,illustration ,,scientific ,,american ,,supplement ,,no4 #gid ,,new ,,york1 ,march #ba1 #ahia ,scientific ,american ,supplement4 ,vol4 ,,xxxi41 ,no4 #gid4 ,scientific ,american established #ahde ,scientific ,american ,supplement1 #e a year4 ,scientific ,american and ,supplement1 #g a year4 99 99 99 99 99 ,,table ,,of ,,contents ,i4 ,,botany4--,new ,race of ,dwarf ,dahlias4--,a new and valuable flowering plant1 with portrait of the introducer4--#a illustration4 ,,ii4 ,,chemistry4--,carbon in ,organic ,substances4--,by ,j4 ,,messinger4-- ,an improved method of determining carbon by inorganic combustions4--#a illustration4 ,,iii4 ,,civil ,,engineering4--,a ,new ,integrator4--,by ,prof4 ,,karl ,,pearson4 ,m4,a4--,an apparatus for use for the engineer in working up areas1 indicator diagrams1 etc4--#d illustrations4 ,best ,diameter of ,car ,wheels4--,the size of car wheels from the standpoint of ,american engineering4--,a plea for a moderate sized wheel4 ,improved ,overhead ,steam ,traveling ,crane4--,a crane constructed for use in steel works4--,great power and range4--#c illustrations4 ,some ,hints on ,spiking ,track4--,a most practical article for telling exactly how to conduct the operation on the ground4--#a illustration4 ,,iv4 ,,electricity4--,electrical ,laboratory for ,amateurs4--,by ,,geo4 ,m4 ,,hopkins4--,a simple collection of apparatus for conducting a complete series of electrical experiments4--#ag illustrations4 ,the ,action of the ,silent ,discharge on ,chlorine4--,how an electric discharge affects chlorine gas4--,an important negative result4 ,v4 ,,ethnology4--,some ,winnebago ,arts4--,an interesting article upon the arts of the ,winnebago ,indians4--,a recent paper before the ,new ,york ,academy of ,sciences4 ,,vi4 ,,medicine ,,and ,,hygiene4--,the ,philosophy of ,consumption4 --,by ,dr4 ,j4,s4 ,,christison4--,a review of the present theories of consumption1 and the role played in it by its bacillus4 ,,vii4 ,,music4--,spacing the ,frets on a ,banjo ,neck4--,by ,prof4 ,c4,w4 ,,maccord4--,a most practical treatment of this subject1 with full explanations4--#a illustration4 ,,viii4 ,,ordnance4--,high ,explosives in ,warfare4--,by ,commander ,f4,m4 ,,barber1 ,u4,s4,n4--,an elaborate review of modern explosives in their applicability to ordnance1 etc4 ,the ,experiments at the ,annapolis ,proving ,grounds4--,the recent tests at ,annapolis described and illustrated4--,views of the projectiles1 plates1 etc4--#c illustrations4 ,,ix4 ,,physics4--,aro-,picnometer4--,an entirely novel form of hydrometer1 of very extended use and application4--#a illustration4 ,x4 ,,technology4--,fabric for ,upholstery ,purposes4--,full technical description of the method of producing a new and characteristic fabric4--#a illustration4 ,gaseous ,illuminants4--,by ,prof4 ,,vivian ,b4 ,,lewes4--,continuation of this important article1 treating of the water gas and special processes1 with analyses4 ,glove ,making4--,early history of glove making in ,america4--,its present aspects and processes4 ,reversible ,ingrain or ,pro-,brussels ,carpet4--,an imitation of ,brussels carpet on the ,ingrain principle4--,full description of the process of making4--#c illustrations4 ,the ,manufacture and ,use of ,plaster of ,paris4--,an excellent treatment of a subject hitherto little written about4--,full particulars of the manufacturing process4 99 99 99 99 99 ,,improved ,,overhead ,,steam ,,traveling ,,crane4 ,we show in ,fig4 #a a general view1 and in ,figs4 #b and #c a side elevation and plan of an overhead steam traveling crane1 which has been constructed by ,mr4 ,thomas ,smith1 of ,rodley1 near ,leeds1 for use in a steel works1 to lift1 lower1 and travel with loads up to #ae tons4 ,for our engravings and description we are indebted to ,industries4 ,the crane is designed for hoisting and lowering while traveling transversely or longitudinally1 and all the movements are readily controlled from the cage1 which is placed at one end of and underneath the transverse beams1 and from which the load can be readily seen4 ,all the gear wheels are of steel and have double helical teeth2 the shafts are also of steel1 and the principal bearings are adjustable and bushed with hard gun metal4 ,this crane has a separate pair of engines for each motion1 which are supplied with steam by the multitubular boiler placed in the cage as shown4 ,the hoisting motions consist of double purchase gearing1 with grooved drum1 treble best iron chain with block and hook1 driven by one pair of #h in4 by #ab in4 engines4 ,the transverse traveling motion consists of gearing1 chain1 and carriage on four tram wheels1 with grooved chain pulleys1 driven by the second pair of #f in4 by #aj in4 engines1 and the longitudinal traveling motion driven by the other pair of #h in4 by #ab in4 engines4 ,the transverse beams are wrought iron riveted box girders1 firmly secured to the end carriages1 which are mounted on four double flanged steel-tired wheels1 set to suit a #ch foot span4 ,illustration3 ,,improved ,,overhead ,,traveling ,,crane ,illustration3 ,,fig4 #b ,,side ,,elevation ,illustration3 ,,fig4 #c ,,plan 99 99 99 99 99 ,,best ,,diameter ,,car ,,wheels4#a ,footnote #a3 ,by ,samuel ,porcher1 assistant engineer motive power department1 ,pennsylvania ,railroad4 ,read at a regular meeting of the ,new ,york ,railroad ,club1 ,feb4 #ai1 #ahia4 ,it goes almost without saying that for any given service we want the best car wheel1 and in general it is evident that this is the one best adapted to the efficient1 safe and prompt movement of trains1 to the necessary limitations improved by details of construction1 and also the one most economical in maintenance and manufacture4 ,it is our aim this afternoon to look into this question in so far as the diameter of the wheel affects it1 and in doing it we must consider what liability there is to breakage or derangement of the parts of the wheel1 hot journals1 bent axles1 the effect of the weight of the wheel itself1 and the effect upon the track and riding of the car1 handling at wrecks and in the shop1 the first cost of repairs1 the mileage1 methods of manufacture1 the service for which the wheel is intended and the material of which it is made4 ,confining ourselves to freight and passenger service1 and to cast iron and steel wheels in the general acceptation of the term as being the most interesting1 we know that cast iron is not as strong as wrought iron or steel1 that the tendency of a rotating wheel to burst is directly proportional to its diameter1 and that the difficulty of making a suitable and perfect casting increases with the diameter4 ,cast iron1 therefore1 would receive no attention if it were not for its far greater cheapness as compared to wrought iron or steel4 ,this fact makes its use either wholly or in part very desirable for freight service1 and even causes some roads in this country1 notably the one with which ,i am connected1 to find it profitable to develop and perfect the cast iron wheel for use in all but special cases4 ,steel1 on the other hand1 notwithstanding its great cost1 is coming more and more into favor1 and has the great recommendations of strength and safety4 ,it is also of such a nature that wheels tired with it run much further before being unfit for further service than those made of cast iron1 and consequently renewals are less frequent4 ,the inference would seem to be that a combination of steel and cast iron would effect the desirable safeness with the greatest cheapness2 but up to the present this state of affairs has not yet been realized to the proper extent1 because of the labor and cost necessary to accomplish this combination and the weakness involved in the manner of joining the two kinds of material together4 ,taking up the consideration of the diameter of the wheel now1 and allowing that on the score of economy cast iron must be used for wheels in freight service1 we are led to reflect that here heavy loads are carried1 and there is a growing tendency to increase them by letting the floor of the car down to a level with the draft timbers4 ,all this makes it desirable to have the wheels strong and small to avoid bent axles and broken flanges1 to enable us to build a strong truck1 to reduce the dead weight of cars to a minimum1 and have wrecks quickly cleared away4 ,the time has not yet come when we have to consider seriously hot journals arising from high speed on freight trains1 and a reasonable degree only of easy riding is required4 ,the effect on the track is1 however1 a matter of moment4 ,judging from the above1 ,i should say that no wheel larger than one #cc in4 in diameter should be used under freight cars4 ,since experience in passenger service shows that larger cast iron wheels do not make greater mileage and cost more per #a1jjj miles run1 and that cast iron wheels smaller than #cc in41 while sometimes costing less per #a1jjj miles run1 are more troublesome in the end1 it is apparent that #cc in4 is the best diameter for the wheels we have to use in freight service4 ,when we take up passenger service we come to a much more difficult and interesting part of the subject1 for here we must consider it in all its bearings1 and meet the complications that varying conditions of place and service impose4 ,in consequence1 ,i do not believe we can recommend one diameter for all passenger car wheels although such a state of simplicity would be most desirable4 ,for instance1 in a sandy country where competition is active1 and consequently speed is high and maintained for a length of time without interruption1 ,i would scarcely hesitate to recommend the use of cast iron for car wheels1 because steel will wear out so rapidly in such a place that its use will be unsatisfactory4 ,if then cast iron is used1 we will find that we cannot make with it as large a wheel as we may determine is desirable when steel is used4 ,and just to follow this line out to its close ,i will state here that we find that #cf in4 seems to be the maximum satisfactory diameter for cast iron wheels1 because this size does not give greater mileage than #cc in41 costs more per #a1jjj miles run1 and seems to be nearer the limit for good foundry results4 ,on the other hand1 a #cf in4 wheel rides well and gives immunity from hot boxes--a most fruitful source of annoyance in sandy districts4 ,it is also easily applicable where all modern appliances under the car are found1 including good brake rigging4 ,in all passenger service1 then1 ,i would recommend #cf in4 as the best diameter for cast iron wheels4 ,next taking up steel wheels1 a great deal might be said about the different makes and patterns1 but as the diameter of wheels of this kind is not limited practically to any extent by the methods of manufacture1 except as to the fastening of the wheel and tire together1 we will note this point only4 ,tires might be so deeply cut into for the introduction of a retaining ring that a small wheel would be unduly weakened after a few turnings4 ,on the other hand1 when centers and tires are held together by springing the former into the latter under pressure1 it is possible that a tire of larger diameter might be overstrained4 ,but allowing that the method of manufacture does not limit the diameter of a steel wheel as it does a cast iron one1 the claim that the larger diameter is the best is open to debate at least1 and1 ,i believe1 is proved to the contrary on several accounts4 ,it is argued that increasing the diameter of a wheel increases its total mileage in proportion1 or even more4 ,whether this be so or not1 there are two other very objectionable features that come with an increase in diameter--the wheel becomes more costly and weighs more1 without giving in all cases a proportionate return4 ,we have to do more work in starting and stopping1 and in lifting the large wheel over the hills1 and when the diameter exceeds a certain figure we have to pay more per #a1jjj miles run4 ,i am very firmly convinced that the matter of dead weight should receive more attention than it does1 with a view to reducing it4 ,the weight of six pairs of #db in4 wheels and axles alone is #ae1jjj to #af1jjj lb4 ,the matter of brakes is coming up for more attention in these days of high speed1 heavy cars and crowded roads1 and the total available braking power1 which has hitherto been but partially taken advantage of1 must be fully utilized4 ,i refer to the fact that many of our wheels in six-wheel trucks have gone unbraked where they should not4 ,as the height of cars and length of trucks cannot well be increased for obvious reasons1 it is necessary to keep the size of the wheels within the limits that will enable us to get efficient brakes on all of them that carry any weight4 ,this is not easy with a #db in4 wheel in a six-wheel truck1 which is usually the kind that requires most adjustment and repairs after long runs4 ,the ,pullman ,co4 has recognized this fact1 and is now replacing its #db in4 wheel with one #ch in4 in diameter4 ,a #db in4 wheel with #d in4 journal has a greater leverage wherewith to overcome the resistance of journal friction than the #ch in4 wheel with the same journal1 and even more than the #cf in4 and #cc in4 wheels with #cc_/d in4 and #ca_/b in4 journals respectively1 but the fact remains that the same amount of work has to be done in overcoming the friction in each case1 and what may be gained in ease of starting with the large wheel is lost in time necessary to do it1 and in the extra weight put into motion4 ,a large wheel increases the liability to bent axles in curving on account of greater leverage unless the size and weight of the axle are increased to correspond1 and the wheel itself must be made stronger4 ,a four or six wheel truck will not retain its squareness and dependent good riding qualities so well with #db in4 wheels as with #cc in4 ones4 ,besides the brakes1 the pipes for air and steam under the cars interfere with large wheels1 and as a consequence of all this #db in4 wheels have been replaced by #cf in4 ones to some extent in some places with satisfactory results4 ,on one road in particular so strong is the inclination away from large wheels that #cj in4 is advocated as the proper size for passenger cars4 ,on the other hand1 there is no doubt a car wheel may be too small1 for the tires of small wheels probably do not get as much working up under the rolls1 and therefore are not as tough or homogeneous4 ,small wheels are more destructive to frogs and rail joints4 ,they revolve faster at a given speed1 and when below a certain size increase the liability to hot journals if carrying the weight they can bear without detriment to the rest of the wheel4 ,speed alone ,i am not willing to admit is the most prolific source of hot boxes4 ,the weight per square inch upon the bearing is a very important factor4 ,i have found by careful examination of a great many cars that the number of hot boxes bears a close relation to the weight per square inch on the journal and the character of lubrication1 and is not so much affected by the size of wheel or speed4 ,these observations were made upon #db in41 #cf in4 and #cc in4 wheels in the same trains4 ,we find1 furthermore1 that while a #c-c_/h in4 journal on a #cc in4 wheel is apt to heat under our passenger coaches1 a #cc_/d in41 even when worn #c-e_/h in41 journal on a #cf in4 wheel runs uniformly cool4 ,in #ahij on one division there were about #ahj hot boxes with the small wheel1 against #bi with the larger one1 with a preponderance of the latter size in service and cars of the same weight over them4 ,i do not know that there is any more tendency for a large wheel to slide than a small one under the action of the brakes1 but large wheels wear out more brake shoes than small ones1 if there is any difference in this particular4 ,my conclusions are that #db in4 is too large a diameter for steel wheels in ordinary passenger service1 and that #cf in4 is right4 ,but as steel-tired wheels usually become #c in4 smaller in diameter before wearing out1 the wheel should be about #ch in4 in diameter when new4 ,such a wheel can be easily put under all passenger cars and will not have become too small when worn out4 ,a great many roads are using #cf in4 wheels1 but when their tires have lost #c in4 diameter they have become #cc in4 wheels1 which ,i think too small4 ,there are many things ,i have left unsaid1 and ,i am aware that some of the members of the club have had most satisfactory service with #db in4 wheels so far as exemption from all trouble is concerned1 and others have never seen any reason for departing from the most used size of #cc in4 ,one more word about lightness4 ,a wrought iron or cast steel center1 #h or #i light spokes on a light rim inside a steel tire1 makes the lightest wheel1 and one that ought to be in this country1 as it is elsewhere1 the cheapest not made of cast iron4 99 99 99 99 99 ,a ,,new ,,integrator4#a ,footnote #a3 ,a paper read before the ,university ,college ,engineering ,society on ,january #bb4--;,engineering4 ,,by ,,professor ,,karl ,,pearson1 ,m4,a4 ,as ,i fear the title of my paper to our ,society to-night contains two misstatements of fact in its three words1 ,i must commence by correcting it4 ,in the first place1 the instrument to which ,i propose to draw your attention to-night is1 in the narrow sense of the words1 neither an integrator nor new4 ,the name integrator has been especially applied to a class of instruments which measure off on a scale attached to them the magnitude of an area1 arc1 or other quantity4 ,such instruments do not1 as a rule1 represent their results graphically1 and we may take1 as characteristic examples of them1 ,amsler's planimeter and some of the sphere integrating machines4 ,an integrator which draws an absolute picture of the sum or integral is better termed an integraph4 ,the distinction is an important and valuable one1 for while the integraph theoretically can do all the work of the integrator1 the latter gives us in niggardly fashion one narrow answer1 et prterea nil4 ,the superiority of the integraph over the integrator cannot be better pointed out than by a concrete example4 ,the integrator could determine by one process1 the bending moment1 from the shear curve1 at any one chosen point of a beam2 the integraph would1 by an equally simple single process1 gives us the bending moment at all points of the beam4 ,in the language of the mathematician1 the integrator gives only that miserly result1 a definite integral1 but the integraph yields an indefinite integral1 a picture of the result at all times or all points--a much greater boon in most mechanical and physical investigations4 ,members of our ,society as students of ,university ,college have probably become acquainted with a process termed drawing the sum curve from the primitive curve4 ,many have probably found this process somewhat wearisome2 but this is not an unmixed evil1 as the irksomeness of any manual process has more than once led to the invention of a valuable machine by the would-be idler4 ,thus our innate desire to take things easy is a real incentive to progress4 ,it was some such desire as this on my part which led me1 three years ago1 to inquire whether a practical instrument had not been1 or could not be1 constructed to draw sum curves4 ,such an instrument is an integraph1 and the one ,i have to describe to you to-night is the outcome of that inquiry4 ,it is something better than my title1 for it is an integraph1 and not an integrator4 ,illustration3 ,a ,,new ,,integrator ,before ,i turn to its claims to be considered new1 ,i must first remind you of the importance of an instrument of this kind to the draughtsman4 ,i put aside its purely mechanical applications1 where it has been1 or can be1 attached to the indicators of steam engines1 to dynamometers1 dynamos1 and a variety of other instruments where mechanical integration is of value4 ,these lie entirely outside my field1 and ,i propose only to refer to a few of the possible services of the integrator when used by hand1 and not attached to a machine4 ,the simple finding of areas we may omit1 as the planimeter will do that equally well4 ,but of purely graphical processes which the integraph will undertake for us1 ,i may mention the discovery of centroids1 of moments of inertia 7or second moments71 of a scale of logarithms1 of the real roots of cubic equations1 and of equations of higher order 7with1 however1 increasing labor74 ,further1 the calculation