,illustration ,,scientific ,,american ,,supplement ,,no4 #bhf ,,new ,,york1 ,,june #be1 #ahha ,scientific ,american ,supplement4 ,vol4 ,,xi1 ,no4 #bhf4 ,scientific ,american established #ahde ,scientific ,american ,supplement1 #e a year4 ,scientific ,american and ,supplement1 #g a year4 99 99 99 99 99 ,,table ,,of ,,contents4 ,i4 ,,engineering ,,and ,,mechanics4--,one ,thousand ,horse ,power ,corliss ,engine4 #e figures1 to scale1 illustrating the construction of the new one thousand horse power ,corliss engine1 by ,hitch1 ,hargreaves ,co4 ,opening of the ,new ,workshop of the ,stevens ,institute of ,technology4 ,speech of ,prof4 ,r4,w4 ,raymond1 speech of ,mr4 ,horatio ,allen4 ,light ,steam ,engine for ,aeronautical ,purposes4 ,constructed for ,capt4 ,mojoisky1 of the ,russian ,navy4 ,complete ,prevention of ,incrustation in ,boilers4 ,arrangement for purifying boiler water with lime and carbonate of soda4--,the purification of the water4--,examination of the purified water4--,results of water purification4 ,eddystone ,lighthouse4 ,progress of the work4 ,rolling ,mill for ,making ,corrugated ,iron4 #a figure4 ,the new mill of ,schultz1 ,knaudt ,co41 of ,essen1 ,germany4 ,railway ,turntable in the ,time of ,louis ,,xiv4 #a figure4 ,pleasure car4 ,railway and turntable at ,mary-le-,roy ,chateau1 ,france1 in #agad4 ,new ,signal ,wire ,compensator4 ,communication from ,a4 ,lyle1 describing compensators in use on the ,nizam ,state ,railway1 ,east ,india4 ,tangye's ,hydraulic ,hoist4 #b figures4 ,power ,loom for ,delicate ,fabrics4 #a figure4 ,how ,veneering is ,made4 ,,ii4 ,,technology ,,and ,,chemistry4--,the ,constituent ,parts of ,leather4 ,the composition of different leathers exhibited at the ,paris ,exhibition4--,amount of leather produced by different tonnages of #ajj pounds of hides4--,percentage of tannin absorbed under different methods of tanning4--,amounts of gelatine and tannin in leather of different tonnages1 etc4 ,progress in ,american ,pottery4 ,photographic ,notes4--,mr4 ,waruerke's ,new ,discovery4--,method of converting negatives directly into positives4--,experiments of ,capt4 ,bing on the sensitiveness of coal oil--,bitumen plates4--,method of topographic engraving4 ,by ,commandant ,,de ,,la ,,noe4--,succinate of ,iron ,developer4--,method of making friable hydro-cellulose4 ,photo-,tracings in ,black and ,color4 ,dyeing ,reds with ,artificial ,alizarin4 ,by ,m4 ,,maurice ,,prud',,homme4 ,,iii4 ,,electricity1 ,,physical ,,science1 ,,etc4--,on ,faure's ,secondary ,battery4 ,physical ,science in ,our ,common ,schools4--,an exceptionally strong argument for the teaching of physical science by the experimental method in elementary schools1 with an outline of the method and the results of such teaching4 ,on the ,law of ,avogadro and ,ampere4 ,by ,e4 ,,vogel4 ,,iv4 ,,geography1 ,,geology1 ,,etc4--,petroleum and ,coal in ,venezuela4 ,geographical ,society of the ,pacific4 ,the ,behring's ,straits ,currents4--,proofs of their existence4 ,experimental ,geology4--,artificial production of calcareous pisolites and oolites4--,on crystals of anhydrous lime4--#d figures4 ,v4 ,,natural ,,history1 ,,etc4--,coccid4 ,by ,dr4 ,h4 ,,behr4--,an important paper read before the ,california ,academy of ,sciences4--,the marvelous fecundity of scale bugs4--,their uses4--,their ravages4--,methods of destroying them4 ,agricultural ,items4 ,timber ,trees4 ,blood ,rains4 ,,vi4 ,,medicine ,,and ,,hygiene4--,medical ,uses of ,figs4 ,topical ,medication in ,phthisis4 ,,vii4 ,,architecture1 ,,etc4--,suggestions in ,architecture4--,large illustration4--,the ,new ,high ,school for ,girls1 ,oxford1 ,england4 99 99 99 99 99 ,,petroleum ,,and ,,coal ,,in ,,venezuela4 ,,mr4 ,e4 ,h4 ,,plumacher1 ,u4 ,s4 ,consul at ,maracaibo1 sends to the ,state ,department the following information touching the wealth of coal and petroleum probable in ,venezuela3 ,the asphalt mines and petroleum fountains are most abundant in that part of the country lying between the ,river ,zulia and the ,river ,catatumbo1 and the ,cordilleras4 ,the wonderful sand-bank is about seven kilometers from the confluence of the ,rivers ,tara and ,sardinarte4 ,it is ten meters high and thirty meters long4 ,on its surface can be seen several round holes1 out of which rises the petroleum and water with a noise like that made by steam vessels when blowing off steam1 and above there ascends a column of vapor4 ,there is a dense forest around this sand-bank1 and the place has been called ,el ,inferno4 ,dr4 ,edward ,mc,gregor visited the sand-bank1 and reported to the ,government that by experiment he had ascertained that one of the fountains spurted petroleum and water at the rate of #bdj gallons per hour4 ,mr4 ,plumacher says that the petroleum is of very good quality1 its density being that which the ,british market requires in petroleum imported from the ,united ,states4 ,the river1 up to the junction of the ,tara and ,sardinarte1 is navigable during the entire year for flat-bottomed craft of forty or fifty tons4 ,mr4 ,plumacher has been unable to discover that there are any deposits of asphalt or petroleum in the upper part of the ,department of ,colon1 beyond the ,zulia1 but he has been told that the valleys of ,cucuta and the territories of the ,state of ,tachira abound in coal mines4 ,there are coal mines near ,san ,antonia1 in a ravine called ,la ,carbonera1 and these supply coal for the smiths' forges in that place4 ,coal and asphalt are also found in large quantities in the ,department of ,sucre4 ,mr4 ,plumacher has seen1 while residing in the ,state of ,zulia1 but one true specimen of lignite1 which was given to him by a rich land-owner1 who is a ,spanish subject4 ,in the section where it was found there are several fountains of a peculiar substance4 ,it is a black liquid1 of little density1 strongly impregnated with carbonic acid which it transmits to the water which invariably accompanies it4 ,deposits of this substance are found at the foot of the spurs of the ,cordilleras1 and are believed to indicate the presence of great deposits of anthracite4 ,there are many petroleum wells of inferior quality between ,escuque and ,bettijoque1 in the town of ,columbia4 ,laborers gather the petroleum in handkerchiefs4 ,after these become saturated1 the oil is pressed out by wringing4 ,it is burned in the houses of the poor4 ,the people thought1 in #ahbd1 that it was a substance unknown elsewhere1 and they called it the oil of ,columbia4 ,at that time they hoped to establish a valuable industry by working it1 and they sent to ,england1 ,france1 and this country samples which attracted much attention4 ,but in those days no method of refining the crude oil had been discovered1 and therefore these efforts to introduce petroleum to the world soon failed4 ,the plains of ,ceniza abound in asphalt and petroleum4 ,there is a large lake of these substances about twelve kilometers east of ,st4 ,timoteo1 and from it some asphalt is taken to ,maracaibo4 ,many deposits of asphalt are found between these plains and the ,river ,mene4 ,the largest is that of ,cienega de ,mene1 which is shallow4 ,at the bottom lies a compact bed of asphalt1 which is not used at present1 except for painting the bottoms of vessels to keep off the barnacles4 ,there are wells of petroleum in the ,state of ,falcon4 ,mr4 ,plumacher says that all the samples of coal submitted to him in ,venezuela for examination1 with the exception of the lignite before mentioned1 were1 in his opinion1 asphalt in various degrees of condensation4 ,the sample which came from ,tule he ranks with the coals of the best quality4 ,he believes that the innumerable fountains and deposits of petroleum1 bitumen1 and asphalt that are apparent on the surface of the region around ,lake ,maracaibo are proof of the existence below of immense deposits of coal4 ,these deposits have not been uncovered because the territory remains for the most part as wild as it was at the conquest4 99 99 99 99 99 ,,one ,,thousand ,,horse-,,power ,,corliss ,,engine4 ,illustration3 ,,fig4 #a4 ,,dia4 ,,of ,,cylinder #dj'' ,,stroke #aj ft4 ,,revs #da ,,scale ,,of ,,diagrams #dj ,,lbs #a ,,inch ,,fig4 #b4 ,we illustrate one of the largest ,corliss engines ever constructed4 ,it is of the single cylinder1 horizontal1 condensing type1 with one cylinder #dj inches diameter1 and #aj feet stroke1 and makes forty-five revolutions per minute1 corresponding to a piston speed of #ijj feet per minute4 ,at mid stroke the velocity of the piston is #a1djb feet per minute nearly1 and its energy in foot pounds amounts to about #h4f times its weight4 ,the cylinder is steam jacketed on the body and ends1 and is fitted with ,corliss valves and ,inglis ,spencer's automatic ,corliss valve expansion gear4 ,referring to the general drawing of the engine1 it will be seen that the cylinder is bolted directly to the end of the massive cast iron frame1 and the piston coupled direct to the crank by the steel piston rod and crosshead and the connecting rod4 ,the connecting rod is #bh feet long center to center1 and #ab inches diameter at the middle4 ,the crankshaft is made of forged ,bolton steel1 and is #ba inches diameter at the part where the fly-wheel is carried4 ,the fly driving wheel is #ce feet in diameter1 and grooved for twenty-seven ropes1 which transmit the power direct to the various line shafts in the mill4 ,the rope grooves are made on ,hick1 ,hargreaves ,co4's standard pattern of deep groove1 and the wheel1 which is built up1 is constructed on their improved plan with separate arms and boss1 and twelve segments in the rim with joints planed to the true angle by a special machine designed and made by themselves4 ,the weight of the fly-wheel is about #fj tons4 ,the condensing apparatus is arranged below1 so that there is complete drainage from the cylinder to the condenser4 ,the air pump1 which is #cf inches diameter and #b feet #f inches stroke1 is a vertical pump worked by wrought iron plate levers and two side links1 shown by dotted lines1 from the main crosshead4 ,the engine is fenced off by neat railing1 and a platform with access from one side is fitted round the top of the cylinder for getting conveniently to the valve spindles and lubricators4 ,the above engraving1 which is a side elevation of the cylinder1 shows the valve gear complete4 ,there are two central disk plates worked by separate eccentrics1 which give separate motion to the steam and exhaust valves4 ,the eccentrics are mounted on a small cross shaft1 which is driven by a line shaft and gear wheels4 ,the piston rod passes out at the back end of the cylinder and is carried by a shoe slide and guide bar1 as shown more fully in the detailed sectional elevation through the cylinder1 showing also the covers and jackets in section4 ,the cylinder1 made in four pieces1 is built up on ,mr4 ,w4 ,inglis's patent arrangement1 with separate liner and steam jacket casing and separate end valve chambers4 ,this arrangement simplifies the castings and secures good and sound ones4 ,the liner has face joints1 which are carefully scraped up to bed truly to the end valve chambers4 ,the crosshead slides are each #c feet #c inches long and ,i foot #c inches wide4 ,the engine was started last year1 and has worked beautifully from the first1 without heating of bearings or trouble of any kind1 and it gives most uniform and steady turning4 ,it is worked now at forty-one revolutions per minute1 or only #hbj feet piston speed1 but will be worked regularly at the intended #ijj feet piston speed per minute when the spinning machinery is adapted for the increase which the four extra revolutions per minute of the engine will give2 the load driven is over #a1jjj horsepower1 the steam pressure being #ej lb4 to #ee lb41 which1 however1 will be increased when the existing boilers1 which are old1 come to be replaced by new4 ,indicator diagrams from the engines are given on page #cji4 ,the engine is very economical in steam consumption1 but no special trials or tests have been made with it4 ,an exactly similar engine1 but of smaller size1 with a cylinder #cj inches diameter and #h feet stroke1 working at forty-five revolutions per minute1 made by ,messrs4 ,hick1 ,hargreaves ,co4 for ,sir ,titus ,salt1 ,sons ,co4's mill at ,saltaire1 was tested about two years ago by ,mr4 ,fletcher1 chief engineer of the ,manchester ,steam ,users' ,association1 and the results which are given below pretty fairly represent the results obtained from this class of engine4 ,messrs4 ,hick1 ,hargreaves ,co4 are now constructing a single engine of the same type for #a1hjj indicated horse-power for a cotton mill at ,bolton2 and they have an order for a pair of horizontal compound ,corliss engines intended to indicate #c1jjj horse-power4 ,these engines will be the largest cotton mill engines in the world4--,the ,engineer4 ,illustration3 #ajjj ,,horse ,,power ,,corliss ,,engine4--,,by ,,hick4 ,,hargreaves ,,co4 ,result of ,trials with ,saltaire ,horizontal ,engine on ,february #adth and #aeth1 #ahgh4 ,trials made by ,mr4 ,l4,e4 ,fletcher1 ,chief ,engineer ,steam ,users' ,association1 ,manchester4 ,engine single-cylinder1 with ,corliss valves4 ,inglis and ,spencer's valve gear4 ,diameter of cylinder4 #cj;in42 stroke1 #h;ft42 #de revolutions per minute4 ,no4 of trials ,total #a4;,h4,p4 ,,mb ,mean boiler pressure4 ,,mp ,mean pressure on piston at beginning of stroke4 ,,ml ,mean loss between boiler pressure and cylinder4 ,,ma ,mean average pressure on piston4 ,w ,water ,per ,i4,h4,p4 per hour4 ,c ,coal per ,i4,h4,p4 per hour4 ,no4 of trials ,total ,,mb ,,mp ,,ml ,,ma ,w ,c ,i4,h4,p4 lb lb lb lb lb lb ,trial ,no4 #a4 #cja4hi #df4f #dd4aa #b4ec #ba4bc #ah4cgc #b4fii ,trial ,no4 #b4 #cji4ff #dg4fc #dd4de #c4ah #ba4fg #ag4eii #b4efa ,means4 #cje4gge #dg4aae #dd4bh #b4hee #ba4de #ag4ihf #b4fcj ,illustration3 #ajjj ,,horse ,,power ,,corliss ,,engine4--,,by ,,hick1 ,,hargreaves ,,co4 ,illustration3 #ajjj ,,horse ,,power ,,corliss ,,engine4--,,by ,,hick1 ,,hargreaves ,,co4 99 99 99 99 99 ,,opening ,,of ,,the ,,new ,,workshop ,,of ,,the ,,stevens ,,institute ,,of ,,technology4 ,in our ,,supplement ,no4 #bhc we gave reports of some of the addresses of the distinguished speakers1 and we now present the remarks of ,prof4 ,raymond and ,horatio ,allen1 ,esq43 ,,speech ,,of ,,prof4 ,r4 ,w4 ,,raymond4 ,a few years ago1 at one of the meetings of our ,society of ,civil ,engineers we spent a day or so in discussing the proper mode of educating young men so as to fit them for that profession4 ,it is a question that is reopened for us as soon as we arrive at the age when we begin to consider what career to lay out for our sons4 ,when we were young1 the only question with parents in the better walks of life was1 whether their sons should be lawyers1 physicians1 or ministers4 ,anything less than a professional career was looked upon as a loss of caste1 a lowering in the social scale4 ,these things have changed1 now that we engineers are beginning to hold up our heads1 as we have every reason to do2 for the prosperity and well-being of the great nations of the world are attributable1 perhaps1 more to our efforts than to those of any other class4 ,when1 in the past1 the man of letters1 the poet1 the orator1 succeeded1 by some fit expression1 by some winged word1 to engage the attention of the world concerning some subject he had at heart1 the highest praise his fellow man could bestow was to cry out to him1 ,well said1 well said6 ,but now1 when1 by our achievements1 commerce and industry are increased to gigantic proportions1 when the remotest peoples are brought in ever closer communication with us1 when the progress of the human race has become a mighty torrent1 rushing onward with ever accelerating speed1 we glory in the yet higher praise1 ,well done1 well done6 ,under these circumstances1 the question how a young man is best fitted for our profession has become one of increasing importance1 and three methods have been proposed for its solution4 ,formerly the only point in debate was whether the candidate should go first to the schools and then to the workshop1 or first to the shop and then to the schools4 ,it was difficult to arrive at any decision2 for of the many who had risen to eminence as engineers1 some had adopted one order and some the other4 ,there remained a third course1 that of combining the school and the shop and of pursuing simultaneously the study of theory and the exercise of practical manipulation4 ,unforeseen difficulties arose1 however1 in the attempt to carry out this1 the most promising method4 ,the maintenance of the shop proved a heavy expense1 which it was found could not be lessened by the manufacture of salable articles1 because the work of students could not compete with that of expert mechanics4 ,it would require more time than could be allotted1 moreover1 to convert students into skilled workmen4 ,various modifications of this combination of theory and practice1 including more or less of the ,russian system of instruction in shop-work1 have been tried in different schools of engineering1 but never under so favorable conditions as the present4 ,with characteristic caution and good judgment1 ,president ,morton has studied the operation of the scheme of instruction adopted in the ,stevens ,institute1 and1 noting its deficiencies1 has now supplied them with munificent liberality1 giving to it a completeness that leaves seemingly nothing that could be improved upon1 even in a prayer or a dream4 ,still1 no one will be more ready to admit than he who has done all this1 that it is not enough to fit up a machine shop1 be it never so complete1 and light it with an electric lamp4 ,the decision as to its efficiency must come from the students that are so fortunate as to be admitted to it4 ,if such young men1 earnest1 enthusiastic1 with every incentive to exertion and every advantage for improvement1 here1 where they can feel the throbbing of the great heart of enterprise1 within sight of bridges upon which their services will be needed1 within hearing of the whistles of a score of railroads1 and the bells of countless manufactories which will want them2 if such as these1 trained under such instructors and amid such surroundings1 prove to be not fitted for the positions waiting for them to fill1 it will have been definitely demonstrated that the perfect scheme is yet unknown4 ,,speech ,,of ,,mr4 ,,horatio ,,allen4 ,impressed with the very great step in advance which has been inaugurated here this evening1 ,i feel crowding upon me so many thoughts that ,i cannot make sure that1 in selecting from them1 ,i may not leave unsaid much that ,i should say1 and say some things that ,i had better omit4 ,some years ago1 when asked by a wealthy gentleman to what machine-shop he had best send his son1 who was to become a mechanical engineer1 ,i advised him not to send him to any1 but to fit up a shop for him where he could go and work at what he pleased without the drudgery of apprenticeship1 to put him in the way of receiving such information as he needed1 and especially to let him go where he could see things break4 ,great1 indeed1 are the advantages of those who have the opportunity of seeing things break1 of witnessing failures and profiting by them4 ,when men have enumerated the achievements of those most eminent in our profession the thought has often struck me1 ,ah6 if we could only see that man's scrap heap4 ,there are many who are able to construct a machine for a given purpose so that it will work1 but to do this so that it will not cost too much is an entirely different problem4 ,to know what to omit is a rare talent4 ,i once found a young man who could tell students what to store up in their minds for immediate use1 and what to skim over or omit2 but ,i could not keep him long1 for more lucrative positions are always waiting for such men4 ,the advice ,i gave my wealthy friend was given before the ,stevens ,institute had developed in the direction it has now4 ,the foundation of this advice1 namely1 to combine a certain amount of judicious practice with theory1 is now in a fair way to be carried out1 and although things will probably not be permitted to break here1 the students will doubtless have opportunities for looking around them and supplementing their systematic instruction here by observation abroad4 99 99 99 99 99 ,,light ,,steam ,,engine ,,for ,,balloons4 ,we here illustrate one of a couple of compound engines designed and constructed by ,messrs4 ,ahrbecker1 ,son ,hamkens1 of ,stamford ,street1 ,s4,e41 for ,captain ,mojaisky1 of the ,russian ,imperial ,navy1 who intends to use them for aeronautical purposes4 ,the larger of these engines has cylinders #c in4 and #g in4 in diameter and #e in4 stroke1 and when making #cjj revolutions per minute it develops #bj actual horse power1 while its weight is but #aje lbs4 ,the smaller engine--the one illustrated--has cylinders #b in4 and #e in4 in diameter1 and #c in4 stroke1 and weighs #fc lbs41 while when making #dej revolutions it develops #aj actual horse power4 ,the two engines are identical in design1 and are constructed of forged steel with the exception of the bearings1 connecting-rods1 crossheads1 slide valves and pumps1 which are of phosphor-bronze4 ,the cylinders1 with the steam passages1 etc41 are shaped out of the solid4 ,the standards1 as will be seen1 are of very light ,t steel1 the crankshafts and pins are hollow1 as are also the crosshead bolts and piston rods4 ,the small engine drives a single-acting air pump of the ordinary type by a crank1 not shown in the drawing4 ,the condenser is formed of a series of hollow gratings4 ,illustration3 ,,light ,,steam ,,engine ,,for ,,aeronautical ,,purposes ,steam is supplied to the two engines by one boiler of the ,herreshoff steam generator type1 with certain modifications1 introduced by the designers1 to insure the utmost certainty in working4 ,it is of steel1 the outside dimensions being #bb in4 in diameter1 #be in4 high1 and weighs #adb lb4 ,the fuel used is petroleum1 and the working pressure #aij lb4 per square inch4 ,the constructors consider the power developed by these engines very moderate1 on account of the low piston speed specified in this particular case4 ,in some small and light engines by the same makers the piston speed is as high as #ajjj ft4 per minute4 ,the engines now illustrated form an interesting example of special designing1 and ,messrs4 ,ahrbecker1 ,son1 and ,hamkens deserve much credit for the manner in which the work has been turned out1 the construction of such light engines involving many practical difficulties1--,engineering4 99 99 99 99 99 ,mount ,baker1 ,washington ,territory1 has shown slight symptoms of volcanic activity for several years4 ,an unmistakable eruption is now in progress4 99 99 99 99 99 ,,complete ,,prevention ,,of ,,incrustation ,,in ,,boilers4 ,the chemical factory1 ,eisenbuettel1 near ,braunschweig1 distributes the following circular3 ,the principal generators of incrustation in boilers are gypsum and the so-called bicarbonates of calcium and magnesium4 ,if these can be taken put of the water1 before it enters the boiler1 the formation of incrustation is made impossible2 all disturbances and troubles1 derived from these incrustations1 are done away with1 and besides this1 a considerable saving of fuel is possible1 as clear iron will conduct heat quicker than that which is covered with incrustation4 ,j4 ,kolb1 according to ,dingler's ,polyt4 ,journal1 says3 ,a boiler with clear sides yielded with #a kil4 coal #g4e kil4 steam1 after two months only #f4d kil4 steam1 or a decrease of #ag per cent4 ,at the same time the boiler had suffered by continual working4 ,suppose a boiler free from inside crust would yield a saving of only #e per cent4 in fuel 7and this figure is taken very low compared with practical experiments7 it would be at the same time a saving of #c;c4 per cubic meter water4 ,if the cleaning of one cubic meter water therefore costs less than #c;c41 this alone would be an advantage4 ,already1 for a long time1 efforts have been made to find some means for this purpose1 and we have reached good results with lime and chloride of barium1 as well as with magnesia preparations4 ,but these preparations have many disadvantages4 ,corrosion of the boiler-iron and muriatic acid gas have been detected4 7,accounts of the ,magdeburg ,association for boiler management47 ,chloride of calcium1 which is formed by using chloride of barium1 increases the boiling point considerably1 and diminishes the elasticity of steam2 while the sulphate of soda1 resulting from the use of carbonate of soda1 is completely ineffectual against the boiler iron4 ,it increases the boiling point of water less than all other salts1 and diminishes likewise the elasticity of steam 7,wullner74 ,in using magnesia preparation1 the precipitation is only very slowly and incompletely effected--one part of the magnesia will be covered by the mire and the formed carbonate of magnesia in such a way1 that it can no more dissolve in water and have any effect 7,dingler's ,polyt4 ,journal1 #ahgg-gh74 ,the use of carbonate of soda is also cheaper than all other above mentioned substances4 ,one milligramme equivalent sulphate of lime1 in #a liter1 #fh grammes sulphate of lime in #a cubic meter1 requiring for decomposition3 #abj gr4 7#hf-hh per cent47 chloride of barium of commerce--at #e4jj #j4f;c4 ,or1 #ej gr4 magnesia preparation--at #aj4jj #j4e;c4 ,or1 #ee gr4 7#if-ih per cent47 carbonate of soda--at #g4ej #j4da;c4 ,the proportions of cost by using chloride of barium1 magnesia preparation1 carbonate of soda1 will be #f 3 #e 3 #d4 ,,arrangement ,,for ,,purifying ,,boiler-,,water ,,with ,,lime ,,and ,,carbonate ,,of ,,soda4 ,we need for carrying out these manipulations1 according to the size of the establishment1 one or more reservoirs for precipitating the impurities of the water1 and one pure water reservoir1 to take up the purified water2 from the latter reservoir the boilers are fed4 ,the most practical idea would be to arrange the precipitating reservoir in such manner that the purified water can flow directly into the feeding reservoir4 ,the water in the precipitating reservoir is heated either by adding boiling water or letting in steam up to #fj ,c4 at least4 ,the precipitating reservoirs 7square iron vessels or horizontal cylinders--old boilers7 of no more than #d or #d feet1 having a faucet #f inches above the bottom1 through which the purified water is drawn off1 and another one at the bottom of the vessel1 to let the precipitate off and allow of a perfect cleaning4 ,in a factory with six or seven boilers of the usual size1 making together #djj square meters heating surface1 two precipitating reservoirs1 of ten cubic meters each1 and one pure water reservoir of ten or fifteen cubic meter capacity1 are used4 ,in twenty-four hours about #bdj cubic meters of water are evaporated2 we have1 therefore1 to purify twenty-four precipitating reservoirs at ten cubic meters each day1 or ten cubic meters each hour4 ,it is profitable to surround the reservoirs with inferior conductors of heat1 to avoid losses4 ,the contents of the precipitating reservoirs have to be stirred up very well1 and for this purpose we can either arrange a mechanical stirrer or do it by hand1 or the best would be a ,korting steam stirring and blowing apparatus4 ,in using the latter we only have to open the valve1 whereby in a very short time the air driven through the water stirs this up and mixes it thoroughly with the precipitating ingredients4 ,in a factory where boilers of only #ae to #ajj square meters heating surface are1 one precipitating reservoir of two to ten cubic meters and one pure water reservoir of three to ten cubic meters capacity are required4 ,for locomobiles1 two wooden tubs or barrels are sufficient4 ,,the ,,purification ,,of ,,the ,,water4 ,after the required quantity of lime and carbonate of soda which is necessary for a total precipitation has been figured out from the analysis of the water1 respectively verified by practical experiments in the laboratory1 the heated water in the reservoir is mixed with the lime1 in form of thin milk of lime1 and stirred up2 we have to add so much lime1 that slightly reddened litmus paper gives1 after minute's contact with this mixture1 an alkaline reaction1 i4e41 turns blue2 now the solution of carbonate of soda is added and again stirred well4 ,after twenty or thirty minutes 7the hotter the water1 the quicker the precipitation7 the precipitate has settled in large flocks at the bottom1 and the clear water is drawn off into the pure water reservoir4 ,the precipitating and settling of the impurities can also take place in cold water2 it will require1 however1 a pretty long time4 ,in order to avoid the weighing and slaking of the lime1 which is necessary for each precipitation1 we use an open barrel1 in which a known quantity of slaked lime is mixed with three and a half or four times its weight of water1 and then diluted to a thin paste1 so that one kilogramme slaked lime is diluted to twenty-five liters milk of lime4 ,example4--,if we use for ten cubic meters water1 one kilogramme lime1 or in one day 7in twenty-four hours71 #bdj cubic meters #bd kg4 lime1 a vessel four or five feet high and about #gjj liters capacity1 in which daily #bd kg4 lime with about #ajj liters water are slaked and then diluted to the mark #fjj1 constantly stirring1 #be liters of this mixture contain exactly #a kg4 slaked lime4 ,before using1 this milk of lime has to be stirred up and allowed to settle for a few seconds2 and then we draw off the required quantity of milk of lime 7in our case #be liters7 through a faucet about #h inches above the bottom1 or we can dip it off with a pail4 ,for the first precipitate we always need the exact amount of milk of lime1 which we have figured out1 or rather some more1 but for the next precipitates we do not want the whole quantity1 but always less1 as that part of the lime1 which does not settle with the precipitate1 will be good for use in further precipitations4 ,it is therefore important to control the addition of milk of lime by the use of litmus paper4 ,if we do not add enough lime1 it prevents the formation of the flocky precipitate1 and1 besides1 more carbonate of soda is used4 ,by adding too much lime1 we also use more carbonate of soda in order to precipitate the excess of lime4 ,we can therefore add so much lime1 that there is only a very small excess of hydrous lime in the water1 and that after well stirring1 a red litmus paper being placed in the water for twenty seconds1 appears only slightly blue4 ,after a short time of practice1 an attentive person can always get the exact amount of lime which ought to be added4 ,on adding the milk of lime1 we have to dissolve the required amount of pure carbonate of soda in an iron kettle1 in about six or eight parts hot water with the assistance of steam2 add this to the other liquid in the precipitating reservoirs and stir up well4 ,the water will get clear after twenty-five or thirty minutes1 and is then drawn off into the pure water reservoir4 ,,examination ,,of ,,water ,,which ,,has ,,been ,,purified ,,by ,,means ,,of ,,milk ,,of ,,lime ,,and ,,carbonate ,,of ,,soda4 ,in order to be convinced that the purification of the water has been properly conducted1 we try the water in the following manner4 ,take a sample of the purified water into a small tumbler1 and add a few drops of a solution of oxalate of ammonia2 this addition must neither immediately nor after some minutes cause a milky appearance of the water1 but remain bright and clear4 ,a white precipitate would indicate that not enough carbonate of soda had been added4 ,a new sample is taken of the purified water and a solution of chloride of calcium added2 a milky appearance1 especially after heating1 would show that too much carbonate of soda had been added4 ,,results ,,of ,,this ,,water ,,purification4 #a4 ,the boilers do not need to be cleaned during a whole season1 as they remain entirely free from incrustation2 it is only required to avoid a collection of soluble salts in the boiler1 and therefore it is partly drawn off twice a week4 #b4 ,the iron is not touched by this purified water4 ,the water does not froth and does not stop up valves4 ,the fillings in the joints of pipes1 etc41 do not suffer so much1 and therefore keep longer4 #c4 ,the steam is entirely free from sour gases4 #d4 ,the production of steam is easier and better4 #e4 ,a considerable saving of fuel can soon be perceived4 #f4 ,the cost of cleaning boilers from incrustation1 and loss of time caused by cleaning1 is entirely done with4 ,old incrustations1 which could not be cleaned out before1 get decomposed and break off in soft pieces4 #g4 ,the cost of this purification is covered sufficiently by the above advantages1 and besides this1 the method is cheaper and surer than any other4 ,the chemical factory1 ,eisenbuettel1 furnishes pure carbonate of soda in single packages1 which exactly correspond with the quantity1 stated by the analysis1 of ten cubic meters of a certain water4 ,the determination of the quantities of lime and carbonate of soda necessary for a certain kind of water1 after sending in a sample1 will be done without extra charge4--,neue ,zeitung fur ,ruebenzucker ,industrie4 99 99 99 99 99 ,,eddystone ,,lighthouse4 ,the exterior work on the new ,eddystone ,lighthouse is about two thirds done4 ,in the latter part of ,april fifty-three courses of granite masonry1 rising to the height of seventy feet above high water1 had been laid1 and thirty-six courses remained to be set4 ,the old lighthouse had been already overtopped4 ,as the work advances toward completion the question arises3 ,what shall be done with ,john ,smeaton's famous tower1 which has done such admirable service for #abj years8 ,one proposition is to take it down to the level of the top of the solid portion1 and leave the rest as a perpetual memorial of the great work which ,smeaton accomplished in the face of obstacles vastly greater than those which confront the modern architect4 ,the ,london ,news says3 ,were ,smeaton's beautiful tower to be literally consigned to the waves1 we should regard the act as a national calamity1 not to say scandal2 and1 if public funds are not available for its conservation1 we trust that private zeal and munificence may be relied on to save from destruction so interesting a relic4 ,it certainly could not cost much to convey the building in sections to the mainland1 and there1 on some suitable spot1 to re-erect it as a national tribute to the genius of its great architect4 ,when the present lighthouse was built one of the chief difficulties was in getting the building materials to the spot4 ,they were conveyed from ,millbay in small sailing vessels1 which often beat about for days before they could effect a landing at the ,eddystone rocks1 so that each arrival called out the special gratitude of ,smeaton4 99 99 99 99 99 ,,rolling-,,mill ,,for ,,making ,,corrugated ,,iron4 ,,messrs4 ,,schulz1 ,,knaudt ,co41 of ,essen1 who are making an application of corrugated iron in the construction of the interior flues of steam boilers1 have devised a new mill for the manufacture of this form of iron plates1 and which is represented in the accompanying cut1 taken from the ,deutsche ,industrie ,zeitung4 ,the supports of the two accessory cylinders1 ,f ,f1 rest on two slides1 ,g ,g1 which move along the oblique guides1 ,h ,h4 ,as a consequence of this arrangement1 when the cylinders1 ,f ,f1 are caused to approach the cylinder1 ,d1 both are raised at the same instant4 ,when the cylinders1 ,f1 occupy the position represented in the engraving by unbroken lines1 the flat plate1 ,o1 is simply submitted to pressure between the cylinders1 ,d and ,p1 the cylinders1 ,f ,f1 then merely acting as guides4 ,but when1 while the plate is being thus flattened between the principal cylinders1 the accessory cylinders are caused to rise1 the plate is curved as shown by the dotted lines1 ,o' ,o'4 ,to obtain a uniformity in the position of the two cylinders1 ,f ,f1 the following mechanism is employed3 ,each cylinder has an axle1 to which is affixed a crank1 ,q1 connected by means of a rod1 ,r1 with the slide1 ,g4 ,these axles are also provided with toothed sectors1 ,l ,l1 which gear with two screws1 ,l ,l1 whose threads run in opposite directions4 ,these screws are mounted on a shaft1 ,n1 which may be revolved by any suitable arrangement4 ,illustration3 ,,rolling ,,mill ,,for ,,making ,,corrugated ,,iron 99 99 99 99 99 ,,railway ,,turn-,,table ,,in ,,the ,,time ,,of ,,louis ,,xiv4 ,the small engraving which we reproduce herewith from ,la ,nature is deposited at the ,archives at ,paris4 ,it is catalogued in the documents relating to ,old ,marly1 #agad1 under number #aa1cci1 ,vol4 #a4 ,the design represents a diversion called the ,jeu de la ,roulette which was indulged in by the royal family at the sumptuous and magnificent chateau of ,mary-le-,roi4 ,illustration3 ,,pleasure ,,car2 ,,railway ,,and ,,turn-,,table ,,of ,,the ,,time ,,of ,,louis ,,xiv4 ,according to ,alex4 ,guillaumot the apparatus consisted of a sort of railway on which the car was moved by manual labor4 ,in the car1 which was decorated with the royal colors1 are seen seated the ladies and children of the king's household1 while the king himself stands in the rear and seems to be directing operations4 ,the remarkable peculiarity to which we would direct the attention of the reader is that this document shows that the car ran on rails very nearly like those used on the railways of the present time1 and that a turn-table served for changing the direction to a right angle in order to place the car under the shelter of a small building4 ,the picture which we reproduce1 and the authenticity of which is certain1 proves then that in the time of ,louis ,,xiv4 our present railway turn-tables had been thought of and constructed--which is a historic fact worthy of being noted4 ,it is well known that the use of railways in mines is of very ancient date1 but we do not believe that there are on record any documents as precise as that of the ,jeu de la ,roulette as to the existence of turn-tables in former ages4 99 99 99 99 99 ,,new ,,signal ,,wire ,,compensator4 ,to the ,editor of the ,scientific ,american3 ,i send you a plate of my new railway signal wire compensator4 ,here in ,india signal wires give more trouble1 perhaps1 than in ,america or elsewhere1 by expansion and contraction4 ,what makes the difficulty more here is the ignorance and indolence of the point and signalmen1 who are all natives4 ,there have been numerous collisions1 owing to signals falling off by contraction4 ,many devices and systems have been tried1 but none have given the desired result4 ,you will observe the signal wire marked ,d is entirely separated and independent of the wire1 ,e1 leading to lever4 ,on the ,great ,indian and ,peninsula ,railway ,i work one of these compensators1 #a1afj yards from signal1 which stands on a summit the grade of which is #a in #aej2 and on the ,nizam ,state ,railway ,i have one working on a signal #hjj yards4 ,this signal had previously given so much trouble that it was decided to do away with it altogether4 ,it stands on top of a high cutting and on a #a1fjj foot curve4 ,illustration3 ,railway ,signal ,wire ,comensator ,i have noted on the compensator fixed at #a1afj yards1 #ac inches contraction and expansion4 ,the compensator is very simple and not at all likely to get out of order4 ,on new wire1 when ,i fix my compensator1 ,i usually have an adjusting screw on the lead to lever4 ,this ,i remove when the wire has been stretched to its full tension4 ,i have everything removed from lever1 so there can be no meddling or altering4 ,when once the wire is stretched so that no slack remains between lever and trigger1 no further adjustment is necessary4 ,a4 ,,lyle1 ,chief ,maintenance ,inspector1 ,permanent ,way1 ,h4,h4 ,nizam ,state ,railway1 ,e4 ,india4 ,secunderabad1 ,india1 #ahha4 ,,tangye',s ,,hydraulic ,,hoist4 ,illustration3 ,,tangye',s ,,hydraulic ,,hoist4 ,the great merits of hydraulic hoists generally as regards safety and readiness of control are too well known to need pointing out here4 ,we may1 therefore1 at once proceed to introduce to our readers the apparatus of this class illustrated in the above engravings4 ,this is a hoist 7,cherry's patent7 manufactured by ,messrs4 ,tangye ,brothers1 of ,london and ,birmingham1 and which experience has proved to be a most useful adjunct in warehouses1 railway stations1 hotels1 and the like4 ,fig4 #a of our engraving shows a perspective view of the hoist1 ,fig4 #b being a longitudinal section4 ,it will be seen that this apparatus is of very simple construction1 the motion of the piston being transmitted directly to the winding-drum shaft by means of a flexible steel rack4 ,referring to ,fig4 #b1 ,f is a piston working in the cylinder1 ,g2 ,e is the flexible steel rack connected to the piston1 ,f1 and gearing with a toothed wheel1 ,b1 which is inclosed in a watertight casing having cover1 ,d1 for convenient access4 ,the wheel1 ,b1 is keyed on a steel shaft1 ,c1 which passes through stuffing-boxes in the casing1 and has the winding barrel1 ,a1 keyed on it outside the casing4 ,h is a rectangular tube1 which guides the free end of the flexible steel rack1 ,e4 ,the hoist is fitted with a stopping and starting valve1 by means of which water under pressure from any convenient source of supply may be admitted or exhausted from the cylinder4 ,the action in lifting is as follows3 ,the water pressure forces the piston toward the end of the cylinder4 ,the piston1 by means of the flexible steel rack1 causes the toothed wheel to revolve4 ,the winding barrel1 being keyed on the same shaft as the toothed wheel1 also revolves1 and winds up the weight by means of the lifting chain4 ,two special advantages are obtained by this simple method of construction4 ,in the first place1 twice the length of stroke can be obtained in the same space as compared with the older types of hydraulic hoist2 and1 from the directness of the action1 the friction is reduced to a minimum4 ,this simple method of construction renders the hoist very compact and easily fixed2 and1 from the directness with which the power is conveyed from the piston to the winding drum1 and the frictionless nature of the mechanism1 a smaller piston suffices than in the ordinary hydraulic hoists1 and a smaller quantity of water is required to work them4--,iron4 99 99 99 99 99 ,,power ,,loom ,,for ,,delicate ,,fabrics4 ,the force with which the shuttle is thrown in an ordinary power loom moving with a certain speed is always considerable1 and1 as a consequence of the strain exerted on the thread1 it is frequently necessary to use a woof stronger than is desirable1 in order that it may have sufficient resistance4 ,on another hand1 when the woof must be very fine and delicate the fabric is often advantageously woven on a hand loom4 ,in order to facilitate the manufacture of like tissues on the power loom the celebrated ,swiss manufacturer1 ,hanneger1 has invented an apparatus in which the shuttle is not thrown1 but passed from one side to the other by means of hooks1 by a process analogous to weaving silk by hand4 ,a loom built on this principle was shown at work weaving silk at the ,paris ,exhibition of #ahgh4 ,this apparatus1 represented in the annexed figure1 contains some arrangements which are new and interesting4 ,on each side of the woof in the heddle there is a carrier1 ,b4 ,these carriers are provided with hooks1 ,a ,a'1 having appendages1 a a'1 which are fitted in the shuttle1 ,o4 ,the latter is of peculiar construction4 ,the upper ends of the hooks have fingers1 d d'1 which holds the shuttle in position as long as the action of the springs1 e e'1 continues4 ,the distance that the shuttle has to travel includes the breadth of the heddle1 the length of the shuttle1 and about four inches in addition4 ,the motion of the two carriers1 which approach each other and recede simultaneously1 is effected by the levers1 ,c1 ,d1 ,e1 and ,c'1 ,d'1 ,e'4 ,the levers1 ,e1 ,e'1 are actuated by a piece1 ,f1 which receives its motion from the main shaft1 ,h1 through the intervention of a crank and a connecting rod1 ,g1 and makes a little more than a quarter revolution4 ,the levers1 ,e1 ,e'1 are articulated in such a way that the motion transmitted by them is slackened toward the outer end and quickened toward the middle of the loom4 ,while the carriers1 ,b ,b'1 are receiving their alternate backward and forward motion1 the shaft1 ,i 7which revolves only half as fast as the main shaft71 causes a lever1 ,f ,f'1 to swing1 through the aid of a crank1 ,j1 and rod1 ,k4 ,upon the two carriers1 ,b ,b'1 are firmly attached two hooks1 ,m ,m'1 which move with them4 ,when the hook1 ,m1 approaches the extremity of the lever1 ,f1 the latter raises it1 pushes against the spring1 ,e1 and sets free the shuttle1 which1 at the same moment1 meets the opposite hook1 a'1 and1 being caught by it1 is carried over to the other side4 ,the same thing happens when the carrier1 ,b'1 is on its return travel1 and the hook1 ,m'1 mounts the lever1 ,f'1 which is then raised4 ,illustration3 ,,power ,,loom ,,for ,,delicate ,,fabrics4 ,as will be seen from this description1 the woof does not undergo the least strain1 and may be drawn very gently from the shuttle4 ,neither