this is due to the surging movement1 or the elastic tension1 in the current4 ,advantage is taken of this characteristic1 in making a spark4 ,this spark is produced at the instant that the ends of the wires are separated4 ,the ,make and ,break ,system4--,no spark is caused by putting the two ends together1 or by making the connection1 but only by breaking it1 hence it is termed the make and break method of ignition4 ,when the connection is broken the current tries to leap across the gap1 and in doing so develops such an intense heat that the spark follows4 ,as a result of the high temperature it is necessary to use such a material where the gap is formed that it will not be burned4 ,for this purpose platinum1 and other metals are now employed4 ,voltage4--,this plays an important part in ignition4 ,voltage is that quality which gives pressure or intensity to a current4 ,it is the driving force1 just as a head of water gives pressure to a stream of water4 ,high and ,low ,voltage4--,a high tension current1--that is1 one having a high voltage1 will leap across a gap1 whereas a low voltage must have an easy path4 ,when the ends of a wire in a circuit are separated1 air acts as a perfect insulator between them1 and the slightest separation will prevent a low current from jumping across4 ,this is not the case with a high tension current1 where it will leap across and produce the flash known as the jump spark4 ,low ,tension ,system4--,two distinct types of ignition have grown out of the voltage referred to1 in which the make and break system uses the low tension1 because of its simplicity in the electrical equipment4 ,disadvantages of the ,make and ,break4--,there is one serious drawback to the extended use of this system1 and that is the necessity of using a moving part within the cylinder1 to make and break the contact in the conductor1 as it is obvious that this part of the mechanism must be placed within the compressed mixture in order to ignite it4 ,amperes4--,a current is also measured by amperes1--that is1 the quantity flowing4 ,a large conductor will take a greater quantity of current than a small one1 just as in the case of water a large pipe will convey a greater amount of the liquid4 ,resistance4--,all conductors offer resistance to the flow of a current1 and this is measured in ,ohms4 ,the best conductor is silver and the next best is copper1 this latter material being used universally1 owing to its comparative cheapness4 ,iron is a relatively poor conductor4 ,resistance can be overcome to a certain extent1 however1 if a large conductor is used1 but it is more economical to use a small conductor which has small resistance1 like copper1 than a heavy conductor1 as iron1 even though pound for pound the latter may be cheaper4 ,direct ,current4--,there are two kinds of current1 one which flows in one direction only1 called the ,direct4 ,it is produced in a dynamo which has a pair of commutator brushes so arranged that as the armature turns and its wires move through the magnetic fields of a magnet1 and have direction of the current alternate1 these brushes will change the alternations so the current will travel over the working conductors in one direction only4 ,primary and secondary batteries produce a direct current4 ,these will be described in their appropriate places4 ,alternating ,current4--,this is a natural current4 ,all dynamos originally make this kind of current1 but the commutator and brushes in the direct current machine change the output method only4 ,the movement of this current is likened to a rapid to and fro motion1 first flowing1 for an instant1 to one pole1 and then back again1 from which the term alternating is derived4 ,while the sudden breaking in a circuit will produce a spark with either the direct or the alternating currents1 the direct is usually employed for the make and break system1 since batteries are used as the electrical source4 ,on the other hand the jump spark method employs the alternating current1 because the high tension can be most effectively produced through the use of induction coils1 which will be explained in connection with the jump spark method of ignition4 ,generating ,electricity4--,there are two ways to produce a current for operating an ignition system1 one by a primary battery1 and the other by means of a magneto1 a special type of dynamo1 which will be fully explained in its proper place4 ,primary ,battery4--,as we are now concerned with the make and break system1 the battery type of generation1 and method of wiring up the same1 should first be explained4 ,thus1 in ,fig4 #cd1 a primary battery is shown1 in which the zinc cell ,a has an upwardly-projecting wing ,b at one side1 to which the conductor is attached2 and within1 centrally1 is a carbon bar ,c4 ,an electrolyte1 which may be either acid or alkali1 must be placed within the cell4 ,illustration3 ,fig4 #cd4 ,dry ,cell4 ,making a ,dry ,cell4--,the zinc is the negative1 and the carbon the positive electrode4 ,the best material for the electrolyte is crushed coke1 which is carbon1 and dioxide of manganese is used for this purpose1 and the interstices are filled with a solution of sal-ammoniac4 ,the top of the cell is covered with asphaltum1 so as to retain the moistened material and the liquid within the cell1 and thus constituted1 it is called a dry cell4 ,energy in a ,cell4--,a battery is made up of a number of these cells4 ,each cell has a certain electric energy1 usually from one and a half to one and three-quarter volts1 and from twenty-five to forty amperes4 ,the amperage of a cell depends on its size1 or rather by the area of the electrodes2 but the voltage is a constant one1 and is not increased by the change1 formation1 or size of the electrodes4 ,for this reason the cells are used in groups1 forming1 as stated1 a battery1 and to get efficient results1 various methods of connecting them up are employed4 ,illustration3 ,fig4 #ce4 ,series ,connection4 ,wiring ,methods4--,as at least six cells are required to operate a coil1 the following diagrams will show that number to illustrate the different types of connections4 ,series ,connection4--,the six cells1 ,fig4 #ce1 show the carbon electrodes ,a1 of one cell1 connected by means of a wire ,b with the zinc electrode wing ,c of the next cell1 and so on1 the cell at one end having a terminal wire ,d connected with the zinc1 and the cell at the other end a wire ,e connected with the carbon electrode4 ,the current1 therefore1 flows directly through the six cells1 and the pressure between the terminal wires ,d1 ,e1 is equal to the combined pressure of the six cells1 namely1 #a-a_/b #f1 which is equal to #i volts4 ,the amperage1 however1 is that of one cell1 which1 in these diagrams1 will be assumed to be #be4 ,illustration3 ,fig4 #cf4 ,multiple1 or ,parallel ,connection4 ,parallel ,connection4--,now examine ,fig4 #cf4 ,in this case the carbon electrodes ,a are all connected up in series1 that is1 one following the other in a direct line1 by wires ,b1 and the zinc electrodes ,c1 are1 in like manner1 connected up in series with each other by wires ,d4 ,the difference in potential at these terminals ,b1 ,d1 is the same as that of a single cell1 namely1 one and a half volt4 ,the amperage1 on the other hand1 is that of the six cells combined1 or #aej4 ,this method of connecting the cells is also called parallel1 since the two wires forming the connections are parallel with each other1 and remembering this it may be better to so term it4 ,multiple ,connections4--,this is also designated as series multiple since the two sets of cells each have the connections made like the series method1 ,fig4 #ce4 ,the particular difference being1 that the zinc terminals of the two sets of cells are connected up with one terminal wire ,a1 and the carbon terminals of the two sets are joined to a terminal ,b4 ,illustration3 ,fig4 #cg4 ,series-,multiple ,connection4 ,the result of this form of connection is to increase the voltage equal to that of one cell multiplied by the number of cells in one set1 and the amperage is determined by that of one cell multiplied by the two sets4 ,each set of cells in this arrangement is called a battery1 and we will designate them as ,no4 #a1 and ,no4 #b4 ,each battery1 therefore1 being connected in series1 has a voltage equal to #d-a_/b volts1 and the amperage #ej1 since there are two batteries4 ,now the different arrangement of volts and amperes does not mean that the current strength is changed in the batteries or in the cells4 ,if the pressure is increased the flow is lessened4 ,if the current flow1 or the quantity sent over the wires is increased1 the voltage is comparatively less4 ,watts4--,this brings in another element that should be understood4 ,if the current is multiplied by the amperes a factor is obtained1 called ,watts4 ,thus1 as each cell has #a-a_/b volts and #be amperes1 their product is #cg-a_/b watts4 ,to show that the same energy is present in each form of connection let us compare the watts derived from each3 ,series connection3 #i volts #be amperes1 equal #bbe watts4 ,parallel connection3 #a-a_/b volts #aej amperes1 equal #bbe watts4 ,series ,multiple connection3 #d-a_/b volts #ej amperes1 equal #bbe watts4 ,from the foregoing1 it will be seen that the changes in the wiring did not affect the output1 but it enables the user of the current to effect such changes that he may1 for instance1 in case a battery should be weak1 or have but little voltage1 so change connections as to temporarily increase it1 although in doing so it is at the expense of the amperage1 which is correspondingly decreased4 ,it would be well to study the foregoing comparative analysis of the three forms of connections1 so far as the energy is concerned1 because there is an impression that increasing the voltage1 is adding to the power of a current4 ,it does nothing but increase the pressure4 ,there is not one particle of increase in the energy by so doing4 ,illustration3 ,fig4 #ch4 ,circuit ,testing4 ,testing a ,cell4--,the cells should be frequently tested1 to show what loss there is in the amperage4 ,this is done by putting an ammeter in the circuit4 ,if a meter of this kind is not handy1 a good plan is to take off one of the wire connections1 and snap the wire on the terminal1 and the character of the spark will show what energy there is in the cell4 ,testing ,with ,instruments4--,the method of testing with voltmeter and ammeter1 is shown in ,fig4 #ch4 ,the voltmeter is placed in a short circuit between the two terminal wires1 whereas the ammeter is placed in circuit with one of the wires4 ,the reason for this is that the voltmeter registers the pressure1 the power1 or the difference of potential between the two sides of the cell1 and the ammeter shows the quantity of current flowing over the wire4 ,in practice batteries are not used continuously for igniting4 ,they are temporarily employed1 principally for starting1 because their continued use would quickly deplete them4 ,illustration3 ,fig4 #ci4 ,make and ,break1 with ,battery4 ,simple ,battery ,make and ,break ,system4--,in order to show this method in its simplest form1 examine ,fig4 #ci1 which diagrams the various parts belonging to the system4 ,we have illustrated it with two cylinders1 portions of the heads being shown by the outlines ,a1 ,a4 ,b1 ,b represent terminals which project into the cylinders1 and are insulated from the engine heads4 ,through the sides of the engine heads are rock shafts ,c1 the ends within the cylinder having fingers ,d which are adapted to engage with the inner ends of terminals ,b1 ,b4 ,on the ends of the rock shafts outside of the cylinders1 they are provided with levers ,e1 ,e1 one end of each being attached to a spring ,f1 so that the tension of the spring will normally keep the upper end of the finger ,d in contact with the terminal ,b4 ,the cut shows one finger engaging with ,b1 and the other not in contact4 ,the other end of the lever ,e rests beneath a collar or shoulder ,g on a vertical rod ,h4 ,the lower end of this rod engages with a cam ,i on a shaft ,j1 and when the cam rotates the rod drops off the elevated part of the cam1 and in doing so the shoulder ,g strikes the end of the lever ,e and causes the finger to rapidly break away from the terminal ,b1 where the spark is produced4 ,to ,advance the ,spark4--,for the purpose of advancing or retarding the spark1 this rod has1 near its lower end1 a horizontally-movable bar ,k1 which may be moved to and fro a limited distance by a lever ,l1 this lever being the substitute in this sketch of the lever on the steering wheel of an automobile4 ,the spark is advanced or retarded by causing the lower end of the rod ,h to be moved to the left or to the right1 so that it will drop off of the raised portion of the cam earlier or later4 ,the wiring up is a very simple matter4 ,the battery ,m has one end connected up with one terminal of a switch ,n1 while the other terminal of the switch has a wire connection with the terminal plugs ,b1 ,b1 in the cylinder heads4 ,the other end of the battery is connected with the metal of the engine1 which may be indicated by the dotted line ,o which runs to the rock shaft ,c1 and thus forms a complete circuit4 ,the operation is as follows3 ,when the key ,p of the switch is moved over so that it contacts with the terminal ,n1 the battery is thrown into the circuit1 and the current then passes to the plug ,b of the first cylinder1 as the finger ,d in that cylinder is in contact with that terminal1 and it passes along the finger ,d1 and rock-shaft ,c1 to the metal of the engine1 and passes thence to the battery1 this course being indicated by the dotted line ,o4 ,at the same time1 while cylinder ,no4 #b is also connected up with the battery1 the shoulder of the rod ,h has drawn the finger ,d from its contact with the plug ,b1 hence the current cannot pass in that direction4 ,as the cam ,i1 of cylinder ,no4 #a1 turns in the direction of the arrow1 the rod drops down and suddenly makes a break in the terminal of this cylinder1 causing the ignition1 to be followed by a like action in ,no4 #b4 ,the ,magneto in the ,circuit4--,to insure the life of the battery1 so that it may be in service only during that period at the starting1 when the magneto is not active1 the latter is so placed in the circuit1 that1 at the starting1 when1 for instance1 the automobile is being cranked1 it is cut out by the switch on the dash board4 ,illustration3 ,fig4 #dj4 ,make and ,break1 with ,magneto4 ,in ,fig4 #dj1 a simple two-pole switch is used4 ,with the magneto it is necessary to have a three-point switch1 ,r1 and a plain coil ,s is placed between the switch and battery4 ,one side of the magneto ,t is connected by wire ,u with one of the points of the switch ,r1 and the other side of the magneto is connected with the metal of the engine1 which is indicated by the dotted line ,v4 ,in all other respects the mechanism is the same4 ,the starting operation has been explained with reference to the preceding figure1 and when the engine has picked up1 and is properly started1 the switch bar is thrown over so it contacts with the point connected up with the wire ,u leading to the magneto4 ,this1 of course1 cuts out the battery1 and the engine is now running on the magneto alone4 ,the object of the coil ,s is to oppose a rapid change of the current at the moment of the interruption4 ,the coil induces a counter current the moment the break is made1 and as the current continues to flow for a very short period after the break a spark of greater intensity is produced than if the circuit should be permitted to go from the battery to the sparker directly1 as in the previous illustration4 ,the best spark is produced by quickly making the break between the points ,b1 ,d1 so that particular attention has been given to mechanism which will do this effectively4 ,magneto ,spark ,plug4--,one of the devices to obviate the difficulty of providing moving mechanism outside of the engine cylinder1 is shown in ,fig4 #da4 ,in this the coil ,a is connected with a terminal ,b at the head of the device and the other is connected to the plug ,c which screws into the cylinder head4 ,illustration3 ,fig4 #da4 ,magneto ,spark ,plug4 ,within the core is a pivotally-mounted lever ,d1 the upper end ,e of which is attracted by the tubular metallic core ,f1 and the lower end having a contact point ,g1 which is adapted to engage with a stationary point ,h4 ,the pivot ,i1 on which the lever ,d is mounted1 provides a means whereby the lever swings1 and a spring ,j is so arranged that when the lower end of the lever is disengaged from the contact1 the spring will return it to its normal position4 ,in its operation when a contact is formed by the timing device of the magneto1 so as to give a spark1 the circuit passes to the terminal ,b1 coil ,a1 and plug ,c1 thus forming a complete circuit4 ,this energizes the core ,a1 pulling the upper end of the lever1 and at the same time causes the lower end to disengage the two contacts ,g1 ,h1 which breaks the circuit and produces a spark4 ,the breaking of the circuit denergizes the core1 and the spring again draws the lever back to its normal position1 ready for the next completion of the circuit by the timing device4 ,such an arrangement is as simple as the spark plug usually employed in the use of the high tension system1 although it is more expensive than the plug4 ,,chapter ,,viii ,,ignition4 ,,high ,,tension ,this system is used to the largest extent1 so that we ought to have a full explanation of the devices which are required to do the work4 ,while magnetos are used with the low tension system1 for the reasons stated1 they are especially necessary with the ,jump ,spark method4 ,magnetos4--,the most