of the cost of cutting and embanking for railways by the method of ,bruckner ,culmann1 the solution of a very considerable number of rather complex differential equations1 various problems in the storage of water1 and a great variety of statistical questions may all be completely dealt with1 or very much simplified by aid of the integraph4 ,in graphical statics proper the integraph draws successively the curves of shear1 bending moment slope1 and deflection for simple beams2 it does the like service for continuous beams1 after certain analytical or graphical calculations have first been made2 it can further lighten greatly the graphical work in the treatment of masonry arches and of metal ribs4 ,in graphical hydrostatics it finds centers of pressure and gives a complete solution for the shear and bending moment1 curves in ships1 besides curves for their stability4 ,in graphical dynamics the applications of the integraph seem still more numerous4 ,it enables us to pass from curves of acceleration to curves of speed1 and from curves of speed to curves of position4 ,applied to the curve of energy of either a particle or the index point of a rigid body1 it enables us by the aid of easy auxiliary processes to ascertain speeds and curves of action4 ,in a slightly altered form1 that of inverse summation1 we can pass from curves of action to curves of position1 and deal with a great range of resisted motions1 the analysis of which still puzzles the pure mathematician2 the variations of motion in flywheels1 connecting rods1 and innumerable other parts of mechanism1 may all be calculated with much greater ease by the aid of an integraph4 ,shortly1 it is the fundamental instrument of graphic dynamics4 ,it would be needless to further multiply the instances of its application2 the questions we have rather to ask are3 ,can a practical instrument be made which will serve all these purposes8 ,has such an instrument been already put upon the market8 ,if ,i have to answer these questions in the negative1 it is rather a doubtful negative1 for the instrument ,i have to show you to-night goes so far1 and suggests so many modifications and possibilities1 which would take it so much further1 that it is very close to bringing the practical solution to the problem4 ,let me here lay down the conditions which seem essential to a practical integraph4 ,these are1 ,i think1 the following3 #a4 ,the price must be such that it is within the reach of the ordinary draughtsman's pocket4 ,the ,amsler's planimeter at #b #ajs4 or #c may be said to satisfy this first condition4 ,the price for the first complex integraph designed by ,coradi was #bd to #cj4 ,the modified form in which ,i show it to-night is estimated to cost retail #ad4 ,till an equally efficient instrument can be produced for #e ,i shall not consider the price practical4 ,if the error of its reading be not sensibly greater than that of a planimeter1 it is certainly worth double the money4 #b4 ,the instrument must not be liable to get out of order by fair handling and a reasonable amount of wear and tear4 ,i cannot speak at present with certainty as to how far our integraph satisfies this condition2 it is rather too complex to quite win my confidence in this respect4 #c4 ,it must be capable of being used on the ordinary drawing board1 and of having a fairly wide range on it1 i4e41 it must not be limited to working where the primitive is at one part only of the board4 ,this condition takes out of every day practical drawing use the integraph invented by ,professors ,james and ,sir ,william ,thomson1 in which the sum curve is drawn on a revolving cylinder4 ,it is essential that the sum curve should be drawn on the board not far from the primitive1 and that this sum curve can be summed once or twice again without difficulty4 ,the time involved in drawing the four sum curves1 for example1 required in passing from the load curve to the deflection curve of a simple beam1 if these curves were drawn on different pieces of paper and had to be shifted on and off cylinders1 would probably be as long as the ordinary graphical processes4 ,coradi's integraph works on an ordinary drawing board1 but since there are nearly #aj inches between the guide point and tracer1 the sum curve is thrown #aj inches behind the primitive in each integration4 ,thus a double summation requires say #bf inches of board1 and it is impossible to integrate thrice without reproducing the primitive4 ,the fact that the primitive and sum curve are not plotted off on the same base is also troublesome for comparison1 and involves scaling of a new base for each summation4 ,i have endeavored to obviate this by always drawing the second sum curve on a thin piece of paper pinned to the board1 which can then be moved back to the position of the first primitive4 ,but this shifting1 of course1 involves additional labor1 and is also a source of error4 ,i should like to see the trace and guide chariots on the same line of rails1 one below the other1 were this possible without producing the bad effect of a skew1 pull or push4 #d4 ,the practical integraph must not have a greater maximum error than #b per cent4 ,the mathematical calculations1 which are correct to five or six places of decimals1 are only a source of danger to the practical calculator of stresses and strains4 ,they tend to disguise the important fact that he cannot possibly know the properties of the material within #b per cent4 error1 and therefore there is not only a waste of time1 but a false feeling of accuracy engendered by human and mechanical calculation which is over-refined for technical purposes4 ,for comparative purposes ,i have measured the areas of circles of #a inch1 #b inches1 and #c inches radius1 the guide being taken round the circumference by means of a control lineal1 first with an ordinary ,amsler's planimeter and then with the integraph4 ,i have obtained the following results3 ---------------------------------------- --------------------------- ,by integraph4 ,radius ,by -------------------------------- of ,calculated ,planimeter4 ,upper ,upper circle4 areas4 ,middle4 end4 ,middle4 end4 p#b in4 p#b in4 p#d in4 p#d in4 ---------------------------------------- ------------------------ in4 #a #c4adaei #c4adj #c4adj #c4ach #c4abj #c4abj #b #ab4effcf #ab4ee #ab4cf99 #ab4edf #ab4efh #ab4eeb #c #bh4bgdca #bh4bd 444444 444444 #bh4bhj #bh4bhh ---------------------------------------- ------------------------ 99 ,cross bar had to be moved during tracing4 ,from this it follows that the error of the planimeter is less than #j4a per cent4 and that of the integraph about #j4e per cent4 ,obviously we could make this error much less if we excluded small areas measured with large polar distances1 or such polar distances that the cross bar must be shifted4 ,excluding such cases1 we see that the accuracy of the integraph scarcely falls behind that of the planimeter and is quite efficient for practical purposes4 ,it must be borne in mind that the above measurements were made with the control lineal1 an arrangement which carries the guide round a circle of the exact test area4 ,in most cases the curve has to be followed by hand1 and the error will be greater--greater probably for the integraph than for the planimeter1 as the former is distinctly hard to guide well4 ,i think1 then1 we should be safe in saying that the error of the integraph is not likely to be greater and is probably less than #b per cent41 so that in this respect the instrument may be considered a practical one4 #e4 ,a further condition for a good integraph is that it should have a wide range of polar distances1 and that it should be easily set at those distances4 ,one of the conditions ,i gave to the maker of the instrument was that it should be able to take all polar distances from one to ten half-inches4 ,this condition he can scarcely be said to have fulfilled4 ,with polar distances of #a_/b inch and #a inch1 the machine works unsatisfactorily1 which indeed might have been foreseen from the construction of its sliding bars4 ,it works best from #b4e inches to #e inches1 and this is the range to which ,i think we ought to confine the present type of instrument4 ,as the last conditions ,i may note that3 #f4 ,a practical integraph ought to be easy to read4 #g4 ,draw a good clear curve4 ,the scale on the present instrument is very inconvenient1 as it is often almost out of sight2 the curve it draws1 on the other hand1 ,i consider very satisfactory1 when the pencil is loaded1 say1 with a planimeter weight4 ,on the whole1 ,i think you will agree with me that this integraph goes a good way1 if not the whole way1 toward fulfilling the conditions of a practical instrument4 ,i next turn to its construction and the claim it has to be considered in any way new4 ,let me briefly remind our members of the process by which an element ,q ,r of the sum curve 7,fig4 #a7 corresponding to the point ,p on the primitive is drawn2 ,p ,m being the mid-ordinate of ,l ,n1 a horizontal element1 ,p ,b is drawn perpendicular to any vertical line ,a ,b2 and ,o ,a being a constant distance termed the base or polar distance1 ,q ,r is drawn between the ordinates of ,l and ,w1 parallel to ,o ,b4 ,if ,p' be the point where ,p ,m meets ,q ,r1 we note the following relationship of ,p' to ,p4 #a4 ,if ,p moves along a horizontal line1 ,o ,b remains unchanged1 and1 therefore1 ,q ,r or ,p' must move in the straight line ,q ,r parallel to ,o ,b4 #b4 ,if ,p moves along a vertical line1 ,p' does not change1 but ,q ,r turns round it1 remaining parallel to ,o ,b4 ,illustration3 ,,fig4 #a1 #b1 #c ,without taking the trouble1 as ,i ought to have done1 to inquire what previous investigations had achieved in this matter1 ,i thought1 three years ago1 ,i could get an apparatus to save me the trouble of drawing sum curves1 made somewhat after the following fashion4 ,p 7,fig4 #b7 is the guide or point to be taken round the primitive4 ,it is attached to a block1 ,d1 which works along the bar1 ,b ,c1 which in its turn moves on the four wheels1 e e f f1 upon the frame ,r ,s ,u ,t fixed upon the drawing board4 ,o ,a is fixed perpendicular to ,r ,u1 and is such that ,o may be fixed at various points to determine the polar distance4 ,o ,b ,d is a light bar passing freely through ,b and forming one side of a parallel ruler of two or more points1 g g1 h h1 i i4 ,along i i is a slot and in this works a loaded block containing a wheel ,p'1 whose plane is always parallel to i i4 ,this block also passes through a slot in ,d ,e1 an arm at right angles to ,b ,c4 ,a little consideration will show that ,p'1 if worked at all1 would trace out the sum curve of ,p4 ,it was only when ,i showed the rough idea of this to ,professor ,kennedy1 with the view of ascertaining what would be the amount of back-lash and friction1 that ,i learned that ,mr4 ,boys had already invented a very similar integrator4 ,in his model the double parallel ruler is replaced by two endless strings and pulleys1 and the bar1 ,b ,c1 by a ,t square4 ,although this integrator was afterward made in a less crude form1 ,i do not think it has ever been a practical instrument for the draughtsman4 ,shortly afterward ,i came across a work by ,abdank-,abakanowicz1 entitled ,les ,integraphes1 being a study of a new kind of mechanical integrator4 ,the new kind of integrator was really only an independent version of ,boys' instrument1 but in many respects a great improvement4 ,the real merit will ultimately belong to the scientific instrument maker who constructs an instrument reasonably cheap and capable of efficient practical service4 ,abdank-,abakanowicz's integrator however certainly went further in the practical direction than any previously constructed4 ,the drawing board machines1 it is true1 of rather a complex nature1 were actually exhibited to the ,paris ,academy1 but no more have been made4 ,the instrument before me was made by ,coradi1 of ,zurich1 on conditions laid down by me1 namely1 that the cost should not exceed #ad1 and that polar distances should range between one and ten half-inches4 ,the first machine made by ,coradi on these lines was1 by a misunderstanding1 sold in ,germany1 but the one ,i exhibit is the first1 ,i believe1 that has reached ,england1 and to this extent ,i may1 perhaps1 be permitted to call it new4 ,i look upon it rather as a suggestion upon which a still more practical instrument can be made in this country than as a perfect model4 ,i believe there would be a wide sale for such an instrument were it once generally known to exist1 and1 what is more to work efficiently4 ,it remains for me to point out in what the ,abdank-,abakanowicz1 or1 rather1 ,coradi1 integraph differs from ,boys' instrument4 ,two points deserve special attention4 ,in the first place1 the fixed frame is abolished1 and the horizontal motion of ,p 7,fig4 #c71 the guide point1 is produced by putting the whole frame on friction rollers2 in the second place1 as a necessary result of the first change1 the guide point carries about with it its own polar system1 which renders the changes in length of rays much more manageable4 f f1 f' f' is a frame moving on four roughed wheels1 e e e e1 so that it can only move in the direction1 f'1 which we may term horizontal4 f f and f' f' are rails guiding the chariots1 ,a and ,b1 from f to f and from f' to f'4 ,of these chariots1 ,a contains the guide point1 ,p1 to trace out the primitive with1 and ,b the pencil1 ,p'1 to draw the sum curve1 i4e41 the tracer4 ,the chariot1 ,b1 like ,boys' tracer1 is heavily loaded4 g g is a horizontal bar rigidly attached to the crossbars1 q q and q' q'1 of the frame4 ,on g g is a movable pivot1 to which h1 which determines the pole1 k#j h being the polar distance4 k#j is the position of a second point1 k1 on the chariot1 ,a1 when the guide point1 ,p1 is on the initial line1 g g4 l l is a bar with a long slot in it1 in which work the pivots1 h and k2 this bar represents the ray4 ,a projecting arm k k' has been introduced to enable me to shorten the polar distance down to #b in4 and under by removing the pivot1 k to k'4 m m is a bar attached to the block1 n1 which runs on l l1 so that m m is always perpendicular to l l4 ,on the chariot1 ,b1 is another bar1 m' m'1 capable of turning round the pivot1 d1 and always maintained parallel to m m by the rods1 m m'1 m m'4 ,attached to m' m' is a wheel1 w1 whose axis is parallel to m' m'4 ,this wheel1 therefore1 always moves perpendicular to m' m'1 and therefore to m m2 hence it moves parallel to the ray1 h k4 ,a pencil1 ,p'1 attached traces out the sum curve4 ,if we wish to use the machine as an integrator1 we have merely to measure the vertical distance traversed by ,p'1 or the distance ,b has run along f' f'4 ,this is done by means of a scale on f f'4 ,if k be brought down to k#j1 w runs parallel to g g1 or ,p' traces out a horizontal straight line1 which is thus the base line4 ,if k be fixed as near as possible to k#j1 which is done by means of a screw in f f at k#j1 the chariot1 ,b1 can be run down f' f' as nearly opposite to k#j as can be guessed at2 a horizontal line may then be drawn as base line1 and the guide point1 ,p1 brought into this line by a clamping screw with which it is provided4 ,the instrument is then ready for action4 ,there is a brake on one of the roughed wheels to check or stop the motion of the integraph when required4 ,the instrument works best when the chariots1 ,a and ,b1 are about opposite to each other2 when they are at opposite extremities of f f and f' f' respectively1 the pull at ,p tends to produce a skewing couple4 ,if the chariot1 ,b1 could be put upon f f and work1 if needful1 by a double parallelogram from m m1 we should have1 excepting the skew pull1 some great practical advantages4 ,we might throw the whole of the weight of the machine on the one pair of friction wheels1 and replace the other pair by a single wheel1 the portion q' f' f' q' of the machine virtually disappearing4 ,three wheels1 of course1 would be a real improvement4 ,further1 we should have the sum curve and primitive drawn to the same base line1 and the simplification in the number of parts ought largely to reduce the cost of the instrument4 ,to be able to perform inverse summation 7which in the language of differential calculus is to find y as a function of x1 when we are given yf7dy_/dx71 and not dy_/dxf7x7 as usual71 we only want a means of making the plane of the wheel1 w1 parallel instead of perpendicular to m' m'1 and it is easy to design a modification in the construction which will allow of this change4 ,i hope the above description of the integraph may have made its construction and method of working sufficiently clear4 ,those of you who have a taste for mechanical work1 and the necessary tools1 might1 ,i think1 with some patience1 construct a workable integraph4 ,i expect the pivots would be the hardest part of the work4 ,i hope1 some day1 myself to have another instrument made with a more readily changeable polar distance1 with trace and guide points working in the same vertical1 and a wheel permitting of inverse summation4 ,if this project is ever carried out1 ,i hope ,i may be permitted to communicate further particulars to our society4 99 99 99 99 99 ,after some forty years of immersion in the waters of the pool of ,echoschacht1 not far from ,hermannstadt1 several human bodies have been brought to the surface in a state of perfect preservation4 99 99 99 99 99 ,,some ,,hints ,,on ,,spiking ,,track4 ,the usual dimensions of track spikes are #ea_/b ,x #i4af inches square1 their weight about half a pound each4 ,their common defects are brittleness and imperfect points4 ,in spiking track1 the most important points to be attended to are the proper spacing of the ties and driving the spikes in such a manner that the ties shall be held in place at right angles to the track and the rails in true gauge2 to insure the latter1 the track gauge should always be used when spiking the gauge side1 the rail being held to proper position by a lining bar4 ,the gauge should be kept about #f or #h in4 ahead of the tie being spiked and should not be lifted until the spikes are driven home2 gauges should be tested regularly and every morning when they are to be used all day1 so as to insure a true gauge all the time4 ,the two inner spikes should be set on one side of the tie and the two outer spikes on the other1 as indicated in the accompanying sketch4 ,this prevents the tie from slewing around1 and thus deranging the gauge of the track1 as well as interfering with the proper spacing of the ties4 ,the joints and centers should be spiked first1 which will bring the rails to their proper position on the ties1 which in turn will assist intermediate spiking4 ,each tie should be carefully gauged as spiked and1 as before indicated1 the ties with the broadest faces being selected for the joints4 ,in gauging ties it is very convenient to have measured off on the handles of the mauls in the hands of the forward spikers the distance from the outside of the rail to the end of the tie4 ,this distance will then be gauged on the tie1 when it will be lifted to the rail and securely spiked2 the gauge is then used1 and the loose rail held in place with the lining bar as previously indicated1 loose gauge being given on curves1 in accordance with directions of the engineer1 the allowance for which is about #a_/h in4 on a #b curve1 up to about #c_/d in4 on a #ab curve4 ,this widening of the gauge should begin on the tangent1 back of the ,p4,c41 the full amount of excess over true gauge being reached by the time the ,p4,c4 is reached and continue all the way around the curve1 running from the ,p4,t4 in the same manner as back of the ,p4,c4 ,the spikes should always be driven home straight and at right angles with the face of the ties4 ,when the foreman in charge of the track-laying work sees a spiker1 when the spike is nearly home1 strike the spike head laterally1 which is done to make it lie snugly to the rail1 he should at once check such imperfect work and put the man who does it at other work4 ,the foreman in charge of gang of spikers should be experienced in this branch of the work1 and by weeding out imperfect workers1 can soon get together a first-rate gang of spikers4 ,but no trouble will be experienced from carelessly driven spikes1 if the tie has the spike holes bored into it1 before laying4 ,this is considered good practice1 but rather expensive4 ,illustration ,for