does this latter exert any friction on the chain1 since it does not move on it as in ordinary looms4 ,in this apparatus1 therefore1 there may be employed for the chain very delicate threads1 which1 in other looms1 would be injured by the shuttle passing over them4 ,looms constructed on this plan have for some time been in very successful use in ,switzerland4 99 99 99 99 99 ,,how ,,veneering ,,is ,,made4 ,the process of manufacture is very interesting4 ,the logs are delivered in the mill yard in any suitable lengths as for ordinary lumber4 ,a steam drag saw cuts them into such lengths as may be required by the order in hand2 those being cut at the time of our visit were four feet long4 ,after cutting1 the logs are placed in a large steam box1 #ae feet wide1 #bb feet long1 and six feet high1 built separate from the main building4 ,this box is divided into two compartments4 ,when one is filled entirely full1 the doors are closed1 and the steam1 supplied by the engine in the main building1 is turned on4 ,the logs remain in this box from three to four hours1 when they are ready for use4 ,this steaming not only removes the bark1 but moistens and softens the entire log4 ,from the steam box the log goes to the veneer lathe4 ,it is here raised1 grasped at each end by the lathe centers1 and firmly held in position1 beginning to slowly revolve4 ,every turn brings it in contact with the knife1 which is gauged to a required thickness4 ,as the log revolves the inequalities of its surface of course first come in contact with the keen-edged knife1 and disappear in the shape of waste veneer1 which is passed to the engine room to be used as fuel4 ,soon1 however1 the unevenness of the log disappears1 and the now perfect veneer comes from beneath the knife in a continuous sheet1 and is received and passed on to the cutting table4 ,this continues until the log is reduced to about a seven inch core1 which is useless for the purpose4 ,the veneer as it comes rolling off the log presents all the diversity of colors and the beautiful grain and rich marking that have perhaps for centuries been growing to perfection in the silent depths of our great forests4 ,from the lathe1 the veneer is passed to the cutting table1 where it is cut to lengths and widths as desired4 ,it is then conveyed to the second story1 where it is placed in large dry rooms1 air tight1 except as the air reaches them through the proper channels4 ,the veneer is here placed in crates1 each piece separate and standing on edge4 ,the hot air is then turned on4 ,this comes from the sheet iron furnace attached to the boiler in the engine room below1 and is conveyed through large pipes regulated by dampers for putting on or taking off the heat4 ,there is also a blower attached which keeps the hot air in the dry rooms in constant motion1 the air as it cools passing off through an escape pipe in the roof1 while the freshly heated air takes its place from below4 ,these rooms are also provided with a net-work of hot air pipes near the floor4 ,the temperature is kept at about #afe1 and so rapid is the drying process that in the short space of four hours the green log from the steam box is shaved1 cut1 dried1 packed1 and ready for shipment4 ,after leaving the dry rooms it is assorted1 counted1 and put up in packages of one hundred each1 and tied with cords like lath1 when it is ready for shipment4 ,bird's-eye maple veneer is much more valuable and requires more care than almost any other1 and this is packed in cases instead of tied in bundles4 ,the drying process is usually a slow one1 and conducted in open sheds simply exposed to the air4 ,mr4 ,densmore's invention will revolutionize this process1 and already gives his mill a most decided advantage4 ,the mill will cut about #cj1jjj feet of veneer in a day1 and this cut can be increased to #dj1jjj if necessary4 ,mr4 ,densmore has already received several large orders1 and the rapidly increasing demand for this material is likely to give the mill all the work it can do4 ,the timber used is principally curled and bird's-eye maple1 beech1 birch1 cherry1 ash1 and oak4 ,these all grow in abundance in this vicinity1 and the beautifully marked and grained timber of our forests will find fitting places in the ornamental uses these veneers will be put to4 99 99 99 99 99 ,,the ,,constituent ,,parts ,,of ,,leather4 ,the constituent parts of leather seem to be but little understood4 ,the opinions of those engaged in the manufacture of leather differ widely on this question4 ,some think that tannin assimilates itself with the hide and becomes fixed there by reason of a special affinity4 ,others regard the hide as a chemical combination of gelatine and tannin4 ,we know that the hide contains some matters which are not ineradicable1 but only need a slight washing to detach them4 ,we deem it advisable1 in order to examine the hide properly so-called1 to dispense with those eradicable substances which may be regarded1 to some extent1 as not germain to it1 and confine our attention to the raw stock1 freed from these imperfections4 ,it is well known that a large number of vegetable substances are employed as tanning agents4 ,our researches have been directed to leather tanned by means of the most important of these agents4 ,many questions present themselves in the course of such an examination4 ,among others1 that most important one1 from a practical point of view1 of the weight the tanning agent gives to the hide1 that is to say1 the result in leather of weight given to the raw material4 ,the degree of tannage is also to be considered2 the length of time during which the tanning agent is to be left with the hide2 in short1 the influence upon the leather of the substances used in its production4 ,that is why we have made the completest possible analysis of different leathers4 ,besides ordinary oak bark there are used at present very different substances1 such as laurel1 chestnut1 hemlock1 quebracho and pine bark1 sumac1 etc4 ,water is an element that exists in all hides1 and it is necessary to take it into consideration in the analysis4 ,it is present in perceptible quantity even in dry hides4 ,this water cannot be entirely eradicated without injuring the leather1 which will lose in suppleness and appearance4 ,water should then be considered as one of the elements of leather1 but it must be understood that if it exceeds certain limits1 say #ab to #ad per cent41 it becomes useless and even injurious4 ,moreover1 if there is any excess over the normal quantity1 it becomes deceptive and dishonest1 as in such a case one sells for hides that which is nothing but water4 ,supposing that a hide1 instead of only #ad per cent41 contained #ah per cent4 of water1 it is evident that in buying #ajj pounds of such a hide one would pay for four pounds of water at the rate for which he purchased the hide4 ,there are1 also1 some matters soluble in air1 which are formed to a large extent from fat arising as much from the hide as from tanning substances4 ,the air dissolves at the same time a certain amount of organic acid and resinous products which the hide has absorbed4 ,after treating with air1 alcohol is used1 which dissolves principally the coloring matters1 tannin which has not become assimilated1 bodies analogous to resin1 and some extractive substances4 ,that which remains after these methods have been pursued ought to be regarded as the hide proper1 that is to say1 as the animal tissue saturated with tannic acid4 ,in this remainder one is able to estimate with close precision that which belongs to the hide4 ,the hide being an elementary tissue of unchangeable form1 it is easy1 in determining the elementary portion1 to find the amount of real hide remaining in the product4 ,with these elements one can arrive at a solution of some of the questions we are discussing4 ,we give below1 according to this method1 a table showing the composition of the different leathers exhibited at the ,paris ,exposition of #ahgh4 ,they are the results of careful research1 and we have based our work upon them3 ,matter ,soluble ,fixed in ,air ,tannin ,matter ,solu- ble in ,alcohol ,moisture ,gelatine ---- ---- ---- ---- ---- ,steer hide1 hemlock tanned 7heavy leather7 #aj4ie #d4ae #ai4gg #ci4a #bf4jc ,sheepskins1 sumac 7,hungarian7 #aj4h #aj4c #ab4a #dj4c #bf4e ,finished calf1 pine bark tanned 7,hungarian7 #aa4b #a4g #g4d #da4f #ch4a ,steer hide1 quebracho tanned 7heavy leather7 #aa4g #a4f #aa4b #dc4a #cb4d chestnut #ac4e #j4bi #a4ii #de4df #ch4gf ,finished calfskins1 oak tanned 7,chateau ,renault7 #ab4d #j4cc #c4ei #df4gd #cf4id ,steer hide1 laurel tanned 7heavy leather7 #ab4d #a4je #g4ie #dg4dg #ca4ac oak tanned after three years in the vats 7heavy leather7 #aa4de #j4cg #c4ca #di4he #ce4jb ,the following table shows the amount of leather produced by different tannages of #ajj pounds of hides3 ,pounds4 ,hemlock #bee4g ,sumac #bdh4a ,pine #bdj4c ,quebracho #bcb ,chestnut #bai4i ,oak #bac4i ,laurel #baj4f ,oak1 lasting three years #bjf ,it is important to mention here the large proportion of resinous matter hemlock-tanned leather contains4 ,this resin is a very beautiful red substance1 which communicates its peculiar color to the leather4 ,we should mention here that in these calculations we assume that the hide is in a perfectly dry state1 water being a changeable element which does not allow one to arrive at a precise result4 ,these figures show the enormous differences resulting from diverse methods of tanning4 ,hemlock1 which threatens to flood the markets of ,europe1 distinguishes itself above all4 ,the high results attributable to the large proportion of resin that the hide assimilates1 explain in part the lowness of its price1 which renders it so formidable a competitor4 ,one is also surprised at the large return from sumac-tanned hides when it is remembered in how short a time the tanning was accomplished1 which1 in the present case1 only occupied half an hour4 ,the figures show us that the greatest return is obtained by means of those tanning substances which are richest in resin4 ,in short1 hemlock1 sumac1 and pine1 which give the greatest return1 are those containing the largest amount of resin4 ,thus1 hemlock bark gives #aj4eh per cent4 of it1 and sumac leaves #bb4g per cent41 besides the tannin which they contain4 ,we know also that pine bark is very rich in resin4 ,there is1 then1 advantage to the tanner1 so far as the question of result is concerned1 in using these materials4 ,there is1 however1 another side to the question1 as the leather thus surcharged with resin is of inferior quality1 generally has a lower commercial value1 and is often of a color but little esteemed4 ,the percentage of tannin absorbed by the different methods of tannages appears in the following table3 ,hemlock #fd4b ,sumac #fa4d ,pine #ij4h ,quebracho #ge4c ,chestnut #he4b ,oak #gf4i ,laurel #fd4h ,oak1 three years in the vat #gj4b ,the subjoined is a statement of the gelatine and tannin in leather of different tannages1 and also shows the amount of azote or elementary matter contained in each3 ,gelatine4 ,tannin4 ,azote4 ,hemlock #fj4d #ci4f #aj4hh ,sumac #fj4d #ci4f #aa ,pine bark #eb4e #dg4e #i4ef ,quebracho #eg4a #db4i #aj4d ,chestnut #ec4ig #df4jc #i4gi ,oak #ee4hg #dd4ac #aj4bd ,laurel #fj4d #ci4f #aj4id ,oak1 #c years in vat #eh4ge #da4be #aj4fe ,it is not pretended that these figures are absolutely correct1 as they often vary in certain limits even for similar products4 ,they form1 however1 a fair basis of calculation4 ,as to whether leather is a veritable combination1 it seems to us that this question should be answered affirmatively4 ,in fact1 the resistance of leather properly so-called to neutral dissolvents1 argues in favor of this opinion4 ,furthermore1 the perceptible proportion of tannin remaining absorbed by a like amount of hide is another powerful argument4 ,it remains for us to say here that the differences observable in the quantity of fixed tannin ought to arise chiefly from the different natures of these tannins1 which have properties differing as do those of one plant from another1 and which really have but one property in common1 that of assimilating themselves with animal tissues and rendering them imputrescible4 ,in conclusion1 these researches determine the functions of resinous matters which frequently accompany tannin2 they show a very simple method for estimating the results of one's work1 as well as the degree of tannage4--,muntz ,schoen1 in ,la ,halle aux ,cuirs4--,shoe ,leather ,reporter4 99 99 99 99 99 ,,new ,,high ,,school ,,for ,,girls1 ,,oxford4 ,the new ,high ,school for ,girls at ,oxford1 built by ,mr4 ,t4,g4 ,jackson1 for the ,girls' ,public ,day ,school ,company1 ,limited1 was opened ,september #bc1 #ahhj1 when the school was transferred from the temporary premises it had occupied in ,st4 ,giles's4 ,the new building stands in ,st4 ,giles's road1 ,east1 to the north of ,oxford1 on land leased from ,university ,college1 and contains accommodation for about #bgj pupils in #aa class-rooms1 some of which communicate by sliding doors1 besides a residence for the mistress1 an office and waiting-room1 a room for the teachers1 cloak rooms1 kitchens1 and other necessary offices1 and a large hall1 #ej ft4 by #cj ft41 for the general assembling of the school together and for use on speech-days and other public occasions4 ,the principal front faces ,st4 ,giles's road1 and is shown in the accompanying illustration4 ,the great hall occupies the whole of the upper story of the front building1 with the office and cloak-rooms below it1 and the principal entrance in the center4 ,the class-rooms are all placed in the rear of the building1 to secure quiet1 and open on each floor into a corridor surrounding the main staircase which occupies the center of the building4 ,the walls are built of ,headington stone in rubble work1 with dressings of brick1 between which the walling is plastered1 and the front is enriched with cornices and pilasters1 and a hood over the entrance door1 all of terra cotta4 ,the hinder part of the building is kept studiously simple and plain on account of expense4 ,behind the school is a large playground1 which is provided with an asphalt tennis-court1 and is picturesquely shaded with apple-trees1 the survivors of an old orchard4 ,the builders were ,messrs4 ,symm ,co41 of ,oxford2 and the terra cotta was made by ,messrs4 ,doulton1 of ,lambeth4 ,mr4 ,e4 ,long was clerk of works4--,building ,news4 ,illustration3 ,,suggestions ,,in ,,architecture--,,new ,,high ,,school1 ,,oxford 99 99 99 99 99 ,,progress ,,in ,,american ,,pottery4 ,no advance in any industry has been more sure than in that of pottery and chinaware1 under the ,american tariff1 or more rapid in the past four or five years4 ,it took ,europe three centuries and the jealous precautions of royal pottery proprietors to build up the great protectorates that made their distinctive trade-marks of such value4 ,the earlier lusters of the ,italian faience were guild privacies or individual secrets1 as was almost all the craft of the earlier art-worker4 ,royal patronage in ,england was equivalent to a protective tariff for ,josiah ,wedgwood2 and everywhere the importance of guarding the china nurseries has been understood4 ,we have in this country broadcast and in abundance every type of material needed for the finest china ware1 and for the finer glasses and enamels4 ,the royal manufactories in ,europe were hard put to it sometimes for want of discovering kaolin beds in their dominions1 but the resources of the ,united ,states in these particulars needed something more than to be brought to light4 ,the manipulation and washing of the clays to render them immediately useful to the potteries depends entirely upon the reliance of these establishments upon home materials4 ,the ,missouri potteries have their supplies near home1 but these supplies must be put upon the market for other cities in condition to compete with the clays of ,europe4 ,there are fine kaolin beds in ,chester and ,delaware counties in this ,state2 there are clay beds in ,new ,jersey1 and the recent needs of ,ohio potteries have uncovered fine clay in that ,state4 ,this shows that not only for the manufacture itself1 but for the development of material here1 everything depends upon the stimulus that protection gives4 ,ohio china and ,cincinnati pottery are known all over the country4 ,the ,chelsea ,works1 near ,boston1 however1 are as distinguished for their clays and faience1 and for lustrous tiles especially 7to be used in household decoration7 can rival the rich show that the ,doulton ware made at the ,centennial4 ,other ,new ,england potteries are eminent for terra cotta and granite wares4 ,on ,long ,island and in ,new ,york city there are porcelain and terra cotta factories of established fame1 and the first porcelain work to succeed in home markets was made at the still busy factories of ,greenpoint4 ,new ,jersey potteries take the broad ground of the useful1 first of all1 in their manufacture of excellent granite and cream-colored ware for domestic use1 but every year turn out more beautiful forms and more artistic work4 ,the ,etruria ,company especially have succeeded in giving the warm flesh tints to the ,parian for busts and statuettes1 now to be seen in many shop windows4 ,these goods ought always to be labeled and known as ,american--it adds to their value with any true connoisseur4 ,some of these establishments1 more than others1 have the enterprise to experiment in native clays1 for which the whole trade owes their acknowledgments4 ,the demand all through the country by skillful decorators for the pottery forms to work upon1 points to still greater extensions in this business of making our own china1 and to the employment and good pay of more thousands than are now employed in it4 ,a collection of ,american china1 terra cotta1 etc41 begun at this time and added to from year to year1 will soon be a most interesting cabinet4 ,both in the eastern and western manufactories ingenious workers are rediscovering and experimenting in pastes and glazes and colors1 simply because there is a large demand for all such1 and they can be supplied at prices within the reach of most buyers4 ,it needs only to point out this flourishing state of things1 through the let-alone principle1 which protection insures to this industry1 to exhibit the threatened damage of the attempt1 under cover of earthenware duties1 to get a little free trade through at this session4--,philadelphia ,public ,ledger4 99 99 99 99 99 ,,photographic ,,notes4 ,mr4 ,warnerke's ,new ,discovery4--,very happily for our art1 we are at the present moment entering upon a stage of improvement which shows that photography is advancing with vast strides toward a position that has the possibility of a marvelous future4 ,in ,england1 especially1 great advances are being made4 ,the recent experiments of our accomplished colleague1 ,mr4 ,warnerke1 on gelatine rendered insoluble by light1 after it has been sensitized by silver bromide and developed by pyrogallic acid1 have revealed to us a number of new facts whose valuable results it is impossible at present to foretell4 ,it seems1 however1 certain that we shall thus be able to accomplish very nearly the same effects as those obtained by bichromatized gelatine1 but with the additional advantage of a much greater rapidity in all the operations4 ,in my own experiments with the new process of phototypie1 ,i hit upon the plan of plunging the carbon image1 from which all soluble gelatine had been removed1 into a bath of pyrogallic acid1 in order to still further render impermeable the substance forming the printing surface4 ,i also conceived the idea of afterward saturating this carbon image with a solution of nitrate of silver1 and of subsequently treating it with pyrogallic acid1 in order to still further render impermeable the substance forming the printing surface4 ,but the process described by ,mr4 ,warnerke is quite different2 by means of it we shall be able to fix the image taken in the camera1 in the same way as we develop carbon pictures1 and afterward to employ them in any manner that may be desirable4 ,thus the positive process of carbon printing would be modified in such a manner that the mixtures containing the permanent pigment should be sensitized with silver bromide in place of potassium bichromate4 ,in this way impressions could be very rapidly taken of positive proofs1 and enlargements made1 which might be developed in hot water1 just as in the ordinary carbon process1 and at least we should have permanent images4 ,mr4 ,warnerke's highly interesting experiments will no doubt open the way to many valuable applications1 and will realize a marked progress in the art of photography4 ,method for ,converting ,negatives ,directly into ,positives4--,captain ,bing1 who is employed in the topographic studios of the ,ministry of ,war1 has devised a process for the direct conversion of negatives into positives4 ,the idea is not a new one2 but several experimenters1 and notably the late ,thomas ,sutton1 have pointed out the means of effecting this conversion2 it has never1 however1 so far as ,i know1 been introduced into actual practice1 as is now the case4 ,the process which ,i am about to describe is now worked in the studios of the ,topographic ,service4 ,the negative image is developed in the ordinary way1 but the development is carried much further than if it were to be used as an ordinary negative4 ,after developing and thoroughly washing1 the negative is placed on a black cloth with the collodion side downward1 and exposed to diffuse light for a time1 which varies from a few seconds to two or three minutes1 according to the intensity of the plate4 ,afterward the conversion is effected by moistening the plate afresh1 and then plunging it into a bath which is thus composed3 ,water #gjj cub4 cents4 ,potassium bichromate #cj grams4 ,pure nitric acid #cjj cub4 cents4 ,in a few minutes this solution will dissolve all the reduced silver forming the negative2 the negative image is therefore entirely destroyed2 but it has served to impress on the sensitive film beneath it a positive image1 which is still in a latent condition4 ,it must1 therefore1 be developed1 and to do this1 the film is treated with a solution of-- ,water #a1jjj grams ,pyrogallic acid #be ,citric acid #bj ,alcohol of #cf #ej cub4 cents4 ,the process is carried on exactly as if developing an ordinary negative2 but the action of the developer is stopped at the precise moment when the positive has acquired intensity sufficient for the purpose for which it is to be used4 ,fixing1 varnishing1 etc41 are then carried on the usual way4 ,the great advantage