important element in this system is the magneto1 so we shall try and make the subject as explicit as possible4 ,as stated1 a magneto is a special type of dynamo which will now be explained4 ,for this purpose it will be necessary to show the elementary operation of an alternating current dynamo4 ,alternating ,current4--,in ,fig4 #db ,a is a bar of soft iron1 around which is a coil of wire ,b1 the wire being insulated1 so that it will not touch the bar4 ,there is no magnetism in this bar1 and this simple form of structure is shown1 merely to represent what is called the field of a dynamo4 ,the object of the coil of wire is to make a magnet of the bar1 for the moment a current is sent over the wire1 a magnet is formed1 and the magnetism leaves the bar the moment the current ceases to flow4 ,if this bar should be of hard steel it would retain the magnetism4 ,illustration3 ,fig4 #db4 ,illustrating ,alternating ,current4 ,illustration3 ,fig4 #dc4 ,alternating ,current4 ,second position4 ,now1 the primary difference between the magneto and the dynamo1 is that this field bar is a permanent magnet in the magneto1 whereas the field is only a temporary magnet in the dynamo4 ,this should always be kept in mind4 ,the end of a magnet1 whether it is a temporary one1 or permanent1 has a magnetic field of force at the ends as well as at all parts of it1 exterior to the surface of the bar4 ,such a field is indicated1 and in the dynamo1 no such field exists unless a current is passing over the wire ,b1 which is called the field winding4 ,the ,u-shaped piece of metal ,c represents the armature4 ,it is shown hinged to the top of two posts1 for clearness in understanding1 and is adapted to turn to the right1 and in turning the loop passes the end of the field bar ,b1 and passes through the magnetic field which is indicated by the dotted lines ,d4 ,illustration3 ,fig4 #dd4 ,alternating ,current4 ,third position4 ,now1 if the loop is simply permitted to remain in the position shown in ,fig4 #db1 a current would flow through the loop1 this transference of the current being called induction1 and this characteristic of the flow of electricity will be explained and its utility explained4 ,cutting ,lines of ,force4--,the loop will now be turned to the right so that it passes the magnetic field and goes beyond it in its revolution4 ,this motion of passing the armature through the magnetic field is called cutting the lines of force4 ,while the loop was lying within the magnetic field1 and also when it was moving through the field1 the current set up in the loop flowed in the direction of the darts ,f1 or to the right1 through the pivots ,d4 ,in ,fig4 #dc the loop is shown as having made a quarter turn1 and it is now vertical1 or at right angles to its former position4 ,the loop in thus passing away loses its force1 until it reaches the position shown in ,fig4 #dd1 when there is a surging back of the current to the opposite direction1 as indicated by the arrows4 ,illustration3 ,fig4 #de4 ,alternating ,current4 ,fourth position4 ,when the loop reaches the lowest position1 shown in ,fig4 #de1 it again begins to get the influence of the magnetic field1 and a reversal back to its former direction takes place1 this surging movement back and forth being due to the reversal of the polarity in the coil brought about by the position in which it is placed relative to the magnetic field4 ,it is now an easy matter to connect the ends of the loop with wire conductors4 ,this is shown in ,fig4 #df1 where a small metal wheel ,g is placed on each end of the spindle1 and in having a strip of metal bearing ,h on the wheel4 ,these are not commutator brushes1 but are merely wiping brushes to take the current from the turning parts4 ,wires ,i connect with these wiping bars1 and through them the current is transmitted to perform the work4 ,illustration3 ,fig4 #df4 ,making the ,circuit4 ,plurality of ,loops4--,the dynamo may have a plurality of loops1 which are called coils1 and there may be a single magnet or any number of magnets4 ,instead of driving these coils past the face of the magnet1 or magnets1 the latter may be driven past the coils4 ,in fact with most of the alternating current machines the fields are the rotating parts and the armatures1 or the coils1 are fixed4 ,the voltage is increased if the coils have a large number of turns on the armature1 and also if the armature1 or the turning part1 is speeded up4 ,voltage will also be higher if larger or more powerful magnets are used in the magnetos4 ,the ,electro-,magnet4--,the permanent magnet1 such as is used in the magneto1 is distinguished by the fact that it contains a permanent charge of magnetism1 but this is not an electro-magnet4 ,this is a magnet made of soft iron1 so it will be readily demagnetized4 ,while not shown in the diagrams1 an iron core may be placed within the loop or coil1 and this is done in all dynamos1 because the iron core acts as a carrier of the magnetism1 concentrating it at the center1 because it is a much better conductor than air4 ,illustration3 ,fig4 #dg4 ,the ,dynamo4 ,illustration3 ,fig4 #dh4 ,the ,magneto4 ,the ,dynamo ,form4--,consult the diagram1 ,fig4 #dg4 ,the iron heads ,a represent the bar in the previous diagrams1 and ,b the wire around the bar4 ,c is the armature1 which in this case represents a number of loops1 or coils1 and ,d is the commutator1 which is used in the direct current machine to correct the alternations referred to in the previous diagrams1 so as to send the current in one direction only1 the commutator brushes ,e being used to carry off the current for use4 ,the ,magneto ,form4--,the metal loop ,f1 in ,fig4 #dh1 being a permanent magnet1 the armature1 ,g1 formed of a plurality of loops1 has no field wires to connect with it1 as in the case of the dynamo4 ,advantage of the ,magneto4--,the magneto has a pronounced advantage over the dynamo1 as a source of power for ignition purposes1 in the particular that the strength of the magnetic field is constant4 ,in a dynamo this varies with the output1 because when used on an automobile where the speed is irregular1 the voltage will vary4 ,the voltage of the magneto is a constant one1 and is thus better adapted to meet the needs of ignition4 ,induction ,coil4--,the induction coil is a device which is designed to produce a very high voltage from a low tension1 so that a current from it will leap across a gap and make a hot spark4 ,we stated in a previous section that a current leaps across from one conductor to another1 so that electricity can be transferred from a wire to another not touching it1 by means of induction4 ,look at ,fig4 #di1 which represents two wires side by side4 ,the current is flowing over one wire ,a1 and by bringing wire ,b close to ,a1 but not touching it1 a current will be induced to leap across the gap and the wire ,b will be charged4 ,if the ends of the wire ,b are brought together1 so as to form a circuit1 and a current detector is placed in the circuit it will be found that a current is actually flowing through it1 but it is now moving in a direction opposite to the current flowing through ,a4 ,illustration3 ,fig4 #di4 ,current by ,induction4 ,changing the ,current4--,but we have still another thing to learn4 ,if the two wires are not of the same thickness it would not prevent the current from leaping across1 but another astonishing thing would result4 ,first1 we shall use a wire ,b double the thickness of wire ,a4 ,if now1 we had an instrument to test the voltage and the amperage1 it would be found that the voltage in ,b is less than that in ,a1 and also that the amperage is greater4 ,second1 if the conditions are reversed1 and the wire ,a is thicker than ,b1 the latter will have an increase of voltage1 but a lower ampere flow than in ,a4 ,now this latter condition is just what is necessary to give a high tension4 ,voltage is necessary to make a current leap across a gap4 ,by this simple illustration we have made an induction coil which may be used for making a high tension jump spark4 ,construction of a ,coil4--,two wires side by side do not have the appearance of a coil1 and even though such an arrangement might make a high tension current1 it would be difficult to apply4 ,to put the device in such a shape that it can be utilized1 a spool is made1 as shown in ,fig4 #ej4 ,illustration3 ,fig4 #ej4 ,induction ,coil4 ,this spool ,a has a number of layers of thick1 insulated wire ,b first wound around it1 the layers being well insulated from each other1 and the opposite ends brought out at one end or at the opposite ends1 as shown at ,c1 ,d4 ,on this is a layer of finer wire1 also insulated1 this wire ,e having its terminals also brought out at the ends of the spool1 and after the whole is thus wound1 the outside of the coil is covered with a moisture proof material4 ,the ,primary ,coil4--,the winding of thick wire is called the primary coil4 ,the current from the battery or the electric generator is led to this inner coil4 ,illustration3 ,fig4 #ea4 ,typical ,induction ,coil4 ,the ,secondary ,coil4--,the fine wire wrapping represents the secondary coil1 which is raised to a high voltage1 and this actuates the sparking mechanism4 ,in the art it is customary to illustrate the various contrivances by certain conventional forms4 ,fig4 #ea shows the manner of designating an induction coil in a diagram1 in which the heavy zig-zag line indicates the primary1 and the lighter zig-zag lines the secondary coil4 ,illustration3 ,fig4 #eb4 ,contact ,maker4 ,contact ,maker4--,a simple little device used in the primary circuit of an induction coil1 is known as a contact maker4 ,this1 as shown in ,fig4 #eb1 is merely a case ,a1 through which is a shaft ,b that carries within the shell a cam ,c4 ,a spring finger ,d has its free end normally bearing against the cam1 and when the nose on the cam moves out the spring finger1 the latter is moved outwardly so it contacts with a plug ,e in the side wall of the case1 although it is insulated therefrom4 ,this contact establishes a current through the plug1 spring finger and case4 ,the diagram1 ,fig4 #ec1 illustrates the principles of construction and arrangement of a high tension jump spark ignition1 in which the electrical source is a battery actuating an induction coil4 ,high ,tension ,with ,battery and ,coil4--,the battery ,a has one side connected up by wire ,b with one terminal of the primary ,c in the induction coil1 and the other side of the battery has a wire ,d leading to the contact maker4 ,a switch ,e is placed in the line of this wire4 ,illustration3 ,fig4 #ec4 ,typical ,circuiting1 ,jump ,spark ,ignition4 ,the other terminal of the primary has a wire ,f leading to the insulated contact plug ,g of the contact maker4 ,this completes the generating circuit4 ,the cam ,h is on a shaft ,i1 which travels one half the speed of the engine shaft4 ,one side of the secondary coil ,j has a wire ,k leading to the spark plug1 while the other terminal of the secondary has a wire ,l which is grounded on the engine ,m4 ,when the nose of the cam pushes over the spring finger and closes the cam1 the circuit through the finger flows through the primary coil and excites the secondary4 ,when the cam again immediately breaks the circuit a high tension current is momentarily induced in the secondary1 so that the current leaps the gap in the spark plug and makes the spark4 ,illustration3 ,fig4 #ed4 ,metallic ,core1 ,induction ,coil4 ,metallic ,core for ,induction ,coil4--,in the previous description of the induction coil it was stated that the spool might be made of wood4 ,these coils are also provided with metal cores1 which can be used to make what is called a vibratory coil4 ,the ,condenser4--,a necessary addition to the circuiting provided by an induction coil1 is a condenser4 ,this is used in the primary circuit to absorb the self-induced current of the primary and thus cause it to oppose the rapid fall of the primary current4 ,the condenser is constructed of a number of tinfoil sheets1 of suitable size1 each sheet having a wing at one end1 and these sheets are laid on top of each other1 with the wings of the alternate sheets at opposite ends4 ,very thin sheets of waxed paper are placed between the tin foil sheets so that they are thus insulated from each other4 ,the wings at the ends are used to make connections for the conducting wires4 ,the device is not designed to conduct electricity1 but to act as a sort of absorbent1 if it might so be termed4 ,the large surface affords a means where more or less of the current moves from the conductor at one end to the conductor at the other end1 and as it is designed to absorb a portion of the current in the line it is merely bridged across from one side of the circuit to the other4 ,illustration3 ,fig4 #ee4 ,condenser4 ,the diagram1 ,fig4 #ee1 represents the conventional form of illustrating it in sketching electrical devices4 ,operation of a ,vibrator ,coil4--,the illustration1 ,fig4 #ef1 shows the manner in which a vibrator coil is constructed and operated4 ,the coil comprises a metal core ,a1 the primary winding ,b being connected at one terminal1 by a wire ,c1 with a post ,d1 and the other terminal by a wire ,e with one side of a battery ,f4 ,a switch ,g is in the line of this conductor4 ,illustration3 ,fig4 #ef4 ,vibrator ,coil and ,connections4 ,the post ,d holds the end of a vibrating spring ,h1 which has a hammer ,h on its free end1 which is adapted to contact with the end of the metal core ,a1 but is normally held out of contact1 so that it rests against the end of an adjusting screw ,i which passes through a post ,j4 ,the post ,j is connected up with the battery by a wire ,k1 and a wire ,l also runs from the wire ,k to the conductor ,c1 through a condenser ,m4 ,the secondary coil ,n1 has the outlet wires ,o1 ,p1 which run to the spark plug ,q on the engine4 ,the operation is as follows3 ,when the switch ,g closes the circuit1 the battery thus thrown in the primary coil magnetizes the core ,a1 and the hammer ,h is attracted to the end of the core1 thus breaking the circuit at the contact screw ,i4 ,the result is that the core is immediately demagnetized1 and the spring ,h draws the hammer back to be again attracted by the core which is again magnetized1 so that the hammer on the vibrator arm ,h goes back and forth with great rapidity4 ,from the foregoing explanations it will be understood how the primary induces a high tension current in the secondary1 and in order that the spark may occur at the right time1 a timer for closing and opening the primary circuit must be provided4 ,by this means an induced high tension current is caused to flow at the time the spark is needed in the cycle of the engine operation4 ,the ,distributer4--,the distributer is a timing device which controls both the primary and the secondary currents1 and it also has reference to the revolving switch on the shaft of a magneto whereby the current is distributed to the various cylinders in regular order4 ,fig4 #eg shows a form of distributer which will illustrate the construction4 ,a is the shaft which is driven at one half the engine speed4 ,it is usually run by suitable gearing direct from the shaft of the magneto4 ,illustration3 ,fig4 #eg4 ,the ,distributer4 ,its outer end rests in a bearing plate ,b1 of insulating material1 which plate serves as the disk to hold the contact plates1 #a1 #b1 #c1 #d1 to correspond with the four cylinders to which the current is to be distributed4 ,wires #e1 #f1 #g1 and #h1 run to the respective spark plugs ,c from these contact plates4 ,the projecting end of the shaft ,a carries thereon a contact finger ,d1 which is designed to contact with the respective plates1 and an insulating ring ,e is interposed between the shaft and finger so as to prevent short circuiting of the high tension current4 ,on the side of the finger is a hub ,f1 integral therewith1 and a wiper attached to a post bears against the hub so as to form continuous contact4 ,a wire leads from the post to one terminal of the secondary coil4 ,illustration3 ,fig4 #eh4 ,circuiting with ,distributer4 ,circuiting ,with ,distributer4--,the diagram ,fig4 #eh shows the complete connections of a system which comprises a magneto1 induction coil1 condenser1 and a distributer4 ,the magneto ,a has on its armature shaft ,b two revolving disks ,c1 ,d1 one of which must be insulated from the shaft1 and one end of the coil ,e of the armature is connected with one of these disks1 and the other end of the coil is attached to the other disk4 ,alongside of these disks is another disk ,f which has projecting points ,g to engage with and make temporary contact with a spring finger which actuates the interrupter ,i1 this being a contact breaker which breaks the primary current at the time a spark is required4 ,one terminal of this interrupter is connected by a wire ,j with one end of the primary winding ,k1 of the induction coil1 and the other end of the primary has a wire ,l which runs to the disk ,c4 ,the other terminal of the interrupter has a wire ,m leading to a condenser ,n1 and from the other side of the condenser is a wire ,o leading to the wire ,j before described4 ,the wiper of the other disk ,d has a wire connection with the wire ,m4 ,the distributer shaft ,p is so mounted that it may receive its motion from the shaft of the magneto1 and for this purpose the latter shaft has a gear ,q one half the diameter of the gear ,r on the distributer shaft4 ,the distributer ,s has been described with sufficient clearness in a preceding diagram1 to show how the wires ,t lead therefrom and connect up with the spark plugs ,u4 ,one terminal of the secondary coil ,v is connected by a wire ,w with the wiper ,x which contacts with the hub of the distributer