boring the holes quickly and accurately1 a proper template should be made1 by which the ties are marked for the borers1 who should be provided with boring machines1 by the use of which a hole1 square with the face of the tie is bored4 ,the boring machines should be so arranged as not to cut the hole beyond the required depth1 which should be slightly less than the length of the spike4 ,the diameter of the holes should be about #a-af of an inch less than the thickness of the spike4 ,this not only does away with the spike tearing its way through the timber and thus injuring its fiber to a great extent and causing it to be much more susceptible to rot1 but it is said to increase the adhesion of the spike in hard wood ties at least #ej per cent4 ,but in order that the best results may be obtained1 the spike should be flattened on either side of the sloping point1 which will generally prevent it leaving the hole4 ,the spikers should carefully avoid striking the rail with their mauls1 as such carelessness often produces fracture1 which sometimes causes the rail to break in two at such points1 which is liable to produce derailment and serious accident4 ,spike mauls should weigh not less than nine nor more than ten pounds1 and should be on straight handles1 not less than #c ft4 long4 ,after considerable use1 the face of the maul will become somewhat rounded1 and when this takes place it should be sent to the shop to be redressed4 ,the last blow on the spike should be only sufficiently hard to cause its throat to fit snugly on the rail2 a harder blow will often fracture the spike in such a manner as to cause the head in a short time to break off and leave the rail unsupported at that point4 ,foremen should not allow a spike to be pulled1 especially in frosty weather1 until it has been first struck a light blow to break the rust and loosen its hold in the wood4 ,the filling of old spike holes with wooden plugs is bad practice1 for the reason that they will cause the spike in a short time to slip from its place2 to fill the holes with sand is much better1 and spikes driven in holes so filled will hold much more firmly4 ,the best form of spike ,i have seen is the curved safety railroad spike2 this spike takes in the tie a position which enables it to resist the thrust of the rail against it much more effectually than the ordinary spike can possibly do4 ,i have seen in good condition1 one of these curved spikes which was said to have been driven eight times4 ,the cost of the curved safety spike is more than that of the ordinary spike1 but it is better made1 holds the track better1 and1 ,i believe1 is worth more than the difference asked for it4--,j4,a4 ,hall1 on ,construction and ,maintenance of ,track1 before ,american ,society of ,civil ,engineers4 99 99 99 99 99 ,,the ,,experiments ,,at ,,the ,,annapolis ,,proving ,,grounds4 ,the desperate war that has been waging between the gun and armor plate1 ever since the period when protective plates were first applied to naval constructions1 is familiar to all4 ,in this conflict the advantage seems to lean toward the side of the gun1 the power of penetration of which can be increased to almost indefinite limits1 at least theoretically1 while we quickly reach the extreme thicknesses of metal that can be practically employed for the protection of ships4 ,so1 in recent times1 researches have been making upon the efficacy of armor plating1 no longer in its exaggeration of thickness1 but in the intrinsic quality of the metal of which it is composed4 ,metallurgists have applied themselves to the work and have thus brought out various products1 among which the plates called compound1 of ,messrs4 ,cammell ,co41 have obtained a great notoriety4 ,these plates1 formed of a true plating of steel upon a bed of soft iron1 have been much in vogue in the ,english navy1 and seemed as if they were to be adopted about everywhere4 ,the ,creusot works alone1 of all competitors1 were able to fight against the general infatuation4 ,many comparative experiments had already demonstrated the superiority of the ,creusot all steel plates over the ,cammell plates1 but ,messrs4 ,schneider ,go4 were not willing to stop here1 and finally produced the new nickel steel plate1 which is by far superior to their steel plates4 ,some comparative trials of these various armor plates have recently been made by a military commission of the ,united ,states at the ,annapolis proving grounds4 ,three plates1 one a ,cammell1 the second a steel1 and the third a nickel steel 7the two last from ,creusot71 were here submitted to firing1 under absolutely identical conditions4 ,our engravings show the proving grounds and the details of the arrangements adopted for backing the plates4 ,of the three plates1 the ,cammell was the thickest 7#aa in47 ,the steel one was #ajc_/d in4 in thickness1 and the nickel steel #aja_/b in4 ,the last1 therefore1 was at a disadvantage with respect to the two others4 ,the plates were arranged tangentially to an arc of a circle whose center was occupied by the pivot of the gun1 and consequently at right angles with the latter4 ,the piece employed was a #f in4 gun1 #ce calibers in length4 ,the distance of its muzzle from the plates attacked was #bh ft4 ,illustration ,the charge was #dd lb4 of brown prismatic powder4 ,the projectile was a #ajj lb4 ,holtzer shell4 ,under these circumstances1 the initial velocity was #b1jgd ft4 and the energy at the impact was #i1igj1cif ft4 lb4 ,a beginning was made by firing four shots at each plate in the bisectrix of the corners4 ,then the #f in4 gun was replaced by an #h in4 one1 throwing a #bji lb4 ,firth projectile1 with an energy at the impact of #bj1gie1jjj ft4 lb4 ,each of the plates then received in its center a final blow from this projectile4 ,our engraving represents the state of the plates after this last shot4 ,illustration3 ,,armored ,,plate ,,tests ,,at ,,annapolis ,there is no need of being a great expert in questions of artillery to discover on what side the superiority is found1 and to see that the ,cammell plate1 almost entirely in fragments1 is absolutely incapable of protection1 while its two competitors are still in a state to resist4 ,in one of our engravings may be seen1 too1 the state of the shells after each of the three shots4 ,illustration ,the commission immediately and unanimously classified the three plates in the following order of superiority3 7#a7 ,nickel steel2 7#b7 all steel2 7#c7 compound4 ,this triumph of ,french industry merits mention so much the more in that it was obtained in a series of experiments made in a foreign country--that is to say1 under indisputable conditions of impartiality4-,l',illustration4 99 99 99 99 99 ,,high ,,explosives ,,in ,,warfare4#a ,footnote #a3 ,a lecture delivered before the ,franklin ,institute1 ,philadelphia1 ,november #bh1 #ahij4 ,from the ,journal of the ,institute4 ,,by ,,commander ,f4,m4 ,,barber1 ,u4,s4,n4 ,in commencing my paper this evening ,i desire to call your attention to the fact that ,i am dealing with a subject which1 though not theoretical1 is still hardly practical1 for as a matter of fact high explosives cannot be said to have yet been regularly used in warfare1 and ,i hope you will pardon me if in consequence my statements appear in some respects unsatisfactory and my theories unsound4 ,my subject1 however1 is no more obscure than future naval warfare generally4 ,all civilized nations are spending millions of money for fighting purposes directly in opposition to the higher feelings of the better class of their inhabitants4 ,the political atmosphere of ,europe is the cause of this1 but its consequence is the development of theoretical plans of ships which are no sooner commenced than the rapid march of mechanical1 chemical1 and electrical science shows them to be faulty in some particular feature1 and others are laid down only to be superseded in their turn4 ,none of these crafts are obsolete 7to use the popular expression of the day74 ,all are theoretically better than any which have stood the test of battle2 but each excels its predecessor in some particular feature4 ,the use of high explosives is the direct cause of the very latest transformations in marine architecture1 and is destined to work still greater changes2 but it will require a war between the most civilized nations of the world1 and a long war1 to either confirm or condemn the many theoretical machines and methods of destruction that modern science has produced4 ,i say a war between the most civilized nations1 since it is only they that can supply the educated intellect that is necessary to both attack and defense4 ,under other circumstances false conclusions as to weapons and results are certain to be drawn4 ,at the bombardment of ,alexandria1 the ,english armorclads1 with their rifled guns1 were not nearly as efficient against the feeble chalk fortifications as our wooden ships would have been with smooth bore guns4 ,on the other hand ,i saw on shore after the bombardment hundreds of torpedoes and miles of cable that the ,egyptians did not understand how to use4 ,the ,french war with ,china was equally unsatisfactory from a military point of view4 ,the ,chinese at ,foochow were annihilated because the ,french opened fire first1 and the only shell that penetrated a ,french ironclad was filled with lamp black instead of powder4 ,the national riots that we are accustomed to hear of in ,south ,america are likewise of little instructive value2 they buy their weapons of more civilized people1 but there is always something fatally defective about the tactics pursued in using them4 ,it may be said in general terms that in these days of extreme power in fighting machines1 the greater the efficiency the less the simplicity and the more knowledge required in the care of the weapons4 ,when powder was merely powder the advice of the old adage to trust in ,god and keep your powder dry was ample to maintain the efficiency of the powder for all purposes2 but nowadays if you keep your powder dry you will burst your gun1 and if you keep your gun-cotton dry you are liable to blow up your ship4 ,it is rather difficult to-day to define what high explosives are1 in contradistinction to gunpowder4 ,thirty years ago we could say that powder was a mechanical mixture and the others were chemical compounds2 but of late years this difference has disappeared4 ,the dynamical difference1 however1 still remains4 ,gunpowder in its most efficient form is a slow-burning composition1 which exerts a relatively low pressure and continues it for a long time and to a great distance4 ,high explosives1 on the contrary1 in their most efficient form1 are extremely quick-burning substances1 which exert an enormous pressure within a limited radius4 ,ordinary black gunpowder consists of a mechanical mixture of seventy-five per cent4 of saltpeter1 fifteen per cent of charcoal1 and ten per cent4 of sulphur4 ,the most important of the high explosives are formed by the action of nitric acid upon organic substances or other hydrocarbons1 the compound radical ,,no#b being substituted for a portion of the hydrogen in the substance4 ,the bodies thus formed are in a condition of unstable equilibrium2 but if well made from good material1 they become stable in their instability1 very much like ,prince ,rupert's drops1 those little glass pellets which endure almost any amount of rough usage2 but once cracked1 fly into infinitesimal fragments4 ,the power exerted by these nitro-substitution products is due to the fact that they detonate1 i4e41 they are instantaneously converted into colorless gas at a very high temperature1 and in addition they have almost no solid residue4 ,nitro-glycerine actually leaves none at all1 while gunpowder leaves sixty-eight per cent4 ,the first departure in gunpowder from the old-time constituents of black powder just mentioned was for the purpose of obtaining less pressure and slower combustion than could be produced by mere granulating or caking4 ,this was accomplished by using underburned charcoal1 together with sugar and about one and one-half per cent4 of water4 ,this is the brown powder most generally used at present and with satisfactory results2 but the abstraction of its moisture increases its rapidity of combustion to a dangerous degree1 besides which the underburned charcoal is itself unstable4 ,the next change demanded is smokelessness1 and to accomplish it recourse is had to the high explosive field1 mechanically mixing various substances with them to reduce and regulate their rapidity of action4 ,just now some form of gun-cotton is most in use mixed with nitrate of ammonia1 camphor and other articles4 ,the tendency of these mixtures is to absorb moisture1 and the gun-cotton in them to decompose1 and there is no smokeless powder which can to-day be considered successful4 ,such a powder1 however1 will undoubtedly be an accomplished fact in the near future4 ,military men seem to be a great deal at variance as to its value in the field1 but there can be no doubt of its value for naval purposes2 it is a necessity forced upon us by the development of torpedo warfare4 ,first came the simple torpedo1 at the end of an ordinary boat's spar4 ,then came the special torpedo boat with its great speed1 then the revolving cannon and rapid-fire gun to meet the torpedo boat4 ,at present the possible rapidity of fire is much greater than can be utilized1 on account of the smoke2 hence the necessity of smokeless powder4 ,smokelessness is1 however1 principally a martial demand that has been made upon the science of explosives and has attracted public attention on that account4 ,the commercial demands for various other properties have been much greater than the military1 and between gunpowder near one end of the line in point of power and nitro-glycerine near the other1 there are now over #cej different explosives manufactured1 and most of these have been invented within the last twenty years4 ,the simplest application of high explosives in warfare is in connection with torpedoes1 since within the same bulk a much more efficient substance can be obtained than gunpowder1 and with reasonable care there is very little danger of premature explosions by reason of accidental shocks4 ,torpedoes were made by the ,chinese many years ago1 they were tried in our war of independence1 and also by the ,russians during the ,crimean war2 but the first practical and successful use of them as a recognized weapon was during our war of secession1 when thirty-seven vessels were either sunk or seriously injured by them4 ,gunpowder was used in these torpedoes1 though it is stated that attempts were made to use other substances without success4 ,since that time all maritime nations have made a close study of the subject and have adopted various high explosives1 according to the results of their experiments4 ,in general terms it may be stated that explosive chemical compounds have been found more suitable than explosive mixtures1 because of the uniformity of direction in which they exert their pressure1 and from the fact that water does not injure them4 ,mixtures may be very powerful1 but they are erratic and require tight cases4 ,in the ,united ,states we use dynamite for harbor mines4 ,it is composed of seventy-five per cent4 nitro-glycerine and twenty-five per cent4 silica2 but blasting gelatine and forcite gelatine will probably be adopted1 when they can be satisfactorily manufactured here1 as they are more powerful4 ,the former is composed of ninety-two per cent4 of nitro-glycerine and eight per cent4 of gun-cotton1 and the latter of ninety-five per cent4 of nitro-gelatine and five per cent4 unnitrated cellulose4 ,for naval use we have adopted gun-cotton as being the most convenient4 ,in ,europe gun-cotton is generally used for both fixed mines and movable torpedoes2 ,russia1 ,austria1 and ,italy use blasting gelatine also4 ,in actual warfare but little experience has been had4 ,two ,peruvian vessels were sunk by dynamite in the ,chili-,peruvian war1 one ,turk by means of gun-cotton during the ,turco-,russian war of #ahgg1 and two ,chinese by gun-cotton in the ,franco-,chinese war of #ahhd4 ,in making experiments to determine the relative strength of the different explosives under water1 very curious and puzzling results have been obtained4 ,nitro-glycerine being the simplest and most complete in its chemical decomposition1 and apparently the most powerful in air1 it was natural to suppose that it would be the same in submarine work1 but it was found by ,gen4 ,abbot1 at ,willets ,point1 after repeated experiments1 as shown in his report of #ahha1 that it was not so powerful in its effect by twenty per cent4 as dynamite ,no4 #a1 although the dynamite contained twenty-five per cent4 of an absolutely inert substance4 ,his idea was that it was too quick in its action1 and1 since water is slightly compressible1 a minute fraction of time is required in the development of the full force of the explosive4 ,gen4 ,abbot's results for intensity of action per unit of weight of the most important substances is as follows3 ,blasting gelatine444444444444444444444444444 #adb ,forcite 444444444444444444444444444 #acc ,dynamite ,no4 #a444444444444444444444444444444 #ajj ,gun-cotton1 wet44444444444444444444444444444 #hg ,nitro-glycerine444444444444444444444444 44444 #ha ,gunpowder444444444444444444444444444444 #bj to #ej ,col4 ,bucknill1 of the ,royal ,engineers1 in his publication of #ahhh1 gives the following3 ,blasting gelatine444444444444444444444444444 #adb ,forcite 444444444444444444444444444 #acc ,dynamite ,no4 #a444444444444444444444444444444 #ajj ,gun-cotton1 dry44444444444444444444444444444 #ajj 44444444444444444444444444444 #hj ,gunpowder444444444444444444444444444444 44444 #be ,in both tables dynamite ,no4 #a is assumed as the standard of comparison4 ,col4 ,bucknill states that his gun-cotton results differ from ,gen4 ,abbot's1 because he experimented with much larger quantities1 viz41 #ejj-pound charges4 ,gen4 ,abbot's experiments led him to believe that an instantaneous mean pressure of #f1ejj pounds per square inch would give a fatal blow to the double bottom of a modern armorclad1 and he developed a formula which gives this blow with blasting gelatine at the following distances under water1 viz43 ,pounds4 ,at #e feet4444444444444444444444444444444444 #d #aj 4444444444444444444444444444444444 #ag #bj 4444444444444444444444444444444444 #fg #cj 4444444444444444444444444444444444 #afj #dj 4444444444444444444444444444444444 #caa ,col4 ,bucknill's experiments caused him to believe that a pressure of #ab1jjj pounds per square inch is required1 and his formula1 which is somewhat different from ,abbot's1 gives widely different results at close quarters1 but they approach each other as the distance increases4 ,his results are as follows3 ,pounds4 ,at #e feet44444444444444444444444444444444 #bca_/b #aj 44444444444444444444444444444444 #ge #bj 44444444444444444444444444444444 #agg #cj 44444444444444444444444444444444 #bgd #dj 44444444444444444444444444444444 #cfi ,regarding the comparative effects of gunpowder and the high explosives1 ,i think ,gen4 ,abbot's estimate of a varying value for powder is more admissible than the fixed value assigned by ,col4 ,bucknill4 ,gunpowder gives a push and detonating compounds a shock2 as the quantities increase1 the push reaches farther than the shock4 ,according to ,gen4 ,abbot1 #ajj pounds of dynamite ,no4 #a will have a destructive horizontal range of #af4c feet1 while the same amount of gunpowder will only have a range of #c4c feet4 ,five hundred pounds of dynamite1 however1 will have a horizontal range of #ce feet1 and #ejj pounds of gunpowder will have #ai4e feet2 the ratio has diminished from five to two4 ,whether #f1ejj pounds or #ab1jjj pounds per square inch is necessary to crush the bottom of an armorclad will depend largely upon how far apart the frames of the ship are spaced and what other bracing is supplied1 as well as many local circumstances4 ,it is difficult to judge exactly of these matters4 ,some four years ago the ,italian government adopted treble bottoms for their heaviest ships as a result of experiments with seventy-five pounds of gun-cotton 7the charge of an ordinary ,whitehead locomotive torpedo7 against a caisson which was a fac-simile of a portion of the proposed ships4 ,only two of the bottoms were broken through1 and when the space between the two inner bottoms was filled with