of this process consists in the fact of its rendering positives of much greater delicacy than those that are taken by contact2 and1 on the other hand1 by means of it we are able to avoid two distinct operations1 when for certain kinds of work we require positive plates where a negative would be of no service4 ,m4 ,v4 ,rau1 the assistant who has carried out this process under the direction of ,captain ,bing1 has described it in a work which has just been published by ,m4 ,gauthier-,villars4 ,experiments of ,captain ,bing on the ,sensitiveness of ,coal ,oil4--,the same ,captain of ,engineers has undertaken a series of very interesting experiments on the sensitiveness to light of one or two substances to which bitumen probably owes its sensitiveness1 but which1 contrary to what takes place with bitumen1 are capable of rendering very beautiful half tones1 both on polished zinc and on albumenized paper4 ,these sensitive substances are extracted by dissolving marine glue or coal-tar in benzine4 ,by exposure to light1 both marine-glue and coal-tar turn of a sepia color1 and1 in a printing-frame1 they render a visible image1 which is not the case with bitumen2 their solvents are in the order of their energy2 chloroform1 ether1 benzine1 turpentine1 petroleum spirit1 and alcohol4 ,of these solvents1 benzine is the best adapted for reducing the substances to a fluid state1 so as to enable them to flow over the zinc4 ,the images obtained1 which are permanent1 and which are very much like those of the ,daguerreotype1 are fixed by means of the turpentine and petroleum spirit4 ,they are washed with water1 and then carefully dried4 ,it is possible to obtain prints with half-tones in fatty ink by means of plates of zinc coated with marine-glue4 ,some attempts in this direction were shown to me1 which promised very well in this respect4 ,we are1 therefore1 in the right road1 not only for economically producing permanent prints on paper1 but also for making zinc plates in which the phototype film of bichromatized gelatine is replaced by a solution of marine-glue and benzine4 ,the substance known in commerce under the name of pitch or coal-tar will produce the same results4 ,bitumen ,plates4--,a new method of making bitumen plates by contact has also been introduced into the topographical studios4 ,the plan1 or the original drawing1 is placed against a glass plate1 coated with a mixture of bitumen and of marine-glue dissolved in benzine4 ,the marine-glue gives the bitumen greater pliancy1 and prevents it from scaling off when rubbed1 particularly when the plate is retouched with a dry point4 ,these bitumen plates are so thoroughly opaque to the penetration of the actinic rays1 that the printing-frame may be left for any time in full sunlight without any fear of fog being produced on the zinc plate from which the prints are to be taken4 ,method for ,topographic ,engraving by ,commandant de la ,no4--,before leaving the interesting studios of which ,i have been speaking1 ,i ought to mention a very ingenious application which has been made of a process called topogravure1 invented by ,commandant de la ,no1 who is the director of this important department4 ,a plate of polished zinc is coated with bitumen in the usual way1 and then exposed directly to the light under an original drawing1 or even under a printed plan4 ,so soon as the light has sufficiently acted1 which may be seen by means of photometric bands equally transparent at the plate1 all the bitumen not acted upon is dissolved4 ,as it is a positive which has acted as matrix1 the uncovered zinc indicates the design1 and the ground remains coated with insoluble bitumen4 ,the plate is then etched with a weak solution of nitric acid in water1 and the lines of the design are thus slightly engraved2 the surface is then re-coated with another layer of bitumen1 which fills up all the hollows1 and is then rubbed down with charcoal4 ,all the surface is thus cleaned off1 and the only bitumen which remains is that in the lines1 which1 though not deep1 are sufficiently so to protect the substance from the rubbing of the charcoal4 ,when this is done we have an engraved plate which can be printed from1 like a lithographic stone2 it is gummed and wetted in the usual way1 and it gives prints of much greater delicacy and purity than those taken directly from the bitumen4 ,the ink is retained by the slight projection of the surface beyond the line1 so that it cannot spread1 and a kind of copper plate engraving is taken by lithographic printing4 ,besides1 in arriving at this result1 there is the advantage of being able to use directly the original plans and drawings1 without being obliged to have recourse to a plate taken in the camera2 the latter is indispensable for printing in the usual way on bitumen where the impression on the sensitive film is obtained by means of a negative4 ,it will be seen that this process is exceedingly ingenious1 and not only is its application very easy1 but all its details are essentially practical4 ,succinate of ,iron ,developer4--,i have received a letter from ,m4 ,borlinetto1 in which he states that he has been induced by the analogy which exists between oxalic and succinic acids to try whether succinate of iron can be substituted for oxalate of iron as a developer4 ,to prove this he prepared some proto-succinate of iron from the succinate of potassium and proto-sulphate of iron1 following the method given by ,dr4 ,eder for the preparation of his ferrous oxalate developer4 ,he carried out the development in the same way as is done by the oxalate1 and he found that the succinate of iron is even more energetic than the oxalate4 ,the plate develops regularly with much delicacy1 and gives a peculiar tone4 ,it is necessary to take some fresh solution at every operation1 on account of the proto-succinate of iron being rapidly converted into per-succinate by contact with the air4 ,method of ,making ,friable ,hydro-,cellulose4--,at the meeting of the ,photographic ,society of ,france1 ,m4 ,girard showed his method of preparing cellulose in a state of powder1 specially adapted for the production of pyroxyline for making collodion4 ,carded cotton-wool is placed in water1 acidulated with #c per cent4 of sulphuric or nitric acid1 and is left there from five to fifteen seconds2 it is then taken out and laid on a linen cloth1 which is then wrung so as to extract most of the liquid4 ,in this condition there still remains from #cj to #dj per cent4 of acidulated water2 the cotton is divided into parcels and allowed to dry in the open air until it feels dry to the touch1 though in this condition it still contains #bj per cent4 of water4 ,it is next inclosed in a covered jar1 which is heated to a temperature of #fe ,c42 the desiccation therefore takes place in the closed space1 and the conversion of the material is completed in about two or three hours4 ,in this way a very perfect hydro-cellulose is obtained1 and in the best form for producing excellent pyroxyline4--,corresp4 ,photo ,mews4 99 99 99 99 99 ,,photo ,,tracings ,,in ,,black ,,and ,,color4 ,two new processes for taking photo tracings in black and color have recently been published--,nigrography and ,anthrakotype--both of which represent a real advance in photographic art4 ,by these two processes we are enabled for the first time to accomplish the rapid production of positive copies in black of plans and other line drawings4 ,each of these new methods has its own sphere of action2 both1 therefore1 should deserve equally descriptive notices4 ,for large plans1 drawn with lines of even breadth1 and showing no gradated lines1 or such as shade into gray1 the process styled nigrography1 invented by ,itterbeim1 of ,vienna1 and patented both in ,germany and ,austria1 will be found best adapted4 ,the base of this process is a solution of gum1 with which large sheets of paper can be more readily coated than with one of gelatine2 it is1 therefore1 very suitable for the preparation of tracings of the largest size4 ,the paper used must be the best drawing paper1 thoroughly sized1 and on this the solution1 consisting of #be parts of gum arabic dissolved in #ajj parts of water1 to which are added #g parts of potassium bichromate and ,i part of alcohol1 is spread with a broad1 flat brush4 ,it is then dried1 and if placed in a cool1 dark place will keep good for a long time4 ,when used1 it is placed under the plan to be reproduced1 and exposed to diffused light for from five to ten minutes--that is to say1 to about #ad of ,vogel's photometer2 it is then removed and placed for twenty minutes in cold water1 in order to wash out all the chromated gum which has not been affected by light4 ,by pressing between two sheets of blotting-paper the water is then got rid of1 and if the exposure has been correctly judged the drawing will appear as dull lines on a shiny ground4 ,after the paper has been completely dried it is ready for the black color4 ,this consists of #e parts of shellac1 #ajj parts of alcohol1 and #ae parts of finely-powdered vine-black4 ,a sponge is used to distribute the color over the paper1 and the latter is then laid in a #b to #c per cent4 bath of sulphuric acid1 where it must remain until the black color can be easily removed by means of a stiff brush4 ,all the lines of the drawing will then appear in black on a white ground4 ,these nigrographic tracings are very fine1 but they only appear in complete perfection when the original drawings are perfectly opaque4 ,half-tone lines1 or the marks of a red pencil on the original1 are not reproduced in the nigrographic copy4 ,anthrakotype is a kind of dusting-on process4 ,it was invented by ,dr4 ,sobacchi1 in the year #ahgi1 and has been lately more fully described by ,captain ,pizzighelli4 ,this process--called also ,photanthrakography--is founded on the property of chromated gelatine which has not been acted on by light to swell up in lukewarm water1 and to become tacky1 so that in this condition it can retain powdered color which had been dusted on it4 ,wherever1 however1 the chromated gelatine has been acted on by light1 the surface becomes horny1 undergoes no change in warm water1 and loses all sign of tackiness4 ,in this process absolute opacity in the lines of the original drawing is by no means necessary1 for it reproduces gray1 half-tone lines just as well as it does black ones4 ,pencil drawings can also be copied1 and in this lies one great advantage of the process over other photo-tracing methods1 for1 to a certain extent1 even half-tones can be produced4 ,for the paper for anthrakotype an ordinary strong1 well-sized paper must be selected4 ,this must be coated with a gelatine solution 7gelatine #a1 water #cj parts71 either by floating the paper on the solution1 or by flowing the solution over the paper4 ,in the latter case the paper is softened by soaking in water1 is then pressed on to a glass plate placed in a horizontal position1 the edges are turned up1 and the gelatine solution is poured into the trough thus formed4 ,to sensitize the paper1 it is dipped for a couple of minutes in a solution of potassium bichromate 7#a in #be71 then taken out and dried in the dark4 ,the paper is now placed beneath the drawing in a copying-frame1 and exposed for several minutes to the light2 it is afterward laid in cold water in order to remove all excess of chromate4 ,a copy of the original drawing now exists in relief on the swollen gelatine1 and1 in order to make this relief sticky1 the paper is next dipped for a short time in water1 at a temperature of about #bh or #cj ,c4 ,it is then laid on a smooth glass plate1 superficially dried by means of blotting-paper1 and lamp-black or soot evenly dusted on over the whole surface by means of a fine sieve4 ,although lamp-black is so inexpensive and so easily obtained1 as material it answers the present purpose better than any other black coloring substance4 ,if now the color be evenly distributed with a broad brush1 the whole surface of the paper will appear to be thoroughly black4 ,in order to fix the color on the tacky parts of the gelatine1 the paper must next be dried by artificial heat--say1 by placing it near a stove--and this has the advantage of still further increasing the stickiness of the gelatine in the parts which have not been acted upon by light1 so that the coloring matter adheres even more firmly to the gelatine4 ,when the paper is thoroughly dry1 place it in water1 and let it be played on by a strong jet2 this removes all the color from the parts which have been exposed to the light1 and so develops the picture4 ,by a little gentle friction with a wet sponge1 the development will be materially promoted4 ,a highly interesting peculiarity of this anthrakotype process is the fact that a copy1 though it may have been incorrectly exposed1 can still be saved4 ,for instance1 if the image does not seem to be vigorous enough1 it can be intensified in the simplest way2 it is only necessary to soak the paper afresh1 then dust on more color1 etc42 in short1 repeat the developing process as above described4 ,in difficult cases the dusting-on may be repeated five or six times1 till at last the desired intensity is obtained4 ,by this process1 therefore1 we get a positive copy of a positive original in black lines on a white ground4 ,of course1 any other coloring material in a state of powder may be used instead of soot1 and then a colored drawing on a white ground is obtained4 ,very pretty variations of the process may be made by using gold or silver paper1 and dusting-on with different colors2 or a picture may be taken in gold bronze powder on a white ground4 ,in this way colored drawings may be taken on a gold or a silver ground1 and very bright photo tracings will be the result4 ,some examples of this kind1 that have been sent us from ,vienna1 are exceedingly beautiful4 ,summing up the respective advantages of the two processes we have above described1 we may say that nigrography is best adapted for copying drawings of a large size2 the copies can with difficulty be distinguished from good autographs1 and they do not possess the bad quality of gelatine papers--the tendency to roll up and crack4 ,drawings1 however1 which have shadow or gradated lines cannot be well produced by this process2 in such cases it is better to adopt anthrakotype1 with which good results will be obtained4--,photographic ,news4 99 99 99 99 99 ,,on ,m4 ,c4 ,,faure',s ,,secondary ,,battery4 ,the researches of ,m4 ,gaston ,plant on the polarization of voltameters led to his invention of the secondary cell1 composed of two strips of lead immersed in acidulated water4 ,these cells accumulate1 and1 so to speak1 store up the electricity passed into them from some outside generator4 ,when the two electrodes are connected with any source of electricity the surfaces of the two strips of lead undergo certain modifications4 ,thus1 the positive pole retains oxygen and becomes covered with a thin coating of peroxide of lead1 while the negative pole becomes reduced to a clean metallic state4 ,now1 if the secondary cell is separated from the primary one1 we have a veritable voltaic battery1 for the symmetry of the poles is upset1 and one is ready to give up oxygen and the other eager to receive it4 ,when the poles are connected1 an intense electric current is obtained1 but it is of short duration4 ,such a cell1 having half a square meter of surface1 can store up enough electricity to keep a platinum wire #a millim4 in diameter and #h centims4 long1 red-hot for ten minutes4 ,m4 ,plant has succeeded in increasing the duration of the current by alternately charging and discharging the cell1 so as alternately to form layers of reduced metal and peroxide of lead on the surface of the strip4 ,it was seen that this cell would afford an excellent means for the conveyance of electricity from place to place1 the great drawback1 however1 being that the storing capacity was not sufficient as compared with the weight and size of the cell4 ,this difficulty has now been overcome by ,m4 ,faure2 the cell as he has improved it is made in the following manner3 ,the two strips of lead are separately covered with minium or some other insoluble oxide of lead1 then covered with an envelope of felt1 firmly attached by rivets of lead4 ,these two electrodes are then placed near each other in water acidulated with sulphuric acid1 as in the ,plant cell4 ,the cell is then attached to a battery so as to allow a current of electricity to pass through it1 and the minium is thereby reduced to metallic spongy lead on the negative pole1 and oxidized to peroxide of lead on the positive pole2 when the cell is discharged the reduced lead becomes oxidized1 and the peroxide of lead is reduced until the cell becomes inert4 ,the improvement consists1 as will be seen1 in substituting for strips of lead masses of spongy lead2 for1 in the ,plant cell1 the action is restricted to the surface1 while in ,faure's modification the action is almost unlimited4 ,a battery composed of ,faure's cells1 and weighing #aej lb41 is capable of storing up a quantity of electricity equivalent to one horsepower during one hour1 and calculations based on facts in thermal chemistry show that this weight could be greatly decreased4 ,a battery of #bd cells1 each weighing #ad lb41 will keep a strip of platinum five-eighths of an inch wide1 one-thirty-second of an inch thick1 and #i ft4 #aj in4 long1 red-hot for a long time4 ,the loss resulting from the charging and discharging of this battery is not great2 for example1 if a certain quantity of energy is expended in charging the cells1 #hj per cent4 of that energy can be reproduced by the electricity resulting from the discharge of the cells2 moreover1 the battery can be carried from one place to another without injury4 ,a battery was lately charged in ,paris1 then taken to ,brussels1 where it was used the next day without recharging4 ,the cost is also said to be very low4 ,a quantity of electricity equal to one horse power during an hour can be produced1 stored1 and delivered at any distance within #c miles of the works for #a;d4 ,therefore these batteries may become useful in producing the electric light in private houses4 ,a #a1bej horsepower engine1 working dynamo-machines giving a continuous current1 will in one hour produce #a1jjj horse-power of effective electricity1 that is to say #hj per cent4 of the initial force4 ,the cost of the machines1 establishment1 and construction will not be more than #dj1jjj1 and the quantity of coal burnt will be #b lb4 per hour per effective horse-power1 which will cost 7say7 d4 ,the apparatus necessary to store up the force of #a1jjj horses for twenty-four hours will cost #dh1jjj1 and will weigh #a1ejj tons4 ,this price and these weights may become much less after a time4 ,the expense for wages and repairs will be less than d4 per hour per horse-power1 which would be #bd a day1 or #h1hjj a year2 thus the total cost of one horse-power for an hour stored up at the works is d4 ,allowing that the carriage will cost as much as the production and storing1 we have what is stated above1 viz41 that the total cost within #c miles of the works is #a;d4 per horse-power per hour4 ,this quantity of electricity will produce a light1 according to the amount of division1 equivalent to from #e to #cj gas burners1 which is much cheaper than gas4--,chemical ,news4 99 99 99 99 99 ,,physical ,,science ,,in ,,our ,,common ,,schools4 ,footnote3 ,read before the ,state ,normal ,institute at ,winona1 ,minnesota1 ,april #bh1 #ahha1 by ,clarence ,m4 ,boutelle1 ,professor of ,mathematics and ,physical ,science in the ,state ,normal ,school4 ,very little1 perhaps1 which is new can be said regarding the teaching of physical science by the experimental method4 ,special schools for scientific education1 with large and costly laboratories1 are by no means few nor poorly attended2 scientific books and periodicals are widely read2 scientific lectures are popular4 ,but1 while in many schools of advanced grade1 science is taught in a scientific way1 in many others the work is confined to the mere study of books1 and in only a few of our common district schools is it taught at all4 ,i shall advocate1 and ,i believe with good reason1 the use of apparatus and experiments to supplement the knowledge gained from books in schools where books are used1 the giving of lessons to younger children who do not use books1 and the giving of these lessons to some extent in all our schools4 ,and the facts which ,i have gathered together regarding the teaching of science will be used with all these ends in view4 ,physics--using the term in its broadest sense--has been defined as the science which has for its object the study of the material world1 the phenomena which it presents to us1 the laws which govern 7or account for7 these phenomena1 and the applications which can be made of either classes of related phenomena1 or of laws1 to the wants of man4 ,thus broadly defined1 physics would be one of two great subjects covering the whole domain of knowledge4 ,the entire world of matter1 as distinguished from the world of mind1 would be presented to us in a comprehensive study of physics4 ,i shall consider in this discussion only a limited part of this great subject4 ,phenomena modified by the action of the vital force1 either in plants or in animals1 will be excluded2 ,i shall not1 therefore1 consider such subjects as botany or zology4 ,geology and related branches will also be omitted by restricting our study to phenomena which take place in short1 definite1 measurable periods of time4 ,and lastly1 those subjects in which1 as in astronomy1 the phenomena take place beyond the control of student and teacher1 and in which their repetition at pleasure is impossible1 will not be considered4 ,natural philosophy1 or physics1 as this term is generally used1 and chemistry1 will1 therefore1 be the subjects which we will consider as sources from which to draw matter for lessons for the children in our schools4 ,the child's mind has the receptive side1 the sensibility1 the most prominent4 ,his senses are alert4 ,he handles and examines objects about him4 ,he sees more1 and he learns more from the seeing1 than he will in later years unless his perceptive powers are definitely trained and observation made a habit4 ,his judgment and his will are weak4 ,he reasons imperfectly4 ,he chooses without appropriate motives4 ,he needs the building up and development given by educational training4 ,nature points out the method4 ,sensibility being the characteristic of his mind1 we must appeal to him through his senses4 ,we must use the concrete2 through it we must act upon his weak will and immature judgment4 ,from