finger ,x1 and the other terminal of the primary is grounded at ,y1 which represents the metal of the engine4 ,,chapter ,,ix ,,mechanical ,,devices ,,utilized ,,in ,,power ,one of the most important things in enginery is the capacity to determine the power developed4 ,although the method of ascertaining this appears to be somewhat complicated1 it is really simple1 and will be comprehended the more readily if it is constantly borne in mind that a certain weight must be lifted a definite distance within a particular time4 ,the ,unit of ,time4--,the unit of time is either the second1 or the minute1 usually the latter1 because it would be exceedingly difficult to make the calculations1 or rather to note the periods as short as a second1 and a very simple piece of mechanism to ascertain this1 is to mount a horizontal shaft ,a1 ,fig4 #ei1 in bearings ,b1 ,b1 and affix a crank ,c at one end4 ,it will be assumed that the shaft is in anti-friction bearings so that for the present we shall not take into account any loss by way of friction4 ,a cord1 with one end attached to the shaft and the other fixed to a weight ,d1 the latter weighing1 say #eej pounds1 is adapted to be wound on the shaft as it is turned by the crank4 ,knowing the length of the cord and the time required to wind it up1 it will be an easy matter to figure out the power exerted to lift the weight1 which means1 the power developed in doing it4 ,illustration3 ,fig4 #ei4 ,illustrating the ,unit of ,time4 ,suppose the cord is #ajj feet long1 and it requires one and a half minutes to raise the weight the full limit of the cord4 ,it is thus raising #eej pounds #ajj feet in #de seconds4 ,one horse power means that we must raise #eej pounds one foot in one second of time1 hence we have developed only #a_/deth of one horse power4 ,instead of using the crank1 this shaft may be attached to the engine shaft so it will turn slowly4 ,then add sufficient weight so that the engine will just lift it1 and wind the cord on the shaft4 ,you can then note the time1 for1 say1 one minute1 and when the weight is lifted1 make the following calculation3 ,weight lifted one hundred feet in one minute of time was #hbe pounds4 ,multiply #ajj by #hbe1 which equals #hb1ejj4 ,this represents foot pounds4 ,illustration3 ,fig4 #fj4 ,the ,proney ,brake4 ,as there are #cc1jjj foot pounds in a horse power1 #hb1ejj divided by this figure will show that #b-a_/b horse power were developed4 ,the ,proney ,brake4--,such a device is difficult to handle1 but it is illustrated merely to show the simplicity of the calculation4 ,as a substitute for this mechanism1 a device1 called the ,proney brake has been devised1 which can be used without rewinding of a cord4 ,this is accomplished by frictional means to indicate the power1 and by the use of weights to determine the lift4 ,the following is a brief description of its construction3 ,the engine shaft ,a1 ,fig4 #fj1 which is giving out its power1 and which we want to test1 has thereon a pulley ,b1 which turns in the direction of the arrow4 ,resting on the upper side of the pulley is a block ,c1 which is attached to a horizontal lever ,d by means of bolts ,e1 these bolts passing through the block ,c and lever ,d1 and having their lower ends attached to the terminals of a short sprocket chain ,f4 ,block segments ,g are placed between the chain and pulley ,b1 and when the bolts ,e are tightened the pulley is held by frictional contact between the block ,c and the segments ,g4 ,the free end of the lever has a limited vertical movement between the stops ,h1 and a swinging receptacle ,i1 on this end of the lever1 is designed to receive weights ,j4 ,the first thing to do is to get the dimensions of the pulley1 its speed1 and length of the lever4 ,by measurement1 the diameter of the pulley is six inches4 ,to get the circumference multiply this by #c4adaf4 ,the distance around1 therefore1 is a little over #ah4hd inches4 ,the speed of the pulley being #bbe times per minute1 this figure1 multiplied by #ah4hd1 gives the perimeter of the pulley #dbci inches4 ,as we must have the figures in feet1 dividing #dbci by #ab1 we have #cec4be feet4 ,the length of the lever from the center of the pulley to the suspension point of the receptacle1 is #d feet1 and this divided by the radius of the pulley 7which is #f inches71 gives the leverage4 ,one half of six inches1 is three inches1 or #a_/d of one foot1 and #d divided by this number1 is #a' #d1 or #a-a_/c feet1 which is the leverage4 ,now1 let us suppose the weight ,j is #abjj pounds4 ,this must be multiplied by the leverage1 #a-a_/c feet1 which equals #ahjj1 and this must be multiplied by the feet of travel in the pulley1 namely1 #cec4be1 which is equal to #fce1hej4 ,this represents foot pounds4 ,now1 following out the rule1 as there are #cc1jjj foot pounds in a horse power1 the foregoing figure1 #fce1hej1 divided by #cc1jjj1 equals #ai horse power within a fraction4 ,reversing ,mechanism4--,a thorough knowledge of the principles underlying the various mechanical devices1 and their construction1 is a part of the education belonging to motors4 ,one of the important structures1 although it is very simple1 when understood1 requires some study to fully master4 ,this has reference to reversing mechanism1 which is1 in substance a controllable valve motion1 whereby the direction of the valve is regulated at will4 ,all motions of this character throw the valve to a neutral point which is intermediate the two extremes1 and the approach to the neutral means a gradual decrease in the travel of the valve until the reciprocating motion ceases entirely at the neutral position4 ,illustration3 ,fig4 #fa4 ,double ,eccentric ,reversing ,gear4 ,illustration3 ,fig4 #fb4 ,reversing ,gear1 ,neutral4 ,double ,eccentric ,reversing ,gear4--,a well known form of gear is shown in ,fig4 #fa1 in which the engine shaft ,a has two eccentrics ,b1 ,c1 the upper eccentric ,b being connected with the upper end of a slotted segment ,d by means of a stem ,e1 and the other eccentric ,c is connected with the lower end of the segment by the stem ,f4 ,the eccentrics ,b1 ,c1 are mounted on the shaft so they project in opposite directions4 ,the slotted segment carries therewith the pin ,g of a valve rod ,h1 and the upper end of the segment has an eye ,i1 to which eye is a rod ,j operated by a lever4 ,illustration3 ,fig4 #fc4 ,reversing ,gear1 ,reversed4 ,illustration3 ,fig4 #fd4 ,single ,eccentric ,reversing ,gear4 ,by this arrangement the link may be raised or lowered1 and as the valve rod pin has no vertical movement1 either the connecting link ,e or ,f may be brought into direct line with the valve rod ,h4 ,fig4 #fa shows the first position1 in which the valve rod ,h is in direct line with the upper connecting rod ,e1 actuated by the cam ,b4 ,fig4 #fb shows the neutral position4 ,here the pin ,g serves as a fulcrum for the rocking movement of the segment2 whereas in ,fig4 #fc the valve rod ,h is in line with the lower connecting rod ,f1 so that the valve is pushed to and fro by the eccentric ,c4 ,illustration3 ,fig4 #fe4 ,balanced ,slide ,valve4 ,it is more desirable1 in many cases1 to use a single eccentric on the engine shaft1 which can be done by pivoting the segment ,l1 ,fig4 #fd1 to a stationary support ,m1 and connecting one end of the segment by a link ,n with the single eccentric ,o4 ,in this construction the valve rod ,p is shifted vertically by a rod ,q1 operated from the reversing lever1 thus providing a changeable motion through one eccentric4 ,balanced ,slide ,valves4--,in the chapter pertaining to the steam engine1 a simple form of slide valve was shown1 and it was stated therein that the pressure of the steam bearing on the valve would quickly grind it down4 ,to prevent this various types of balanced valves have been made1 a sample of which is shown in ,fig4 #fd4 ,the valve chest ,a has in its bottom two ports ,c1 ,d1 leading to the opposite ends of the cylinder1 and within is the sliding valve ,e1 which moves beneath an adjustable plate ,f connected with the top or cover ,g of the valve chest4 ,illustration3 ,fig4 #ff4 ,valve ,chest4 ,double ,port ,exhaust4 ,this is also modified1 as shown in ,fig4 #ff1 in which case the slide valve ,h bears against the cover ,i at two points1 so that as there is steam on the upper surface to a slightly greater area than on the lower side1 there is sufficient downward pressure to hold it firmly on its seat1 and at the same time not cause any undue grinding4 ,this valve also has double exhaust ports ,j1 ,j4 ,balanced ,throttle ,valve4--,fig4 #fg will give a fair idea of the construction of throttle valves1 the illustration showing its connection with a simple type of governor4 ,illustration3 ,fig4 #fg4 ,balanced ,throttle-,valve4 ,engine ,governors4--,probably the oldest and best known governor for regulating the inlet of steam to an engine1 is what is known as the ,watt design4 ,this is shown in ,fig4 #fh4 ,the pedestal ,a which supports the mechanism1 has an upwardly-projecting stem ,b1 to the upper end of which is a collar ,c1 to which the oppositely-projecting pendent arms ,d are hinged4 ,these arms carry balls ,e at their free ends4 ,illustration3 ,fig4 #fh4 ,watt's ,governor4 ,the lower part of the stem has thereon a sliding collar ,f1 and links ,g1 with their lower ends hinged to the collar1 have their upper ends attached to the swinging arms ,d4 ,the collar has an annular groove at its lower end1 to receive therein the forked end of one limb of a bell-crank lever ,h1 the other limb of this lever being connected up with the engine throttle1 by means of a link ,l4 ,centrifugal motion serves to throw out the balls1 as indicated by the dotted lines ,j1 and this action raises the bell-crank lever1 and opens the throttle valve4 ,numerous types of governors have been constructed1 some of which operate by gravity1 in connection with centrifugal action4 ,some are made with the balls adapted to swing downwardly1 and thrown back by the action of springs4 ,others have the balls sliding on horizontally-disposed arms1 and thrown back by the action of springs2 and gyroscopic governors are also made which are very effective4 ,illustration3 ,fig4 #fi4 ,the ,original ,injector4 ,fly wheel governors are not uncommon1 which are placed directly on the engine shaft1 or placed within the fly wheel itself1 the latter being a well known form for engines which move slowly4 ,injectors4--,the ,injector is one of the anomalies in mechanism4 ,it actually forces water into a boiler by the action of the steam itself1 against its own pressure4 ,it is through the agency of condensation that it is enabled to do this4 ,the illustration1 ,fig4 #fi1 which represents the original type of the device1 comprises a shell ,a1 within which is a pair of conically formed tubes1 ,b1 ,c1 in line with each other1 the small ends of the tubes being pointed towards each other1 and slightly separated4 ,the large end of the conical tube ,c1 which points toward the pipe ,d1 which leads to the water space of the boiler1 has therein a check valve ,e4 ,the steam inlet pipe ,f1 has a contracted nozzle ,g1 to eject steam into the large end of the conical tube ,b1 and surrounding the nozzle ,f is a chamber which has a pipe ,h leading out at one side1 through which cold water is drawn into the injector4 ,surrounding the conical pipes ,b1 ,c1 is a chamber ,i1 which has a discharge pipe ,j4 ,the action of the device is very simple4 ,when steam is permitted to flow into the conical tube ,b1 from the nozzle ,g1 it passes out through the drain port ,j1 and this produces a partial vacuum to form in the space surrounding the nozzle ,g4 ,as a result water is drawn up through the pipe ,h1 and meeting with the steam condenses the latter1 thereby causing a still greater vacuum1 and this vacuum finally becomes so great that1 with the inrushing steam1 and the rapid movement through the conical tubes1 past their separated ends1 a full discharge through the drain ,j is prevented4 ,illustration3 ,fig4 #gj4 ,injector with ,movable ,combining ,tube4 ,as it now has no other place to go the check valve ,e is unseated1 and the cold water is forced into the boiler through the pipe ,d1 and this action will continue as long as condensation takes place at the nozzle ,g4 ,many improvements have been made on the original form1 mostly in the direction of adjusting the steam nozzle1 and to provide the proper proportion of flow between the steam and water1 as this must be adjusted to a nicety to be most effective4 ,an example of a movable tube which closes the outlet to the overflow1 is shown in ,fig4 #gj4 ,the steam inlet tube ,a is at one end of the shell1 and the outlet tube ,b to the boiler1 at the other end1 and intermediate the two is a tube ,c1 with its open flaring end adapted to receive the steam from the tube ,a4 ,this tube is longitudinally-movable1 so that the controlling lever ,d may move it to and fro4 ,a chamber ,e surrounds the nozzle ,a1 and has a water inlet pipe ,f1 while the space ,g between the ends of the pipes ,b1 ,c1 has an outlet ,h1 a single check valve ,i being interposed4 ,in operation the tube ,c may be adjusted the proper distance from the end of the pipe ,b1 and when the current is once established through the injector1 the pipe ,c may be brought into contact with ,b1 and thus entirely cut out the movement of the water to the overflow4 ,feed ,water ,heater4--,an apparatus of this kind is designed to take the exhaust steam from the engine and condense it1 and from the condenser it is again returned to the boiler4 ,the water thus used over again goes into the boiler at a temperature of over #ahj degrees1 and thus utilizes the heat that would otherwise be required to raise the temperature of the water from the natural heat1 say #gj1 up to that point4 ,in ,fig4 #ga the illustration shows a typical heater1 which comprises an outer shell ,a1 each end having a double head1 the inner head ,b being designed to receive the ends of a plurality of horizontally disposed pipes1 and the outer heads ,c1 separated from the inner head so as to provide chambers1 one end having one1 and the other head being provided with two horizontal partitions ,d1 so the water may be diverted back and forth through the three sets of pipes within the shell4 ,illustration3 ,fig4 #ga4 ,feed ,water ,heater4 ,the three sets of pipes1 ,e1 ,f1 and ,g1 are so arranged that they carry the water back and forth from one head to the other1 and for this purpose the water for cooling the steam enters the port ,h at one end1 passes through the upper set of pipes ,e to the other end1 then back through the same set of pipes on the other side of a partition1 not shown1 and back and forth through the two lower sets of pipes ,f1 ,g4 ,the steam enters at the port ,i at the top of the shell1 and passes down1 as it is condensed1 being discharged at the outlet ,j4 ,,chapter ,x ,,valves ,,and ,,valve ,,fittings ,in the use of steam1 compressed gas1 or any medium which must have a controllable flow1 valves are a necessary element2 and the important point is to know what is best adapted for the use which is required in each case4 ,for this reason one of the best guides is to fully understand the construction of each4 ,the following illustrations and descriptions will give a good idea of the various types in use4 ,illustration3 ,fig4 #gb4 ,check ,valve4 ,check ,valve4--,fig4 #gb shows a longitudinal section of a check valve1 which is designed to prevent the water from returning or backing up from the pressure side4 ,the cylindrical body ,a is threaded at each end1 and has an inclined partition ,b therein which has a circular aperture4 ,illustration3 ,fig4 #gc4 ,gate ,valve4 ,the upper side of the shell has an opening1 adapted to be closed by a cap ,c1 large enough to insert the valve ,d1 which is hinged to the upper side of the partition4 ,water or gas is forced in through the valve in the direction of the arrow1 and the hinged valve is always in position to close the opening in the partition4 ,in case the valve should leak it may be readily ground by taking the small plug ,e from the opening1 and with a screw driver1 turning the valve1 and thereby fit it snugly on its seat4 ,illustration3 ,fig4 #gd4 ,globe ,valve4 ,gate ,valve4--,the cylindrical shell ,a has its ends internally threaded1 and is provided1 midway between its ends1 with a partition wall ,b1 having a central aperture4 ,the upper side of the shell has an opening to receive the bonnet ,c1 through which the valve stem ,d passes4 ,this stem carries at its lower end a gate ,e which rests against the partition ,b4 ,the stem ,d is threaded to screw into the threaded bore of the gate4 ,a packing gland ,f surrounds the stem ,d4 ,it will thus be seen that the turning of the stem ,d draws the gate up or down1 and thus effects an opening1 which provides a direct passage for the water through the valve body4 ,globe ,valve4--,a globe valve has the advantage that the valve is forced against its seat by the pressure of the wheel1 differing from the gate valve1 that depends on the pressure of the fluid to keep it tight4 ,the valve body ,a has therein a ,z-shaped partition ,b1 the intermediate1 horizontally-disposed limb of the partition being directly below the opening through the body1 which is designed to receive the bonnet ,c4 ,the bonnet has a central vertical bore1 the lower end of which is threaded to receive the wheel spindle4 ,the lower end of the spindle carries the circular valve1 which is seated in the opening of the ,z-shaped partition4 ,the ,corliss ,valve4--,the valve itself is of the rotary type1 as shown in ,fig4 #ge1 in which the port ,a goes to the cylinder1 and ,b is the passage for the steam from the boiler4 ,the cylindrical valve body ,c has within