coal1 only the outer bottom was broken4 ,according to the formul of either ,abbot or ,bucknill1 there should have been a local pressure of at least #cjj1jjj pounds per square inch on the outer skin1 and yet judicious interior arrangements rendered it harmless to the target4 ,it would not1 however1 be safe to conclude that the torpedo was thus vanquished2 the immediate result was simply to create a demand for larger locomotive torpedoes for local application1 and but little light was thrown upon the results which might be anticipated from a large mine at a greater distance1 whose radius of explosive effect would embrace a larger portion of the ship1 and especially if the ship were nearly over the torpedo4 ,the local effect of a detonation is different from the transmitted shock4 ,experiments in ,england have shown that #ejj pounds of gun-cotton at forty feet below any ship will sink her1 and at a horizontal distance of #ajj feet1 damage to the interior pipes and machinery is to be expected4 ,the fact that the high explosives are so much heavier than gunpowder has an important bearing on the size of the containing case4 ,their sp4 gr4 is as follows3 ,nitro-glycerine444444444444444444444444 4444 #a4f ,blasting gelatine44444444444444444444444444 #a4de ,forcite 44444444444444444444444444 #a4ea ,dynamite ,no4 #a44444444444444444444444444444 #a4f ,wet gun-cotton44444444444444444444444444444 #a4cb ,dry 44444444444444444444444444444 #a4jf ,gunpowder444444444444444444444444444444 4444 #j4i ,their relative efficiency under water per cubic foot1 according to ,bucknill1 is as follows3 ,blasting gelatine44444444444444444444444444 #a4ch ,forcite 44444444444444444444444444 #a4bg ,dynamite ,no4 #a44444444444444444444444444444 #a4jj ,dry gun-cotton44444444444444444444444444444 #j4ff ,wet 44444444444444444444444444444 #j4ff ,gunpowder444444444444444444444444444444 4444 #j4ad ,the wet gun-cotton has twenty-five per cent4 of added water4 ,mines for harbor defense are of two kinds--buoyant and ground4 ,the buoyant are usually spherical1 and contain from #djj to #ejj pounds of explosive4 ,they bring the charge near to the ship's bottom1 but are difficult to manage in a tideway1 and can be easily found by dragging4 ,the ground mines can be made of any size and are not easily found by dragging1 but are of little value in very deep water4 ,they are either cylindrical or hemispherical in shape1 and contain from #ejj to #a1ejj pounds of explosive in from thirty to eighty feet of water4 ,mines of any kind are exceedingly difficult to render efficient when the water is over #ajj feet deep4 ,on account of the tendency of all high explosives to detonate by influence or sympathy1 and the liability of the cases to collapse by great exterior pressure1 harbor mines are separated a certain distance1 according as they are buoyant or ground1 and according to the nature of the explosive4 ,five hundred pounds buoyant gun-cotton mines require #cbj feet spacing4 ,five hundred pounds buoyant blasting gelatine mines require #dej feet spacing4 ,six hundred pounds ground gun-cotton mines require #ahj feet spacing4 ,six hundred pounds ground blasting gelatine mines require #bcj feet spacing4 ,of torpedoes1 other than those described1 we have several modern varieties2 submarine projectiles1 submarine rockets1 automobile and controllable locomotive torpedoes4 ,the first two varieties1 though feasible1 are not developed and have not yet advanced beyond the experimental stage4 ,of the automobile1 we have the ,whitehead1 ,swartzkopf and ,howell4 ,the first two are propelled by means of compressed air and an engine2 the last by the stored-up energy of a heavy fly-wheel4 ,generally speaking1 they are cigar-shaped crafts1 from #aj to #ah feet long and #ae to #ag inches in diameter1 capable of carrying from #ge to #bej pounds of explosive at a rate of #be to #cj knots for #djj yards1 at any depth at which they may be set4 ,of the controllable locomotive torpedoes1 the three representative types are the ,patrick1 ,sims and ,brennan4 ,they are in general terms cigar boats1 about #dj feet long and #b feet in diameter1 carrying charges of #djj pounds of explosive4 ,the ,patrick and ,sims are maintained at a constant depth under water by means of a float4 ,the ,brennan has diving rudders like a ,whitehead or a ,howell4 ,the ,patrick is driven by means of carbonic acid gas through an engine1 and is controlled by an electric wire from shore4 ,the ,sims is driven by electricity from a dynamo on shore through a cable to an electric engine in the torpedo4 ,the ,brennan is driven and controlled by means of two fine steel wires wound on reels in the torpedo1 the reels being geared to the propeller shafts4 ,the wires are led to corresponding reels on shore1 and these are rapidly revolved by means of an engine4 ,a brake on each shore reel controls the torpedo4 ,the speed of all these torpedoes is about #ai knots1 and their effective range one mile4 ,a ,whitehead was successfully used in the ,turco-,russian war of #ahgg4 ,the ,turkish vessel previously mentioned was sunk by one4 ,blasting gelatine1 dynamite and gun-cotton are capable of many applications to engineering purposes on shore in time of war1 and in most cases they are better than powder4 ,they received the serious attention of ,french engineers during the siege of ,paris1 and were employed in the various sorties which were made from the city1 in throwing down walls1 bursting guns1 etc4 ,an explosive for such purposes1 and indeed for most military uses1 should satisfy the following conditions3 7#a7 ,very shattering in its effects4 7#b7 ,insensible to shocks of projectiles4 7#c7 ,plastic4 7#d7 ,easy and safe to manipulate4 7#e7 ,easy to insert a fuse4 7#f7 ,great stability at all natural temperatures and when used in wet localities4 ,neither blasting gelatine1 dynamite nor gun-cotton fulfills all these conditions2 but they satisfy many of them and are more powerful than other substances4 ,for the destruction of walls1 trees1 rails1 bridges1 etc41 it is simply necessary to attach to them small bags of explosive1 which are ignited by means of blasters' fuse and a cap of fulminate of mercury1 or by an electric fuse4 ,we now come to the application of high explosives to warfare in the shape of bursting charges for shells4 ,this is the latest phase of the problem1 and it is undoubtedly fraught with the most important consequences to both attack and defense4 ,difficult as it has been to obtain an exact estimate of the force of different explosives under water1 the problem is far greater out of the water and under the ordinary conditions of shell fire2 the principal obstacle being in the fact that it is physically impossible to control the force of large quantities in order to measure it1 and small quantities give irregular results4 ,theoretically1 the matter has been accomplished by ,berthelot1 the head of the ,french government ,commission of ,explosives1 by calculating the volume of gas produced1 heat developed1 etc42 and this method is excellent for obtaining a fair idea of the specific pressure of any new explosive that may be brought forward1 and determining whether it is worth while to investigate it further2 but the explosives differ so much from each other in point of sensitiveness1 weight1 physical condition1 velocity of explosive wave1 influence of temperature and humidity1 that we cannot determine from mere theoretical considerations all that we would like to know4 ,various methods of arriving at comparative values have been tried1 but the figures are very variable1 as will be seen by the following tables4 ,berthelot's commission1 some ten years ago1 exploded ten to thirty grammes of each in #cjj pound blocks of lead and measured the increased size of the hole thus made4 ,the relative result was3 ,no4 #a dynamite #a4j ,dry gun-cotton #a4ag ,nitro-glycerine #a4bj ,powder blew out and could not be measured4 ,mr4 ,r4,c4 ,williams1 at the ,boston ,institute of ,technology1 in the winter of #ahhh and #ahhi1 tried the same method1 but used six grammes in forty-five pound blocks of lead4 ,he obtained a relative result of-- ,no4 #a dynamite #a4j ,dry gun-cotton #a4cg ,nitro-glycerine #b4ea ,explosive gelatine #b4eg ,forcite gelatine #b4g ,warm nitro-glycerine #b4g ,gunpowder #j4a ,the powder gave great trouble in this case1 also1 by blowing out4 ,m4 ,chalon1 a ,french engineer1 obtained some years ago1 with a small mortar1 firing a projectile of thirty kilos and using a charge of ten grammes of each explosives1 the following ranges3 ,meters4 ,blasting powder #b4f ,no4 #a dynamite #ca4d ,forcite of #ge per cent4 ,n4,g4 #dc4f ,blasting gelatine #de4j ,roux and ,sarran obtained by experiments in bursting small bomb shells the following comparative strengths of ranges3 ,powder #a4j ,gun-cotton #f4e ,nitro-glycerine #aj4j ,in actual blasting work the results vary altogether with the nature of the material encountered1 and with the result that is desired to be accomplished1 viz41 throwing out1 shattering1 or mere displacement4 ,chalon gives for quarrying3 ,powder #a ,dynamite ,no4 #b1 containing #ej per cent4 nitro-glycerine #c ,for open blasting3 ,dynamite ,no4 #c1 containing #cj per cent4 ,n4,g4 #a4j ,dynamite ,no4 #a1 containing #ge per cent4 ,n4,g4 #b4e ,blasting gelatine #c4e ,for tunneling3 ,dynamite ,no4 #c1 containing #cj per cent4 ,n4,g4 #a ,dynamite ,no4 #a1 containing #ge per cent4 ,n4,g4 #c ,explosive gelatine #ai ,finally ,berthelot's theoretical calculations give a specific pressure of-- ,powder #a ,dynamite #ac ,gun-cotton #ad ,nitro-glycerine #af ,blasting gelatine #ag ,it will be observed that the practical results vary largely from the theoretical values1 but they seem to indicate that gun-cotton and ,no4 #a dynamite are very nearly equal to each other1 and that in the nitro-glycerine compounds1 except where gun-cotton is added1 the force appears to be nearly in proportion to the nitro-glycerine contained4 ,from the foregoing it seems fair to estimate roughly the values of bursting charges of shells as follows3 ,powder #a ,gun-cotton and dynamite #f to #aj ,nitro-glycerine #ac to #ae ,blasting gelatine #ae to #ag ,attention has been turned in ,europe for more than thirty years toward firing high explosives in shells2 but it is only within very late years that results have been reached which are claimed as satisfactory1 and it is exceedingly difficult to obtain reliable accounts even of these4 ,dynamite was fired in ,sweden in #ahfg in small quantities1 and a few years later it was fired in ,france4 ,but two difficulties soon presented themselves4 ,if the quantity of nitro-glycerine in dynamite was small1 it could be fired in ordinary shells1 but the effect was no better than with gunpowder4 ,if the dynamite was stronger in nitro-glycerine1 it took but a small quantity to burst the gun4 ,as early as #ahfd1 dry gun-cotton was safely fired in shells in small quantities1 but when a sufficient quantity to fill the shell cavity was used1 the gun burst4 ,some few years ago it was found that if the gun-cotton was either wet or soaked in paraffin1 it could be fired with safety from powder guns in ordinary shells1 provided the quantity was small in proportion to the total weight of the shell--say five or six per cent4 ,but a new difficulty arises from the fact that it breaks the shell up into very small pieces1 and it is an unsettled question among artillerists whether more damage is done to an enemy by breaking a shell into comparatively large pieces and dispersing them a long distance with a bursting charge of powder1 which has a propulsive force1 or by breaking it with a detonating compound into fine pieces1 which are not driven nearly so far4 ,when used against troops there is also the objection to the high explosive shell that it makes scarcely any smoke in bursting1 and smoke at this point is useful to the artillerist in rectifying his aim4 ,in the matter of shells for piercing armor1 however1 there are no two opinions regarding the nature of the bursting charge4 ,to pierce modern armor at all a shell must be made of forged steel1 so thick that the capacity of the cavity for the bursting charge is reduced to one-fourth or one-fifth of what it is in the common shell2 the result is that a charge of powder is frequently not powerful enough to burst the shell at all2 it simply blows the plug out of the filling hole in the rear4 ,in addition it is found that in passing through armor1 the heat generated is so great that the powder is prematurely ignited4 ,if then we can fill the small cavity in the shell with an explosive which will not ignite prematurely1 and yet will burst the shell properly after it has passed through the armor1 the problem will be solved4 ,wet or paraffined gun-cotton can be made sluggish enough to satisfy the first condition2 but at present the difficulty is to make it explode at all4 ,the more sluggish the gun-cotton1 the more powerful must be the fuse exploders to detonate it1 and such exploders are themselves liable to premature ignition in passing through the armor4 ,the ,italians and ,germans claim to have accomplished the desired result up to a thickness of five inches of armor2 gun-cotton and fuse both working well4 ,but the ,english authorities say that no one has yet accomplished it4 ,the ,austrians claim to have succeeded in this direction within the last year with a new explosive called ecrastite 7supposed to be blasting gelatine combined with sulphate or hydrochlorate of ammonia1 and claimed to be one and one-half times as powerful as dynamite74 ,with a gun of #h4bd inches caliber and an armor-piercing shell weighing #bjf4f pounds1 containing a bursting charge of #ae4hh pounds of ecrastite1 they are said to have perforated two plates four inches thick1 and entered a third four-inch plate where the shell exploded4 ,there is a weak point in this account in the fact that the powder capacity of the shell is said to be #d4d pounds4 ,this amount is approximately correct1 judging from our own eight-inch armor-piercing shell1 but if this is true1 there could not have been more than nine pounds of ecrastite in the shell instead of sixteen1 or else there is an exceedingly small proportion of blasting gelatine in ecrastite1 and if that is the case it is not one and one-half times as powerful as dynamite4 ,if it is weak stuff1 it is probably insensitive1 and even if it were strong1 one swallow does not make a summer4 ,the ,english fired quantities of blasting gelatine from a two-inch ,nordenfeldt gun in #ahhd1 but when they tried it in a seven-inch gun1 in #ahhe1 they burst the gun at once4 ,i have only analyzed this ,austrian case1 because the statement is taken from this year's annual report of the ,office of ,naval ,intelligence1 which is an excellent authority1 and to illustrate the fact that of the thousands of accounts1 which we see in foreign and domestic newspapers1 concerning the successful use of high explosives in shells1 fully ninety per cent4 are totally unreliable4 ,in many cases they are in the nature of a prospectus from the inventors of explosives or methods of firing1 who are aware of the fact that it is almost impossible to dispute any statements that they may choose to make regarding the power of their new compounds1 and thinking1 as most of them do1 that power alone is required4 ,referring to the qualities that ,i have previously cited as being required in a high explosive for military purposes1 it is sooner or later found that nearly all the novelties proposed lack some of the essentials and soon disappear from the advertising world only to be succeeded by others4 ,the most common defect is lack of keeping qualities4 ,they will either absorb moisture or will evaporate2 or further chemical action will go on among the constituents1 making them dangerously sensitive or completely inert1 or they will separate mechanically according to their specific gravities4 ,for further clearness on the subject of the shell charges which have so far been discussed1 the following table is added of weight and sizes of shells for ,united ,states naval guns1 with their bursting charges of powder3 #f-;inch com4 cast steel shell #ca_/b to #d cal4 long1 wt4 #ajj lb41 charge #f lb4 #h #bej #ada_/b lb4 #aj #ejj #bg #ab #hej #de ,,armor-,,piercing ,,forged ,,steel ,,shell4 #f-;inch1 #c calibers long1 weight #ajj lb1 charge #aa_/b lb4 #h #bej #c #aj #ejj #ea_/b #ab #hej #aa ,the chief efficiency of small quantities of high explosives having reduced itself to the case of armor-piercing projectiles1 it next became evident that there was an entirely new field for high explosives into which powder had entered but little1 and this was the introduction of huge torpedo shells1 which did nor rely for their efficiency upon the dispersion of the pieces of the shell1 but upon the devastating force of the bursting charge itself upon everything within the radius of its explosive effect4 ,it is in this field that we may look for the most remarkable results1 and it is here that the absolute power of the explosive thrown is of the utmost importance1 provided that it can be safely used4 ,attention was at once turned in ,europe to the manufacture of large projectiles with great capacity for bursting charges1 and it has resulted in the production of a class of shells #da_/b to #f calibers long1 with walls only #j4d of an inch thick4 7,if they are made thinner1 they will swell and jam in the gun when fired47 ,these shells are used in long guns up to #f and #ha_/b inches caliber1 and in mortars up to #aa4b inches4 ,they are made from disks of steel1 #c to #d feet in diameter and #a inch thick1 and are forced into shape by hydraulic presses4 ,the base is usually screwed in1 but some of the ,german shell are made in two halves which screw together4 ,the ,italians were the first in this new field of investigation1 but the ,germans soon followed1 and after trying various materials were at length reasonably successful with gun-cotton soaked in paraffin4 ,their #h4d inch mortar shells of #e calibers contain #db pounds2 those of #f calibers contain #eg pounds2 and the #aa4b inch mortar shells of #e calibers contain #aaj pounds4 ,the projectile velocity used with the mortars is about #hjj f4s4 ,the effect of these shells against ordinary masonry and earth fortifications is very great4 ,the charge of forty-two pounds has broken through a masonry vault of three feet four inches thick1 covered with two feet eight inches of cement and with three to five feet of earth over all4 ,the shell containing fifty-seven pounds1 at a range of two and one-half miles1 broke through a similar vault covered with ten feet of earth2 but with seventeen feet of earth the vault resisted4 ,in #ahhc1 experiments at ,kummersdorf showed that a shell containing the fifty-seven pound charge would excavate in sand a crater sixteen feet in diameter and eight feet deep1 with a capacity of twenty-two cubic yards4 ,the ,italians have had similar experiences2 but it is notable that in both ,germany and ,italy several guns and mortars have burst4 ,the velocity in the guns is not believed to exceed #a1bjj to #a1cjj f4s41 and it is not thought that the quantity of gun-cotton is as great in the gun shells as in the mortars4 ,i have lately been informed on good authority that the use of gun-cotton shells has been abandoned in the ,german navy as too dangerous4 ,the ,french1 in their investigations in this field1 found gun-cotton too inconvenient1 and decided upon melenite4 ,this substance has probably attracted more attention in the military world than all others combined1 on account of the fabulous qualities that have been ascribed to it4 ,its composition was for a long time entirely a secret2 but it is now thought to consist principally of picric acid1 which is formed by the action of nitric acid upon phenol or phenyillic alcohol1 a constituent of coal tar4 ,the actual nature of melenite is not positively known1 as the ,french government1 after buying it from the inventor1 ,turpin1 are said to have added other articles and improved it4 ,this is probable1 since ,french experiments in firing against a partially armored vessel1 the ,bellequense1 developed an enormous destructive effect1 while the ,english1 who afterward bought it1 conducted similar experiments against the ,resistance1 and obtained no better results than with powder4 ,the proof that the ,bellequense experiments were deemed of great value by the ,french lies in