his natural curiosity we must develop attention4 ,his naturally strong perceptive powers must be made yet stronger2 they must be led in proper directions and fixed upon appropriate objects4 ,he must be led to appreciate the relation between cause and effects--to associate together related facts--and to state what he knows in a definite1 clear1 and forcible manner4 ,object lessons1 conversational lessons1 lessons on animals1 lessons based on pictures and other devices1 have been used to meet this demand of the child's mental make up4 ,good in many respects1 and vastly better than mere book work1 they have faults which ,i shall point out in connection with the corresponding advantages of easy lessons in the elements of science4 ,i shall not quibble over definitions4 ,object lessons may1 perhaps1 properly be said to include lessons such as it seems to me should be given--lessons drawn from natural philosophy or chemistry--but ,i use the term here in the sense in which it is often used1 as meaning lessons based upon some object4 ,a thimble1 a knife1 a watch1 for instance1 each of these being a favorite with a certain class of object teachers1 may be taken4 ,the objections are3 #a4 ,little new knowledge can be given which is simple and appropriate4 ,most children already know the names of such objects as are chosen1 the names of the most prominent parts1 the materials of which they are composed and their uses4 ,much that is often given should be omitted altogether if we fairly regard the economy of the child's time and mental strength4 ,it doesn't pay to teach children that which isn't worth remembering1 and which we don't care to have them remember4 #b4 ,study of the qualities of materials is a prominent part of lessons on objects4 ,such study is really the study of physical science1 but with objects such as are usually selected is a very difficult part to give to young children4 ,ask the student who has taken a course in chemistry whether the study of the qualities of metals and their alloys is easy work4 ,ask him how much can readily be shown1 and how much must be taken on authority4 ,have him tell you how much or how little the thing itself suggests1 and how much must he memorized from the mere book statement and with difficulty4 ,study of materials is good to a certain extent1 but it is often carried much too far4 ,consider a conversational lesson on some animal4 ,lessons are sometimes given on cats4 ,as an element in a reading lesson--to arouse interest--to hold the attention--to secure correct emphasis and inflection--to make sure of the reading being good3 such work is appropriate4 ,but let us see what the effect upon the pupil is as regards the knowledge he gains of the cat1 and the effect upon his habits of thought and study4 ,the student gives some statement as to the appearance--the size--or some act of his cat4 ,it is usually an imperfect statement drawn from the imperfect memory of an imperfect observation4 ,and the teacher1 having only a general knowledge of the habits of cats1 can correct in only a general way4 ,thus habits of faulty and incorrect observation and inaccurate memory are fastened upon the child4 ,it is no less by the correction of the false than by the presenting of the true1 that we educate properly4 ,besides this there is the fact that traits1 habits1 and peculiarities of animals are not always manifested when we wish them to be4 ,suppose a teacher asks a child to notice the way in which a dog drinks1 for example2 the child may have to wait until long after all the associated facts1 the reasons why this thing was to be observed--the lesson as a whole of which this formed a part--have all grown dim in the memory1 before the chance for the observation occurs4 ,pictures are less valuable as educational aids than objects2 at best they are but partially and imperfectly concrete4 ,the study of pictures tends to cultivate the imagination and taste1 but observation and judgment are but little exercised4 ,a comparison of the kind of knowledge gained in either of the above ways with that gained by a study of science as such1 will make some of the advantages of the latter evident4 ,an act of complete knowledge consists in the identifying of an attribute with a subject4 ,attributes of quality--of condition--of relation1 may be gained from lessons in which objects or pictures are used4 ,attributes of action which are unregulated by the observer may be learned from the study of animals4 ,but very little of actions and changes which can be made to take place under specified conditions1 and with uniformity of result1 can be learned until physical science is drawn upon4 ,and yet consider the importance of such study4 ,changes around him appeal most strongly to the child4 ,why does this thing do as it does8 is more frequent than ,why is this thing as it is8 ,he sees changes of place1 of form1 of size1 of composition1 taking place2 his curiosity is aroused2 and he is ready to study with avidity1 and in a systematic manner1 the changes which his teacher may present to him4 ,consider the peculiarities belonging to the study of changes of any sort4 ,the interest is held1 for the mind is constantly gaining the new4 ,the attention cannot be divided--all parts of the change1 all phases of the action1 must be known1 and to be known must be observed2 while in other forms of lessons the attention may be diverted for a moment to return to the consideration of exactly what was being observed before4 ,it goes without saying that in one case quick and accurate observation1 a retentive memory1 and the association of causes and effects follow1 and that in the other they do not4 ,i advocate1 therefore1 the teaching of physical science in our schools--in all our schools4 ,physical science taught by the experimental method4 ,an experiment has been defined as a question put to ,nature1 a question asked in things rather than in words1 and so conditioned that no uncertain answer can be given4 ,nature says that all matter gravitates1 not in words1 but in the swing of planets around the sun1 and in the leap of the avalanche4 ,and men have devised ingenious machines through which ,nature may tell us the invariable laws of gravitation1 and give some hint as to why it is true4 ,there are two kinds of experiments1 and two corresponding kinds of investigators4 ,i4 ,in original investigation there are the following elements3 #a4 ,the careful determination of all the conditions under which the experiment takes place4 #b4 ,the observation of exactly what happens1 with a painstaking elimination of all previous notions as to what ought to happen4 #c4 ,the change of conditions1 one at a time1 with a comparison of the results obtained with the changes made1 in order to determine that each condition has been given just its appropriate weight in the experiment4 #d4 ,the classification and explanation of the result4 #e4 ,the extension of the knowledge gained by turning it to investigations suggested by what has already been learned4 #f4 ,the practical application of the knowledge gained4 ,,ii4 ,in ordinary experiments for educational purposes the experimenter follows in a general way in the footsteps of the original investigator4 ,there are the following elements to be considered3 #a4 ,the arrangement of conditions in general imitation of the original investigator4 ,this arrangement needs only to be general4 ,for example1 if an original investigation were undertaken to determine the composition of a metallic oxide1 the metal and the oxygen would both be carefully saved to be measured and weighed and fully tested4 ,the ordinary experiment would be considered successful if oxygen and the metal were shown to result4 #b4 ,the careful consideration of what should happen4 #c ,the determination that the expected either does or does not happen1 with examination of reasons and elimination of disturbing causes in the latter case4 #d4 ,the accepting as true of the classification and explanation already given4 ,theories1 explanations1 and laws are thus accepted every day by minds which could never have originated either them or the experiments from which they were derived4 ,the method of original investigation1 strictly considered1 presents many difficulties4 ,a long course of preliminary training--a thorough knowledge of what has been done in a given field already--a quick imagination--a genius for devising forms of apparatus which will enable him to work well under particular conditions in the most simple and effective way--the faculty of suspending judgment1 and of seeing what happens1 all that happens1 and just how it happens--patience--caution--courage--qui ck judgment when a completed experiment presses for an explanation--these are some of the characteristics which must belong to the original worker4 ,were we all capable of doing such work there would be these advantages1 among others1 of studying for ourselves3 #a4 ,what we find out for ourselves we remember longer and recall more readily than what we acquire in any other way4 ,this advantage holds true whether the facts learned are entirely new or only new to us4 ,almost every man whose life has been spent in study has a store of facts which he discovered1 and on which he built hopes of future greatness until he found out later that they were old to the knowledge of the world he lived in4 ,and these things are among those which will remain longest in his memory4 #b4 ,associated facts would be learned in studying in this way which would remain unknown otherwise4 ,but all the advantages would be associated with disadvantages too4 ,long periods of time would have to be given for comparatively small results4 ,the history of science is full of instances in which years were spent in the elaboration of some law1 or principle1 or theory which the school boy of to-day learns in an hour and recites in a breath4 ,why does water rise in a pump8 ,do all bodies1 large and small1 fall equally fast8 ,the principles which answer and explain such questions can be made so clear and evident to the mind of a pupil that he would almost fancy they must have been known from the first instead of having waited for the hard1 earnest labor of intellectual giants4 ,and science has gone on1 and for us and for our pupils would still go on1 only as accompanied with numerous mistakes and disappointments4 ,what method shall we adopt in the teaching of science8 ,it must differ according to the age and capacity of the pupils4 ,an excellent modification of the method of original investigation may be arranged as follows3 ,the children are put in possession of all facts relating to conditions1 the teacher explaining them as much as may be necessary4 ,the experiment is performed1 the pupils being required to observe exactly what takes place1 the experiments selected being of such a nature that any previous judgment as to what ought to occur is as nearly impossible as may be4 ,we predict from knowledge1 real or supposed1 of facts which are associated in our minds with any new subject under consideration4 ,children often know in a general1 vague1 and indefinite way that which1 for the sake of a full and systematic knowledge1 we may desire them to study4 ,what they know will unconsciously modify their expectations1 and their expectations in turn may modify their observations4 ,we are apt to believe that happens which we expect will happen4 ,there ought to be no difficulty1 however1 in finding simple and appropriate experiments with which the child is entirely unacquainted1 and in which anything beyond the wildest guess work is1 for him1 impossible4 ,the principal use which can be made of this method is in the mere observation of what takes place4 ,nothing which the child notices correctly need be rejected1 no matter how far removed from the chief event on the object of the experiment4 ,care that the pupil shall see all1 and separate the essential from the accidental1 is all that is necessary4 ,but the original investigator assigns reasons1 and with care the children may be allowed to attempt that4 ,this1 however1 should not be carried far2 incorrect explanations should be criticised2 and the class should at length be given all the elements of the correct explanation which they have not determined for themselves4 ,later1 pupils should be encouraged to name related phenomena1 to mention things which they have seen happen which are due to associated causes1 and to suggest variations for the experiment and tests for its explanation4 ,good results may be made to follow this kind of work even with very young pupils4 ,a child grows in mental strength by using the powers he has1 and mistakes seen to be such are not only steps toward a correct view of the subject under consideration1 but are steps toward that habit of mind which spontaneously presents correct views at once in study which comes later in life4 ,another method is this3 ,the pupil may know what is expected to happen1 as well as the conditions given1 and held responsible for an observation of what does happen and a comparison of what he really observes with what he expects to observe4 ,explanations are usually given a class1 often in books with which they are furnished1 instead of being drawn from them1 in whole or in part1 by questioning1 when physical science is studied in this way4 ,indeed1 this method is a necessity when text books are used1 unless experiments from some outside source are introduced4 ,who shall perform the experiments8 ,with young pupils everywhere1 and in most of our common1 and even in many of our graded schools1 the experiments must be performed by the teacher4 ,with young pupils the time is too limited1 and the responsibility and necessary care too great to permit of any other plan being practical4 ,in many of our schools the small supply of apparatus renders this necessary even with larger pupils4 ,added to the reasons already given is the important one that in no other way--by no other plan--can the teacher be as readily sure that his pupils observe and reason fully for themselves4 ,in this normal school a course in physics1 in which the experiments are all performed in the class room by the teacher1 is followed by a course in chemistry1 in which the members of the class perform the experiments for themselves in the laboratory4 ,and1 notwithstanding the age1 maturity1 and previous observation of the pupils1 a great deal must be done both in the laboratory and in the recitation room to be sure that all that happens is seen--that the purpose is clearly held in the mind--that the reason is fully understood4 ,with older pupils and greater facilities1 however1 the experiments should be performed by the pupils themselves4 ,constant watchfulness is necessary1 it is true1 to insure to the pupil the full educational value of the experiment4 ,with this watchfulness it can be done1 and the advantages are numerous4 ,among them are3 #a4 ,the learning of the use and care of apparatus4 #b4 ,the learning of methods of actual construction1 from materials at hand1 of some of the simpler kinds of apparatus4 #c4 ,the learning of the importance of careful preparation4 ,an experiment may be performed in a few minutes before a class which has taken an hour or more of time in its preparation4 ,the pupil fully appreciates its importance1 and is in the best condition to remember it only when he has had a part of the hard work attending that preparation4 ,again1 conditions under which an experiment is successfully performed are often not appreciated when merely stated in words4 ,to prepare hydrogen gas1 pass a thistle tube and a delivery tube through a cork which fit tightly in the neck of a bottle1 etc41 is simple enough4 ,let a pupil try with a cork which does not fit tightly and he will never forget that condition4 #d4 ,the learning of the importance of following directions4 ,chemistry1 especially1 is full of those cases where this means everything4 ,sometimes1 not often in experiments performed in school1 however1 it may mean even life or death4 ,the time for experiments should be carefully considered4 ,when performed by the teacher they should be taken up during the recitation3 #a4 ,if used as a foundation to build upon1 at the beginning of the lesson4 #b4 ,if used as a summary1 at the close4 #c4 ,they should be closely connected with the points which they illustrate4 #d4 ,when very short1 or when so difficult as to demand the whole attention of the teacher1 they may be given and afterward discussed4 ,if long or easy1 they may be discussed while the work is going on4 ,changes which take place slowly1 as those which are brought about by the gradual action of heat1 for instance1 are best taken up in this latter way4 #e4 ,exceptions may be necessary1 as when experiments which demand special preparation immediately before they are presented are given when the recitation begins1 or cases in which experiments are kept until near the close of a recitation1 when the teacher finds that attention flags and the lesson seems to have lost its interest to the pupils as soon as the experiments have been given4 ,when performed by the pupils themselves1 experiments should come before the recitation as a part of the preparation for the work of the class room4 ,even in those cases in which the teacher performs the work1 opportunity should be given1 from time to time1 for the performing of the experiment by the pupils themselves4 ,this can be done in several ways4 ,during the course in physics here ,i am in the habit of leaving apparatus on the table in my room for at least one day1 often for a longer time1 and of giving permission to my class to perform the experiments for themselves when their time permits and the nature of the experiment makes it an advantage to get a nearer view than was possible in the class work4 ,i leave it to them to decide when to perform the experiments1 or whether it is to their advantage to take the time to perform them at all4 ,i make no attempt to watch either pupils or apparatus1 although ,i would often assist or explain at intermissions or during the afternoon4 ,the apparatus was largely used1 and the effect on recitations was a good one4 ,for advanced pupils1 and those who can be fully trusted1 the plan is a good one4 ,the only question is the safety of the apparatus2 each teacher can decide for himself regarding the advisability of the plan for his own school4 ,with smaller pupils their own safety may render it best to keep apparatus out of their hands1 except under the immediate direction of the teacher4 ,with all pupils that is1 doubtless1 the best plan where chemicals are concerned4 ,another method is to allow pupils to assist the teacher in the preparation of experiments1 to call occasionally upon members of the class to come forward and give the experiment in the place of the teacher1 and to encourage home work relating to experiments4 ,this latter is often spontaneous on the part of older pupils1 and can be brought about with the smaller ones by the use of a little tact2 many of the toys of the present day have some scientific principle at bottom2 let the teacher find out what toys his young pupils have1 and encourage them to use them in a scientific way4 ,in whatever ways experiments be used1 the class should be made to consider the following elements as important in every case3 #a4 ,the purpose of the experiment4 ,the same experiment may be performed at one time for one purpose1 at another time for another4 ,the purpose intended should be made the prominent thing1 all others being subordinated to it4 ,many chemical reactions1 for instance1 can be made to yield either one of two or more substances for study or examination1 or use1 while it may be the purpose of the experiment to close only one of them4 #b ,the apparatus4 ,all elements should be considered4 ,the necessary should be separated from that which may vary4 ,in cases where the various parts must have some definite relation to the others as regards size or position1 all that should be considered with care4 ,in complex apparatus the exact office of each part should be understood4 #c4 ,a clear understanding of what happens4 ,to this ,i have already referred4 #d4 ,why it happens4 #e4 ,in what other way it might be made to happen4 ,in chemistry almost every substance can be prepared in several different ways4 ,the common method is in most cases made so by some consideration of convenience1 cheapness1 or safety4 ,often only one method is considered in one place in a text book4 ,in a review1 however1 several methods can be associated together4 ,tests1 uses1 etc41 will vary1 too1 and should be studied with that fact in view4 ,in physics phenomena illustrating a given principle can usually be made to take place in several different ways4 ,often very simple apparatus will do to illustrate some fact for which complex and costly apparatus would be convenient4 ,in such case the study of the experiment with that fact in view becomes important to us who need to simplify apparatus as much as possible4 #f4 ,special precautions which may be necessary4 ,some experiments always work well1 even in the hands of those not used to the work4 ,others are successful--sometimes safe1 even--only when the greatest care is taken4 ,substances are used constantly in work in chemistry which are deadly poisons1 others which are gaseous and will pass through the smallest holes4 ,in physics the experiments usually present fewer difficulties of this sort4 ,but special care is necessary to complete success here4 #g4 ,other things shown by the experiment4 ,while the main object should be kept in most prominent view in all experimental work1 the fullest educational value will come only when all that can be learned by the use of an experiment is carefully considered4 ,in selecting just the work to be taken up with a given class of children1 attention must be paid to the selection of the appropriate matter to be presented and the well adapted method of presenting it4 ,the following points should be carefully considered3 #a4 ,the matter must be adapted to the capacity of the child4 ,this must be true both as regards the quality and the quantity4 ,the tendency will be to teach too much when the matter presented is entirely new1 but too little in many cases where the pupil already knows the subject in a general way4 ,matter is valuable only when given slowly enough to permit of its being fully understood and memorized1 while on the other hand method is valuable only when it secures the development of attention and the various faculties of the child's mind by presenting a sufficient amount of the new4 #b4 ,the work must be based on what is already known4 ,this1 one of the best known of the principles of teaching1 is of