the aperture ,b a gate ,d1 one edge of which rests against the abutment through which the port ,a is formed1 and this gate has within it the bar ,e which is connected with the crank outside of the casing4 ,the ,corliss ,valve-,operating ,mechanism4--,as the operation of the valves in the ,corliss type of engine is so radically different from the ordinary reciprocation engine1 a side view of the valve grouping and its connecting mechanism are shown in ,fig4 #gf4 ,illustration3 ,fig4 #ge4 ,corliss ,valve4 ,the cylinder has an inlet valve ,a at each end1 and an outlet valve ,b at each end for the discharge of the steam4 ,c is a valve rod from the eccentric which operates the valves1 and ,d a wrist plate1 having an oscillatory or rocking motion around its center ,e4 ,the attachments ,f ,f1 of the steam rods1 open the inlet ports ,a ,a1 and ,g ,g1 are the attachments of exhaust rods which open and close the exhaust valves ,b ,b4 ,h ,h are catches which can be unhooked from the stems of the valves ,a by the governor rods ,j ,j4 ,the vertical links ,k1 ,k are connected at their lower ends with the pistons of dash pots1 and have their upper ends attached to the valve spindles1 and act to close the valves ,a ,a when the catches ,h are released by the governor rods ,j by means of the weights of the pistons in the dash pots4 ,illustration3 ,fig4 #gf4 ,corliss ,valve-operating ,mechanism4 ,the dash pots ,l ,l act in such a manner as to cushion the descent of the links ,k and thus prevent undue shock4 ,m is a wrist plate pin by which the valve rod ,c can be released from the wrist plate4 ,the whole purpose of the mechanism is to provide a means for closing the valves which are at the steam inlet ports1 by a sudden action4 ,the exhaust valves1 on the other hand1 are not so tripped but are connected directly with the wrist plate which drives all four of the valves4 ,the wrist plate or spider has a rocking motion1 being driven by an eccentric rod from the engine-shaft4 ,the mechanism thus described gives a variable admission as the load varies1 but a constant release of the exhaust and a constant compression to act as a cushion4 ,illustration3 ,fig4 #gg4 ,angle ,valve4 ,it gives a high initial pressure in the cylinder1 and a sharp cut off1 hence it is found to be very efficient4 ,angle ,valve4--,one of the most useful is the angle valve1 which is designed to take the place of an angle bend or knee in the line of the piping4 ,the mechanism is the same as in the well known globe valve construction1 the bonnet ,a being on a line with one of the right-angled limbs of the body4 ,the pressure of the fluid should always be on the lower side of the valve ,c1 coming from the direction of the arrow ,b1 for the reason that should the steam pressure be constant on the other side1 it would be difficult to repack the gland ,d without cutting off the steam from the pipe line4 ,illustration3 ,fig4 #gh4 ,rotary ,valve4 ,illustration3 ,fig4 #gi4 ,two-way ,rotary4 ,referring back to the illustration of the globe valve1 it will be noticed that the same thing1 so far as it pertains to the direction of the steam1 applies in that construction1 and a common mistake is to permit the pressure of the steam to be exerted so that it is constantly acting against the packing of the spindle4 ,rotary ,valves4--,two forms of rotary valves are shown1 one as illustrated in ,fig4 #gh1 where the rotating part1 or plug1 ,a has one straight-way opening ,b1 which coincides with two oppositely-projecting ports ,c1 ,d4 ,the other form1 ,fig4 #gi1 has an ,l-shaped opening ,e through the rotating plug ,f1 and the casing1 in which the plug is mounted has three ports1 one1 ,g1 being the inlet1 and the other two ,h1 ,i1 at right angles for the discharge of the fluid4 ,illustration3 ,fig4 #hj4 ,rotary ,type4 ,illustration3 ,fig4 #ha4 ,two-way ,rotary ,type4 ,rotable ,engine ,valves4--,so many different forms of the rotable valve have been made1 that it is impossible to give more than a type of each4 ,for engine purposes the plugs are usually rotated in unison with the engine shaft1 and a single delivery valve of this kind is shown in ,fig4 #hj4 ,this has three ports in the casing1 namely the inlet port ,a1 and two outlet ports ,c1 ,d4 ,the plug has a curved cut out channel ,e1 and this extends around the plug a distance equal to nearly one-half of the circumference1 so that the steam will be diverted into1 say1 ,b1 for a period equal to one-quarter turn of the plug1 and then into port ,c1 for the same length of time4 ,fig4 #ha shows a valve which has a double action4 ,the plug ,g has two oppositely-disposed curved channels1 ,h1 ,i1 and the casing has a single inlet port ,j1 and two oppositely-disposed outlet ports ,k1 ,l4 ,illustration3 ,fig4 #hb4 ,butterfly ,throttle4 ,illustration3 ,fig4 #hc4 ,angle ,throttle4 ,when the plug turns the port ,l serves to convey the live steam to the engine1 while the other port ,k at the same time acts as the exhaust1 and this condition is alternately reversed so that ,l acts as the discharge port4 ,throttle ,valves4--,the throttle valves here illustrated are those used in connection with gasoline engines4 ,the best known is the ,butterfly valve1 shown in ,fig4 #hb1 and this is also used as a damper1 for regulating the draft in furnaces and stoves4 ,this type is made in two forms1 one in which the two wings of the valve are made to swing up or down in unison1 and the other1 as illustrated1 where the disk ,a is in one piece1 and turns with the spindle ,b to which it is fixed4 ,illustration3 ,fig4 #hd4 ,slide ,throttle4 ,illustration3 ,fig4 #he4 ,two-slide ,throttle4 ,in ,fig4 #hc the wing ,c is curved1 so that by swinging it around the circle1 the opening of the discharge pipe ,d is opened or closed4 ,another design of throttle is represented in ,fig4 #hd4 ,one side of the pipe ,a has a lateral extension ,b1 which is double1 so as to receive therein a sliding plate ,c1 which is easily controllable from the outside4 ,fig4 #he shows a form of double sliding plate1 where the double lateral extensions project out in opposite directions1 as at ,d1 ,d1 and within these extensions are sliding plates which are secured together in such a way that as one is pushed in the other also moves in1 and thus acts in unison to close or to open the space between them4 ,it is the most perfect form of throttle valve1 as it causes the gases to open directly into the center of the outgoing pipe4 ,blow-off ,valves4--,the illustration shows a type of valve which is used on steamboats and very largely on farm boilers throughout the country4 ,the pipe ,a from the boiler has cast therewith1 or otherwise attached1 a collar ,b1 which has a standard ,c projecting upwardly at one side1 to the upper end of which is hinged a horizontal lever ,d1 which has a weight at its other end4 ,illustration3 ,fig4 #hf4 ,blow-off ,valve4 ,the upper end of the pipe has a conically-ground seat1 to receive a conical valve ,e1 the stem of which is hinged1 as at ,f1 to the level4 ,the weight may be adjusted to the pressure desired before blowing out and the only feature in this type of valve is the character of the valve seat1 which is liable1 through rust1 and other causes1 to leak4 ,pop1 or ,safety ,valve4--,as it has been found more desirable and practical to use a form of valve which is not liable to deterioration1 and also to so arrange it that it may be manually opened1 the ,safety ,pop valve was devised4 ,illustration3 ,fig4 #hg4 ,safety ,pop ,valve4 ,this is shown in ,fig4 #hg1 in which the valve seat base ,a1 which is attached to the top of the boiler1 has a cup-shaped outlet ,b1 that is screwed to it1 and this carries a lever ,c1 by means of which the valve may be manually opened4 ,a vertical shell ,d is attached to the cup-shaped portion1 and this has a removable cap ,e4 ,the valve ,f is seated within a socket in the base1 and has a disk head1 to receive the lower end of a coiled spring ,g4 ,the spring is supported in position by a stem ,h which extends down from the head1 and an adjusting nut ,i serves to regulate the pressure desired before the steam in the boiler can act4 ,,chapter ,,xi ,,cams ,,and ,,eccentrics ,more or less confusion arises from the terms cams and eccentrics4 ,a cam is a wheel which may be either regular in shape1 like a heart-wheel1 or irregular1 like a wiper-wheel4 ,the object in all forms of cams is to change motion from a regular into an irregular1 or reversely1 and the motion may be accelerated or retarded at certain points1 or inverted into an intermittent or reciprocating movement1 dependent on the shape of the cam4 ,a cam may be in the shape of a slotted or grooved plate1 like the needle bar of a sewing machine1 where a crank pin works in the slot1 and this transmits an irregular vertical movement to the needle4 ,a cam may have its edge provided with teeth1 which engage with the teeth of the engaging wheel1 and thus impart1 not only an irregular motion but also a turning movement1 such forms being largely used to give a quickly rising or falling motion4 ,what are called wiper-wheels are designed to give an abrupt motion and such types are used in trip hammers1 and to operate stamp mills4 ,in harvesters1 printing presses1 sewing machines1 and mechanism of that type1 the cam is used in a variety of forms1 some of them very ingenious and complicated4 ,illustration3 ,fig4 #hh4 ,heart-shaped4 ,illustration3 ,fig4 #hi4 ,elliptic4 ,illustration3 ,fig4 #ij4 ,double ,elliptic4 ,cams are also used for cutting machines1 or in tracing apparatus where it would be impossible to use ordinary mechanism4 ,all such forms are special1 requiring care and study to make their movements co-relate with the other parts of the mechanism that they are connected up with4 ,simple ,cams4--,fig4 #hh shows a form of the most simple character1 used1 with some modifications1 to a larger extent than any other4 ,it is called the heart-shaped cam1 and is the regular type4 ,fig4 #hi is an elliptical cam1 which is also regular4 ,what is meant by regular is a form that is the same in each half portion of its rotation4 ,fig4 #ij is a double elliptic1 which gives a regular movement double the number of times of that produced by the preceding figure1 and the differences between the measurements across the major and minor axes may vary1 relatively1 to any extent4 ,illustration3 ,fig4 #ia4 ,single ,wiper4 ,illustration3 ,fig4 #ib4 ,double ,wiper4 ,illustration3 ,fig4 #ic4 ,tilting ,cam4 ,wiper ,wheels4--,wiper wheels are cams which give a quick motion to mechanism1 the most common form being the single wiper1 as shown in ,fig4 #ia4 ,the double wiper cam1 ,fig4 #ib1 has1 in some mechanism1 a pronounced difference between the lengths of the two fingers which form the wipers4 ,the form of cam shown in ,fig4 #ic is one much used in iron works for setting in motion the tilt hammer4 ,only three fingers are shown1 and by enlarging the cam at least a dozen of these projecting points may be employed4 ,cam ,sectors4--,fig4 #id shows a type of cam which is designed for rock shafts4 ,the object of this form of cam is to impart a gradually increasing motion to a shaft4 ,assuming that ,a is the driving shaft1 and ,b the driven shaft1 the cam ,c1 with its short end ,d1 in contact with the long end ,e of the sector ,f1 causes the shaft ,b to travel at a more accelerated speed as the other edges ,g1 ,h1 approach each other4 ,illustration3 ,fig4 #id4 ,cam ,sector4 ,illustration3 ,fig4 #ie4 ,grooved ,cam4 ,illustration3 ,fig4 #if4 ,reciprocating ,motion4 ,cylinder ,cam4--,fig4 #ie shows one form of cylinder ,a with a groove ,b in it1 which serves as a means for moving a bar ,c back and forth4 ,the bar has a projecting pin ,d1 which travels in the groove4 ,this form of movement may be modified in many ways1 as for instance in ,fig4 #if1 where the drum ,e has a sinuous groove ,f to reciprocate a bar ,g to and fro1 the groove being either regular1 so as to give a continuous back and forth movement of the bar2 or adapted to give an irregular motion to the bar4 ,illustration3 ,fig4 #ig4 ,pivoted ,follower for ,cam4 ,double ,cam ,motion4--,cams may also be so arranged that a single one will produce motions in different directions successively1 as illustrated in ,fig4 #ig4 ,the horizontal bar ,a1 hinged at ,b to the upper end of a link ,c1 has its free end resting on the cam ,d4 ,the arm ,a has also a right-angled arm ,e extending downwardly1 and is kept in contact with the cam by means of a spring ,f4 ,connecting rods ,g1 ,h1 may be hinged to the arm ,e and bar ,a1 respectively1 so as to give motion to them in opposite directions as the cam revolves4 ,eccentrics4--,an eccentric is one in which the cam or wheel itself is circular in form1 but is mounted on a shaft out of its true center4 ,an eccentric may be a cam1 but a cam is not always eccentric in its shape4 ,the term is one in direct contrast with the word eccentric4 ,illustration3 ,fig4 #ih4 ,eccentric4 ,illustration3 ,fig4 #ii4 ,eccentric ,cam4 ,fig4 #ih shows the wheel1 or the cam1 which is regular in outline1 that is circular in form1 but is mounted on the shaft out of its true center4 ,in this case it is properly called an eccentric cam but in enginery parlance it is known as the eccentric1 as represented in ,fig4 #ii4 ,triangularly-,formed ,eccentric4--,fig4 #ajj illustrates a form of cam which has been used on engines4 ,the yoke ,a being integral with the bar ,b1 gives a reciprocating motion to the latter1 and the triangular form of the cam ,c1 which is mounted on the shaft ,d1 makes a stop motion at each half-revolution1 then produces a quick motion1 and a slight stop only1 at the half turn1 and the return is then as sudden as the motion in the other direction4 ,illustration3 ,fig4 #ajj4 ,triangularly-formed ,eccentric4 ,,chapter ,,xii ,,gears ,,and ,,gearing ,for the purpose of showing how motion may be converted from a straight line or from a circular movement into any other form or direction1 and how such change may be varied in speed1 or made regular or irregular1 the following examples are given1 which may be an aid in determining other mechanical devices which can be specially arranged to do particular work4 ,while cams and eccentrics may be relied on to a certain extent1 there are numerous places where the motion must be made positive and continued4 ,this can be done only by using gearing in some form1 or such devices as require teeth to transmit the motion from one element to the other4 ,the following illustrations do not by any means show all the forms which have been constructed and used in different machines1 but they have been selected as types merely1 in order to give the suggestions for other forms4 ,racks and ,pinions4--,the rack and pinion is the most universal piece of mechanism for changing motion4 ,fig4 #aja illustrates it in its most simple form4 ,when constructed in the manner shown in this figure it is necessary that the shaft which carries the pinion shall have a rocking motion1 or the rack itself must reciprocate in order to impart a rocking motion to the shaft4 ,illustration3 ,fig4 #aja4 ,rack and ,pinion4 ,illustration3 ,fig4 #ajb4 ,rack ,motion4 ,this is the case also in the device shown in ,fig4 #ajb1 where two rack bars are employed4 ,a study of the cams and eccentrics will show that the transference of motion is limited1 the distances being generally very small2 so that the rack and pinions add considerably to the scope of the movement4 ,the ,mangle ,rack4--,the device called the mangle rack is resorted to where a back and forth1 or a reciprocating movement is to be imparted to an element by a continuous rotary motion4 ,illustration3 ,fig4 #ajc4 ,plain ,mangle ,rack4 ,illustration3 ,fig4 #ajd4 ,mangle ,rack ,motion4 ,illustration3 ,fig4 #aje4 ,alternate ,circular ,motion4 ,the plain mangle racks are shown in ,figs4 #ajc and #ajd1 the former of which has teeth on the inside of the opposite parallel limbs1 and the latter1 ,fig4 #ajd1 having teeth not only on the parallel sides1 but also around the circular parts at the ends4 ,this form of rack may be modified so that an alternate circular motion will be produced during the movement of the rack in either direction4 ,fig4 #aje is such an instance4 ,a pinion within such a rack will turn first in one direction1 and then in the next in the other direction1 and so on4 ,if the rack is drawn back and forth the motion imparted to the pinion will be such as to give a continuous rocking motion to the pinion4 ,controlling the ,pinion4--,many devices have been resorted to for the purpose of keeping the pinion in engagement with the teeth of the mangle rack4 ,one such method is shown in ,fig4 #ajf4 ,illustration3 ,fig4 #ajf4 ,controlling ,pinion for ,mangle ,rack4 ,the rack ,a has at one side a plate ,b1 within which is a groove ,c1 to receive the end of the shaft ,d1 which carries the pinion ,e4 ,as the mangle rack moves to such a position that it reaches the end of the teeth ,f on one limb1 the groove ,c diverts the pinion over to the other set of teeth ,g4 ,all these mangle forms are substitutes for cranks1 with the advantage that the mangle gives a uniform motion to a bar1 whereas the to and fro motion of the crank is not the same at all points of its travel4 ,examine the diagram1 ,fig4 #ajg1 and note the movement of the pin ,a which moves along the path ,b4 ,the crank ,c in its turning movement around the circle ,d1 moves the pin ,a into the different positions #a1 #b1 #c1 etc41 which correspond with the positions on the circle ,d4 ,illustration3 ,fig4 #ajg4 ,illustrating ,crank-pin ,movement4 ,the ,dead ,centers4--,there is also another advantage which the rack possesses4 ,where reciprocating motion is converted into circular motion1 as in the case of the ordinary steam