the fact that they immediately laid down a frigate--,dupuy de ,lome--in which four-inch armor is used1 not only on the side1 but about the gun stations1 to protect the men2 this thickness having been found sufficient to keep out melenite shell4 ,in most armorclads1 the armor is very heavy about the vitals1 but the guns are frequently much exposed4 ,the best authenticated composition for melenite consists of picric acid1 gun cotton and gum arabic1 and lately it is stated that the ,french have added cresilite to it4 ,cresilite is another product of coal tar4 ,melenite is normally only three times as strong as gunpowder2 but it is said to owe its destructive qualities in shells to the powerful character of the exploder which ignites it4 ,it has been known for some years that all explosives 7including gunpowder7 are capable of two orders of explosion according as they are merely ignited or excited by a weak fuse or as they are powerfully shocked by a more vigorous excitant4 ,fulminate of mercury has been found most serviceable for the latter purpose4 ,with melenite the ,french have reproduced all the results that the ,germans have effected with gun-cotton and have found that a shell containing #aai pounds of it will penetrate nearly ten feet of solid cement1 but will not penetrate armored turrets six to eight inches thick4 ,the ,french claim that melenite has an advantage over gun-cotton in not being so dangerous to handle and being insensible to shock or friction1 and they have obtained a velocity of #a1cjj f4s4 with the #hh inch mortar and claim to have obtained #b1jjj f4s4 in long guns up to #fb inch caliber4 ,however this may be1 they are known to have had severe accidents at the manufactory at ,belfort and at least one #ef inch gun was burst at the ,bellequense experiments in firing a sixty-six pound shell containing twenty-eight pounds of melenite4 ,the ,french are said to have large quantities of melenite shells in store1 but they are not issued to service4 ,probably one reason why we have so many conflicting yet positive accounts of great successes in ,europe with torpedo shells is because each nation wishes its neighbors to think that it is prepared for all eventualities1 and they are obliged to keep on hand large quantities of some explosive1 whether they have confidence in it or not4 ,fortunately we are not so situated1 but singularly enough what we have done in the field of high explosive projection has been accomplished by private enterprise1 and we have attacked the problem at exactly the opposite point from which ,european nations have undertaken it4 ,while they have assumed that the powder gun with its powerful and relatively irregular pressures was a necessity and have endeavored to modify the explosive to suit it1 we have taken the explosive as we have found it1 and have adapted the gun to the explosive4 ,at present the prominent weapon in this new field is the pneumatic gun1 but it is obvious that steam1 carbonic acid gas1 ammonia or any other moderate and regulatable pressure can be used as well as compressed air2 it is merely a question of mechanical convenience4 ,in throwing small quantities of certain high explosives1 powder guns can be used satisfactorily1 but when large quantities are required1 the mechanical system of guns possess numerous advantages4 ,all the high explosives are subject to premature detonation by shock2 each of them is supposed to have its own peculiar shock to which it is sensitive2 but what this shock may be is at present unknown4 ,we do know1 however1 that premature explosions in guns are more liable to occur when the charge in the shell is large than when it is small4 ,this is due to the fact that when the gun is fired1 the inertia of the charge in the shell is overcome by a pressure proportional to the mass and acceleration1 which pressure is communicated to the shell charge by the rear surface of the cavity1 and the pressure per unit of mass will vary inversely as this surface4 ,if1 then1 the quantity of explosive in the shell forms a large proportion of the total weight of the shell1 we approach in powder guns a condition of shock to it which is always dangerous and frequently fatal4 ,the pressure behind the projectile varies from twelve to fifteen tons per square inch1 but it is liable to rise to seventeen and eighteen tons1 and in the present state of the manufacture of gunpowder we cannot in ordinary guns regulate it nearer than that4 ,it is not a matter of so much importance so far as the guns are concerned1 when using ordinary projectiles1 as the gun will endure a pressure of from twenty-five to thirty tons per square inch2 but with high explosives in the shell it is a vitally serious matter4 ,from all ,i can learn regarding ,european practice1 it appears that not only are the explosives made sluggish1 but the quantity seldom exceeds thirty per cent4 of the weight of the shell1 and the velocities1 notwithstanding1 are kept very low4 ,in the pneumatic gun the velocity is low also1 but so is the pressure in the gun4 ,the pressure in the firing reservoir is kept at the relatively low figure of #a1jjj pounds per square inch or less1 and the air is admitted to the chamber of the gun by a balance valve which cuts off just the quantity of air 7within a very few pounds7 that is required to make the shot4 ,the gun is long1 and advantage is taken of the expansion of the air4 ,in no case can the pressure rise in the gun beyond that in the reservoir4 ,up to the present time there have been no accidents in using the most powerful explosives in their natural state1 and in quantities over fifty per cent4 of the weight of the projectile4 ,i have seen projectiles weighing #iej pounds1 and containing #ejj pounds of explosives 7#cjj pounds of the blasting gelatine and #bjj pounds of ,no4 #a dynamite7 thrown nearly a mile and exploded after disappearing under water4 ,according to ,gen4 ,abbot's formula such a projectile would have sunk any armorclad floating within forty-seven feet of where it struck4 ,apparently there is no limit to the percentage of explosive that can be placed in the shell except the mechanical one of having the walls thick enough to prevent being crushed by the shock of discharge4 ,in the large projectiles a transverse diaphragm is introduced to strengthen the walls and to subdivide the charge4 ,the development of the pneumatic gun has been attended with some other important discoveries1 which may be of interest4 ,it is well known that mortar fire is very inaccurate1 except at fixed long distances1 in consequence of the high angle1 the slowness of flight of the projectile1 the variability of the powder pressure1 and the inability to change the elevation and the charge of powder rapidly4 ,in the pneumatic gun1 the complete control of the pressure remedies the most important of the mortar's defects and makes the fire accurate from long ranges down to within a few yards of the gun4 ,it is obvious that the pressure can be usefully controlled in two ways3 7#a7 by keeping the elevation of the gun fixed and using a valve that can be set to cut off any quantity of air1 according to the range desired2 7#b7 by keeping the pressure in the reservoir constant1 and using a valve which will cut off the same quantity of air every time1 changing the elevation of the gun according to the distance4 ,another important discovery consists in the application of subcalibered projectiles for obtaining increased range4 ,the gun is smooth-bored and a full-sized projectile is a cylinder with hemispherical ends1 to the rear of which is attached a shaft having metal vanes placed at an angle1 which causes the projectile to revolve round its longer axis during flight4 ,a subcalibered projectile1 however1 being of less diameter than the bore of the gun1 has the vanes on its exterior1 and is held in the axis of the gun by means of gas checks which drop off as the projectile leaves the muzzle4 ,the shock to the explosive is1 of course1 greater than in the full-sized projectile1 but the increase can be calculated1 and so far a dangerous limit has not been reached4 ,from the fifteen-inch gun with a pressure of #a1jjj pounds per square inch and a velocity of about #hjj f4s41 a range of #d1jjj yards has been obtained at an elevation of #cj #bj1 with a ten-inch subcalibered projectile1 about eight calibers long and weighing #ejj pounds4 ,this projectile will contain #bbj pounds of blasting gelatine4 ,with improved full-sized projectiles weighing #a1jjj pounds1 a range of #b1ejj yards will doubtless be obtained4 ,at elevations below #ae these long projectiles are liable to ricochet1 and what is now wanted is a projectile which will stay under water at all angles of fall and will run parallel to the surface like a locomotive torpedo4 ,such a projectile has yet to be invented2 but ,i have seen a linked shell1 which has been experimented with from a nine-inch powder gun1 that partially meets this condition4 ,it is made of several sections united by means of rope or electric wire in lengths of #ajj to #aej feet4 ,when fired all sections remain together for some distance2 the rear section then first begins to separate2 then the next1 and so on4 ,it is primarily intended to envelop an enemy's vessel1 and to remedy the present uncertainty of elevation in a gun mounted in a pitching boat2 but it is found that when it strikes the water in its lengthened out condition1 it will neither dive nor ricochet1 but will continue for some distance just under the surface until all momentum is lost1 when it will sink4 ,this projectile is at present crude1 and has never been tried loaded1 but it will probably be developed into something useful in time4 ,i have confined my remarks in the foregoing discussion principally to such methods of using high explosives in shells as have proved themselves successful beyond an experimental degree1 and practically they reduce themselves to two1 viz41 using a sluggish explosive in small quantities from an ordinary powder gun1 and using any explosive from a pneumatic or other mechanical gun4 ,naturally1 the success of the latter method will soon induce the manufacture of powders having an abnormally low maximum pressure4 ,there is undoubtedly a field for the use of such powders in connection with an air space in the gun to still further regulate the pressure2 but nothing of this sort has yet been attempted4 ,many methods of padding the shell have been devised for reducing the shock in powder guns1 but the variability of the powder pressure is too great to have yet rendered any such method successful4 ,a method was patented by ,gruson in ,germany of filling a shell with the two harmless constituents of an explosive and having them unite and explode by means of a fulminate fuse on striking an object4 ,he used for the constituents nitric acid and dinitro-benzine1 and was quite successful2 but the system has not met with favor1 on account of the inconvenience4 ,the explosive was about four times as powerful as gunpowder4 ,that the advantage of using the most powerful explosives is a real one can be easily shown4 ,the eight inch pneumatic gun in ,new ,york harbor1 with a projectile containing fifty pounds of blasting gelatine and five pounds of dynamite1 easily sunk a schooner at #a1hfd yards range from the torpedo effect of the shell falling alongside it4 ,this same shell1 if filled with gunpowder1 would have contained but twenty-five pounds1 and have had but one-ninth the power4 ,the principal ,european nations are now building armored turrets sunk in enormous masses of cement1 as a result of their experiences with gun-cotton and melenite4 ,the fifteen inch pneumatic projectile1 which ,i described as being capable of sinking an armorclad at forty-seven feet from where it struck1 would have been capable of penetrating fifty feet of cement had it struck upon a fortification4 ,it was not only a much larger quantity of high explosive than ,europeans have experimented with1 but the explosive itself is probably more than twice as strong as their gun-cotton and five or six times as strong as their melenite4 ,in the plans of ,gen4 ,brialmont1 one of the most eminent of ,european engineers1 he allows in his fortifications about ten feet of cement over casements1 magazines1 etc4 ,it is evident that this is insufficient for dynamite shells such as ,i have described4 ,at ,fort ,wagner1 a sand work built during our war1 ,gen4 ,gillmore estimated that he threw one pound of metal for every #c4bg pounds of sand removed4 ,he fired over #abb1bcj pounds of metal1 and one night's work would have repaired the damage4 ,the new fifteen inch pneumatic shell will contain #fjj pounds of blasting gelatine1 and judging from the ,german experiments at ,kummsdorf1 which ,i have cited1 one of these fifteen inch shells would throw out a prodigious quantity of sand2 either #ejj pounds to one of shell1 or #b1jjj pounds to one of shell1 according as the estimate of ,gen4 ,abbot or of ,capt4 ,zalinski is used4 ,the former considers that the radius of destructive effect increases as the square root of the charge2 the latter that the area of destructive effect for this kind of work is directly proportional to the charge4 ,the effect of the high explosives upon horizontal armor is very great2 but we have yet to learn how to make it shatter vertical armor4 ,no fact about high explosives is more curious than this1 and there is no theory to account for it satisfactorily4 ,as previously stated1 the ,french have found that four inches of vertical armor is ample to keep out the largest melenite shells1 and experiments at ,annapolis1 in #ahhd1 showed that masses of dynamite ,no4 #a1 weighing from seventy-five to #ajj pounds1 could be detonated with impunity when hung against a vertical target composed of a dozen one inch iron plates bolted together4 ,in conclusion1 ,i may say that in this country we are prone to think that the perfection of the methods of throwing high explosives in shell is vastly in favor of an unprotected nation like ourselves1 because we could easily make it very uncomfortable for any vessels that might attempt to bombard our sea coast cities4 ,this is true as far as it goes1 but unfortunately the use of high explosives will not stop there4 ,i lately had explained to me the details of a system which is certainly not impossible for damaging ,new ,york from the sea by means of dynamite balloons4 ,the inventor simply proposed to take advantage of the sea breeze which blows toward ,new ,york every summer's afternoon and evening4 ,without ever coming in sight of land1 he could locate his vessel in such a position that his balloons would float directly over the city and let fall a ton or two of dynamite by means of a clock work attachment4 ,the inventor had all the minor details very plausibly worked out1 such as locating by means of pilot balloons the air currents at the proper height for the large balloons1 automatic arrangements for keeping the balloon at the proper height after it was let go from the vessel1 and so on4 ,his scheme is nothing but the idea of the drifting or current torpedo1 which was so popular during our war1 transferred to the upper air4 ,an automatic flying machine would be one step farther than this inventor's idea1 and would be an exact parallel in the air to the much dreaded locomotive water torpedo of to-day4 ,there seems to be no limit to the possibilities of high explosives when intelligently applied to the warfare of the future1 and the advantage will always be on the side of the nation that is best prepared to use them4 99 99 99 99 99 ,,the ,,manufacture ,,and ,,use ,,of ,,plaster ,,of ,,paris4 ,it has long been a familiar fact that gypsum yields on baking a material which possesses the power of setting with water to a firm mass1 this setting being accomplished much more quickly than is the case with mortar4 ,the explanation of the setting of plaster was first given by ,lavoisier1 who pointed out that gypsum is an hydrated salt1 and that the set plaster is in fact gypsum reformed1 the change brought about by baking being merely loss of water of crystallization4 ,the beds of gypsum of most importance both formerly and at the present time in the plaster manufacture occur in the neighborhood of ,paris in the lower tertiary formation4 ,different beds differ 7#a7 in respect of character and quantity of admixed materials and 7#b7 in the structure of the gypsum itself4 ,with regard to the first point1 some deposits contain a notable proportion of carbonate of lime1 a fact which under certain circumstances may considerably influence the character of the plaster4 ,in the matter of structure two principal varieties occur 7#a7 granular and 7#b7 fibrous4 ,further1 hardness of the granular kind varies considerably4 ,these differences of structure in the original material appear to exercise an influence on the properties of the plaster4 ,thus according to ,payen the plaster formed from the granular variety sets more gradually than that derived from the fibrous1 and forms a denser mass4 ,the softer kinds of the granular gypsum are those principally used in the production of plaster for the moulds of potteries4 ,in the old fashioned process which is still employed for making the common kinds of plaster1 the material is exposed to the direct action of flame4 ,large lumps are placed in the lower part of the furnace1 above them smaller lumps1 and1 after the heating has been carried on for some time1 finely divided material is filled in at the top4 ,the outer portion of the larger lumps is always overburnt1 and in the upper part of the furnace the presence of shining crystalline particles generally indicates the fact that some gypsum has remained unchanged4 ,provided that the amount of unburnt and overburnt material does not exceed about #cj per cent4 of the total1 the plaster is suitable for many applications4 ,it was early observed that set plaster could be revivified by a second baking1 but attempts in this direction were not uniformly successful1 it being found that the dehydrated substance in some cases refused to set with water4 ,it behaved in fact similarly to the natural anhydrous calcium sulphate which is unaffected by water4 ,these failures were found to be due to the employment of too high a temperature1 and such plaster was termed dead burnt4 ,although this fact was ascertained long ago1 yet ignorance of what had already been done has probably been the cause of many disappointments in attempts at revivification which have been made from time to time by persons unacquainted with the history of the subject4 ,the view generally adopted with regard to the theory of these processes is that plaster consists of anhydrous calcium sulphate1 ,ca,s,o#d1 in a condition probably amorphous1 different from that of natural crystallized ,ca,s,o#d1 known to mineralogists under the name of anhydrite4 ,by the influence of a high temperature it appears probable that a molecular change is gradually induced with production of a crystalline structure1 and probably an increase of specific gravity1 resulting in the artificial reproduction of the mineral anhydrite4 ,no determination appears to have been published of the specific gravity of plaster prepared by complete baking at a low temperature4 ,the theory is1 however1 confirmed by the results obtained by workers on the subject of mineralogical synthesis1 who have shown that the material which has been produced at high temperatures has the specific gravity and other physical properties of the mineral anhydrite4 ,it was formerly supposed that plaster prepared by baking at a temperature above #cjj degrees loses completely its power of setting4 ,later observations1 however1 as those of ,landrin1 negative this view4 ,between #cjj degrees and #djj degrees ,landrin obtained plasters setting almost instantaneously when mixed with a small amount of water4 ,when the temperature employed approached #djj degrees1 the set plaster was softer1 but the setting still took place quickly4 ,these observations appear to show that the change to anhydrite is a very gradual process at temperatures below a red heat4 ,reference has been made to the differences in 7#a7 time of setting of plaster and 7#b7 in hardness of the resulting material4 ,both of these properties are affected by the mode of baking4 ,the hardest material is frequently obtained from the quick-setting plasters1 but for certain purposes this rapidity in setting is of great