at least as great importance in physical science as in any other department of knowledge4 ,it seems to me in many cases to be more important here than elsewhere4 ,it is not necessary to reach each point by passing over every other point usually considered4 ,lessons in electricity or sound1 for instance1 can be given to children who have done nothing with other parts of science4 ,but a natural beginning must be made1 and an orderly sequence of lessons adopted4 ,children will not do what adults would find almost impossible in covering gaps between lessons4 ,science may be compared to a great temple4 ,pillars1 each built of many curiously joined stones1 standing at the very entrance1 represent the departments of science so far as man has studied them4 ,we need not dig down and study the foundations with the children2 we need not study every pillar nor choose any particular one rather than some other2 but we must learn something of every stone--of each great fact--in the pillar we select1 be it ever so little4 ,the original investigator climbs to stones never before reached1 or boldly ventures away into the dim recesses beyond the entrance to bring back hints of what may be known and believed a hundred years hence1 perhaps4 ,the exact investigator measures each stone4 ,patiently and toilsomely scientific men examine them with glass and reagent4 ,we need not do this1 but we must omit none of the stones4 #c4 ,the work must be continuous4 ,to continue the figure1 the stones must be considered in some regular order4 ,one lesson in electricity1 one in sound1 then one in some other department is injurious4 ,we remember best by associated facts1 and1 while with the child this is less so than with the man1 one great object of this work is to teach him to remember in that way4 #d4 ,experiments should never be performed for mere show4 ,of two experiments which illustrate a fact equally well it is often best to select the most striking and brilliant one4 ,the attention and interest of the child will be gained in this way when they would not be to so great an extent in any other4 ,the point of the experiment1 however1 should never be lost sight of in attention to the merely wonderful in it4 ,with older pupils1 and especially with those who use books for themselves and perform the experiments there considered1 the fact that experiments demand work1 downright hard work1 with care1 and patience1 and perseverance1 and courage1 cannot be kept too prominently before them4 #e4 ,every lesson should have a definite object4 ,not the general value of the experiment1 but some one thing which it shows should be the object considered4 #f4 ,each experiment should be associated with some truth expressed in words4 ,the experiment should be remembered in connection with a definite statement in each case4 ,the memory of either the experiment1 or the principle apart from the experiment1 is a species of half knowledge which should be avoided4 ,an unillustrated principle must1 when the necessity arises1 be stored in the memory2 and in the systematic study of books this necessity will often come4 ,but we should never crowd this abstract work on the memory unassisted by the suggestive concrete1 when the concrete aid is possible4 #g4 ,all that is taught should be true4 ,it is not necessary to attempt to exhaust a subject1 nor to attempt to teach minute details regarding it to the pupils in our schools1 but it is necessary that every statement given to the pupil to be learned and remembered should contain no element of falsehood4 ,the student in mathematics experiences a feeling of growing strength and power when he finds1 in algebra1 that the formula he used in arithmetic in extracting a square root has grown in importance by leading indirectly to a theorem of which it is only one particular case--a theorem with a more definite proof1 and a larger capability for use than he had thought possible4 ,when he finds a still simpler proof for the binomial theorem in his study of the calculus1 his feeling of increasing power and the desire for still greater results deepens and intensifies4 ,were he to find1 on the contrary1 that from a false notion of the means to be used in making a thing simple1 his teacher in arithmetic had taught him what is false1 we should approve his feeling of disgust and disappointment4 ,early impressions are the most lasting1 and the hardest part of school work for the teacher is the unteaching of false ideas1 and the correcting of imperfectly formed and partially understood ideas4 ,i took a case from mathematics1 the exact science1 to illustrate this point4 ,but ,i must not neglect to notice the difference between that subject and physical science4 ,the latter consists of theories1 hypotheses1 and so-called laws1 supported by observed facts4 ,the facts remain1 but time has overthrown many of the hypotheses and theories1 and it will doubtless overthrow more and give us something better and truer in their place4 ,while a careful distinction between what is known and what is believed is necessary1 ,i should always class the teaching of accepted theories and hypotheses with the teaching of the true4 ,but teachers1 with more of imagination than good sense1 teach distinctions which do not exist1 generalizations which do not generalize1 and do incalculable mischief by so doing4 #h4 ,experimental work should be thoroughly honest as to conditions and results4 ,if an experiment is not the success you expected it would be1 say so honestly1 and if you know why1 explain it4 ,the pupil should be taught to know just what is1 theory or expectation to the contrary notwithstanding4 ,discoveries in physical science have often originated in a search for the reason for some unexpected thing4 ,the relation of the study of science to books on science should be considered4 ,for the work done with pupils before they are given books to use for themselves1 any attempt to follow a text book is to be deplored4 ,the study of the properties of matter1 for instance1 would be a fearful and wonderful thing to set a class of little ones at as a beginning in scientific work4 ,just what matter1 and force1 and molecules1 and atoms are may be well enough for the student who is old enough to begin to use a book1 but they would be but dry husks to a younger child4 ,many of the careful classifications and analyses of topics in text books had far better be used as summaries than in any other way2 and a definition is better when the pupil knows it is true than when he is about to find out whether it is or not4 ,an ideal course in science would be one in which nothing should be learned but that found out by the observation of the pupil himself under the guidance of the teacher1 necessary terms being given1 but only when the thing to be named had been considered1 and the mind demanded the term because of a felt need4 ,practically such a method is impossible in its fullest sense1 but a closer approach to it will be an advantage4 ,among the numerous good results which will follow the study of physical science are the following3 #a4 ,the cultivation of all the faculties of the child in a natural order1 thus making him grow into a ready1 quick1 and observing man4 ,education in schools is too often shaped so as to repress instead of cultivate the instinctive desire for the knowledge of things which is found in every child4 #b4 ,the mechanical skill which comes from the preparation and use of apparatus4 #c4 ,the ability to follow directions4 #d4 ,the belief in stated scientific facts1 the understanding of descriptions1 diagrams1 etc4 #e4 ,the habitual scientific use of events which happen around us4 #f4 ,the study of the old to find the new4 ,the principle of the telephone1 for instance1 is as old as spoken language4 ,the mere#a pulses in the air--carrying all the characteristics of what you say--may set in vibration either the drum of my ear1 or a disk of metal4 ,how simple--and how simple all true science is--when we understand it4 ,transcribers note #a3 corrected from 'more' #h4 ,the cultivation of the scientific judgment1 and the inventive powers of the mind4 ,one great original investigator1 made such by the direction given his mind in one of our common schools1 would be cheaply bought at the price of all that the study of science in our schools will cost for the next quarter of a century4 #h4 ,honesty4 ,if there is a study whose every tendency is more in the direction of honesty and truthfulness--both with ourselves and with others--than is the study of experimental science1 ,i do not know what it is4 ,physical science1 then1 will help in making men and women out of our boys and girls4 ,it is worthy of a fair1 earnest trial everywhere4 ,a few minutes each day in which a class or a school study science in some of the ways ,i have indicated will give a knowledge at the end of a term or a year of no mean value4 ,the time thus spent will have rested the pupils from their books1 to which they will return refreshed1 and instead of being time lost from other study the work will have been made enough more earnest and intense to make it again4 ,apparatus for illustrating many of the ordinary facts of physics can be devised from materials always at hand4 ,many more can be made by any one skilled in the use of tools4 ,in chemistry1 the simplicity of the apparatus1 and comparative cheapness of ordinary chemicals1 make the use of a large number of beautiful and instructive experiments both easy and cheap4 ,a nation is what its trades and manufactures--its inventions and discoveries--make it2 and these depend on its trained scientific men4 ,boys become men4 ,their growing minds are waiting for what ,i urge you to offer4 ,science has never advanced without carrying practical civilization with it--but it has never truly advanced save by the use of the experimental method4 ,and it never will4 ,let us then look forward to the time when our boys and young men--our girls and young women--shall extend the boundaries of human knowledge by its use1 fitted so to do by what we may have done for them4 99 99 99 99 99 ,,geographical ,,society ,,of ,,the ,,pacific4 ,this society is a recent organization1 the objects of which are to encourage geographical exploration and discovery2 to investigate and disseminate geographical information by discussion1 lectures1 and publications2 to establish in this1 the chief maritime city of the ,western ,states1 for the benefit of commerce1 navigation1 and the industrial and material interests of the ,pacific slope1 a place where the means will be afforded of obtaining accurate information not only of the countries bordering on the ,pacific ocean1 but of every part of the habitable globe2 to accumulate a library of the best books on geography1 history1 and statistics2 to make a collection of the most recent maps and charts--especially those which relate to the ,pacific coast1 the islands of the ,pacific and the ,pacific ocean--and to enter into correspondence with scientific and learned societies whose objects include or sympathize with geography4 ,the society will publish a bulletin and an annual journal1 which will interchange with geographical and other societies4 ,monthly meetings are to be held1 at which original papers will be read or lectures be given2 and to which1 as well as to the entertainments to distinguished travelers1 to the conversazioni1 and to the informal evenings1 the fellows of the society will have the privilege of introducing their friends4 ,the initiation fee to the society is #aj2 monthly dues #a2 life fellowship #ajj4 ,at a meeting held at the ,palace ,hotel on the #abth ,may1 the following gentlemen were elected for the ensuing year3 ,president1 ,geo4 ,davidson2 ,vice-,presidents1 ,hon4 ,ogden ,hoffman1 ,wm4 ,lane ,booker1 ,h4,b4,m4 ,consul1 and ,john ,r4 ,jarboe2 ,foreign ,corresponding ,sec41 ,francis ,berton2 ,home ,cor4 ,sec41 ,james ,p4 ,cox2 ,treas41 ,gen4 ,c4 ,i4 ,hutchinson2 ,sec'y1 ,c4 ,mitchell ,grant1 ,f4,r4,g4,s4 ,the council is composed of the following3 ,hon4 ,joseph ,w4 ,winans1 ,hon4 ,j4,f4 ,sullivan1 ,ralph ,c4 ,harrison1 ,a4,s4 ,hallidie1 ,thos4 ,e4 ,stevin1 ,f4,a4,g4,s41 ,w4,w4 ,crane1 ,jr41 ,w4,j4 ,shaw1 ,c4,p4 ,murphy1 ,thos4 ,brice1 ,edward ,l4,g4 ,steele1 ,gerrit ,l4 ,lansing1 ,joseph ,d4 ,redding4 ,the ,trustees are ,geo4 ,davidson1 ,wm4 ,lane ,booker1 ,hon4 ,jno4 ,s4 ,hager1 ,geo4 ,chismore1 ,m4,d41 ,selim ,franklin4 99 99 99 99 99 ,,the ,,behring',s ,,straits ,,currents4 ,it will be remembered that a short time since we mentioned the fact that ,w4,h4 ,dall1 of the ,u4 ,s4 ,coast ,survey1 who has passed a number of years in ,alaskan waters1 on ,coast ,survey duty1 denied the existence of any branch of the ,kuro ,shiwo1 or ,japanese warm stream1 in ,behring's ,straits4 ,that is1 he failed to find evidence of the existence of any such current1 although he had made careful observations4 ,at the islands in ,behring's ,straits1 his vessel had sailed in opposite directions with ebb and flood tide1 and he thought the only currents there were tidal in their nature4 ,the existence or non-existence of this current is an important point in ,arctic research on this side of the continent4 ,at the last meeting of the ,academy of ,sciences1 ,prof4 ,davidson1 of the ,u4 ,s4 ,coast ,survey1 author of the ,alaska ,coast ,pilot1 refuted ,dr4 ,dall's opinion of the non-existence of a branch of the ,kuro ,shiwo1 or ,japanese warm stream1 from the north ,pacific into the ,arctic ,ocean1 through ,behring's ,straits4 ,he said that in #aheg he gave to the ,academy his own observations1 and recently he had conferred with ,capt4 ,c4,l4 ,hooper1 who commanded the ,u4 ,s4 steamer ,thomas ,corwin1 employed as a revenue steam cruiser in the ,arctic and around the coast of ,alaska4 ,capt4 ,hooper confirms the opinions of all previous navigators1 every one of which1 except ,dr4 ,dall1 say that a branch of this warm stream passed northward into the ,arctic through ,behring's ,strait4 ,it is partly deflected by ,st4 ,lawrence ,island1 and closely follows the coast on the ,alaskan side1 while a cold current comes out south1 past ,east ,cape in ,siberia1 skirting the ,asiatic shore past ,kamschatka1 and thence continues down the coast of ,china4 ,he said ice often extended several miles seaward1 from ,east ,cape on the ,asiatic side of ,behring ,strait1 making what seamen call a false cape1 and indicating cold water1 while no such formation makes off on the ,american side1 where the water is #ab degrees warmer than on the ,asiatic shore off the ,diomede islands1 situated in the middle of ,behring's ,strait1 the current varies in intensity according to the wind4 ,frequently it is almost nothing for several days1 when after a series of southerly winds the shallow ,arctic basin has been filled1 under a heavy pressure1 with an unusual volume of water1 and a sudden change to northerly winds1 makes even a small current setting southward for a few days1 just as at times the surface currents set out our ,golden ,gate continuously for #bd and #dh hours1 as shown by the ,united ,states ,coast ,survey tide gauges4 ,whalers report that the incoming water then flows in1 under the temporary outflowing stream4 ,old trees1 of a variety known to grow in tropical ,japan1 are floated into the ,arctic basin as far as past ,point ,barrow1 on the ,american side1 but none are found on the ,asiatic side1 or near ,wrangell ,land1 where a cold stream exists1 and ice remains late in the season4 ,on the northern side of the ,aleutian islands are found cocoanut husks and other tropical productions stranded along the beaches4 ,the ,american coast of ,alaska has a much warmer climate than the ,asiatic coast of ,siberia1 and the ,american timber line extends very far north4 ,the ice opens early in the season on the ,american side1 and invariably late on the ,asiatic4 ,capt4 ,c4 ,l4 ,hooper says that when just north of ,behring's ,strait1 off the ,american coast1 in the ,arctic basin1 the ,u4,s4 steamer ,thomas ,corwin1 when becalmed for #bd hours1 drifted #dj miles to the northward4 ,from all these1 and other facts1 and the unanimous testimony of ,american whalemen1 who have for years spent many months annually in the ,arctic1 and from his own observations1 he argued that a branch of the ,kuro-,shiwo or ,japanese warm stream1 unquestionably runs northward through ,behring's ,strait into the ,arctic basin along the northwestern coast of ,alaska4 ,prof4 ,davidson then called to mind the testimony in regard to the existence of ,plover ,island1 between ,herald ,island and ,wrangell ,land1 which he said was first made public through this academy4 ,the evidence of ,capts4 ,williams and ,thomas ,long were recited and highly praised4 ,one of the officers of ,admiral ,rodgers' expedition climbed to near the top of ,herald ,island1 at a time of great refraction1 when probably a false horizon existed1 and hence did not see ,plover ,island1 although ,wrangell ,land was in sight4 ,prof4 ,davidson thinks all the authorities are against ,dr4 ,dall1 who attributes the warm current he observed on the ,american coast to water from the ,yukon ,river and to the large expanse of shallow water exposed to the sun's rays4 ,as ,dall's observations only covered a few days of possibly exceptional weather1 and the whalers and ,captain ,hooper's cover vastly longer periods1 and whalers all say it is a pretty hard thing to beat southward through ,behring's ,strait1 owing to the northerly current setting into the ,arctic1 we are forced to the conclusion that ,dr4 ,dall has mistaken the exception for the rule1 and his conclusions are therefore erroneous4 ,when1 in #ahbd1 ,wrangell went north1 he1 like others1 always found broken ice and considerable open water4 ,in #ahfg1 when ,capt4 ,thomas ,long made his memorable survey of the coast of ,wrangell ,land1 the season was an exceptionally open one1 and in ,california we had heavy rains1 extending into ,july4 99 99 99 99 99 ,,experimental ,,geology4 ,,artificial ,,production ,,of ,,calcareous ,,pisolites ,,and ,,oolites4 ,mr4 ,stanislas ,meunier communicates to ,le ,nature an account of some interesting specimens of globular calcareous matter1 resembling pisolites or peastones both in appearance and structure1 which were accidentally formed as follows3 ,the ,northern ,railway ,company1 ,france1 desiring to purify some calciferous water designed for use in steam boilers1 hit upon the ingenious expedient of treating it with lime water whose concentration was calculated exactly from the amount of lime held in the liquid to be purified4 ,the liquids were mixed in a vast reservoir1 to which they were led by parallel pipes1 and by which they were given a rapid eddying motion4 ,the transformation of the bicarbonate into neutral carbonate of lime being thus effected with the accompaniment of a circling motion1 the insoluble salt which precipitated1 instead of being deposited in an amorphous state1 hardened into globules1 the sizes of which were strictly regulated by the velocity of the currents4 ,those that have been formed at one and the same operation are uniform1 but those formed at different times vary greatly--their diameters varying by at least one millimeter to one and a half centimeters4 ,the surface of the smaller globules is smooth1 but that of the larger ones is rough4 ,even by the naked eye1 it may be seen that both the large and small globules are formed of regularly superposed concentric layers4 ,if an extremely thin section be made through one of them it is found that the number of layers is very great and that they are remarkably regular 7,a74 ,by the microscope1 it has been ascertained that each layer is about #j4jjg of a millimeter in thickness4 ,on observing it under polarized light the calcareous substance is discovered to be everywhere crystallized1 and this suggests the question whether the carbonate has here taken the form of aragonite or of calcite4 ,examination has shown it to be the latter4 ,the density of the globules 7#b4eh7 is similar to that of ordinary varieties of calcite4 ,it is probable that if the operation were to take place under the influence of heat1 under the conditions above mentioned1 aragonite would be formed4 ,it is hardly necessary to dwell upon the possible geological applications of this mode of forming calcareous oolites and pisolites4 ,,on ,,crystals ,,of ,,anhydrous ,,lime4 ,some time ago it was discovered that some limestone1 which had been submitted for eighteen months to a heat of nearly #a1jjj degrees in the smelting furnaces of ,leroy-,descloges 7,france71 had given rise to perfectly crystallized anhydrous lime4 ,figure ,c shows three of these crystals magnified #cjj diameters4 ,it will be noticed that they have a striking analogy with grains of common salt4 ,they are1 in fact1 cubes 7often imperfect71 but do not polarize light1 as a substance of the first crystalline system should4 ,however1 it is rarely the case that the crystals do not have some action on light4 ,most usually1 when the two ,nicol prisms are crossed so as to cause extinction1 the crystals present the appearance shown at ,d4 ,that is to say1 while the central portion is totally inactive there are seen on the margins zones which greatly brighten the light4 ,illustration ,a and ,b4--,calcareous ,pisolites and ,oolites produced artificially4 ,a4--,external aspect and section of a ,pisolite4 ,b4--,details of internal structure as seen by the microscope4 ,c and ,d4--,crystals of anhydrous ,lime obtained artificially4 ,c4--,crystals seen under the microscope in the natural light4 ,d4--,crystals seen under the microscope in polarized light4 ,the phenomenon is explained by the slow carbonization of the anhydrous lime under the influence of the air2 the external layers passing to the state of carbonate of lime or ,iceland spar1 which1 as well known1 has great influence on polarized light4 ,this transformation1 which takes place without disturbing the crystalline state1 does not lead to any general modification of the form of the crystals1 and the final product of carbonization is a cubic form known in mineralogical language as epigene4 ,as the molecule of spar is entirely different in form from the molecule of lime1 the form of the crystal is not absolutely preserved1 and there are observed on the edges of the epigene crystal certain grooves which correspond with a loss of substance4 ,these grooves are quite visible1 for example1 on the crystal to the left in ,fig4 ,d4 ,up to the present time anhydrous lime has been known only in an amorphous state4 ,the experiment which has produced it in the form noted above would doubtless give rise to crystallized states of other earthy oxides likewise1 and even of alkalino-earthy oxides4 ,,coccid4 ,footnote3 ,a paper recently read before the ,california ,academy of ,sciences4 ,by ,,dr4 ,h4 ,,behr4 ,with the exception of ,hymenoptera there is no group of insects that interfere in so many ways in good and evil with our own interests1 as that group of ,homoptera called ,coccid4 ,but while the ,hymenoptera command our respect by an intellect that approaches the human1 the ,coccus tribe possesses only the lowest kind of instinct1 and its females even pass the greater part of their lives in a mere vegetation state1 without the power of locomotion or perception1 like a plant1 exhibiting only organs of assimilation and reproduction4 ,but strange to say1 these two groups1 otherwise so very dissimilar1 exhibit again a resemblance in their product4 ,both produce honey and wax4 ,it is true1 the honey of this tribe is almost exclusively used by the ants4 ,but ,i have tasted the honey-like secretion of an ,australian lecanium living2 on the leaves of ,eucalyptus dumosus2 and the manna mentioned in ,scripture is considered the secretion of ,coccus manniparus 7,ehrenberg7 that feeds on a tamarix1 and whose product is still used by the native tribes round ,mount ,sinai4 ,several species of ,coccides are used for the production of wax2 many more1 among which the ,cochenill1 for dyes4 ,all these substances can be obtained in other ways1 even the ,cochenill is to a great extent superseded by aniline dyes1 but in regard to one production1 indispensable to a great extent1 we are entirely dependent on some insects of this family2 it is the ,shellac1 lately also found in the desert regions around the ,gila and ,colorado on the ,larrea ,mexicana4 ,you will remember that excellent treatise on this variety of ,shellac1 written by ,professor ,j4,m4 ,stillman at ,berkeley1 on its chemical peculiarities4 ,but all these different forms of utility fall very lightly in weight1 and can not even be counted as an extenuating circumstance1 when we compare them to the enormous evils brought on farmer and gardener by the hosts of those ,coccides that visit plantations1 hothouses1 and orchards4 ,to combat successfully against these insect-pests we have first to study their habits and then adapt to them our remedies1 which you will see are more effective when well administered than those which we possess against insect pests of other classes4 ,i give here only the outlines of their natural history1 peculiarities that are common to all1 for it would be impossible to go into detail4 ,where there are exceptions of practical importance ,i will mention them4 ,in countries with a well defined winter the winged males appear as soon as white frosts are no more usual1 and copulate with the unwieldy limbless female1 that looks more like a gall or morbid excrescence1 than a living animal4 ,shortly after the young ones are perceptible near the withered body of their mother1 covered by waxy secretions that look somewhat like a feathery down4 ,these young ones are lively enough1 they move about with agility1 and it is not till high summer that they fasten themselves permanently1 and lose feet and antennae1 organs of locomotion and perception that are no more of any use to them4 7,there is a slight difference in this regard between different genera1 as for instance1 ,coccus and ,dorthesia retain these organs in different degrees of imperfection1 ,lecanium and ,aspidiotus losing every trace of them47 ,in this limbless1 senseless state the females remain fall and winter4 ,toward the end of winter these animated galls begin to swell1 and those containing males enter the state of the chrysalis1 from which the males emerge at the beginning of the warm season and fecundate the gall-like females1 which undergo neither chrysalis state nor any other change1 but die1 or we may call it dissolve into their offspring1 for there scarcely remains anything of them1 except a pruinous kind of down1 after having given birth to the young ones4 ,now we come to the practical deduction from these facts4 ,it is clear that the only time when the scalebug can emigrate and infest a new tree is the time when it is a larva1 that is1 when it has the power of locomotion4 ,in countries with a pronounced winter this time begins much later than with us1 but it ends about the same time1 that is1 the beginning of ,august4 ,i have seen the male of ,aspidiotus in ,february1 so that the active larva may be expected in ,march1 and the active ,lecanium ,hesperidum ,i have seen last year1 ,june #bg1 at ,colonel ,hooper's ranch in ,sonoma ,county4 ,we may safely fix the time of the active scalebug from ,march to ,august4 ,notwithstanding the agility of the young scalebug1 the voyage from one tree to another1 considering the minute size of the traveler1 is an undertaking but seldom succeeding1 but one female bug1 if we take into account its enormous fertility1 is sufficient to cover with its grandchildren next year a tree of moderate size4 ,besides there is another and much more effective way of transmigration by the kind assistance of the ant who colonizes the scalebug as well for its wax as it colonizes the ,aphis for its honey4 ,birds on their feathers and the gardener himself on his dress contribute to spread them4 ,but even the ant can not transplant the scalebug when it is once firmly fixed by its rostrum4 ,it is evident1 therefore1 that the time for the application of insecticides is the time when all the scalebugs are fixed1 that is about the end of ,july or beginning of ,august4 ,all previous application will clean the tree or plant only for a time1 and does not prevent a more or less numerous immigration from the neighboring vegetation1 especially if an ant-hill is not far off4 ,as to the insecticide1 there are to be applied two very effective ones1 each with its advantages and disadvantages4 #a4 ,petroleum and its different preparations4 #b4 ,lye or soap4 ,the petroleum is the best disinfectant4 ,it can safely be applied to any cutting or stem1 as long as it is not planted1 but is one of the most invidious substances when applied to vegetation in the garden1 or fields4 ,if effectively applied1 it can not be prevented from running down the bark of the tree and entering the ground1 where every drop binds a certain amount of earth to an insoluble substance1 in which state it remains for ever4 ,with every application the quantity of these insoluble compounds is augmented and sterility added4 ,if ,i am not mistaken1 it was near ,antwerp--at least ,i am certain it was in ,belgium--where the first experience of this kind is recorded4 ,in ,france1 preparations of coal tar have been recommended and have been lately used in the form of a paint4 ,may be that in this form the substance is not so apt to enter into combinations with the soil4 ,at any rate1 the method is of too recent a date to permit any conclusions about the final result of these applications1 as the invidious nature of the substance produces1 by gradual accumulation1 its effects1 which are not perceived until they are irreparable4 #b4 ,lye or soap4 ,the application of these insecticides requires more care1 and is therefore more troublesome4 ,but instead of attracting fertility from the soil1 they add to it4 ,in ,southern ,europe soap and water has been for many years the remedy against the ,lecanium ,hesperidum4 ,the method applied by the farmers in ,portugal1 as described to me by ,dr4 ,bleasdale1 is perhaps the most perfect one4 ,the ,portuguese have very well observed that the colonization of scalebugs always begins at the lowest end of the trunk and pretend1 therefore1 that the scalebug comes out of the ground4 ,this1 of course1 is not the case1 but may their interpretation be an error1 they have been practical enough in utilizing their observation about the invasion beginning near the roots4 ,they knead a ring of clay round the tree1 in which ring the soap water runs when they wash the tree1 and besides1 they fill frequently the little ditch formed by this ring4 ,this arrangement of course is only possible in climates of a rainy summer4 ,as it is our object to make our knowledge as available as possible for practical purposes1 ,i repeat for the benefit of cultivators the advice1 without repeating the reasoning3 #a4 ,use the petroleum for disinfecting imported trees and cuttings3 #b4 ,use soap for cleaning trees planted in your orchard4 #c4 ,if you must use the petroleum in your garden1 use it in ,august1 when a single application is sufficient4 99 99 99 99 99 ,,agricultural ,,items4 ,the exportation of dried apples from this country to ,france has greatly increased of late years1 and now it is said that a large part of this useful product comes back in the shape of ,normandy cider and light claret4 ,a4,b4 ,goodsell says in the ,new ,york ,tribune3 ,put your hen feed around the currants4 ,i did this twice a week during ,may and ,june1 and not a currant worm was seen1 while every leaf was eaten off other bushes #aej feet distant1 and not so treated4 ,buckwheat may be made profitable upon a piece of rough or newly cleared ground3 ,no other crop is so effective in mellowing rough1 cloddy land4 ,the seed in northern localities should be sown before ,july #ab2 otherwise early frosts may catch the crops4 ,grass and clover may sometimes be sown successfully with buckwheat4 ,the ,london ,news says3 ,of all poultry breeding1 the rearing of the goose in favorable situations is said to be the least troublesome and most profitable4 ,it is not surprising1 therefore1 that the trade has of late years been enormously developed4 ,geese will live1 and1 to a certain extent1 thrive on the coarsest of grasses4 ,when a cow has a depraved appetite1 and chews coarse1 indigestible things1 or licks the ground1 it indicates indigestion1 and she should have some physic4 ,give one pint and a half of linseed oil1 one pound of ,epsom salts1 and afterward give in some bran one ounce of salt and the same of ground ginger twice a week4 ,asiatic breeds of fowl lay eggs from deep chocolate through every shade of coffee color1 while the ,spanish1 ,hamburg1 and ,italian breeds are known for the pure white of the eggshell4 ,a cross1 however remote1 with ,asiatics1 will cause even the last-named breeds to lay an egg slightly tinted4 ,in setting out currant bushes care should be exercised not to place any buds under ground1 or they will push out as so many suckers4 ,currants are great feeders1 and should be highly manured4 ,to destroy the worm1 steep one table-spoonful of hellebore in a pint of water1 and sprinkle the bushes4 ,two or three sprinklings are sufficient for one season4 ,mr4 ,joseph ,harris1 of ,rochester1 makes a handy box for protecting melons and cucumbers from insect enemies4 ,take two strips of board of the required size1 and fasten them together with a piece of muslin1 so the muslin will form the top and two sides of the box4 ,then stretch into box form by inserting a small strip of wood as a brace between the two boards4 ,this makes a good1 serviceable box1 and1 when done with for the season1 it can be packed into a very small space1 by simply removing the brace and bringing the two board sides together4 ,as there is no patent on the contrivance1 anybody can make the boxes for himself4 ,mr4 ,c4 ,s4 ,read recently said before the ,london ,fanners' ,club3 ,american agriculturists get up earlier1 are better educated1 breed their stock more scientifically1 use more machinery1 and generally bring more brains to bear upon their work than the ,english farmer4 ,the practical conclusion is1 that if farmers in ,england worked hard1 lived frugally1 were clad as meanly as those of the ,states1 were content to drink filthy tea three times a day1 read more and hunted less1 the majority of them may continue to live in the old country4--,n4 ,e4 ,farmer4 99 99 99 99 99 ,,timber ,,trees4 ,a paper was read by ,sir ,r4 ,christison at the last meeting of the ,edinburgh ,botanical ,society upon the ,growth of ,wood in #ahhj4 ,in a former paper1 he said1 he endeavored to show that1 in the unfavorable season of #ahgi1 the growth of wood of all kinds of trees was materially less than in the comparatively favorable season of #ahgh4 ,he had now to state results of measurements of the same trees for the recent favorable season of #ahhj4 ,the previous autumn was unfavorable for the ripening of young wood1 and the trees in an unprepared condition were exposed during a great part of ,december1 #ahgi1 to an asperity of climate unprecedented in this latitude4 ,this might have led one to expect a falling off in the growth of wood1 and it appeared1 from comparison of measurements1 that1 with very few exceptions1 the growth of wood last year was even more below the average of favorable years than that of the bad year1 #ahgi4 ,thus1 in fifteen leaf-shedding trees of various species1 exclusive of the oak1 the average growth of trunk girth in three successive years was3 #ahgh1 #h-ajths2 #ahgi1 #de-ajjths2 #ahhj1 #c-ajths and a half4 ,in four specimens of the oak tribe1 the growth was3 #ahgh1 #h-ajths2 #ahgi1 #gg-ajjths2 #ahhj1 #ed-ajjths4 ,in twenty specimens of the evergreen ,pinaceae the growth was3 #ahgh1 #h-ajths2 #ahgi1 #g-ajths2 #ahhj1 #f-ajths and a half4 ,after giving details in regard to particular trees1 ,sir ,robert stated1 as general deductions from his observations1 that leaf-shedding trees1 exclusive of the oak1 suffered most2 that the evergreen ,pinaceae suffered least2 and that there was some power of resistance on the part of the oak tribe which was remarkable1 the power of resistance of the ,hungary oak being particularly deserving of attention4 ,in another communication on the extent of the season of growth1 ,sir ,robert stated1 as the result of observations on five leaf-shedding and five evergreen trees1 that in the case of the former1 even in a fine year1 the growth of wood was confined very nearly1 if not entirely1 to the months of ,june1 ,july1 and ,august2 while in the case of the latter growth commenced a month sooner1 terminating1 however1 about the same time4 ,mr4 ,a4 ,buchan said it was proposed that the inquiry should be taken up more extensively over ,scotland4 99 99 99 99 99 ,,medical ,,uses ,,of ,,figs4--,prof4 ,bouchut speaks 7,comptes ,rendus7 of some experiments he has made1 going to show that the milky juice of the fig-tree possesses a digestive power4 ,he also observed that1 when some of this preparation was mixed with animal tissue1 it preserved it it from decay for a long time4 ,this fact1 in connection with ,prof4 ,billroth's case of cancer of the breast1 which was so excessively foul smelling that all his deodorizers failed1 but which1 on applying a poultice made of dried figs cooked in milk1 the previously unbearable odor was entirely done away with1 gives an importance to this homely remedy not to be denied4--,medical ,press and ,circ4 99 99 99 99 99 ,,blood ,,rain4 ,the sensibilities of ignorant or superstitious people have at various times been alarmed by the different phenomena of so-called blood1 ink1 or sulphur rains4 ,ehrenberg very patiently collected records of the most prominent instances of these1 and published them in his treatise on the dust of trade winds4 ,some1 it is known1 are due to soot2 others1 to pollen of conifers or willows2 others1 to the production of fungi and algae4 ,many of the tales of the descent of showers of blood from the clouds which are so common in old chronicles1 depends1 says ,mr4 ,berkeley1 the mycologist1 upon the multitudinous production of infusorial insects or some of the lower algae4 ,to this category belongs the phenomenon known under the name of red snow4 ,one of the most peculiar and remarkable form1 which is apparently virulent only in very hot seasons1 is caused by the rapid production of little blood-red spots on cooked vegetables or decaying fungi1 so that provisions which were dressed only the previous day are covered with a bright scarlet coat1 which sometimes penetrates deeply into their substance4 ,this depends upon the growth of a little plant which has been referred to the algae1 under the name of ,palmellae prodigiosa4 ,the rapidity with which this little plant spreads over meat and vegetables is quite astonishing1 making them appear precisely as if spotted with arterial blood2 and what increases the illusion is1 that there are little detached specks1 exactly as if they had been squirted from a small artery4 ,the particles of which the substance is composed have an active molecular motion1 but the morphosis of the production has not yet been properly observed4 ,the color of the so-called blood rain is so beautiful that attempts have been made to use it as a dye1 and with some success2 and could the plant be reproduced with any constancy1 there seems little doubt that the color would stand4 ,on the same paste with the blood-rain there have been observed white1 blue1 and yellow spots1 which were not distinguishable in structure and character4 99 99 99 99 99 ,,topical ,,medication ,,in ,,phthisis4 ,dr4 ,g4,h4 ,mackenzie reports in the ,lancet an acute case of phthisis which was successfully treated by him by causing the patient to respire as continuously as possible1 through a respirator devised for the purpose1 an antiseptic atmosphere4 ,the result obtained appears to bear out the experiments of ,schller of ,greifswald1 who found that animals rendered artificially tuberculous were cured by being made to inhale creosote water for lengthened periods4 ,intermittent spraying or inhaling does not produce the same result4 ,in order to insure success the application to the lungs must be made continuously4 ,for this purpose ,dr4 ,mackenzie has used various volatile antiseptics1 such as creosote1 carbolic acid1 and thymol4 ,the latter1 however1 he has discarded as being too irritating and inefficient4 ,carbolic acid seems to be absorbed1 for it has been detected freely in the urine after it had been inhaled2 but this does not happen with creosote4 ,as absorption of the particular drug employed is not necessary1 and therefore not to be desired1 ,dr4 ,mackenzie now uses creosote only1 either pure or dissolved in one to three parts of rectified spirits4 ,whether1 says he1 the success so far attained is due to the antidotal action of creosote and carbolic acid on a specific tubercular neoplasm1 or to their action as preventives of septic poisoning from the local center in the lungs1 it is certain that their continuous1 steady use in the manner just described has a decidedly curative action in acute phthisis1 and is therefore1 worthy of an extended trial4 99 99 99 99 99 ,,on ,,the ,,law ,,of ,,avogadro ,,and ,,ampere4 ,the ,scientific ,american ,supplement of ,may #ad1ahha1 contains1 under this head1 ,mr4 ,wm4 ,h4 ,greene's objections to my demonstration 7in ,no4 #bgj of the same paper7 of the error of ,avogadro's hypothesis4 ,the most important part of my argument is based on the evidence afforded by the compound cyanogen2 and ,mr4 ,greene1 directing his attention to this subject in the first place1 states that because cyanogen combines with hydrogen or with chlorine1 without diminution of volumes1 ,i have concluded that the hypothesis falls to the ground4 ,this statement has impressed me with the conviction that ,mr4 ,greene has failed to perceive the difficulty which is at the bottom of the question1 and ,i will1 therefore1 present the subject more fully and comprehensively4 ,the molecule of any elementary body is1 on the ground of the hypothesis1 assumed to be a compound of two atoms1 and the molecule of carbon consequently ,c#bbd2 that of nitrogen ,n#bbh4 ,combination of the two1 according to the same hypothesis1 takes place by substitution2 the atoms are supposed to be set free and to exchange places1 forming a new compound different from the original only in this3 that each new particle contains an atom of each of the two different substances1 while each original particle consists of two identical atoms4 ,the product is1 therefore1 assumed to be1 and can1 under the circumstances1 be no other than particles of the composition ,,cn and weight #bf4 ,these particles are molecules1 according to the definition laid down1 just as ,c#b and ,n#b2 but there is this essential difference1 that the specific gravity of cyanogen gas1 #bf1 coincides with the molecular weight1 while the assumed molecular weight1 ,n#bbh1 is twice as great as the specific gravity of the gas1 ,n#ad4 ,in using the term molecular weight1 it is to be remembered that it does not express the weight of single molecules1 but only their relative weight1 millions of millions molecules being contained in the unit of volume4 ,but on the hypothesis that there is the same number of molecules in the same volume of any gas1 the specific gravities of gases can be1 and are1 identified with their molecular weights1 and1 on the ground of the hypothesis again1 the unit of the numbers which enter into every chemical reaction and constitute the molecular weight1 is stipulated to be that contained in two volumes4 ,the impossibility of the correctness of the hypothesis is now revealed by the fact just demonstrated1 that in the case of nitrogen the specific gravity does not coincide with the molecular weight4 ,if equal volumes contain the same number of molecules1 the specific gravities and the molecular weights must be the same2 and if the specific gravities and molecular weights are not the same1 equal volumes cannot contain the same number of molecules4 ,the assumed molecular weight of nitrogen is twice as great as the specific gravity1 but the molecular weight and the specific gravity of cyanogen are identical2 the number of molecules contained in one volume of cyanogen must1 therefore1 necessarily be twice as great as the number contained in one of nitrogen1 and this is fully and completely borne out by the chemical facts4 ,in saying that when cyanogen combines with chlorine there is naturally no condensation1 ,mr4 ,greene has no idea that this natural law is fatal to his artificial law of ,avogadro and ,ampere2 for1 continues he1 the theory is fulfilled by the actual reaction4 ,it is not4 ,the theory requires two vols4 of cyanogen and two vols4 of chlorine1 that is1 the unit of numbers1 to enter into reaction and to produce two vols4 of the compound4 ,but they produce four vols41 and the non-condensation is therefore in opposition to the theory4 ,it is true beyond doubt that the molecular weight of cyanogen chloride is contained in two volumes1 in spite of the hypothesis1 not on the ground of it2 two vols4 two vols41 producing four vols42 two vols4 could1 theoretically1 contain only half the unit of numbers1 and there seems to be no escape from the following general conclusions3 #a4 ,two vols4 of ,c,n,cl1 representing the unit of numbers1 