engine1 there are two points in the travel of a crank where the thrust of the piston is not effective1 and that is at what is called the dead centers4 ,in the diagram1 ,fig4 #ajh1 the ineffectiveness of the thrust is shown at those points4 ,let ,a represent the piston pushing in the direction of the arrow ,b against the crank ,c4 ,when in this position the thrust is the most effective1 and through the arc running from ,d to ,e1 and from ,h to ,g1 the cylinder does fully four-fifths of the work of the engine4 ,illustration3 ,fig4 #ajh4 ,the ,dead ,center4 ,while the crank is turning from ,g to ,d1 or from ,i to ,j1 and from ,k to ,l1 no work is done which is of any value as power4 ,if1 therefore1 a mangle bar should be used instead of the crank it would add greatly to the effectiveness of the steam used in the cylinder4 ,illustration3 ,fig4 #aji4 ,crank ,motion ,substitute4 ,crank ,motion ,substitute4--,in ,fig4 #aji the pinion ,a is mounted so that its shaft is in a vertical slot ,b in a frame ,c4 ,the mangle rack ,d1 in this case1 has teeth on its outer edge1 and is made in an elongated form4 ,the pinion shaft moves up and down the slot and thus guides the pinion around the ends of the rack4 ,illustration3 ,fig4 #aaj4 ,mangle ,wheel4 ,mangle ,wheels4--,the form which is the most universal in its application is what is called the mangle wheel4 ,in ,fig4 #aaj is shown a type wherein the motion in both directions is uniform4 ,mangle wheels take their names from the ironing machines called mangles4 ,in apparatus of this kind the movement back and forth is a slow one1 and the particular form of wheels was made in order to facilitate the operation of such machines4 ,in some mangles the work between the rollers is uniform back and forth4 ,in others the work is done in one direction only1 requiring a quick return4 ,in still other machines arrangements are made to provide for short strokes1 and for different speeds in the opposite directions1 under certain conditions1 so that this requirement has called forth the production of many forms of wheels1 some of them very ingenious4 ,illustration3 ,fig4 #aaa4 ,quick ,return ,motion4 ,the figure referred to has a wheel ,a1 on one side of which is a peculiarly-formed continuous slot ,b1 somewhat heart-shaped in general outline1 one portion of the slot being concentric with the shaft ,c4 ,within the convolutions of the groove is a set of teeth ,d1 concentric with the shaft ,c4 ,the pinion ,e1 which meshes with the teeth ,d1 has the end of its shaft ,f resting in the groove ,b1 and it is also guided within a vertical slotted bar ,g4 ,the pinion ,e1 therefore1 travels over the same teeth in both directions1 and gives a regular to and fro motion4 ,quick ,return ,motion4--,in contradistinction to this is a wheel ,a1 ,fig4 #aaa1 which has a pair of curved parallel slots1 with teeth surrounding the slots4 ,when the wheel turns nearly the entire revolution1 with the pinion in contact with the outer set of teeth1 the movement transmitted to the mangle wheel is a slow one4 ,illustration3 ,fig4 #aab4 ,accelerated ,circular ,motion4 ,when the pinion arrives at the turn in the groove and is carried around so the inner teeth are in engagement with the pinion1 a quick return is imparted to the wheel4 ,accelerated ,motion4--,aside from the rack and mangle type of movement1 are those which are strictly gears1 one of them being a volute form1 shown in ,fig4 #aab4 ,this gear is a face plate ,a1 which has teeth ,b on one face1 which are spirally-formed around the plate4 ,these mesh with a pinion ,c1 carried on a horizontal shaft ,d4 ,this shaft is feathered1 as shown at ,e1 so that it will carry the gear along from end to end4 ,illustration3 ,fig4 #aac4 ,quick ,return ,gearing4 ,the gear has cheek-pieces ,f to guide it along the track of teeth4 ,as the teeth approach the center of the wheel ,a1 the latter impart a motion to the gear which is more than twice the speed that it receives at the starting point1 the speed being a gradually increasing one4 ,quick ,return ,gearing4--,another much more simple type of gearing1 which gives a slow forward speed and a quick return action1 is illustrated in ,fig4 #aac4 ,a is a gear with internal teeth through one half of its circumference1 and its hub ,b has teeth on its half which is opposite the teeth of the rim4 ,a pinion ,c on a shaft ,d is so journaled that during one half of the rotation of the wheel ,a1 it engages with the rim teeth1 and during the other half with the hub teeth4 ,as the hub ,b and gear ,c are the same diameter1 one half turn of the pinion ,c will give a half turn to the wheel ,a4 ,illustration3 ,fig4 #aad4 ,scroll ,gearing4 ,as the rim teeth of the wheel ,a are three times the diameter of the pinion ,c1 the latter must turn once and a half around to make a half revolution of the wheel ,a4 ,scroll ,gearing4--,this is a type of gearing whereby at the close of each revolution the speed may be greater or less than at the beginning4 ,it comprises two similarly-constructed gears ,a1 ,b1 each with its perimeter scroll-shaped1 as shown4 ,the diagram shows their positions at the beginning of the rotation1 the short radial limb of one gear being in line with the long limb of the other gear1 hence1 when the gears rotate1 their speeds relative to each other change1 being constantly accelerated in one or decreased in the other4 ,,chapter ,,xiii ,,special ,,types ,,of ,,engines ,in describing various special types of motors1 attention is first directed to that class which depend on the development of heat in various gases1 and this also necessitates some explanation of ice-making machinery1 and the principles underlying refrigeration4 ,it is not an anomaly to say that to make ice requires heat4 ,ice and boiling water represent merely the opposites of a certain scale in the condition of matter1 just as we speak of light and darkness1 up and down1 and like expressions4 ,we are apt to think zero weather is very cold4 ,freezing weather is a temperature of #cb degrees4 ,at the poles #gj degrees below have been recorded4 ,in interstellar space1--that is1 the region between the planets1 it is assumed that the temperature is about #eac degrees ,fahrenheit1 below zero1 called absolute zero4 ,the highest heat which we are able to produce artificially1 is about #aj1jjj degrees by means of the electric arc4 ,we thus have a range of over #aj1ejj degrees of heat1 but it is well known that heat extends over a much higher range4 ,assuming1 however1 that the figures given represent the limit1 it will be seen that the difference between ice and boiling water1 namely1 #ahj degrees1 is a very small range compared with the temperatures referred to4 ,in order to effect this change power is necessary1 and power requires a motor of some kind4 ,hence it is1 that to make a lower temperature1 a higher degree of heat is necessary1 and in the transit between a high and a low temperature1 there is considerable loss in this respect1 as in every other phase of power mechanism1 as has been pointed out in a previous chapter4 ,in order that we may clearly understand the phenomena of heat and cold1 let us take a receiver which holds a cubic foot of gas or liquid1 and exhaust all the air from it so the vacuum will be equivalent to the atmospheric pressure1 namely1 #ad4g pounds per square inch4 ,alongside is a small vessel containing one cubic inch of water1 which is heated so that it is converted into steam1 and is permitted to exhaust into the receiver4 ,when all the water is converted into steam and fills the receiver we shall have the same pressure inside the receiver as on the outside4 ,it will be assumed1 of course1 that there has been no loss by condensation1 and that the cubic inch of water has been expanded #agjj times by its conversion into steam4 ,in a short time the steam will condense into water1 and we now have1 again1 a partial vacuum in the receiver1 due1 of course1 to the change in bulk from steam to water4 ,each time the liquid is heated it produces a pressure1 and the pressure indicates the presence of heat2 and whenever it cools a loss of pressure is indicated1 and that represents cold1 or the opposite of heat4 ,now1 putting these two things together1 we get the starting point necessary in the development of power4 ,let us carry the experiment a step further4 ,liquids are not compressible4 ,gases are4 ,the first step then is to take a gas and compress it1 which gives it an increase of heat temperature1 dependent on the pressure4 ,if the same receiver is used1 and say1 two atmospheres are compressed within it1 so that it has two temperatures1 and the exterior air cools it down to the same temperature of the surrounding atmosphere1 we are ready to use the air within to continue the experiment4 ,let us convey this compressed gas through pipes1 and thus permit it to expand2 in doing so the area within the pipes1 which is very much greater than that of the receiver1 grows colder1 due to the rarefied gases within4 ,now bearing in mind the previous statement1 that loss of pressure indicates a lowering of temperature1 we can see that first expanding the gas1 or air1 by heat1 and then allowing it to cool1 or to produce the heat by compressing it1 and afterwards permitting it to exhaust into a space which rarefies it1 will make a lower temperature4 ,it is this principle which is used in all refrigerating machines1 whereby the cool pipes extract the heat from the surrounding atmosphere1 or when making ice1 from the water itself1 and this temperature may be lowered to any extent desired1 dependent on the degree of rarefaction produced4 ,let us now see how this applies to the generation of power in which we are more particularly interested4 ,all liquids do not evaporate at the same temperature as water4 ,some require a great deal more than #bab degrees2 others1 like1 for instance1 dioxide-of-carbon1 will evaporate at #aaj degrees1 or about one half the heat necessary to turn water into steam4 ,on the other hand1 all gases act alike so far as their heat absorption is concerned1 so that by using a material with a low evaporative unit1 less fuel will be required to get the same expansion1 which means the same power4 ,to illustrate this1 let us assume that we have equal quantities of water1 and of dioxide-of-carbon1 and that is to be converted into a gas4 ,it will take just double the amount of fuel to convert the water into a gaseous state4 ,as both are now in the same condition1 the law of heat absorption is the same from this time on4 ,the dioxide-of-carbon engine is one1 therefore1 which uses the vapor of this material1 which1 after passing through the engine1 is condensed and pumped back to the boiler to be used over and over4 ,in like manner1 also1 ether1 which has a low point of vaporization1 is used in some engines1 the principle being the same as the foregoing type4 ,rotary ,engines4--,many attempts have been made to produce a rotary type of steam engine1 and also to adapt it for use as an internal combustion motor4 ,the problem is a complicated one for the following reasons3 ,first1 it is difficult to provide for cut-off and expansion4 ,a rotating type1 to be efficient1 must turn at a high rate of speed1 and this makes the task a more trying one4 ,second1 the apparent impossibility of properly packing the pistons4 ,the result is a waste of steam1 or the gas used to furnish the power4 ,third1 the difficulty in providing a suitable abutment so as to confine the steam or gas1 and make it operative against the piston4 ,illustration3 ,fig4 #aae4 ,simple ,rotary ,engine4 ,in ,fig4 #aae is shown a type of rotary which is a fair sample of the characteristics of all motors of this form4 ,it comprises an outer cylindrical shell1 or casing1 ,a1 having a bore through the ends1 which is above the true center of the shell1 to receive a shaft ,b4 ,this shaft carries a revolving drum ,c of such dimensions that it is in contact with the shell at its upper side only1 as shown at ,d1 leaving a channel ,e around the other portions of the drum4 ,the steam inlet is at ,f1 which is one-eighth of the distance around the cylinder1 and the exhaust is at ,g1 the same distance from the point ,d1 on the other side4 ,the inlet and the outlet pipes are1 therefore1 at the contracted parts of the channel4 ,the drum has a pair of radially-movable blades ,h ,h1 which may move independently of each other1 but usually they are connected together1 thus dispensing with the use of any springs to keep their ends in contact with the shell4 ,when steam enters the inlet ,f the pressure against the blade ,h drives the drum to the right1 and the drum and shell1 by contacting at ,d1 form an abutment4 ,each charge of steam drives the drum a little over a half revolution4 ,a great deal of ingenuity has been exercised to arrange this abutment so that the blades may pass and provide a steam space for a new supply of steam4 ,in certain types a revolving abutment is formed1 as shown1 for instance1 in ,fig4 #aaf4 ,the shell ,a1 in this case1 has two oppositely-disposed inlet and outlet ports1 ,b1 ,c1 respectively1 and between each set of ports is a revolving gate1 formed of four wings ,d1 mounted on a shaft ,e1 in a housing outside of the circular path ,f1 between the drum ,g and shell ,a4 ,the drum ,g is mounted on a shaft ,h which is centrally within the shell1 and it has two oppositely-projecting rigid blades ,i4 ,when steam enters either of the supply ports ,b1 the drum is rotated1 and when the blades reach the revolving gates1 the latter are turned by the blades1 or1 they may be actuated by mechanism connected up with the driving shaft4 ,illustration3 ,fig4 #aaf4 ,double-feed ,rotary ,engine4 ,caloric ,engine4--,this is an engine which is dependent on its action upon the elastic force of air which is expanded by heat4 ,the cylinder of such a motor has means for heating it1 and thus expanding the air1 and a compressor is usually employed which is operated by the engine itself1 to force compressed air into the cylinder4 ,it is not an economical engine to work1 but it is frequently used in mines1 in which case the compressor is located at the surface1 and the engine operated within the mine1 thus serving a double purpose1 that of supplying power1 and also furnishing the interior with fresh air4 ,all engines of this character must run at a slow speed1 for the reason that air does not absorb heat rapidly1 and sufficient time must be given to heat up and expand the air1 so as to make it effective4 ,adhesion ,engine4--,a curious exhibition of the action of a gas against a solid1 is shown in what is called an ,adhesion ,engine4 ,fig4 #aag shows its construction4 ,a plurality of disks ,a are mounted on a shaft ,b1 these disks being slightly separated from each other4 ,the steam discharge pipe ,c is flattened at its emission end1 as shown at ,d1 so the steam will contact with all the disks4 ,the steam merely contacts with the sides of the disks1 the movement of the steam being substantially on the plane of the disks themselves1 and the action sets up a rapid rotation1 and develops a wonderful amount of power4 ,illustration3 ,fig4 #aag4 ,adhesion ,motor4 ,it will be understood that the disks are enclosed by a suitable casing1 so that the steam is carried around and discharged at a point about three quarters of the distance in the circumference4 ,this motor is given to illustrate a phase of the subject in the application of a motor fluid1 like steam1 or heated gases1 that shows great possibilities4 ,it also points out a third direction in which an expansive fluid may be used4 ,thus the two well-known methods1 namely1 pressure1 and impact forces1 may be supplemented by the principle of adhesion1 in which the expansive force of a gas1 passing alongside of and in contact with a plain surface1 may drag along the surface in its train4 ,such an exhibition of force has an analogy in nature by what is known as capillary attraction1 which shows adhesion4 ,for instance1 sap flowing up the pores of trees1 or water moving along the fibers of blotting paper1 illustrates movement of liquids when brought into contact with solids4 ,,chapter ,,xiv ,,enginery ,,in ,,the ,,development ,,of ,,the ,,human ,,race ,the energy of a nation may be expressed by its horse power4 ,it is not numbers1 or intellect1 or character1 or beliefs that indicate the progress of a people in a material sense4 ,it is curious how closely related enginery is with the advancement of a people4 ,nothing can be more striking to illustrate this than railroads as a feature of development in any country4 ,power in ,transportation4--,without the construction and maintenance of mechanical power1 railroads would be impossible4 ,to be able to quickly and cheaply move from place to place1 is the most important factor in human life4 ,the ability of people to interchange commodities1 and to associate with others who are not in their own intimate community1 are the greatest civilizing agencies in the world4 ,power vs4 ,education and the ,arts4--,education1 the cultivation of the fine arts1 and the desire for luxuries1 without the capacity for quickly interchanging commodities and to intermingle with each other1 are ineffectual to advance the interests of any nation1 or to maintain its prosperity4 ,lack of ,power in the ,ancient ,world4--,the ,greeks and the ,romans had a civilization which is a wonder even to the people of our day4 ,they had the arts and architecture which are now regarded as superb and incomparable4 ,they had schools of philosophy and academies of learning2 their sculpture excites the admiration of the world2 and they laid the foundation theories of government from which we have obtained the basis of our laws4 ,the ,early ,days of the ,republic4--,when