practical inconvenience4 ,thus the moulder in pottery work must have leisure to fill in every detail of a design often complicated and intricate before the material with which he is working becomes intractable4 ,thus for many of the more refined purposes to which plaster is applied1 extreme hardness in the set plaster is of less vital importance than a convenient period of setting4 ,on the other hand1 plasters which set very slowly give as a rule too soft a material1 as well as being inconvenient in use4 ,plasters which hit off the happy medium are alone suitable for the work of the potter4 ,the finer varieties of plaster prepared especially for use in potteries are obtained by a treatment which differs in many respects from that described above for the commoner kinds4 ,in the first place1 the direct contact of fuel or even flame is avoided1 since this reduces some of the sulphate to sulphide of calcium1 the presence of which is in many respects objectionable4 ,secondly1 it is necessary that there should be a better control over the temperature1 since1 as has been seen1 if the heating be carried too far the plaster1 if not partially dead burnt1 will set too quickly for the particular purpose to which it is to be put4 ,the arrangement employed in ,france is known as the four a boulanger1 or baker's furnace4 ,the temperature attained in the furnace itself never exceeds low redness4 ,the material preferred is the softer kind of the granular variety of gypsum4 ,this is put in in pieces of about #ba_/b inches in thickness4 ,after the baking several lumps are broken up and examined to see that there are no shining crystalline particles1 which would indicate that some of the gypsum had remained unchanged4 ,before use the plaster is ground very fine4 ,this point is of considerable practical importance4 ,the consistency attained should be such that the material may be rubbed between the finger and thumb without any feeling of grittiness4 ,should there be particles of a size to be characterized as grit1 these will after use appear at the surface of the mould1 with the result that the mould will have to be abandoned long before it is really worn out1 i4e41 before the details have lost their sharpness4 ,it is manifestly of considerable practical importance to understand the conditions which determine the time of the setting up of plaster4 ,according to ,payen1 the rapidity of setting1 provided the plaster has dehydrated at a temperature sufficiently low1 depends entirely on the structure of gypsum employed4 ,thus1 according to him1 the fibrous kinds gives a plaster setting almost instantaneously4 ,the water1 he says1 penetrates the material freely1 setting takes places almost simultaneously throughout the mass4 ,the hydration of each particle is accompanied by an expansion1 and under the conditions specified1 this expansion being unresisted takes place to the maximum extent1 with the result of leaving cavities between the crystals1 and producing a set plaster of less coherence and density4 ,on the other hand1 where granular crystalline gypsum has been used1 setting begins at the surface of each group of crystals before the water has penetrated to the interior2 the hydration is in consequence more gradual1 and resistance being offered to the expansion of the inner parts1 a harder and denser material is obtained4 ,that this expansion contains an element of truth is indicated by the practice of employing the granular crystalline variety for the preparation of moulding plaster4 ,the explanation appears1 however1 to be inadequate in several respects1 especially in view of the fact that plasters for moulding are reduced to a fine state of division before use4 ,it seems as if this treatment must1 in great part at any rate1 break up the crystalline aggregates4 ,in order to discover a more satisfactory explanation1 let us examine the results of the chemical analysis of plasters used in commerce4 ,one is struck by the large percentage of water they usually contain4 ,thus1 four samples of ordinary plaster analyzed by ,landrin have an average of #ij4ag per cent4 of ,ca,s,o#d and #g4e per cent4 of water1 while two samples of best plaster contained #hi4h per cent4 of ,ca,s,o#d and #g4ic per cent4 of water4 ,these numbers do not add up to #ajj1 the difference being due to silica and other impurities of the original gypsum1 amounting altogether to about #c per cent4 ,it might be suggested that the reason why these plasters set more slowly than completely dehydrated plaster is owing simply to the fact that they contain1 apparently1 some unaltered gypsum1 which serves to dilute the action4 ,were this so1 a similar result1 as far as time of setting is concerned1 should be obtained with a plaster containing a corresponding quantity of dead-burnt material4 ,this1 however1 is not found to be the case4 ,the time of setting appears1 then1 to be connected in some special and peculiar manner with the retention of water by the burnt plaster4 ,the following explanation of this connection is offered1 an explanation only tentative at present1 owing to want of experimental data4 ,the following substances are known3 ,gypsum1 and set plaster1 ,ca,s,o#d #b ,h#b,o1 containing #bj4ic per cent4 of water4 ,plaster completely burned at moderate temperature1 ,ca,s,o#d1 probably amorphous4 ,anhydrite and dead-burned plaster1 ,ca,s,o#d1 crystalline4 ,selenitic deposit from boilers1 #b ,ca,s,o#d ,h#b,o1 or ,ca,s,o#d #a_/b ,h#b,o1 containing #f4b per cent4 of water4 ,the circumstance that the hot calcium sulphate can crystallize with #a_/d its normal amount of water indicates that for this proportion of water it has a greater attraction than for the other #c_/d4 ,having a similar bearing is the fact that when burned at lower temperatures1 gypsum only loses the last portions of water with extreme slowness4 ,now1 if it be the case that anhydrous calcium sulphate has a greater attraction for the first half molecule of water1 then the operation of hydration will proceed very rapidly at first1 more slowly afterward4 ,many such cases are known1 e4g41 that of copper sulphate4 ,conversely1 if only #c_/d of the water of hydration be expelled during the baking of gypsum1 the material obtained should hydrate itself more slowly4 ,for our present purpose it will be convenient to recalculate the numbers given by ,landrin 7vide supra7 so as to make the calcium sulphate and water add up to #ajj4 ,this treatment of the numbers gives a mean result for the six analyses of #g4fh per cent4 of water1 the amounts not varying by more than #a per cent4 ,it will be seen that the dehydration has never passed the composition corresponding to #b ,ca,s,o#d ,h#b,o2 indeed1 the material approximates more nearly to the composition #c ,ca,s,o#d ,h#b,o4 ,it appears probable1 therefore1 that in the successful preparation of plaster the whole1 or nearly the whole1 of the gypsum is changed1 but that this change does not result in the production of ,ca,s,o#d1 or of a mixture of ,ca,s,o#d and ,ca,s,o#d #b ,h#b,o1 but of a lower hydrate of calcium sulphate4 ,in the case of the analyses1 given by ,landrin1 of fine plaster for potteries1 the percentages of water 7#h4ad and #h4jh7 correspond closely to that of a hydrate1 #c ,ca,s,o#d #b ,h#b,o1 which would contain #h4a per cent4 of water4 ,some surprise may have been excited by the fact that the well known method of revivifying hydrated calcium sulphate has recently formed the subject of a patent 7,eng4 pat41 ,no4 #ae1djf74 ,the method described in the specification consists in reducing the materials 7waste moulds1 etc47 to small lumps1 and baking between the temperatures of #ie and #cjj4 ,it is mentioned that the whole of the water must not be expelled4 ,this is no doubt correct1 but it must be effected by regulating the time of baking1 since by prolonging the operation all the water of crystallization can be expelled far below #cjj4 ,to secure even baking the mass is kept stirred by mechanical stirrers1 a necessary precaution1 since the operation is to be carried out in an ordinary kiln4 ,the process is stopped when a portion of the plaster is found to set in the required time1 a method of regulation which will probably be found to work well in practice4--,chem4 ,trade ,jour4 99 99 99 99 99 ,,spacing ,,the ,,frets ,,on ,a ,,banjo ,,neck4 ,,by ,,prof4 ,c4,w4 ,,maccord4 ,the amateur performer on the banjo1 if he be of a mechanical turn1 is often tempted to exercise his skill by making an instrument for himself2 and the temptation is the greater because he can confine himself to the essentials4 ,the excellence of a banjo in respect to power and tone depends mainly upon the rim and the neck1 that is1 supposing the parchment head to be of proper quality2 but then the preparation of the heads is a business of itself1 and the amateur is no more expected to make the head than to make the strings4 ,so again1 all the minor accessories1 such as pegs and tail pieces1 brackets and bridges1 are kept in stock for his benefit1 and he may justly claim all the credit if his efforts in connection with the two principal parts first mentioned result in the production of a superior instrument4 ,among these ready-made items is a fret wire of peculiar section1 furnished with a flange ready for insertion into fine saw cuts across the neck1 which much facilitates his work4 ,of course1 the correctness of the notes depends entirely upon the accuracy with which the frets are spaced1 and the accompanying diagram exhibits a convenient method of determining the spaces by graphic means4 ,illustration3 ,,spacing ,,for ,,banjo ,,frets ,it is to be understood that when the distance from the nut1 ,n1 to the bridge1 ,b1 has been determined1 the first fret is to be placed at #a_/ah of that distance from the nut1 the distance from the first to the second is to be #a_/ah of the remainder1 and so on4 ,to determine these distances by computation1 then1 is a simple enough arithmetical exercise2 but it is exceedingly tedious1 since the denominators of the fractions involved increase with great rapidity2 being successive powers of the comparatively large number #ah1 they soon become enormous4 ,in the large diagram1 the distance1 ,a ,c1 on the horizontal line corresponds to the distance1 ,n ,b1 on the instrument4 ,at ,a erect a vertical line1 and mark upon it a point ,b such that ,b ,c shall be exactly eighteen times any convenient unit1 ,b ,i4 ,in the illustration ,b ,c is #bf inches1 and ,b ,i is #aa_/b inches1 so that ,b ,c is #bg inches in length4 ,about ,c as a center describe the arcs1 ,b ,l1 ,i ,k1 and through ,i draw a vertical line1 cutting ,b ,l in ,d2 draw the radius ,d ,c1 cutting the inner arc1 ,i ,k1 in ,j1 through ,j draw another vertical1 cutting ,b ,l in ,e1 and so on4 ,in the triangles1 ,a ,b ,c1 #a ,d ,c1 #b ,e ,c1 we have ,b ,i ,d ,j ,e ,f #a_/ah of the hypotenuse in each case1 therefore the bases1 ,a ,c1 #a ,c1 #b ,c1 are divided in the same proportion1 as required1 at the points #a1 #b1 #c4 ,and we might extend the arcs1 ,b ,l1 ,i ,k1 and repeat the above operation until all the frets were located4 ,but should that be done1 the diagram might become inconveniently large1 and some of the intersections might not be reliably determined4 ,in order to avoid this1 the spacing of the outer arc may be stopped at any convenient division1 as ,l4 ,the vertical by which that point is determined cuts ,b ,c at ,b'1 and through ,b' a new arc1 ,b' ,l'1 is described4 ,through the points in which this arc cuts the radial lines already drawn1 a new series of verticals is passed1 which will divide another portion of ,a ,c as required1 and by repeating this process the spacing of the whole neck may be effected by a diagram of reasonable size4 99 99 99 99 99 ,,glove ,,making4 ,glove making is almost a century old in this country1 having been begun in the neighborhood of ,gloversville and ,johnstown1 ,n4,y41 about #ahjc4 ,until #ahfb the manufacture of gloves in ,fulton ,county1 although even then the chief manufacturing industry1 was of comparatively small importance4 ,gloversville and ,johnstown were then quiet villages of from three to four thousand people4 ,the flourishing establishments of to-day1 or such of them as then existed1 were small and comparatively unimportant4 ,in #ahfb the stimulating influence of a high protective tariff showed itself in the increased business at ,gloversville1 ,johnstown1 and the adjoining hamlet1 ,kingsboro4 ,these became at once the leading sources of supply for the home market gloves of a medium grade4 ,the quality of the product has steadily improved1 and the variety has been increased1 until now ,american-made gloves are steadily driving out the foreign gloves4 ,the skill of ,american glovers is equal to that of foreign glove makers1 and in some respects--notably in the quality of the stitching1 and1 in some grades1 the shape--the ,american gloves are the best4 ,foreign expert workmen have been drawn over here from the great glove centers of ,europe1 so that the greatest skill has been secured here4 ,the annual value of the glove industry in ,fulton ,county has reached about #g1jjj1jjj4 ,one hundred and seventy-five glove makers and #bj1jjj people in ,fulton ,county draw their subsistence directly from glove making4 ,some of the firms have a business reaching from #ajj1jjj to #ejj1jjj yearly4 ,the majority1 however1 have small shops1 and do a small but profitable business4 ,most of the work in ,fulton ,county1 as abroad1 is done at the homes of the workers4 ,the streets of ,gloversville and ,johnstown are lined with pretty and tasteful homes1 in which the hum of the sewing machine is constantly heard during the working hours of the day1 but the workers are exceptionally fortunate in being able while earning good wages to enjoy all the comforts and surroundings of home1 and in being practically their own masters and mistresses4 ,before the leather can be cut and sewed into the handsome articles that are sold over the counters of the retail dry goods houses and furnishing goods stores as gloves1 the skins from which they are made must be specially prepared4 ,the two important points in this preparation are the removal of the albuminous portion of the skin and the retention and chemical changing of the gelatinous part1 so that it shall become pliable1 elastic1 and resist decomposition4 ,there are various methods which produce these results1 and they are technically known as tanning1 alum dressing1 oil dressing1 and ,indian dressing4 ,each method produces a leather distinctly different from that produced by any other4 ,all the preliminary processes of these various methods are alike in principle1 although they vary somewhat in detail4 ,the object in all is to remove the hair from the hide1 separate the fleshy and albuminous matter1 and leave only the gelatinous1 which alone is susceptible to the chemical action and can be transformed by it into leather4 ,when the skins are received in the factory they are thoroughly soaked to open out the texture and prepare them for the removal of the hair4 ,then the skins are placed in vats of lime water1 where1 for two or three weeks1 the lime works into the flesh and albuminous matter1 and loosens the hair4 ,the skins having thus been properly softened1 the dirty but picturesque operation of beaming for removing the hair ensues4 ,before each beamer1 as the workman is called1 is an inclined semi-cylindrical slab of wood covered with zinc4 ,the skin is first spread upon this1 and the broad1 curved beam of the knife glides across it from end to end1 scraping and removing all the loosened hair1 the scarf skin1 and the small portion of animal matter adhering to the skin4 ,after the unhairing1 kid skins must be fermented in a drench of bran1 whose purpose is to completely decompose the remaining albuminous matter1 and also to remove all traces of the lime4 ,the operation is extremely delicate4 ,while the gelatine is not so sensitive to the decomposing action of the ferment1 nevertheless great care is required to prevent overfermentation and resulting damage to the texture of the skin4 ,it is impossible for even the most experienced to tell just how long the fermentation should continue4 ,sometimes the work is done in two or three hours1 and sometimes it requires as many days4 ,incessant watchfulness both day and night is required to detect the critical moment4 ,with the less delicate skins this bran bath is not necessary4 ,lime and acid solutions accomplish the same purpose4 ,when the gelatine matter is all removed the skins are ready for the actual curative process4 ,oil dressing or ,indian dressing--which merely differ in application1 but are founded upon the same principle--is the most simple method of curing skins4 ,the principle of each is the soaking of the gelatine fibers of the skin with oil1 the union of the latter and the gelatine appearing in the form of oxide1 and resulting in the insoluble1 undecomposable1 pliant1 and tough material known to the commercial world as leather4 ,the first step in the oil dressing1 after the skins have been duly soaked to render them porous and absorptive1 is to cover them with fish oil and place them in the stocks or fulling machines--huge wooden hammers with notched faces working in iron cases--where they are beaten and turned1 and subjected to a uniform pressure until the oil is gradually absorbed4 ,after taking them out1 hanging them up1 and stretching them1 the oil and fulling process is repeated according to the thickness of the skin1 and until every part of it is full of oil4 ,after this the skins are dried in a mild heat that causes the oxidization of the oil4 ,this being completed1 all the superfluous oil is removed by putting the skins in an alkali bath4 ,then the curing process is complete4 ,with the preparation of kid leather alum is the astringent curative agent4 ,its operation is accompanied by that of others whose purpose is to secure elasticity and pliability1 and mainly to preserve that beautiful texture which makes kid leather superior to all others4 ,these assistants in the process are eggs1 flour1 and salt4 ,they are combined into what is called a custard4 ,a proper quantity of the custard and a number of skins having been put together in a dash wheel1 where they are thrown about for some time1 the open pores of the skin absorb the custard freely1 and become swelled by the chemical union of the custard and the skin4 ,in trade parlance this swelling is known as plumping4 ,this having progressed satisfactorily1 the skins are folded together with the fleshy side outward1 and are dried by a gentle heat4 ,they are now cured1 but they are yet hard and rough4 ,another objectionable feature is that they are of unequal thickness4 ,breaking and staking1 as they are called1 are now resorted to1 to make the skins soft1 pliable1 and of even texture1 removing the superfluous chemicals with which they become charged1 and the stiffness by manipulating the fibers4 ,much trained skill and dexterity1 especially in knee and arm staking1 are required in the stretching1 which is the essential feature of these operations4 ,breaking is first resorted to4 ,the break beam1 which is armed at each end with a knife edge1 oscillates up and down4 ,in a frame beneath it the operator stretches the dried and stiff skin4 ,the break beam comes down upon the skin1 stretches and softens it1 and removes much surplus custard4 ,the operator presents a new surface to each stroke of the break beam1 and in a very short space of time the entire skin is rendered soft and pliable4 ,further manipulation upon the arm or knee stake--of which a dull1 semicircular knife blade1 supported upon a suitable standard upon the floor or upon a beam about opposite the worker's elbow is the main feature--is required4 ,the skin must be drawn across this knife blade with a considerable application of force so as to reduce the unduly thick parts1 stretch the skin and secure a uniform thickness suitable for gloves4 ,much dexterity1 especially in the case of fine skins1 is required in this operation to avoid cutting or tearing4 ,the operator places the fleshy side of the skin over the knife1 grasps the two ends of the skin1 and placing his knee upon it and slowly drawing the skin across the knife edge1 he brings his weight to bear upon it4 ,if the operator is skilled and experienced the skin yields quickly1 when needed1 to the strain applied and a uniform texture is secured4 ,the operation of