the constituent weights1 ,c#ab1 ,n#ad1 ,cl#ce4e1 must each1 likewise1 represent the same number2 the molecular weight is1 therefore1 contained in one vol4 of ,n or ,cl1 but in two of ,c,n,cl and equal numbers are not contained in equal volumes4 #b4 ,the weights ,n#ad1 ,cl#ce4e occupy in the free state one volume1 but in the combination1 ,c,n,cl1 two volumes2 their specific gravity is1 therefore1 by chemical action reduced to one half4 ,the fact thus elicited of the variability and variation of the specific gravity is of fundamental importance and involves the irrelevancy of the mathematical demonstration of the hypothesis4 ,in this demonstration the specific gravity is assumed to be constant1 and this assumption not holding good1 and the number of molecules in unit of volume being reduced to one half when the specific gravity is reduced to the same extent by chemical action1 it is obvious that the mathematical proof must fail4 ,mr4 ,greene states that ,i have proceeded to demolish ,c4 ,clerk ,maxwell's conclusion from mathematical reasoning4 ,this is incorrect2 ,i have found no fault with the conclusion of the celebrated mathematician1 and consider his reasoning unimpeachable4 ,i am also of opinion that he is entitled to great credit and respect for the prominent part he has taken in the development of the kinetic theory1 and further think that it was for the chemists to produce the fact of the variability of the specific gravities1 which they would probably not have failed to do but for the prevalence of ,avogadro's hypothesis1 which is virtually the assertion of the constancy of the specific gravities4 #c4 ,the unit of numbers being represented by ,cl#ce4e1 it is likewise represented by ,h#a1 and as the product of the union of the two elements is ,h,cl1 #cf4e two vols41 combination takes place by addition and not by substitution2 consequently are #d4 ,the elementary molecules not compounds of atoms8 ,and the distinction between atoms and molecules is an artificial one1 not justified by the natural facts4 #e4 ,is the molecular weight not in every instance two volumes8 ,these conclusions overthrow all the fundamental assumptions on which the hypothesis rests1 and leave it1 in the full meaning of the term1 without support4 ,though ,mr4 ,greene states that my arguments are based upon entirely erroneous premises1 he has not even attempted to invalidate a single one of my premises4 ,as he considers the non-condensation to be natural in the case of cyanogen and chlorine1 the condensation of two vols4 of ,h,cl two vols4 of ,h#c,n to two vols4 of ,,nh#d;,cl ought to appear to him unnatural4 ,he1 however1 contends for it1 and tries1 on this solitary occasion1 to strengthen his opinion by authority1 though the proof1 if it could be given1 that ammonium chloride at the temperature of volatilization is decomposed into its two constituents1 would be insufficient to uphold the theory4 ,the ground on which ,mr4 ,greene assumes a partial decomposition at #cej ,c4 is the slight excess of the observed density 7#ad4dc7 over that corresponding to four vols4 7#ac4cge74 ,there is1 however1 a similar slight excess in the case of the vapor of ammonium cyanide1 the same values being respectively #aa4d and #aa2 and as this compound is volatile at #ajj ,c and1 at the same time1 is capable to exist at a very high temperature1 being formed by the union of carbon with ammonia1 nobody has ever1 as far as ,i am aware1 maintained that it is completely or partially decomposed at volatilization4 ,the excess of weight not being due1 therefore1 to such cause in this case1 it cannot be due to it in the other4 ,the question being whether the molecular weight of ammonium chloride is two vols4 or four vols41 an idea of the magnitude of the assumed decomposition is conveyed by the proportion of the volume of the decomposed salt to the volume of the non-decomposed1 and ,mr4 ,greene's quotation of the percentage of weight is irrelevant and misleading1 and his number not even correct4 ,a mixture containing #a4jee vols4 of spec4 gr4 #bf4ge #bh4bb and #ab4cb #ac4cge #afd4gh ------ ------ #ac4cge #aic has the spec4 gr4 #aic _/ #ac4cge #ad4dc4 ,the proportion in one vol4 of the undecomposed to the decomposed salt is1 therefore1 as #a to #aa4fh and the percentage of volume of the former #j4jghi1 and that of weight #bh4bb _/ #aic #j4adf1 and not #j4af4 ,it is not easy to imagine why a small fraction of the heavy molecules should be volatilized undecomposed1 the temperature being sufficient to decompose the great bulk4 ,marignac assumes1 indeed1 partial decomposition1 but the difficulties which he encountered in making the experiments1 on the results of which his opinion rests1 were so great that he himself accords to the numbers obtained by him only the value of a rough approximation4 ,the heat absorbed in volatilization will comprise the heat of combination as well as of aggregation1 if decomposition takes place1 and will therefore be the same as that set free at combination4 ,favre and ,silbermann found this to be #gdc4e at ordinary temperature1 from which ,marignac concludes that it would be #gae for the temperature #cej2 he found as the heat of volatilization #gjf1 but considers the probable exact value to be between #fag and #hah4a ,footnote #a3 ,see ,comptes ,rendus1 t4 lxvii41 p4 #hgg4 ,an uncertainty within so wide a range does not justify the confidence of ,mr4 ,greene which he expresses in these words3 ,it is1 therefore1 extremely probable that ammonium chloride is almost entirely dissociated1 even at the temperature of volatilization4 ,by ,boettinger's apparatus a decomposition may possibly have been demonstrated1 but it remains to be seen whether it is not due to some special cause4 ,when ,mr4 ,greene says that the relations between the physical properties of solids and liquids and their molecular composition can in no manner affect the laws of gases1 nobody is likely to dissent2 but the conclusion that their discussion is foreign to the question of the number of molecules in unit of volume does by no means follow4 ,if the specific gravity of a solid or the weight of unit of volume represents a certain number of molecules1 and is found to occupy two volumes in a compound of the solid with another solid1 the number of molecules in one volume is reduced to one half4 ,this ,i have shown to be the case in a number of compounds1 and the decrease of the specific gravity with increase of the complexity of composition appears to be a general law1 as may be concluded from the very low specific gravity of the most highly organized compounds1 for instance the fatty bodies1 the molecules of which1 being composed of very many constituents1 are of heavy weight2 and likewise the compounds which occur in combination with water and without it1 the simpler compound having invariably a greater specific gravity than the one combined with water2 for instance3 ,ba,h#b,o#b sp4 gr4 #d4die #h;,h#b,o #a4fef ,s#b;,h#b,o#b #c4fbe #h;,h#b,o #a4cif ,fe,s,o#d #c4ach #g;,h#b,o #a4heg and so in every other case4 ,this is now a recurrence of what takes place in gases1 and proves the fallacy of the hypothesis2 for if these compounds could be volatilized the vapor densities would necessarily vary in the inverse proportion of the degree of composition4 ,the reproach that ,berthelot has been endeavoring for nearly a quarter of a century to hold back the progress of scientific chemistry1 is a great and unjustifiable misrepresentation of the distinguished chemist and member of the ,institute of ,france1 who has done so much for thermo-chemistry1 and the more unfortunate as it seems to serve only the purpose of a prelude to the following sentences3 ,but ,mr4 ,vogel cannot claim1 as can ,mr4 ,berthelot1 any real work or experiment1 however roughly performed1 suggested by the desire to prove the truth of his own views4 ,let him not1 then1 bring forth old and long since explained discrepancies1 444 but when he will have discovered new or overlooked facts 444 chemists will gladly listen4 444 ,mr4 ,greene is here no longer occupied to investigate whether what ,i have said concerning ,avogadro's hypothesis is true or false1 but with myself he has become personal1 and in noticing his remarks my sole object is to contend against an error which is much prevalent4 ,if1 according to ,mr4 ,greene1 the real work of science consists in experimenting1 and conclusions unsupported by our own experiments have no value1 it does not appear for what purpose he has published his answer to my paper2 an experiment of his1 settling ,marignac's uncertain results1 would have justified the reliance he places on them4 ,the ground he takes is utterly untenable4 ,experiments are necessary to establish facts2 without them there could be no science1 and the highest credit is due to those who perform successfully difficult or costly experiments4 ,experimenting is1 however1 not the aim and object of science1 but the means to arrive at the truth2 and discoveries derived from accumulated and generally accepted facts are not the less valuable on account of not having been derived from new and special experiment4 ,it is1 further1 far from true that the real work of science consists in experimenting2 mental work is not less required1 and the greatest results have not been obtained by experimenters1 but by the mental labor of those who have1 from the study of established facts1 arrived at conclusions which the experimenters had failed to draw4 ,this is naturally so1 because a great generalization must explain all the facts involved1 and can be derived only from their study2 but the attention of the experimenter is necessarily absorbed by the special work he undertakes4 ,i refer to the three greatest events in science3 the discovery of the ,copernican system1 the three laws of ,kepler1 and ,newton's law of gravitation1 none of which is due to direct and special experimentation4 ,copernicus was an astronomer1 but the discovery of his system is due chiefly to his study of the complications of the ,ptolemaic system4 ,kepler is a memorable witness of what can be accomplished by skillful and persistent mental labor4 ,his discoveries were secrets extorted from nature by the most profound and laborious research4 ,the discovery of his third law is said to have occupied him seventeen years4 ,newton's great discovery is likewise the result of mental labor2 he was enabled to accomplish it by means of the laws of ,kepler1 the laws of falling bodies established by ,galileo1 and ,picard's exact measurement of a degree of a meridian4 ,if1 then1 mental work is as indispensable as experimental1 it is not less true that there are men more specially fitted for the one1 others for the other1 and the best interests of science will be served when experiments are made by those specially adapted1 skillful1 and favorably situated1 and the possibly greatest number of men1 able and willing to do mental work1 engage in extracting from the accumulated treasures of experimental science all the results which they are capable to yield4 ,any truth discovered by this means is clear gain1 and saves the waste of time1 labor1 and money spent in unnecessary experiment4 ,mr4 ,greene's zeal for experiment and depreciation of mental work would be in order1 if ways and means were to be found to render the advancement of science as difficult and slow as possible2 they are decidedly not in the interest of science1 and can not have been inspired by a desire for its promotion4 ,as the evidence of the specific heats of the fallacy of ,avogadro's hypothesis involves lengthy explanations1 the subject is reserved for another paper4 ,san ,francisco1 ,cal41 ,may1 #ahha4 ,e4 ,,vogel4 99 99 99 99 99 ,,dyeing ,,reds ,,with ,,artificial ,,alizarin4 ,by ,m4 ,,maurice ,,prud',,homme4 ,since several years1 the methods of madder dyeing have undergone a complete revolution1 the origin of which we will seek to point out4 ,when artificial alizarin1 thanks to the beautiful researches of ,graebe and ,liebermann1 made its industrial appearance in #ahfi1 it was soon found that the commercial product1 though yielding beautiful purples1 was incapable of producing brilliant reds 7,c4 ,koechlin74 ,while admitting that the new product was identical with the alizarin extracted from madder1 we were led to conclude that in order to produce fine ,turkey reds1 the coloring matters which accompany alizarin must play an important part4 ,this was the idea propounded by ,kuhlmann as far back as #ahbh 7,soc4 ,ind4 de ,mulhouse1 #di1 p4 #hf74 ,according to the researches of ,,mm4 ,schtzenberger and ,schiffert1 the coloring matters of madder are alizarin1 purpurin1 pseudopurpurin1 purpuroxanthin1 and an orange matter1 which ,m4 ,rosenstiehl considers identical with hydrated purpurin4 ,subsequently1 there have been added to the list an orange body1 purpuroxantho-carbonic acid of ,schunck and ,roemer1 identical with the munjistin found by ,stenhouse in the madder of ,india4 ,it was known that purpuroxanthin does not dye2 that pseudopurpurin is very easily transformed into purpurin1 and the uncertainty which was felt concerning hydrated purpurin left room merely for the hypothesis that ,turkey-red is obtained by the concurrent action of alizarin and purpurin4 ,in the meantime1 the manufacture of artificial alizarin became extended1 and a compound was sold as alizarin for reds4 ,it is now known1 thanks to the researches of ,perkin1 ,schunck1 ,roemer1 ,graebe1 and ,liebermann1 that in the manufacture of artificial alizarin there are produced three distinct coloring matters--alizarin1 iso or anthrapurpurin1 and flavopurpurin1 the two latter being isomers of purpurin4 ,we may remark that purpurin has not been obtained by direct synthesis4 ,m4 de ,lalande has produced it by the oxidation of alizarin4 ,alizarin is derived from monosulphanthraquinonic acid1 on melting with the hydrate of potassa or soda4 ,it is a dioxyanthraquinone4 ,anthrapurpurin and flavopurpurin are obtained from two isomeric disulphanthraquinonic acids1 improperly named isoanthraflavic and anthraflavic acids1 which are converted into anthrapurpurin and flavopurpurin by a more profound action of potassa4 ,these two bodies are trioxyanthraquinones4 ,we call to mind that alizarin dyes reds of a violet tone1 free from yellow2 roses with a blue cast and beautiful purples4 ,anthrapurpurin and flavopurpurin differ little from each other1 though the shades dyed with the latter are more yellow4 ,the reds produced with these coloring matters have a very bright yellowish reflection1 but the roses are too yellow and the purples incline to a dull gray4 ,experience with the madder colors shows that a mixture of alizarin and purpurin yields the most beautiful roses in the steam style1 but it is not the same in dyeing1 where the roses got with fleur de garance have never been equaled4 ,alizarins for reds all contain more or less of alizarin properly so-called1 from #a to #aj per cent41 along with anthrapurpurin and flavopurpurin4 ,this proportion does not affect the tone of the reds obtained further than by preventing them by having too yellow a tone4 ,the first use of the alizarins for reds was for application of styles1 that is colors containing at once the mordant and the coloring matter and fixed upon the cloth by the action of steam4 ,good steam-reds were easily obtained by using receipts originally designed for extracts of madder 7mixtures of alizarin and purpurin74 ,on the other hand1 the first attempts at dyeing red grounds and red pieces were not successful4 ,the custom of dyeing up to a brown with fleur and then lightening the shade by a succession of soapings and cleanings had much to do with this failure4 ,goods1 mordanted with alumina and dyed with alizarin for reds up to saturation1 never reach the brown tone given by fleur or garancin4 ,this tone is due in great part to the presence of fawn colored matters1 which the cleanings and soapings served to destroy or remove4 ,the same operations have also another end--to transform the purpurin into its hydrate1 which is brighter and more solid4 ,the shade1 in a word1 loses in depth and gains in brightness4 ,with alizarins for reds1 the case is quite different2 they contain no impurities to remove and no bodies which may gain brightness in consequence of chemical changes under the influence of the clearings and soapings4 ,these have only one result1 in addition to the formation of a lake of fatty acid1 that is to make the shades lose in intensity4 ,the method of subjecting reds got up with alizarin to the same treatment as madder-reds was faulty4 ,there appeared next a method of dyeing bases upon different principles4 ,the work of ,m4 ,schtzenberger 7#ahfd7 speaks of the use of sulpho-conjugated fatty acids for the fixation of aniline colors4 ,in ,england1 for a number of years1 dyed-reds had been padded in soap-baths and afterwards steamed to brighten the red4 ,in #ahfg1 ,braun and ,cordier1 of ,rouen1 exhibited ,turkey reds dyed in five days4 ,the pieces were passed through aluminate of soda at #ah ,b41 then through ammonium chloride1 washed1 dyed with garancin1 taken through an oil-bath1 dried and steamed for an hour1 and were finally cleared in the ordinary manner for ,turkey-reds4 ,the oil-bath was prepared by treating olive-oil with nitric acid4 ,this preparation1 invented by ,hirn1 was applied since #ahdf by ,braun 7,braun and ,cordier74 ,since #ahdi1 ,gros1 ,roman1 and ,marozeau1 of ,wesserling1 printed fine furniture styles by block upon pieces previously taken through sulpholeic acid4 ,when the pieces were steamed and washed the reds and roses were superior to the old dyed reds and roses produced at the cost of many sourings and soapings4 ,certain makers of aniline colors sold mixtures ready prepared for printing which were known to contain sulpholeic acids4 ,there was thus an idea in the air that sulpholeic acid1 under the influence of steam1 formed brilliant and solid lakes with coloring matters4 ,these facts detract in nothing from the merit of ,m4 ,horace ,koechlin1 who combined these scattered data into a true discovery4 ,the original process may be summed up under the following heads3 ,printing or padding with an aluminous mordant1 which is fixed and cleaned in the usual manner2 dyeing in alizarin for reds with addition of calcium acetate2 padding in sulpholeic acid and drying2 steaming and soaping4 ,the process was next introduced into ,england1 whence it returned with the following modifications2 in place of olive-oil or oleic acid1 castor oil was used1 as cheaper1 and the number of operations was reduced4 ,castor oil1 modified by sulphuric acid1 can be introduced at once into the dye-beck1 so that the fixation of the coloring matter as the lake of a fatty acid is effected in a single operation4 ,the dyeing was then followed by steaming and soaping4 ,for red on white grounds and for red grounds1 a mordant of red liquor at #e to #f ,b4 is printed on1 with a little salt of tin or nitro-muriate of tin4 ,it is fixed by oxidation at #cj to #ce ,c41 and dunged with cow-dung and chalk4 ,the pieces are then dyed with #a part alizarin for reds at #aj per cent41 to oil for reds 7containing #ej per cent471 #a-fth part acetate of lime at #ae ,b41 giving an hour at #gj and half an hour at the same heat4 ,wash1 pad in oil 7#ej to #ajj grms4 per liter of water71 dry on the drum1 or better1 in the hot flue1 and steam for three-quarters to an hour and a half4 ,the padding in oil is needless1 if sufficient oil has been used in dyeing1 and the pieces may be at once dried and steamed4 ,wash and soap for three-quarters of an hour at #fj4 ,give a second soaping if necessary4 ,if there is no fear of soiling the whites1 dye at a boil for the last half-hour1 which is in part equal to steaming4 ,red pieces and yarns may be dyed by the process just given for red grounds2 or1 prepare in neutral red oil1 in the proportion of #aej grms4 per liter of water for pieces and #ae kilos for #ajj kilos of yarns4 ,for pieces1 pad with an ordinary machine with rollers covered with calico4 ,dry the pieces in the drum1 and the yarn in the stove4 ,steam three-quarters of an hour at #a atmosphere4 ,mordant in pyrolignite of alumina at #aj ,b41 and wash thoroughly4 ,dye for an hour at #gj1 and half an hour longer at the same heat1 using for #ajj kilos of cloth or yarn #bj kilos alizarin at #aj per cent41 #aj kilos acetate of lime at #ah ,b41 and #e kilos sulpholeic acid4 ,steam for an hour4 ,soap for a longer or shorter time1 with or without the addition of soda crystals4 ,there may be added to the aluminous mordant a little salt of tin to raise the tone4 ,lastly1 aluminate of soda may be used as a mordant in place of red liquor or sulphate of alumina4 ,certain firms employ a so-called continuous process4 ,the pieces are passed into a cistern #f meters long and fitted with rollers4 ,this dye-bath contains1 from #c to #e grms4 of alizarin per liter of water1 and is heated to #ih4 ,the pieces take #e minutes to traverse this cistern1 and1 owing to the high temperature and the concentration of the dye liquor1 they come out perfectly dyed4 ,two pieces may even be passed through at once1 one above the other4 ,as the dye-bath becomes exhausted1 it must be recruited from time to time with fresh quantities of alizarin4 ,the great advantage of this method is that it economizes not merely time but coloring matter4 ,the quantity of acetate of lime to be employed in dyeing varies with the composition of the mordant and with that of the water4 ,schlumberger has shown that ,turkey-red contains #d molecules of alumina to #c of lime4 ,rosenstiehl has shown that alumina mordants are properly saturated if two equivalents of lime are used for each equivalent of alizarin1 if the dyeing is done without oil4 ,these figures require to be modified when the oil is put into the dye beck1 as it precipitates the lime4 ,acetate of lime at #ae ,b41 obtained by saturating acetic acid with chalk and adding a slight excess of acetic acid1 contains about mol4 acetate of lime4--,bulletin de la ,socit ,chimique de ,paris4 99 99 99 99 99 ,,the ,,scientific ,,american ,,supplement4 ,,published ,,weekly4 ,,terms ,,of ,,subscription1 #e ,a ,,year4 ,sent by mail1 postage prepaid1 to subscribers in any part of the ,united ,states or ,canada4 ,six dollars a year1 sent1 prepaid1 to any foreign country4 ,all the back numbers of ,,the ,,supplement1 from the commencement1 ,january #a1 #ahgf1 can be had4 ,price1 #aj cents each4 ,all the back volumes of ,,the ,,supplement can likewise be supplied4 ,two volumes are issued yearly4 ,price of each volume1 #b4ej1 stitched in paper1 or #c4ej1 bound in stiff covers4 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