our forefathers established the ,republic there were many misgivings as to the wisdom of including within its scope such a large area as the entire ,atlantic seacoast4 ,from ,maine to ,florida the distance is #abej miles2 and from ,new ,york to the ,mississippi #ijj miles1 comprising an area of #a1bjj1jjj square miles4 ,how could such an immense country ever hold itself together8 ,it was an area nearly as large as that controlled by ,rome when at the height of her power4 ,if it was impossible for the force of ,roman arms to hold such a region within its control1 how much more difficult it would be for the ,colonies to expect cohesion among their scattered peoples4 ,lack of ,cohesiveness in a ,country ,without ,power4--,those arguments were based on the knowledge that every country in ancient times broke apart because there was no unity of interest established1 and because the different parts of the same empire did not become acquainted or associated with each other4 ,the ,railroad as a ,factor in ,civilization4--,the introduction of railroads1 by virtue of motive power1 changed the whole philosophy of history in this respect4 ,even in our own country an example of the value of railroads was shown in the binding effect which they produced between the ,east and the ,west prior to the ,civil ,war4 ,all railroads1 before that period1 ran east and west4 ,few extended north and south4 ,it is popularly assumed that the antagonism between the ,north and the ,south grew out of the question of slavery4 ,this is1 no doubt1 largely so1 as an immediate cause1 but it was the direct cause which prevented the building of railroads between the two sections4 ,it simply renforces the argument that the motor1 the great power of enginery1 was not brought into play to unite people who were antagonistic1 and who could not1 due to imperfect communication1 understand each other4 ,to-day the ,united ,states contains an area nearly as great as the whole of ,europe1 including ,russia1 with their twenty1 or more1 different governments4 ,here we have a united country1 with similar laws1 habits1 customs and religions throughout4 ,in many of those foreign countries the people of adjoining provinces are totally unlike in their characteristics4 ,it has been shown that wherever this is the case it is due to lack of quick and cheap intercommunication4 ,the ,wonderful ,effects of ,power4--,this remarkable similarity in the conditions of the people throughout the ,united ,states is due to the railroads1 that great personification of power1 notwithstanding the diverse customs and habits of the people which daily come to our shores and spread out over our vast country4 ,it has unified the people4 ,it has made ,san ,francisco nearer to ,new ,york than ,berlin was to ,paris in the time of ,napoleon4 ,the people in ,maine and ,texas are neighbors4 ,the results have been so far reaching that it has given stability to the government greater than any other force4 ,but there is another lesson just as wonderful to contemplate4 ,england has an area of only about #eh1jjj square miles1 about the same size as either ,florida1 ,illinois1 or ,wisconsin4 ,england as a ,user of ,power4--,the enginery within her borders is greater than the combined energy of all the people on the globe4 ,through the wonderful force thus set in motion by her remarkable industries she has become the great manufacturing empire of the world1 and has called into existence a carrying fleet of vessels1 also controlled by motors1 so stupendous as to be beyond belief4 ,we may well contemplate the great changes which have been brought about by the fact that man has developed and is using power in every line of work which engages his activities4 ,the ,automobile4--,he does not1 in progressive countries1 depend on the muscle of the man1 or on the sinews of animals4 ,these are too weak and too slow for his needs4 ,look at the changes brought about by the automobile industry within the past ten years4 ,what will the next century bring forth8 ,artificial power1 if we may so term it1 is a late development4 ,it is very young when compared with the history of man4 ,high ,character of ,motor ,study4--,the study of motors requires intellect of a high order4 ,it is a theme which is not only interesting and attractive to the boy1 but the mastery of the subject in only one of its many details1 opens up a field of profit and emoluments4 ,the ,unlimited ,field of ,power4--,it is a field which is ever broadening4 ,the student need not fear that competition will be too great1 or the opportunities too limited1 and if these pages will succeed1 in only a small measure1 in teaching the fundamental ideas1 we shall be repaid for the efforts in bringing together the facts presented4 ,,chapter ,,xv ,,the ,,energy ,,of ,,the ,,sun1 ,,and ,,how ,,heat ,,is ,,measured ,in the first chapter we tried to give a clear view of the prime factors necessary to develop motion4 ,the boy must thoroughly understand the principles involved1 before his mind can fully grasp the ideas essential in the undertaking4 ,while the steam engine has been the prime motor for moving machinery1 it is far from being efficient1 owing to the loss of two-thirds of the energy of the fuel in the various steps from the coal pile to the turning machinery4 ,first1 the fuel is imperfectly consumed1 the amount of air admitted to the burning mass being inadequate to produce perfect combustion4 ,second1 the mechanical device1 known as the boiler1 is not so constructed that the water is able to completely absorb the heat of the fuel4 ,third1 the engine is not able to continuously utilize the expansive force of the steam at every point in the revolution of the crankshaft4 ,fourth1 radiation1 the dissipation of heat1 and condensation1 are always at work1 and thus detract from the efficiency of the engine4 ,the gasoline motor1 the next prime motor of importance1 is still less efficient in point of fuel economy1 since less than one-third of the fuel is actually represented in the mechanism which it turns4 ,the production of energy1 in both cases1 involves the construction of a multiplicity of devices and accessories1 many of them difficult to make and hard to understand4 ,to produce power for commercial purposes1 at least two things are absolutely essential4 ,first1 there must be uniformity in the character of the power produced2 and1 second1 it must be available everywhere4 ,water is the cheapest prime power1 but its use is limited to streams or moving bodies of water4 ,if derived from the air currents no dependence can be placed on the regularity of the energy4 ,heat is the only universal power on the globe4 ,the sun is the great source of energy4 ,each year it expends in heat a sufficient force to consume over sixty lumps of coal1 each equal to the weight of the earth4 ,of that vast amount the earth receives only a small part1 but the portion which does come to it is equal to about one horse power acting continuously over every thirty square feet of the surface of our globe4 ,the great problem1 in the minds of engineers1 from the time the steam engine became a factor1 was to find some means whereby that energy might be utilized1 instead of getting it by way of burning a fuel4 ,one of the first methods proposed was to use a lens or a series of mirrors1 by means of which the rays might be focused on some object1 or materials1 and thus produce the heat necessary for expansion1 without the use of fuel4 ,wonderful results have been produced by this method2 but here1 again1 man meets with a great obstacle4 ,the heat of the sun does not reach us uniformly in its intensity2 clouds intervene and cut off the rays2 the seasons modify the temperature2 and the rotation of the globe constantly changes the direction of the beams which fall upon the lens4 ,the second method consists in using boxes covered with glass1 the interior being blackened to absorb the heat1 and by that means transmit the energy to water1 or other substances adapted to produce the expansive force4 ,devices of this character are so effective that temperatures much above the boiling point of water have been obtained4 ,the system is1 however1 subject to the same drawbacks that are urged against the lens1 namely1 that the heat is irregular1 and open to great variations4 ,these defects1 in time1 may be overcome1 in conserving the force1 by using storage batteries1 but to do so means the change from one form of energy to another1 and every change means loss in power4 ,the great problem of the day is this one of the conversion of heat into work4 ,it is being done daily1 but the boy should understand that the direct conversion is what is required4 ,for instance1 to convert the energy1 which is in coal1 into the light of an electric lamp1 requires at least five transformations in the form of power1 which may be designated as follows3 #a4 ,the burning of the coal4 #b4 ,the conversion of the heat thus produced into steam4 #c4 ,the pressure of the steam into a continuous circular motion in the steam engine4 #d4 ,the circular motion of the steam engine into an electric current by means of a dynamo4 #e4 ,the change from the current form of energy to the production of an incandescent light in the lamp itself1 by the resistance which the carbon film offers to the passage of the current4 ,should an inventor succeed in eliminating only one of the foregoing steps1 he would be hailed as a genius1 and millions would not be sufficient to compensate the fortunate one who should be able to dispense with three of the steps set forth4 ,the ,measurement of ,heat4--,to measure heat means something more than simply to take the temperature4 ,as heat is work1 or energy1 there must be a means whereby that energy can be expressed4 ,it has been said that the basis of all true science consists in correct definitions4 ,the terms used1 therefore1 must be uniform1 and should be used to express certain definite things4 ,when those are understood then it is an easy matter for the student to grope his way along1 as he meets the different obstacles1 for he will know how to recognize them4 ,before specifically explaining the measurement it might be well to understand some of the terms used in connection with heat4 ,the original theory of heat was1 that it was composed of certain material1 although that matter was supposed to be subtle1 imponderable and pervading everything4 ,this imponderable substance was called ,caloric4 ,it was supposed that these particles mutually attracted and repelled each other1 and were also attracted and repelled by other bodies1 so that they contracted and expanded4 ,the phenomenon of heat was thus accounted for by the explanation that the expansion and contraction made the heat4 ,this was known as the ,material ,theory of ,heat4 ,but that phase of the explanation has now been abandoned1 in favor of what is known as the dynamical1 or mechanical theory1 which is regarded merely as a mode of motion1 or a sort of vibration1 wherein the particles move among each other1 with greater or less rapidity or in some particular manner4 ,thus1 the movements of the atoms may be accelerated1 or caused to act in a certain way1 by friction1 by percussion1 by compression1 or by combustion4 ,heat is the universal result of either of those physical movements4 ,notwithstanding that the material theory of heat is now abandoned1 scientists have retained1 as the basis of all heat measurements1 the name which was given to the imponderable substance1 namely1 ,caloric4 ,it is generally written ,calorie1 in the text books4 ,a calorie has reference to the quantity of heat which will raise the temperature of one kilogram of water1 one degree ,centigrade4 ,as one kilogram is equal to about two pounds1 three and a quarter ounces1 and one degree ,centigrade is the same as one and two-thirds degrees ,fahrenheit1 it would be more clearly expressed by stating that a caloric is the quantity of heat required to raise the temperature of one and one-fifth pound of water one degree ,fahrenheit4 ,this is known as the scientific unit of the thermal or heat value of a caloric4 ,but the engineering unit is what is called the ,british ,thermal ,unit1 and designated in all books as ,b4 ,t4 ,u4 ,this is calculated by the amount of heat which is necessary to raise a kilogram of water one degree ,fahrenheit4 ,according to ,berthelot1 the relative value of calorics and ,b4 ,t4 ,u4 are as follows3 ,,heats ,,of ,,combustion ---------------------------------------- ----------- ,substance4 ,calories4 ,b4 ,t4 ,u4 ---------------------------------------- ----------- ,hydrogen #cd1ejj #fb1ajj ,carbon to carbon dioxide #h1acg #ad1fdg ,carbon to carbon monoxide #b1dhi #d1dhj ,carbon monoxide #b1dce #d1chc ,methane #ac1cdc #bd1jag ,ethylene #ab1ahb #ba1hih ,cellulose #d1bjj #g1efj ,acetylene #ab1adb #ba1hef ,peat #e1idj #aj1fib ,naphthalene #i1fij #aj1hdb ,sulphur #b1ejj #d1ejj ,when it is understood that heat is transmitted in three different ways1 the value of a measuring instrument1 or a unit1 will become apparent4 ,thus1 heat may be transmitted either by conduction1 convection1 or radiation4 ,conduction is the method whereby heat is transmitted from one particle to another particle1 or from one end of a rod1 or other material to the other end4 ,some materials will conduct the heat much quicker than others1 but if we have a standard1 such as the calorie1 then the amount of heat transmitted and also the amount lost on the way may be measured4 ,convection applies to the transmission of heat through liquids and gases4 ,if heat is applied to the top or surface of a liquid1 the lower part will not be affected by it4 ,if the heat is applied below1 then a movement of the gas or liquid begins to take place1 the heated part moving to the top1 and the cooler portions going down and thus setting up what are called convection currents4 ,radiation has reference to the transference of heat from one body to another1 either through a vacuum1 the air1 or even through a solid4 ,by means of the foregoing table1 which gives the heats developed by the principal fuels1 it is a comparatively easy matter to determine the calorific value of fuels1 which is ascertained by making an analysis of the fuel4 ,the elements are then taken together1 and the table used to calculate the value4 ,suppose1 for instance1 that the analysis shows that the fuel has seventy-five per cent4 of carbon and twenty-five per cent4 of hydrogen4 ,it is obvious that if we take seventy-five per cent4 of #h1acg 7which is the index for carbon71 and twenty-five per cent4 of #dc1ejj 7the index of hydrogen71 and adding the two together1 the result1 #ad1gbg1 would represent the calorific value of the fuel4 ,,glossary ,,of ,,words ,,used ,,in ,,text ,,of ,,this ,,volume ,absolute4 ,independent2 free from all limitations4 ,amplitude4 ,greatness of extent2 the state or quality of being sufficient4 ,absorbent4 ,a material which will take up a liquid4 ,absorbing4 ,taking up1 or taking in4 ,absorption4 ,the act or process of taking up or fully occupying4 ,abutment4 ,a wall2 a stop4 ,accuracy4 ,correctness2 positiveness4 ,accession4 ,added to2 addition1 or increase4 ,accelerate4 ,quickened2 hurried4 ,accessible4 ,available2 capable of being reached4 ,accelerated4 ,a quickening1 as of process or action4 ,actuating4 ,moved or incited by some motive4 ,advance ,spark4 ,the term applied to the movement of the mechanism in an internal combustion engine1 which will cause the electric spark to act before the crank has passed the dead center4 ,aeration4 ,to add air2 to impregnate with oxygen4 ,alkali4 ,in chemistry it is known as a compound of hydrogen and oxygen1 with certain chemicals4 ,anything which will neutralize an acid4 ,allusion4 ,referring to2 noticed4 ,anomaly4 ,a deviation from an ordinary rule2 irregular4 ,adhesion4 ,to cling to2 to stick together4 ,adjustment4 ,to arrange in proper order2 to set into working condition4 ,alternating ,a current which goes back and current4 forth in opposite directions2 unlike a direct current which flows continuously in one direction4 ,ampere4 ,the unit of current2 the term in which strength of current is measured4 ,an ampere is an electromotive force of one volt through a resistance of one ohm4 ,amplitude4 ,the state or quality of being broad1 or full4 ,analysis4 ,the separation into its primitive or original parts4 ,annular4 ,pertaining to or formed like a ring4 ,armature4 ,the part of a dynamo or motor which revolves1 and on which the wire coils are wound4 ,assuming4 ,taking on2 considered to be correct or otherwise4 ,asphaltum4 ,a bituminous composition used for pavements1 properly made from natural bitumen1 or from asphalt rock4 ,atmospheric4 ,referring to2 noticed4 ,available4 ,capable of being employed or used4 ,bearings4 ,the part in mechanism in which journals or spindles rest and turn4 ,bifurcated4 ,in two parts2 branching1 like a fork4 ,blow-off valve4 ,a valve so arranged that at certain pressures the valve will automatically open and allow the steam to escape from the boiler4 ,bombard4 ,an assault2 an attack by shot or shell4 ,bonnet4 ,the cap of a valve1 which is so arranged that while it permits the valve stem to turn1 will also prevent leakage4 ,butterfly-valve4 ,a form of valve which is usually flat1 and adapted to open out1 or turn within the throat or pipe4 ,caloric4 ,pertaining to heat4 ,cam4 ,a rotating wheel1 or piece1 either regular or irregular1 non-circular1 or eccentric4 ,carbon4 ,a material like coke1 ground or crushed4 ,it required high heat to burn it1 and it is used for the burning material in electric arc lamps4 ,carbureter4 ,the device used to mix air and gaseous fuel in an internal combustion engine4 ,carbonized4 ,put into a charred form2 coke is carbonized