transforming the skin into leather is now finished1 but age is necessary to secure perfect pliability and softness4 ,the skins are1 therefore1 laid away to let the slow chemical operation going on within them be completed4 ,the visitor can now watch the further processes of manufacture by visiting the dye rooms4 ,skins which have already been aged are immersed in dye vats1 where the delicate colors are imparted to them4 ,the same care is not required in obtaining the ordinary range of dark colors1 for these are brushed on1 the skin being spread upon a glass slab and the dye being painted on with a brush4 ,after they are dyed the skins are sometimes somewhat hard1 and in some classes have to be staked again in order to restore their pliability4 ,the finishing touches to a kid skin are secured by rubbing the grain side over with a size1 which imparts a gloss4 ,the experience of ,gloversville manufacturers with buck gloves has enabled them to impart a special finish to a skin which is very popular under the title of ,mocha4 ,this is the same as suede finish1 which is produced in other countries by shaving off the grain side of the skin at an early stage of its progress4 ,the ,gloversville method is much better1 however1 and has more perfect results4 ,here the grain is removed1 and the velvet finish secured by buffing the surface on an emery wheel4 ,the surface of the leather is cut away in minute particles by this process1 and the result is an exceedingly even and velvety texture1 superior to that obtained by other methods4 ,european manufacturers do not approach the ,americans in this respect4 ,the leathermaker leaves off and the glovemaker begins4 ,a marble slab lies before the cutter on a table1 and every particle of dirt or other inequality is removed before doling4 ,the skin is spread1 flesh side up1 upon the slab1 and the cutter goes over it with a broad bladed chisel or knife1 shaving down inequalities and removing all the porous portions4 ,the dexterity with which this is done makes the operation appear extremely simple1 but any but a skilled and experienced operative would almost surely cut through the skin4 ,the most delicate part of the glovemaker's art1 in which exact judgment is required1 comes in preparing the tranks or slips1 from which the separate gloves are cut4 ,the trank must be so cut as to have just enough leather to make a glove of a certain size and number4 ,the operation would be easy enough if the material were hard and stiff1 and if the elasticity were uniform1 but this is rarely the case4 ,to accomplish this operation the trank must be firmly stretched in one direction1 and while so stretched a redell stamps the proper dimensions in the other direction1 to which the leather is trimmed4 ,upon the nicety with which this operation is performed depends the question of whether the finished glove will stretch evenly or too much or too little in one direction or the other4 ,after this the trank or outline of the glove must be cut out4 ,in olden times of glove manufacture an outline was traced upon the leather and the pattern was cut with shears4 ,modern invention has produced dies and presses which are universally used4 ,the steel die has the outline of a double glove1 including the opening for the thumb piece4 ,the die rests upon the bed of the press4 ,several tranks are laid upon it1 the lever is drawn1 and in a moment the blanks are cut out clean and smooth4 ,the gussets1 facings1 etc41 are cut from the waste leather in the thumb opening at the same operation4 ,similar dies are used in the cutting of the thumb pieces and fourchettes or strips forming the sides of the fingers4 ,the pieces now go to the great sewing rooms of the factory1 where are long rows of busy sewing girls4 ,if the manufacturer of years ago could revisit the scenes of his earthly toil1 and wander through the sewing rooms of a modern factory1 he would doubtless be greatly amazed at the sight presented there4 ,in his day such a thing was unknown4 ,the glove was then held in position by a hand clamp1 while the sewing girl pushed the needle in and out1 making an overseam4 ,all this is done now in an infinitely more rapid manner by machine1 and with resulting seams that are more regular and strong than those made by the hand sewer4 ,the overseam sewers earn large wages1 and their places are much coveted4 ,overlapping seams are produced on the pique machine1 which is a most ingenious mechanism4 ,the essential feature of this machine is a long steel finger with a shuttle and bobbin working within1 and the finger of the glove is drawn upon this steel finger1 permitting the seam to be sewn through and through4 ,the visitor to the factory can see also the minor operations of embroidering1 lining--in finished gloves--sewing the facing1 sewing the buttonholes1 putting on the buttons1 and trimming with various kinds of thread4 ,before the gloves are ready for the boxes one more operation remains4 ,the gloves are somewhat unsightly as they come from the sewers' hands1 and must be made trim and neat4 ,to secure these desirable results the gloves are taken to the laying-off room4 ,in this are long tables with a long row of brass hands projecting at an acute angle4 ,these are filled with steam and are too hot to touch4 ,these steam tables by ingenious devices are so arranged that it is impossible to burn the glove or stiffen the leather by too much heat1 a common defect in ordinary methods4 ,the operation of the laying-off room is finished with surprising quickness4 ,before each table stands an operator1 who slips a glove over each frame1 draws it down to shape1 and after a moment's exposure to the warmth removes it1 smooth1 shapely1 and ready for the box4 ,the frames upon which the gloves are drawn are long and narrow for fine gloves and short and stubby for common ones4 ,then the glove is taken to the stock room1 where there are endless shelves and bins to testify to the chief drawback to glove making1 the necessity for innumerable patterns4--,the ,mercer4 99 99 99 99 99 ,,fabric ,,for ,,upholstery ,,purposes4 ,the object of this invention is to produce a firm1 solid1 dust-resisting1 and durable woven cloth1 composed1 preferably1 entirely of cotton1 but it may be of a cotton warp combined with a linen or other weft1 and is particularly applicable for covering the seats and cushions of railway and other carriages1 for upholstering purposes1 for bed ticking1 and for various other uses4 ,to effect this object1 a cotton warp and1 preferably1 a cotton weft also are employed1 or a linen1 worsted1 or other weft may be used4 ,both the yarns for warp and weft may be either dull or polished1 according to the appearance and finish of cloth desired4 ,the fabric is woven in a plain loom1 and the ends are drawn through say eight heald shafts1 but four1 sixteen1 or thirty-two heald shafts might be employed4 ,when eight heald shafts are employed1 the warp is drawn as follows3 ,the #ast warp end in the first heald shaft1 the #b;d warp end in the second heald shaft1 and so on1 the remaining six warp ends being drawn in1 in consecutive order1 through the remaining six heald shafts2 the #ith warp end is drawn in through the first heald shaft1 and so on1 the drawing in of the other ends being repeated as above4 ,the order of the shedding is as follows3 #ast change4 ,the #ast and #c;d heald shafts fall1 the rest remaining up4 #b;d change4 ,the #eth and #gth shafts fall1 and the #ast and #c;d rise4 #c;d change4 ,the #b;d and #dth shafts fall1 and the #eth and #gth rise4 #dth change4 ,the #fth and #hth shafts fall1 and the #b;d and #dth shafts rise4 ,the result is that each weft thread1 a1 passes under six warp threads1 b1 and over two warp threads1 in the manner illustrated by the accompanying diagram4 ,in drawing in1 when four heald shafts are employed1 the #ast warp end is drawn in through the #ast heald shaft1 the #b;d through the #b;d shaft1 the #c;d through the #ast1 the #dth through the #b;d1 the #eth through the #c;d1 the #fth through the #dth1 the #gth through the #c;d1 and #hth through the #dth shaft1 and repeating with the #ith end through the #ast shaft4 ,in shedding1 the #ast heald shaft is lowered1 then the #c;d1 then the #b;d1 and then #dth4 ,the result1 in this case1 is still the same1 viz41 that each weft thread passes under six warp ends and over two warp ends4 ,although a cotton warp is spoken of in some cases1 worsted or other yarn can be added to the cotton warp to obtain a variation in the pattern or design4--,jour4 of ,fabrics4 ,illustration 99 99 99 99 99 ,,reversible ,,ingrain ,,or ,,pro-,,brussels ,,carpet4 ,the object of this invention is to manufacture1 in a cheap fabric1 a closer imitation of ,brussels carpets4 ,as is well known1 an ordinary ,brussels carpet is made with a pattern on one side only1 but according to this invention1 it is intended to produce a pattern on both sides of the ingrain or pro-,brussels carpet1 so that it will be reversible4 ,in manufacturing a reversible carpet of this class according to the present invention1 the pattern is formed by means of the warp and weft combined1 and any suitable ingrain warp operated by the harness or jacquard of the loom may be used4 ,in combination with ingrain warp1 a fine catching or binding warp1 operated by the gear or jacquard harness of the loom1 is employed1 such fine catching warp being used to bind the weft into the fabric1 therefore1 if the fabric be woven two-ply1 the ingrain warps are thrown on both the under and upper surfaces of the fabric1 as well as in between the weft1 according to the pattern being woven1 by which means four colors are shown on both sides of the fabric1 two being produced by the weft1 and two by the ingrain warps4 ,more than four colors1 however1 can be produced upon each side by multiplying the number of colored wefts and warps employed4 ,if the fabric woven be a three-ply1 with the addition of the ingrain warps thrown on each face of the fabric1 then five or more colors would be imparted to the carpet1 as any number of colors can be used to form a given pattern1 by planting or arranging the colors in the warp1 and the remaining colors by the wefts1 and so on4 ,the ingrain warp thread1 therefore1 together with the weft1 used as stated above1 produces an effective pattern on both sides of the carpet2 consequently1 it becomes reversible1 and this can be accomplished whether the carpet woven be two1 three1 or other number of ply4 ,by reference to the accompanying sheets of drawings1 this invention will be better understood4 ,fig4 #a is an enlarged cross section of an improved carpet1 a three-ply1 that is to say1 it is a carpet wherein three shuttles are employed1 each carrying a differently colored weft2 a represents the weft threads which may be composed of any suitable fiber1 b and c are cotton or other fine warp threads1 which are employed for binding the weft together1 while d and e represent the ingrain or woolen warp1 where it will be seen that each ingrain warp1 besides lying between the weft1 is thrown on both sides of the fabric1 for the purpose of forming figures thereon4 ,it will1 therefore1 be seen that a carpet made according to ,fig4 #a will show five colors--three colors produced by the weft and two colors produced by the ingrain warp4 ,fig4 #b represents a carpet made with two-ply1 in which case only four colors will be produced1 two by the weft and two by the ingrain warp4 ,it is1 consequently1 obvious that a carpet made in the manner above described will have a corresponding pattern or figure on both its sides1 allowing it to be used on both sides4 ,fig4 #c also shows a two-ply carpet1 but1 in this case1 six colors are produced1 i4e41 two colors by the weft and four by the ingrain warp1 marked d1 d1 e1 and e1 the warp being so manipulated by the harness as to make the carpet reversible1 and having a corresponding pattern or figure on both sides4--,journal of ,fabrics4 ,illustration3 ,fig4 #a ,illustration3 ,fig4 #b ,illustration3 ,fig4 #c 99 99 99 99 99 ,,ar,o-,,picnometer4 ,a modified arometer has been recently patented by ,aug4 ,eichhorn1 in ,dresden1 ,germany 7,deutsches ,reichs-,patent1 ,no4 #di1fhc71 which will prove a great boon to chemists1 distillers1 physicians1 etc41 as it affords an easy means of determining the specific gravity of liquids1 especially such of which only small quantities can be conveniently obtained4 ,with the ordinary arometers1 as hitherto constructed1 a considerable quantity of the test fluid is required1 and an elaborate calculation necessary for each determination4 ,in the new aro-picnometer these drawbacks are ingeniously avoided1 so that the specific gravity of any liquid can be quickly and easily obtained with astonishing accuracy4 ,the new and important feature of this instrument consists in a glass bulb1 c--see accompanying sketch--which is filled with the liquid whose gravity is to be determined4 ,thus1 instead of floating the entire apparatus in the test fluid1 only a very small quantity of the latter is required1 an advantage which can hardly be overestimated1 considering how difficult it is in many instances to procure the necessary supply4 ,illustration a _/ - - - - - - - - - - - - - - - _/ - - - b - _/ - - e_/_/ d - c - - _/ - _/ - - - - - - - - f_/ - - - v - - _/ ,the glass bulb1 c1 when filled with the test fluid1 is closed by means of an accurately fitting glass stopper1 d1 and the instrument is then placed in a glass cylinder filled with distilled water of #ag4e deg4 temperature 7,centigrade74 ,the gravity is then at once shown on the divided scale in the tube1 a4 ,the lower bulb1 f1 contains some mercury2 e is a small glass knob1 which serves to maintain the balance1 while b is an empty glass bulb 7floater74 ,these instruments are admirably adapted for determining the gravity of alcohol1 petroleum1 benzine1 and every kind of oil1 also for testing beer1 milk1 vinegar1 grape juice1 lye1 glycerine1 urine1 etc4 ,as the process is an exceedingly simple one and free from the drawbacks of the arometer1 we are justified in concluding that the aro-picnometer will soon be in general use4 ,h4 ,,hensoldt1 ,ph4,d4 ,petrographical ,laboratory1 ,school of ,mines1 ,columbia ,college4 99 99 99 99 99 ,continued from ,,supplement1 ,no4 #gic1 page #abffi4 ,,gaseous ,,illuminants4#a ,footnote3 ,lectures recently delivered before the ,society of ,arts1 ,london4 ,from the ,journal of the ,society4 ,,by ,,prof4 ,,vivian ,b ,,lewes4 ,,iv4 ,mr4 ,frank ,livesey1 in the concluding sentence of a paper read before the ,southern ,district ,association of ,gas ,managers and ,engineers during the past month1 on ,a ,ready ,means of ,enriching ,coal ,gas1 speaking of enrichment by gasolene by the ,maxim-,clarke process1 said it should1 in many cases1 take the place of cannel1 to be replaced in its turn1 probably1 by a water gas carbureted to #bj or #be candle power4 ,and now1 having fully reviewed the methods either in use or proposed for the enrichment of gas1 we will pass on to this1 the probable cannel of the future4 ,discovered by ,fontana1 in #aghj1 and first worked by ,ibbetson1 in ,england1 in #ahbd1 water gas has added a voluminous chapter to the patent records of ,england1 ,france1 and ,america1 no less than sixty patents being taken out between #ahbd and #aheh1 in which the action of steam on incandescent carbon was the basis for the production of an inflammable gas4 ,up to the latter date the attempts to make and utilize water gas all met with failure2 but about this time the subject began to be taken up in ,america1 and the principle of the regenerator1 enunciated by ,siemens in #ahef1 having been pressed into service in the water-gas generator under the name of fixing chambers or superheaters1 we find water gas gradually approaching the successful development to which it has attained in the ,united ,states during the last ten years4 ,having now1 by the aid of ,american skill1 been brought into practical form1 it is once more attempting to gain a foothold in ,western ,europe--the land of its birth4 ,when carbon is acted upon at high temperatures by steam1 the first action which takes place is the decomposition of the water vapor1 the hydrogen being liberated1 while the oxygen unites with the carbon to form carbon dioxide3 ,carbon4 ,water4 ,c #b;,h#b,o ,,co#b #d;,h#b ,and the carbon dioxide so produced interacts with more red-hot carbon1 forming the lower oxide--carbon monoxide3 ,,co#b ,c #b;,,co ,so that the completed reaction may be looked upon as yielding a mixture of equal volumes of hydrogen and carbon monoxide1 both of them inflammable but non-luminous flames4 ,this decomposition1 however1 is rarely completed1 and a certain proportion of carbon dioxide is invariably to be found in the water gas1 which1 in practice1 generally consists of a mixture of about this composition3 ,,water ,,gas4 ,hydrogen #dh4ca ,carbon monoxide #ce4ic ,carbon dioxide #d4be ,nitrogen #h4ge ,methane #a4je ,sulphureted hydrogen #a4bj ,oxygen #j4ea ------ #ajj4jj ,the above is an analysis of water gas made from ordinary gas coke in a ,van ,steenbergh generator4 ,the ratio of carbon monoxide and carbon dioxide present entirely depends upon the temperature of the generator1 and the kind of carbonaceous matter employed4 ,with a hard1 dense anthracite coal1 for instance1 it is quite possible to attain a temperature at which there is practically no carbon dioxide produced1 while with an ordinary form of generator and a loose fuel like coke1 a large proportion of carbon dioxide is generally to be found4 ,the sulphureted hydrogen in the analysis quoted is1 of course1 due to the high amount of sulphur to be found in the gas coke1 and is practically absent from water gas made with anthracite1 while the nitrogen is due to the method of manufacture1 the coke being1 in the first instance1 raised to incandescence by an air blast1 which leaves the generator and pipes full of a mixture of nitrogen and carbon monoxide 7producer gas71 which is carried over by the first portions of water gas into the holder4 ,the water gas so made has no photometric value1 its constituents being perfectly non-luminous1 and attempts to use it as an illuminant have all taken the form of incandescent burners1 in which thin mantles or combs of highly refractory metallic oxides have been heated to incandescence4 ,in carbureted water gas this gas is only used as the carrier of illuminating hydrocarbon gases1 made by decomposing various grades of hydrocarbon oils into permanent gases by heat4 ,many forms of generator have been used in the ,united ,states for the production of water gas1 which1 after or during manufacture1 is mixed with the vapors and permanent gases obtained by cracking various grades of paraffin oil1 and fixing them by subjecting them to a high temperature2 and in considering the subject of enrichment of coal gas by carbureted water gas1 ,i shall be forced1 by the limited time at my disposal1 to confine myself to the most successful of these processes1 or those which are already undergoing trial in this country4 ,in considering these methods1 we find they can be divided into two classes3 #a4 ,continuous processes1 in which the heat necessary to bring about the interaction of the carbon and steam is obtained by performing the operation in retorts externally heated in a furnace2 and #b4 ,intermittent processes1 in which carbon is first heated to incandescence by an air blast1 and then1 the air blast being cut off1 superheated steam is blown in until the temperature is reduced to a point at which the carbon begins to fail in its action1 when the air is again admitted to bring the fuel up to the required temperature1 the process consisting of alternate formation of producer gas with rise of temperature1 and of water gas with lowering of the temperature4 ,of the first class of generator1 none1 as far as ,i know1 have as yet been practically successful1 the nearest approach to this system being the ,meeze1 in which fire clay retorts in an ordinary setting are employed4 ,in the center of each retort is a pipe leading nearly to the rear end of the retort1 and containing baffle plates4 ,through this a jet of superheated steam and hydrocarbon vapor is injected1 and the mixture passes the length of the inner tube1 and then back through the retort itself--which is also fitted with baffle plates--to the front of the retort1 whence the fixed gases escape by the stand pipe to the hydraulic main1 and the rich gas thus