coal2 charcoal is carbonized wood4 ,carbureted4 ,air or gas to which has been added the gaseous product of petroleum1 or some distillate4 ,centripetal4 ,that which draws inwardly1 or to the center1 like the gravitational action of the earth4 ,centrifugal4 ,that which throws outwardly2 the opposite of centripetal4 ,check valve4 ,a form of valve which will permit liquids to freely flow in one direction1 but which will open automatically1 so as to allow the liquid to flow in the opposite direction4 ,chemical4 ,pertaining to the composition of matter2 or relating to chemistry4 ,chambered4 ,having compartments1 or divided up into recesses4 ,circumference4 ,around the outside4 ,circularly4 ,around2 about the circumference4 ,circulation4 ,the movement of water to and fro through conduits4 ,clearance4 ,the space at the head of a cylinder within which the steam or gases are compressed by the piston4 ,classification4 ,to put in order in a systematic way4 ,coincide4 ,to correspond with identity of parts4 ,cohesion4 ,to stick together4 ,the attraction of material substances of the same kind for each other4 ,coperate4 ,to work together harmoniously4 ,compounding4 ,composed of or produced by the union of two or more parts1 or elements4 ,complicated4 ,very much involved2 not simple4 ,commutator4 ,the revolving part on the armature of a dynamo or motor1 which is divided up into a multiplicity of insulated plates1 which are connected with the coils of the wire around the armature4 ,combustion4 ,burning2 the action of the unity of oxygen with any substance1 which causes it to be destroyed or changed4 ,commodity4 ,any product1 or kind of goods4 ,concaved4 ,hollowed4 ,condensation4 ,the change from a gaseous to a liquid or solid state4 ,condenser4 ,an apparatus which converts a gas into a liquid4 ,concentric4 ,a line which at any point is at the same distance from a common center4 ,conductor4 ,a substance which will convey either heat or electricity from one end to the other4 ,conical4 ,in the form of a cone4 ,conically4 ,in the form of a cone4 ,conduit4 ,a trough1 tube1 or other contrivance1 which will convey liquids or gases from place to place4 ,conduction4 ,the capacity to transmit from one point to another4 ,connecting ,rod4 ,that part of mechanism which connects the piston rod with the crank4 ,conserve4 ,to take care of2 to use judiciously4 ,constant4 ,being the same thing at all times2 not varying4 ,contrivance4 ,any mechanism1 or device which will serve a certain purpose4 ,contra- ,that which is opposite to1 distinction4 comparatively2 taken in conjunction with for the purpose of comparison4 ,cornish4 ,a form of boiler which has the fire tubes within the water space4 ,contact ,breaker4 ,a device which has the current normally in circuit1 and is so arranged that the circuit is broken at certain intervals1 and again immediately restablished4 ,co-relate4 ,belonging to2 having reference to the same order4 ,conventional4 ,the regular manner or method4 ,contact ,maker4 ,a device for making contacts in an electric circuit at regular intervals4 ,convolution4 ,the turns or twists taken4 ,the changes or movement or the peculiar flow of a liquid4 ,control4 ,handling with regularity2 ,the act of guiding4 ,contracted4 ,made smaller4 ,contingency4 ,an event2 under certain conditions4 ,counteract4 ,to antagonize2 to so act as to go against4 ,converting4 ,changing2 to put in an opposite condition4 ,cylindrical4 ,in the form of a cylinder2 barrel-shaped4 ,cyclopedia4 ,a work which gives1 in alphabetical order1 the explanations of terms and subjects4 ,cycle4 ,a period extending over a certain time2 a certain order of events4 ,dead ,center4 ,that point in the turn of a crank where the piston has no effective pull in either direction4 ,denergize4 ,to take power away from4 ,deflecting4 ,to glance off2 to change the regular or orderly course4 ,demagnetized4 ,to take magnetism away from4 ,deterioration4 ,to take away from2 to grow smaller2 to lessen2 to depreciate in quality4 ,deviate4 ,to avoid2 to get around2 not going or doing in the regular way4 ,diagram4 ,a mechanical plan or outline1 as distinguished from a perspective drawing4 ,diametrically4 ,across or through the object2 through the center4 ,dioxide4 ,an oxide containing two atoms of oxygen to the molecule4 ,direct current4 ,an electric current which flows continuously in one direction4 ,dissipated4 ,changed1 or entirely dispensed with2 usually applied to a condition where materials or substances are scattered4 ,distributer4 ,a piece of mechanism in an electric circuit1 which switches the current from one part to the other4 ,dissect4 ,to take apart4 ,dominating4 ,overpowering2 having greatest power4 ,diverse4 ,different2 unlike4 ,dry ,cell4 ,a battery in which the electrolyte is not in a fluid state4 ,duct4 ,either an open trough or conduit1 or a closed path for the movement of gases or liquids4 ,dynamo4 ,a mechanical device for the purpose of generating electricity4 ,eccentric4 ,a wheel having its perimeter so formed that the center is not in the exact middle portion4 ,economy4 ,prudence2 carefulness2 not disposed to be excessive4 ,efficiency4 ,well adapted for the situation2 mechanism which will do the work perfectly1 or cheaply4 ,effectiveness4 ,well done2 to the best advantage4 ,ejecting4 ,throwing out2 sending forth4 ,elastic4 ,that quality of material which tends to cause it to return to its original shape when distorted4 ,elementary4 ,primitive2 the first2 in the simplest state4 ,electric arc4 ,a term applied to the current which leaps across the slightly separated ends of an electric conductor4 ,electricity4 ,an agent1 incapable of being seen1 but which produces great energy4 ,electrolyte4 ,the agent1 or material in a battery1 usually a liquid1 which the current passes through in going from one electrode to the other4 ,elliptical4 ,a form which might be expressed by the outline shape of an egg1 measured from end to end4 ,emolument4 ,pay2 remuneration2 the amount received for employment of any kind4 ,emission4 ,to send out from2 a sending or putting out4 ,energy4 ,force2 power4 ,essential4 ,the main thing2 the important element4 ,evaporate4 ,to convert into vapor1 usually by heat4 ,exhaust4 ,the discharge part of an engine1 or other apparatus4 ,excessive4 ,too much2 more than is required4 ,expansion4 ,enlarged2 the occupying of a greater space4 ,explicit4 ,particularly definite2 carefully explained and understood4 ,external4 ,outside2 the outer surface4 ,facilitating4 ,helping2 aiding in anything4 ,factor4 ,an element in a problem4 ,fahrenheit4 ,one of the standards of heat measurement4 ,a thermometer scale1 in which the freezing point of water is #cb1 and the boiling temperature is #bab4 ,fascinating4 ,attractiveness2 capacity to allure4 ,feathered4 ,applied to the shape of an article1 or to a rib on the side of a shaft1 which is designed to engage with a groove4 ,fertilizer4 ,material for enriching soil and facilitating the growth of vegetables4 ,field4 ,a term applied to the windings and the pole pieces of a dynamo or motor1 which magnetically influence the armature4 ,focal4 ,the point2 the place to which all the elements or forces tend4 ,foot pounds4 ,the unit of mechanical work1 being the work done in moving one pound through a distance of one foot4 ,four-cycle4 ,a gasoline engine1 in which the ignition of the compressed hydro-carbon gases takes place every other revolution4 ,formation4 ,the arrangement of any mechanism1 or a series of elements4 ,formula4 ,the recipe for the doing of a certain thing2 a direction4 ,friction4 ,a retarding motion2 the prevention of a free movement4 ,function4 ,the qualities belonging to an article1 machine or thing2 that which a person is capable of performing4 ,fundamental4 ,the basis2 the groundwork of a thing4 ,gaseous4 ,of the nature of a gas4 ,gearing4 ,usually applied to two or more sets of toothed wheels which coperate with each other4 ,generating4 ,producing2 manufacturing2 bringing out of4 ,globules4 ,the small particles of liquids2 or the molecules comprising fluids4 ,gravitation4 ,the force of the earth which causes all things to move toward it2 the attraction of mass for mass4 ,heart ,wheel4 ,a wheel having the outline of a heart4 ,helical4 ,a spirally-wound form4 ,high ,tension4 ,a term applied to a current of electricity1 which has a very high voltage1 but low amperage4 ,horizontal4 ,level1 like the surface of water2 at right angles to a line which points to the center of the earth4 ,horse ,power4 ,the unit of the rate of work1 equal to #cc1jjj pounds lifted one foot in one minute4 ,hydro-carbon4 ,a gas made from the vaporization of crude petroleum or of its distillates4 ,hydrogen4 ,one of the original elements4 ,the lightest of all gases4 ,ignite4 ,to set on fire4 ,ignition4 ,the term applied to the firing of a charge of gas in a gas or gasoline engine4 ,impact4 ,a blow2 a striking force4 ,impregnated4 ,to instill2 to add to4 ,impulse4 ,a natural tendency to do a certain thing2 determination to act in a certain way through some influence4 ,impinge4 ,to strike against2 usually to contact with at an angle4 ,incomparable4 ,too good or great to measure4 ,inclined4 ,not level2 leaning2 not horizontal4 ,induction4 ,the peculiar capacity of an electric current to pass from one conductor to another through the air4 ,indication4 ,that which shows2 to point out4 ,injector4 ,a device whereby the pressure of the steam in a boiler will force water into the boiler4 ,initially4 ,at first2 the original act4 ,injection4 ,to put into2 to eject from an apparatus1 into some other element4 ,insulated4 ,so covered as to prevent loss of current by contact with outside substances or materials4 ,intimate4 ,close to2 on good terms with4 ,integral4 ,a complete whole2 containing all the parts4 ,instinct4 ,knowledge within2 something which influences conduct or action4 ,interstellar4 ,the space beyond the earth2 that portion of the heavens occupied by the stars4 ,internal4 ,within2 that portion of mechanism which is inside4 ,interposing4 ,to step into2 to place between1 or in the midst of4 ,intensity4 ,fierce2 strong2 above the ordinary4 ,interrupted4 ,to stop2 to take advantage of4 ,interstices4 ,the spaces in between4 ,instantaneous4 ,immediately2 at once2 without waiting4 ,intricate4 ,difficult2 not easy4 ,inquisitive4 ,the desire to inquire into4 ,jacketing4 ,to coat or cover on the outside4 ,jump ,spark4 ,one of the methods of igniting hydro-carbon gases4 ,a current of sufficiently high voltage is used to cause the current to jump across the space between the separated ends of a conductor4 ,kinetic4 ,consisting in or depending on motion4 ,latent4 ,that which is within itself4 ,lateral4 ,branching out from the sides2 usually applied as the meaning for the direction which is at right angles to a fore and aft direction4 ,lines of force4 ,applied to electricity1 air1 water1 or any moving element1 which has a well directed movement in a definite direction4 ,low ,tension4 ,in methods for igniting hydro-carbon charges1 any circuiting which has a low voltage4 ,lubrication4 ,the oiling of mechanical parts to reduce friction4 ,mangle4 ,a machine for smoothing out clothing1 goods1 etc4 ,magneto4 ,a dynamo which has the field pieces1 or poles made of permanent magnets4 ,magnetism4 ,that quality1 or agency by virtue of which certain bodies are productive of magnetic force4 ,manifestation4 ,showing or explaining a state of things2 an outward show4 ,make and ,break4 ,an ignition system1 which provides for throwing in and cutting out an electric circuit4 ,manifold4 ,a system of piping whereby the exhausts of a gasoline engine are brought together into one common discharge4 ,manganese4 ,a hard1 brittle1 grayish white metallic element1 used in the manufacture of paints and of glass1 and also for alloying metals4 ,manually4 ,doing things by hand2 muscular activity4 ,material4 ,substances and parts from which articles are made4 ,mechanically4 ,doing things by means of machinery1 or in some regular order4 ,mobility4 ,the capacity to move about4 ,multiple4 ,a figure used a certain number of times1 is said to be a multiple of a number1 if it will divide the number equally4 ,thus #d is a multiple of #af2 #c is a multiple of #i1 and so on4 ,neutral4 ,neither2 not in favor of any party or thing4 ,normal4 ,as usual2 in the regular way2 without varying from the ordinary manner4 ,ohm's ,law4 ,in electricity1 it is expressed as follows3 #a4 ,the current strength is equal to the electromotive force divided by its resistance4 #b4 ,the electromotive force is equal to the current strength multiplied by the resistance4 #c4 ,the resistance is equal to the electromotive force divided by the current strength4 ,oscillating4 ,moving to and fro1 like a pendulum4 ,orifice4 ,an opening2 a hole4 ,organism4 ,any part of the body1 or any small germ or animalcule4 ,oxidation4 ,the action of air or oxygen on any material1 is called oxidation4 ,thus rust on iron is called oxidation4 ,oxygen4 ,a colorless1 tasteless gas1 the most important in nature1 called the acid-maker of the universe1 as it unites with all substances1 and produces either an acid1 an alkali1 or a neutral compound4 ,parallel4 ,two lines are said to be parallel1 when they are lying side by side and are equally distant from each other from end to end4 ,pendulum4 ,a bar suspended at one end to a pivot pin1 and having its lower end free to swing to and fro4 ,penstock4 ,a reservoir designed to receive and discharge water into a turbine or other form of water wheel4 ,permanent4 ,that which will last2 not easily stopped4 ,pestle4 ,an implement of stone or metal used for breaking and grinding up chemicals1 and other material in a mortar4 ,petroleum4 ,a liquid fuel product1 found in many places1 its component parts being about #ae per cent4 hydrogen and #he per cent4 carbon4 ,perimeter4 ,the outer rim1 or circle4 ,piston4 ,that part of an engine which is attached to the piston rod4 ,pinion4 ,a small gear wheel driven by a larger gear wheel4 ,platinum4 ,an exceedingly hard metal1 used in places for electrical work where the current is liable to burn out ordinary conductors4 ,polarity4 ,the quality of having opposite poles4 ,pre-heating4 ,to heat before the ordinary process of heating commences4 ,ponderous4 ,large2 heavy2 difficult to handle4 ,port4 ,in nautical parlance the left side of a vessel2 the larboard side2 also an opening1 or a conduit for the transmission of gas or liquid4 ,pop valve4 ,a valve designed to open and allow escape of the imprisoned gases when the latter reach a certain pressure4 ,potential4 ,the power2 the term used in electricity to denote the energy in a motor4 ,plurality4 ,more than one2 many4 ,precipice4 ,a high and very steep cliff4 ,pressure4 ,the act of one body placed in contact with another and acting against it or against each other4 ,precaution4 ,taking great care2 being assured of safety4 ,primary ,a cell1 or a number of cells1 made battery4 of pairs of metallic couples1 immersed in an electrolyte of either an acid or an alkali4 ,proney ,brake4 ,a device for testing machinery and determining power1 by means of friction4 ,primeval4 ,the earliest2 the first2 of a low order4 ,proportion4 ,the relation of one thing or number1 to another2 comparative merit4 ,proximity4 ,close to2 near at hand4 ,quadruple4 ,four times4 ,rack4 ,a bar having a number of teeth1 to serve as a step or measure for a pawl1 or a toothed wheel4 ,radial4 ,extending out from the center4 ,radiation4 ,the property of many substances to give forth heat or cold1 or to disperse it4 ,rarified4 ,made less than the normal pressure1 as air1 which is not as dense at a high as at a low altitude4 ,receiver4 ,in telephone apparatus1 that part of the mechanism which transmits the message to the ear4 ,rectilinear4 ,a right line2 a straight direction forwardly4 ,reaction4 ,a force which is counter to a movement in another direction4 ,refrigeration4 ,cooling process2 the art of freezing4 ,refined4 ,purifying2 improved4 ,re-heating4 ,the process of further heating or increasing the temperature during the progress of the work4 ,requisite4 ,the necessary part2 the requirement4 ,residue4 ,the balance2 what is left over4 ,resistance4 ,opposition2 against4 ,reciprocating4 ,one for the other2 moving from one side to the other4 ,refinement4 ,chastity of thought1 taste1 manner1 or actions4 ,retort4 ,a vigorous answer4 ,a receptacle adapted to stand a high heat4 ,revolution4 ,turning1 like the earth in its orbit4 ,rock ,shaft4 ,a shaft which turns part of its rotation in one direction1 and then turns in the other direction4 ,rotation4 ,the turning of a wheel on its axle2 the rotation of the earth on its axis each day4 ,distinguishing from revolution which is a swinging of the entire body of the earth around the sun in its orbit4 ,sal-,ammoniac4 ,a white metallic element4 ,scavenging4 ,to clean out2 to scour4 ,secondary ,a battery which is charged with a ,battery4 current1 and then gives forth an electric current of a definite amount4 ,it is also known as an accumulator1 since its elements continue to accumulate electric energy4 ,secondary coil4 ,in induction coils two wire wrappings are necessary1 the first winding being1 usually1 of heavy wire1 and called the primary2 the second winding is of finer wire1 and is called the secondary coil4 ,sector4 ,an ,a-shaped piece cut from a disk2 distinguish this from a segment1 which is a part cut off from a disk by a single straight line4 ,secondary4 ,occupying a second place2 not of the first kind1 or place4 ,segment4 ,a part cut off from a disk1 by a single line2 the part of a circle included within a chord and its arc4 ,sewerage4 ,the conveyance of waste matter from a building4 ,sinuous4 ,systematic draining by means of pipes or conduits4 ,characterized by bends1 or curves1 or a serpentine curving1 or wave-like outline4 ,slide ,valve4 ,a form1 which moves along a flat surface through which the duct is formed4 ,solution4 ,a liquid having therein different substances mixed together4 ,sprayer4 ,to eject2 to send forth in small particles4 ,stability4 ,fixed2 strength to stand without support4 ,stupendous4 ,immense2 large2 much beyond the largest of the kind4 ,standard4 ,a sample of the measure or extent2 a type or a model4 ,stratify4 ,to deposit1 form1 or range in strata4 ,super ,heating4 ,to heat up beyond the ordinary or normal point4 ,subtle4 ,crafty2 made of light material2 daintily constructed4 ,supersede4 ,in place of2 to take the place of4 ,susceptible4 ,capable of being changed or influenced4 ,suspension4 ,hanging2 floating of a body in fluid4 ,suction4 ,the production of a partial vacuum in a space connected with a fluid under pressure4 ,terminal4 ,the end2 the last part4 ,technical4 ,specially or exclusively pertaining to some art or subject4 ,theoretical4 ,that which is speculative1 as distinguished from practical4 ,throttle ,valve4 ,a device which is designed to cut off the flow of a fluid4 ,throttling4 ,the closing of a port2 the cutting down of a supply4 ,transformation4 ,a complete change2 made over into something else4 ,transmit4 ,to convey2 to send to another part4 ,transference4 ,to convey to another part2 the change from one thing to another4 ,transferred4 ,put over4 ,triple4 ,three2 thrice4 ,turbine4 ,to turn2 a form of water wheel and steam engine1 where the fluid impinges against the blades arranged around the perimeter of the wheel4 ,tubular4 ,hollowed2 like a pipe4 ,two-,cycle4 ,a gasoline engine1 in which the compressed hydro-carbon gases are fired every turn of the crank shaft4 ,typical4 ,the nature or characteristics of a type4 ,undershot4 ,a type of wheel in which the water shoots past and against the blades on the lower side4 ,unison4 ,together2 conjointly2 acting with each other4 ,universally4 ,all over the world2 throughout all space4 ,utility4 ,use2 that which is valuable or of service4 ,vacuum4 ,that part from which all material is taken2 in a limited sense1 air1 which has less density than the normal4 ,vaporizing4 ,to convert into gas1 usually by heat4 ,variable4 ,with differing characteristics2 changeable4 ,venturi ,tube4 ,a form of tube which has a contracted part between its ends4 ,vertical4 ,in the direction of a line which points to the center of the earth4 ,vibrator ,coil4 ,in electrical devices used in the ignition systems of certain types of gasoline engines1 a winding is provided on a metallic core1 which has an armature that is made so it will vibrate4 ,volt4 ,the pressure of an electric current2 the unit of electromotive force4 ,voltage4 ,electromotive force as expressed in volts4 ,volt ,meter4 ,an instrument for indicating the voltage of an electric circuit4 ,watt4 ,the electrical unit of the rate of working in an electric circuit1 the rate being the electromotive force of one volt1 and the intensity of one ampere4 ,weight4 ,the measure of the force toward the center of the earth1 due to gravity4 ,winnowed4 ,taken out2 sifted from4 ,wiping ,bar4 ,a metallic piece which rests against a moving wheel and designed to take a current from or to transmit it to the wheel4 ,the ,motor ,boys ,series 7,trade ,mark1 ,reg4 ,u4 ,s4 ,pat4 ,of47 ,by ,,clarence ,,young #abmo4 ,illustrated4 ,price per volume1 #fj cents1 postpaid4 ,illustration ,the ,motor ,boys or ,chums ,through ,thick and ,thin ,the ,motor ,boys ,overland or ,a ,lone ,trip for ,fun and ,fortune ,the ,motor ,boys in ,mexico4 or ,the ,secret of ,the ,buried ,city ,the ,motor ,boys ,across the ,plains or ,the ,hermit of ,lost ,lake ,illustration ,the ,motor ,boys ,afloat or ,the ,stirring ,cruise of the ,dartaway ,the ,motor ,boys on the ,atlantic or ,the ,mystery of the ,lighthouse ,the ,motor ,boys in ,strange ,waters or ,lost in a ,floating ,forest ,the ,motor ,boys on the ,pacific or ,the ,young ,derelict ,hunters ,illustration ,the ,motor ,boys in the ,clouds or ,a ,trip for ,fame and ,fortune ,the ,motor ,boys ,over the ,rockies or ,a ,mystery of the ,air ,the ,motor ,boys ,over the ,ocean or ,a ,marvellous ,rescue in ,mid-,air ,the ,motor ,boys on the ,wing or ,seeking the ,airship ,treasure ,illustration ,the ,motor ,boys ,after a ,fortune or ,the ,hut on ,snake ,island ,the ,motor ,boys on the ,border or ,sixty ,nuggets of ,gold ,the ,motor ,boys ,under the ,sea or ,from ,airship to ,submarine ,the ,motor ,boys on ,road and ,river 7new7 or ,racing to ,save a ,life ,,cupples ,,leon ,,co41 ,publishers1 ,,new ,,york ,up-to-date ,baseball ,stories ,baseball ,joe ,series ,by ,,lester ,,chadwick ,author of ,the ,college ,sports ,series #abmo4 ,illustrated4 ,price per volume1 #fj cents1 postpaid4 99 99 99 99 99 ,illustration ,ever since the success of ,mr4 ,chadwick's ,college ,sports ,series we have been urged to get him to write a series dealing exclusively with baseball1 a subject in which he is unexcelled by any living ,american author or coach4 ,baseball ,joe of the ,silver ,stars or ,the ,rivals of ,riverside ,in this volume1 the first of the series1 ,joe is introduced as an everyday country boy who loves to play baseball and is particularly anxious to make his mark as a pitcher4 ,he finds it almost impossible to get on the local nine1 but1 after a struggle1 he succeeds4 ,a splendid picture of the great national game in the smaller towns of our country4 ,baseball ,joe on the ,school ,nine or ,pitching for the ,blue ,banner ,joe's great ambition was to go to boarding school and play on the school team4 ,he got to boarding school but found it harder making the team there than it was getting on the nine at home4 ,he fought his way along1 and at last saw his chance and took it1 and made good4 ,baseball ,joe at ,yale or ,pitching for the ,college ,championship ,from a preparatory school ,baseball ,joe goes to ,yale ,university4 ,he makes the freshman nine and in his second year becomes a varsity pitcher and pitches in several big games4 ,baseball ,joe in the ,central ,league or ,making ,good as a ,professional ,pitcher ,in this volume the scene of action is shifted from ,yale ,college to a baseball league of our central states4 ,baseball ,joe's work in the box for ,old ,eli had been noted by one of the managers and ,joe gets an offer he cannot resist4 ,joe accepts the offer and makes good4 ,baseball ,joe in the ,big ,league or ,a ,young ,pitcher's ,hardest ,struggle ,from the ,central ,league ,joe is drafted into the ,st4 ,louis ,nationals4 ,at first he has little to do in the pitcher's box1 but gradually he wins favor4 ,a corking baseball story that fans1 both young and old1 will enjoy4 99 99 99 99 99 ,,cupples ,,leon ,,co41 ,publishers1 ,,new ,,york ,the ,racer ,boys ,series by ,,clarence ,,young ,author of ,the ,motor ,boys ,series1 ,jack ,ranger ,series1 etc4 etc4 ,fine cloth binding4 ,illustrated4 ,price per volume1 #fj;c postpaid4 99 99 99 99 99 ,illustration ,the announcement of a new series of stories by ,mr4 ,clarence ,young is always hailed with delight by boys and girls throughout the country1 and we predict an even greater success for these new books1 than that now enjoyed by the ,motor ,boys ,series4 ,the ,racer ,boys or ,the ,mystery of the ,wreck ,this1 the first volume of the series1 tells who the ,racer ,boys were and how they chanced to be out on the ocean in a great storm4 ,adventures follow in rapid succession in a manner that only ,mr4 ,young can describe4 ,the ,racer ,boys ,at ,boarding ,school or ,striving for the ,championship ,when the ,racer ,boys arrived at the school everything was at a standstill1 and the students lacked ambition and leadership4 ,the ,racers took hold with a will1 got their father to aid the head of the school financially1 and then reorganized the football team4 ,the ,racer ,boys ,to ,the ,rescue or ,stirring ,days in a ,winter ,camp ,here is a story filled with the spirit of good times in winter--skating1 ice-boating and hunting4 ,the ,racer ,boys on ,the ,prairies or ,the ,treasure of ,golden ,peak ,from their boarding school the ,racer ,boys accept an invitation to visit a ranch in the ,west4 ,the ,racer ,boys on ,guard or ,the ,rebellion of ,riverview ,hall ,once more the boys are back at boarding school1 where they have many frolics1 and enter more than one athletic contest4 ,the ,racer ,boys ,forging ,ahead or ,the ,rivals of the ,school ,league ,once more the ,racer ,boys go back to ,riverview ,hall1 to meet their many chums as well as several enemies4 ,athletics play an important part in this volume1 and the rivalry is keen from start to finish4 ,the ,racer ,boys show what they can do under the most trying circumstances4 99 99 99 99 99 ,,cupples ,,leon ,,co41 ,publishers1 ,,new ,,york ,the ,dorothy ,dale ,series ,by ,,margaret ,,penrose ,author of ,the ,motor ,girls ,series #abmo4 ,illustrated4 ,price per volume1 #fj cents1 postpaid4 99 99 99 99 99 ,illustration ,dorothy ,dale3 ,a ,girl of ,to-,day ,dorothy is the daughter of an old ,civil ,war veteran who is running a weekly newspaper in a small ,eastern town4 ,when her father falls sick1 the girl shows what she can do to support the family4 ,dorothy ,dale at ,glenwood ,school ,more prosperous times have come to the ,dale family1 and ,major ,dale resolves to send ,dorothy to a boarding school4 ,dorothy ,dale's ,great ,secret ,a splendid story of one girl's devotion to another4 ,how ,dorothy kept the secret makes an absorbing story4 ,dorothy ,dale and ,her ,chums ,a story of school life1 and of strange adventures among the gypsies4 ,dorothy ,dale's ,queer ,holidays ,relates the details of a mystery that surrounded ,tanglewood ,park4 ,dorothy ,dale's ,camping ,days ,many things happen1 from the time ,dorothy and her chums are met coming down the hillside on a treacherous load of hay4 ,dorothy ,dale's ,school ,rivals ,dorothy and her chum1 ,tavia1 return to ,glenwood ,school4 ,a new student becomes ,dorothy's rival and troubles at home add to her difficulties4 ,dorothy ,dale in the ,city ,dorothy is invited to ,new ,york ,city by her aunt4 ,this tale presents a clever picture of life in ,new ,york as it appears to one who has never before visited the ,metropolis4 ,dorothy ,dale's ,promise ,strange indeed was the promise and given under strange circumstances4 ,only a girl as strong of purpose as was ,dorothy ,dale would have undertaken the task she set for herself4 ,dorothy ,dale in the ,west ,dorothy's father and her aunt inherited a valuable tract of land in the ,west4 ,the aunt1 ,dorothy and ,tavia1 made a long journey to visit the place1 where they had many adventures4 99 99 99 99 99 ,,cupples ,,leon ,,co41 ,publishers1 ,,new ,,york ,the ,motor ,girls ,series ,by ,,margaret ,,penrose ,author of the highly successful ,dorothy ,dale ,series #abmo4 ,illustrated4 ,price per volume1 #fj cents1 postpaid4 99 99 99 99 99 ,illustration ,the ,motor ,girls or ,a ,mystery of the ,road ,when ,cora ,kimball got her touring car she did not imagine so many adventures were in store for her4 ,a tale all wide awake girls will appreciate4 ,the ,motor ,girls on a ,tour or ,keeping a ,strange ,promise ,a great many things happen in this volume4 ,a precious heirloom is missing1 and how it was traced up is told with absorbing interest4 ,the ,motor ,girls at ,lookout ,beach or ,in ,quest of the ,runaways ,there was a great excitement when the ,motor ,girls decided to go to ,lookout ,beach for the summer4 ,the ,motor ,girls ,through ,new ,england or ,held by the ,gypsies ,a strong story and one which will make this series more popular than ever4 ,the girls go on a motoring trip through ,new ,england4 ,the ,motor ,girls on ,cedar ,lake or ,the ,hermit of ,fern ,island ,how ,cora and her chums went camping on the lake shore and how they took trips in their motor boat1 are told in a way all girls will enjoy4 ,the ,motor ,girls on the ,coast or ,the ,waif from the ,sea ,the scene is shifted to the sea coast where the girls pay a visit4 ,they have their motor boat with them and go out for many good times4 ,the ,motor ,girls on ,crystal ,bay or ,the ,secret of the ,red ,oar ,more jolly times1 on the water and at a cute little bungalow on the shore of the bay4 ,a tale that will interest all girls4 ,the ,motor ,girls on ,waters ,blue or ,the ,strange ,cruise of the ,tartar ,before the girls started on a long cruise down to the ,west ,indies1 they fell in with a foreign girl and she informed them that her father was being held a political prisoner on one of the islands4 ,a story that is full of fun as well as mystery4 99 99 99 99 99 ,,cupples ,,leon ,,co41 ,publishers1 ,,new ,,york ,ruth ,fielding ,series ,by ,,alice ,b4 ,,emerson #abmo4 ,illustrated4 ,price per volume1 #dj cents1 postpaid4 99 99 99 99 99 ,illustration ,ruth ,fielding of ,the ,red ,mill or ,jaspar ,parloe's ,secret ,telling how ,ruth1 an orphan girl1 came to live with her miserly uncle1 and how the girl's sunny disposition melted the old miller's heart4 ,ruth ,fielding at ,briarwood ,hall or ,solving the ,campus ,mystery ,ruth was sent by her uncle to boarding school4 ,she made many friends1 also one enemy1 who made much trouble for her4 ,ruth ,fielding at ,snow ,camp or ,lost in the ,backwoods ,a thrilling tale of adventures in the backwoods in winter1 is told in a manner to interest every girl4 ,ruth ,fielding at ,lighthouse ,point or ,nita1 the ,girl ,castaway ,from boarding school the scene is shifted to the ,atlantic ,coast1 where ,ruth goes for a summer vacation with some chums4 ,ruth ,fielding at ,silver ,ranch or ,schoolgirls ,among the ,cowboys ,a story with a western flavor4 ,how the girls came to the rescue of ,bashful ,ike1 the cowboy1 is told in a way that is most absorbing4 ,ruth ,fielding on ,cliff ,island or ,the ,old ,hunter's ,treasure ,box ,ruth and her friends go to ,cliff ,island1 and there have many good times during the winter season4 ,ruth ,fielding at ,sunrise ,farm or ,what ,became of the ,raby ,orphans ,jolly good times at a farmhouse in the country1 where ,ruth rescues two orphan children who ran away4 ,ruth ,fielding and the ,gypsies or ,the ,missing ,pearl ,necklace ,this volume tells of stirring adventures at a ,gypsy encampment1 of a missing heirloom1 and how ,ruth has it restored to its owner4 99 99 99 99 99 ,,cupples ,,leon ,,co41 ,publishers1 ,,new ,,york ,the ,dave ,dashaway ,series ,by ,,roy ,,rockwood ,author of the ,speedwell ,boys ,series and the ,great ,marvel ,series4 #abmo4 ,illustrated4 ,price per volume1 #dj cents1 postpaid4 99 99 99 99 99 ,never was there a more clever young aviator than ,dave ,dashaway4 ,all up-to-date lads will surely wish to read about him4 99 99 99 99 99 ,illustration ,dave ,dashaway the ,young ,aviator or ,in the ,clouds for ,fame and ,fortune ,this initial volume tells how the hero ran away from his miserly guardian1 fell in with a successful airman1 and became a young aviator of note4 ,dave ,dashaway and ,his ,hydroplane or ,daring ,adventures ,over the ,great ,lakes ,showing how ,dave continued his career as a birdman and had many adventures over the ,great ,lakes1 and how he foiled the plans of some ,canadian smugglers4 ,dave ,dashaway and ,his ,giant ,airship or ,a ,marvellous ,trip ,across the ,atlantic ,how the giant airship was constructed and how the daring young aviator and his friends made the hazardous journey through the clouds from the new world to the old1 is told in a way to hold the reader spellbound4 ,dave ,dashaway ,around the ,world or ,a ,young ,yankee ,aviator ,among ,many ,nations ,an absorbing tale of a great air flight around the world1 of adventures in ,alaska1 ,siberia and elsewhere4 ,a true to life picture of what may be accomplished in the near future4 ,dave ,dashaway3 ,air ,champion or ,wizard ,work in the ,clouds ,dave makes several daring trips1 and then enters a contest for a big prize4 ,an aviation tale thrilling in the extreme4 99 99 99 99 99 ,,cupples ,,leon ,,co41 ,publishers1 ,,new ,,york ,the ,speedwell ,boys ,series ,by ,,roy ,,rockwood ,author of ,the ,dave ,dashaway ,series1 ,great ,marvel ,series1 etc4 #abmo4 ,illustrated4 ,price per volume1 #dj cents1 postpaid4 99 99 99 99 99 ,all boys who love to be on the go will welcome the ,speedwell boys4 ,they are clean cut and loyal lads4 99 99 99 99 99 ,illustration ,the ,speedwell ,boys on ,motor ,cycles or ,the ,mystery of a ,great ,conflagration ,the lads were poor1 but they did a rich man a great service and he presented them with their motor cycles4 ,what a great fire led to is exceedingly well told4 ,the ,speedwell ,boys and ,their ,racing ,auto or ,a ,run for the ,golden ,cup ,a tale of automobiling and of intense rivalry on the road4 ,there was an endurance run and the boys entered the contest4 ,on the run they rounded up some men who were wanted by the law4 ,the ,speedwell ,boys and ,their ,power ,launch or ,to the ,rescue of the ,castaways ,here is an unusual story4 ,there was a wreck1 and the lads1 in their power launch1 set out to the rescue4 ,a vivid picture of a great storm adds to the interest of the tale4 ,the ,speedwell ,boys in a ,submarine or ,the ,lost ,treasure of ,rocky ,cove ,an old sailor knows of a treasure lost under water because of a cliff falling into the sea4 ,the boys get a chance to go out in a submarine and they make a hunt for the treasure4 ,the ,speedwell ,boys and ,their ,ice ,racer or ,the ,perils of a ,great ,blizzard ,the boys had an idea for a new sort of iceboat1 to be run by combined wind and motor power4 ,how they built the craft1 and what fine times they had on board of it1 is well related4 99 99 99 99 99 ,,cupples ,,leon ,,co41 ,publishers1 ,,new ,,york 99 99 99 99 99