formed is used either to enrich coal gas or is mixed with water gas made in a separate generator4 ,in some forms the water gas is passed with the oil through the retort4 ,in such a process1 the complete breaking down of some of the heavy hydrocarbons takes place1 and the superheated steam1 acting on the carbon so liberated1 forms water gas which bears the lower hydrocarbons formed with it2 but inasmuch as oil is not an economical source of carbon for the production of water gas1 this would probably make the cost of production higher than necessary4 ,this system has been extensively tried1 and indeed used to a certain extent1 but the results have not been altogether satisfactory1 one of the troubles which have had to be contended with being choking of the retorts4 ,of the intermittent processes1 the one most in use in ,america is the ,lowe1 in which the coke or anthracite is heated to incandescence in a generator lined with firebrick1 by an air blast1 the heated products of combustion as they leave the generator and enter the superheaters being supplied with more air1 which causes the combustion of the carbon monoxide present in the producer gas1 and heats up the firebrick baffles with which the superheater is filled4 ,when the necessary temperature of fuel and superheater has been reached1 the air blasts are cut off1 and steam is blown through the generator1 forming water gas1 which meets the enriching oil at the top of the first superheater1 called the 'carbureter1' and carries the vapors with it through the main superheater1 where the fixing of the hydrocarbons takes place4 ,the chief advantage of this apparatus is that the enormous superheating space enables a lower temperature to be used for the fixing4 ,this does away1 to a certain extent1 with the too great breaking down of the hydrocarbons1 and consequent deposition of carbon4 ,this form of apparatus has just found its way to this country1 and ,i describe it as being the one most used in the ,states1 and the type upon which1 practically1 all water gas plant with superheaters has been founded4 ,the ,springer apparatus1 which is under trial by one of the large gas companies1 differs from the ,lowe merely in construction4 ,in this apparatus the superheater is directly above the generator2 and there is only one superheating chamber instead of two4 ,the air blast is admitted at the bottom1 and the producer gases heat the superheater in the usual way1 and when the required temperature is reached1 the steam is blown in at the top of the generator1 and is made to pass through the incandescent fuel1 the water gas being led from the bottom of the apparatus to the top1 where it enters at the summit of the superheater1 meets the oil1 and passes down with it through the chamber1 the finished gas escaping at the middle of the apparatus4 ,this same idea of making the air blast pass up through the fuel1 while in the subsequent operation the steam passes down1 is also to be found in the ,loomis plant1 and is a distinct advantage1 as the fuel is at its hottest where the blast has entered1 and1 in order to keep down the percentage of carbon dioxide1 it is important that the fuel through which the water gas last passes should be as hot as possible1 to insure its reduction to carbon monoxide4 ,the ,flannery apparatus is again but a slight modification of the ,lowe plant1 the chief difference being that1 as the gas leaves the generator1 the oil is fed into it1 and1 with the gas1 passes through a ,d-shaped retort tube1 which is arranged round three sides of the top of the generator2 and in this the oil is volatilized1 and passes1 with the gas1 to the bottom of the superheater1 in which the vapors are converted into permanent gases4 ,the ,van ,steenbergh plant1 with which ,i have been experimenting for some time1 stands apart from all other forms of carbureted water gas plant1 in that the upper layer of the fuel itself forms the superheater1 and that no second part of any kind is needed for the fixation of the hydrocarbons1 an arrangement which reduces the apparatus to the simplest form1 and leaves no part which can choke or get out of order1 an advantage which will not be underrated by any one who has had experience of these plants4 ,while1 however1 this enormous advantage is gained1 there is also the drawback that the apparatus is not fitted for use with crude oils of heavy specific gravity1 such as can be dealt with in the big external superheaters of the ,lowe class of water gas plant1 but the lighter grades of oil must be used in it for carbureting purposes4 ,i am not sure in my own mind that this1 which appears at first a disadvantage1 is altogether one1 as1 in the first place1 the lighter grades of oil1 if judged by the amount of carbureting power which they have1 are cheaper per candle power1 added to the gas1 than the crude oils1 while their use entirely does away with the formation of pitch and carbon in the pipes and purifying apparatus--a factor of the greatest importance to the gas manufacturer4 ,the fact that light oils give a higher carburation per gallon than heavy crude oil is due to the fact that the latter have to be heated to a higher temperature to convert them into permanent gas1 and this causes an over-cracking of the most valuable illuminating constituents2 and this trouble cannot be avoided1 as1 if a lower temperature is employed1 easily condensible vapors are the result1 which1 by their condensation in the pipes1 give rise to much trouble4 ,the simplicity of the apparatus is a factor which causes a great saving of time and expense1 as it reduces to a minimum the risk of stoppages for repairs1 while the initial cost of the apparatus is1 of course1 low1 and the expense of keeping in order practically nil4 ,when ,i first made the acquaintance of this form of plant1 a few years ago1 the promoters were confident that nothing could be used in it but ,american anthracite1 of the kind they had been in the habit of using in ,america1 and a light naphtha of about #j4fhi specific gravity1 known commercially as #gf deg ,baume4 ,a few weeks' work with the apparatus1 however1 quickly showed that1 with a slightly increased blow1 and a rather higher column of fuel1 gas coke could be used just as well as anthracite1 and that by increasing the column of fuel1 a lower grade of oil could be employed2 so that during a considerable portion of the experimental work nothing but gas coke from the ,horseferry ,road ,works and a petroleum of a specific gravity of about #j4gji were employed4 ,having had control of the apparatus for several months1 and1 with the aid of a reliable assistant1 having checked everything that went in and came out of the generator1 ,i am in a position to state authoritatively that1 using ordinary gas coke and a petroleum of specific gravity ranging from #j4fhi to #j4gji1 #a1jjj cubic feet of gas1 having an illuminating power of twenty-two candles1 can be made with an expenditure of #bh to #cb lb4 of coke and #ba_/b gallons of petroleum4 ,the most important factors1 i4e41 the quantity of petroleum and the illuminating value of the gas1 have also been checked and corroborated by ,mr4 ,heisch and ,mr4 ,leicester ,greville4 ,total gas made #h1gjj cubic feet4 ,time taken3 ,blowing4 #a hour4 ,time taken3 ,making4 #ej minutes4 ,fuel used3 ,gas coke4 #bgj lb4 #ca lb4 per #a1jjj c4f4 ,fuel used3 ,naphtha1 sp4 gr4 #j4gji4 #cd gals4 #b4g gals4 per #a1jjj c4f4 ,illuminating power of gas #ba4i candles4 ,i must admit that these results far exceeded my expectations1 although they only confirmed the figures claimed by the patentee2 and there are not wanting indications that1 when worked on a large scale and continuously1 they might be even still further lowered1 as it is impossible to obtain the most economical results when making less than #aj1jjj cubic feet of the gas1 as the proper temperature of the walls of the generator are not obtained until after several makes2 and it is only after about #h1jjj cubic feet of gas has been made that the best conditions are fulfilled4 ,it will enable a sounder judgment to be formed of the working of the process if the complete experimental figures for a make of gas be taken4 ,,composition ,,of ,,the ,,gas4 ,hydrogen4 #df4ge ,olefines4 #g4ei ,ethane4 #f4hb ,methane4 #aa4bg ,carbon monoxide4 #aa4fe ,carbon dioxide4 #j4ej ,oxygen4 #j4ag ,nitrogen4 #h4be ------- #ajj4jj ,,unpurified ,,gas ,,contained ,carbon dioxide4 #b4cb per cent4 ,sulphureted hydrogen4 #b4hd ,total sulphur per #ajj cu4 ft4 #f4fg ,ammonia4 nil ,bisulphide of carbon4 nil ,gas produced ,naphtha used ,gals4 ,pts4 #ast4 ,make4 #c1fjj cu4 ft4 #aj #g #b;d4 #b1hjj #g #f #c;d4 #b1cjj #e #c ------ --- -- #h1gjj #bd #j ,the last portion of the table shows the economy which arises as the whole apparatus gets properly heated4 ,thus the first make used #c gallons naphtha per #a1jjj cubic feet1 the second #b gallons #f pints per #a1jjj cubic feet1 and the third #b gallons #d pints per #a1jjj cubic feet1 and it is1 therefore1 not unreasonable to suppose that in a continuous make these figures could be kept up1 if not actually reduced still lower4 ,in introducing the oil it is not injected1 but is simply allowed to flow in by gravity1 at a point about half way up the column of fuel1 the taps for its admission being placed at intervals around the circumference of the generator1 and oil at first begins to flow down the inside wall of the generator1 but being vaporized by the heat1 the vapor is borne up by the rush of steam and water gas1 and is cracked to a permanent gas in the upper layer of fuel4 ,this ,i think is the secret of not being able to use heavier grades of oil1 these being sufficiently non-volatile to trickle down the side into the fire box at the bottom1 and so to escape volatilization4 ,i have tried to steam-inject the oil1 but have not found that it yields any better results4 ,one of the first things that strikes any one on seeing a make of gas by this system is the enormous rapidity of generation4 ,mr4 ,leicester ,greville1 who is chemist to the ,commercial ,gas ,company1 in reporting on the process1 says1 ,the make of gas was at the rate of about #hf1jjj cubic feet in #bd hours4 ,a remarkable result1 taking into consideration the size of the apparatus4 ,it is quite possible1 with the small apparatus1 to make #ajj1jjj cubic feet in #bd hours2 indeed the run for which the figures are given are over this estimate2 and it must be borne in mind that this rapidity of make gives the gas manager complete control over any such sudden strains as result from fog or other unexpected demands on the gas-producing power of his works2 while a still more important point is that it does away with the necessity of keeping an enormous bulk of gas ready to meet any such emergency1 and so renders unnecessary the enormous gasholders1 which add so much to the expense of a works1 and take up so much room4 ,perhaps the greatest objection to water gas in the public mind is the dread of its poisonous properties1 due to the carbon monoxide which it contains2 but if we come to consider the evidence before us on the increase of accidents due to this cause1 we are struck by the poor case which the opponents of water gas are able to make out4 ,no one can for a moment doubt the fact that carbon monoxide is one of the deadliest of poisons4 ,it acts by diffusing through the air cells of the lungs1 and forming1 with the coloring matter of the blood corpuscles1 a definite compound1 which prevents them carrying on their normal function of taking up oxygen and distributing it throughout the body1 to carry on that marvelous process of slow combustion which not only gives warmth to the body1 but also removes the waste tissue used up by every action1 be it voluntary or involuntary1 and by hindering this1 it at once stops life4 ,all researches on this subject point to the fact that something under one per cent4 only of carbon monoxide in air renders it fatal to animal life1 and this at first seems an insuperable objection to the use of water gas1 and has1 indeed1 influenced the authorities in several towns1 notably ,paris1 to forbid its introduction for domestic consumption4 ,let us1 however1 carefully examine the subject1 and see1 by the aid of actual figures1 what the risk amounts to compared with the risks of ordinary coal gas4 ,many experiments have been made with the view of determining the percentage of carbon monoxide in air which is fatal to human or1 rather1 animal life1 and the most reliable as well as the latest results are those obtained by ,dr4 ,stevenson1 of ,guy's ,hospital1 in consequence of the two deaths which took place at the ,leeds forge from inhaling uncarbureted water gas containing #dj per cent4 of carbon monoxide4 ,he found that one per cent4 visibly affected a mouse in one and a half minutes1 and in one hour and three quarters killed it1 while one-tenth of a per cent4 was highly injurious4 ,let us1 for the sake of argument1 take this last figure #j4a per cent4 as being a fatal quantity1 so as to be well within the mark4 ,in ordinary carbureted water gas as supplied by the superheater processes1 such as the ,lowe1 ,springer1 etc41 the usual percentage of carbon monoxide is #bf per cent41 but in the ,van ,steenbergh gas--for certain chemical reasons to be discussed later on--it is generally about #ah per cent41 and rarely rises to #bj per cent4 ,an ordinary bedroom will be say #ab ft4 ,x #ae ft4 ,x #aj ft41 and will therefore contain #a1hjj cubic feet of air1 and such a room would be lighted by a single bats-wing burner consuming not more than four cubic feet of gas per hour4 ,suppose now the inmate of that room retires to bed in such a condition of mental aberration that he prefers to blow out the gas rather than take the ordinary course of turning it off--a process1 by the way1 of putting out gas which is decidedly easier in theory than in practice1 especially in his presumed mental condition--you would have in one hour the #a1hjj cubic feet of gas in the room mixed with four fifths of a cubic foot of carbon monoxide--the carbureted water gas being supposed to contain #bj per cent4--or #j4jd per cent4 ,in such a room1 however1 if the doors and windows were absolutely air tight1 and there was no fireplace1 diffusion through the walls would change the entire air once an hour1 so that the percentage would not rise above #j4jd2 while in any ordinary room imperfect workmanship and an open chimney would change it four times in the hour1 reducing the percentage to #j4ja1 a quantity which the most inveterate enemy of water gas could not claim would do more than produce a bad headache1 an ailment quite as likely to have been caused by the same factor that brought about the blowing out of the gas4 ,moreover1 we are now talking about the use of carbureted water gas as an enricher of coal gas1 and not as an illuminant to be consumed per se4 and we may calculate that it would be probably used to enrich a #af-;candle coal gas up to #ag4e candle power4 ,to do this #be per cent4 of #bb candle power carbureted water gas would have to be mixed with it1 and taking the percentage of carbon monoxide in ,london gas at #e per cent4--a very fair average figure--and #ah per cent4 as the amount present in the ,van ,steenbergh gas1 we have #h4be per cent4 of carbon monoxide in the gas as sent out--a percentage hardly exceeding that which is found in the rich cannel gas supplied to such towns as ,glasgow1 where ,i am not aware of an unusual number of deaths occurring from carbon monoxide poisoning4 ,the carbureted water gas has a smell every bit as strong as coal gas1 and a leak would be detected with equal facility by the nose2 and ,i think you will agree with me that the cry raised against the use of carbureted water gas1 for this reason1 is one of the same character that hampered the introduction of coal gas itself at the commencement of this century4 ,we must now turn to the chemical actions which are taking place in the generator of the water gas plant1 and these are more complex in the case of the ,van ,steenbergh plant than in those of the ,lowe type1 and1 for that reason1 yield a gas of more satisfactory composition4 ,taking gas as made by the ,lowe or ,springer process1 and contrasting it with the ,van ,steenbergh gas1 we are at once struck by several marked differences4 ,in the first place the hydrogen is far higher and the marsh gas or methane lower in the ,van ,steenbergh than in the ,lowe process1 this being due to the sharper cracking that takes place in the short column of cherry red coke1 as compared with the lower temperature employed for a longer space of time in the ,lowe superheater4 ,next we notice a difference of #aj per cent4 in the carbon monoxide1 which is greatly reduced in the ,steenbergh generator by the carbon monoxide and marsh gas reacting on each other as they pass over the red hot surface of coke with formation of acetylene1 which adds to the illuminants1 this action also reducing the quantity of marsh gas present4 ,lowe ,van ,steenbergh gas4 gas4 ,hydrogen444444444444444444444 #bg4ad #df4ge ,marsh gas44444444444444444444 #be4ce #aa4bg ,carbon monoxide44444444444444 #bf4hd #ah4fe ,illuminants444444444444444444 #ad4fc #g4ei ,ethane44444444444444444444444 ---- #f4hb ,carbon dioxide444444444444444 #c4jb #j4ej ,oxygen44444444444444444444444 #j4ae #j4ag ,nitrogen444444444444444444444 #b4hg #h4be ------ ------ #ajj4jj #ajj4jj ,in the illuminants1 if we add the higher members of the methane series present to the olefines1 we see they are about equal in each gas1 while the low percentage of nitrogen in the ,lowe gas is due to more careful working1 and could easily be attained with the ,van ,steenbergh plant by allowing the first portion of water gas to wash out the producer gas before the hopper on top is closed4 ,the cracking of the naphtha by the red hot coke is undoubtedly a great advantage1 for1 as ,i have pointed out1 the cracking of rushing petroleum is an exothermic reaction1 so that the coke at the top of the generator gets hotter and hotter1 and it is no unusual thing to see the coke at the beginning of the make cherry red at the bottom and dull red at the top1 while at the end of the make it is almost black at the bottom and cherry red at the top1 in this way attaining the same advantage in working that the ,springer and ,loomis do by their down blast1 that is1 having the fuel at its hottest where the gas finally leaves it1 so as to reduce the quantity of carbon dioxide1 and so lessen the expense of purification4 ,it will be well now to turn for a few moments to the gas obtained by cracking the light petroleum oils by themselves4 ,the ,russian and ,american petroleum differ so widely in composition that it was necessary to see in what way the gases obtained from them differed2 and to do this1 equal quantities of ,american naphtha and a ,russian naphtha were cracked1 by passing through an iron tube filled with coke1 and in each case heated to a cherry red heat1 the gases being measured1 and then analyzed1 with the following results3 ,american4 ,russian4 ,no4 of cubic feet per gallon444 #gb #ajd ---- ---- ,hydrogen44444444444444444444444 #bf4j #de4c ,methane444444444444444444444444 #da4f #bb4c ,ethane4444444444444444444444444 #ab4e #ac4i ,olefines44444444444444444444444 #ad4a #aa4f ,carbon monoxide4444444444444444 #c4c #c4e ,carbon dioxide44444444444444444 #a4g #b4c ,oxygen4444444444444444444444444 #j4h #a4a ,nitrogen44444444444444444444444 ,nil4 ,nil4 ----- ----- #ajj4j #ajj4j ,showing that1 if the ,russian oil is a little lower in illuminants1 it quite makes up by extra volume1 but it seemed to me to deposit a much larger proportion of carbon4 ,taking #ba_/b gallons of ,american naphtha1 it would give roughly #ahj cubic feet of gas of the above composition1 while the remaining gas would be the ordinary water gas4 ,taking the analysis of this as given1 and calculating from it what would be the composition of a mixture of it with the naphtha gas1 we obtain3 ,calculated4 ,actual4 ,hydrogen4444444444444444444444 #dg4ji #db4ji ,methane44444444444444444444444 #e4dh #aa4bg ,olefines4444444444444444444444 #b4ec #g4ei ,ethane444444444444444444444444 #b4ag #f4cb ,carbon monoxide444444444444444 #cj4jg #ah4fe ,carbon dioxide4444444444444444 #c4gh #b4cb ,oxygen444444444444444444444444 #j4ef #j4ag ,nitrogen4444444444444444444444 #g4ag #h4be ,sulphureted hydrogen4444444444 #a4ae #b4hd ------ ------ #ajj4jj #ajj4jj ,showing how great the effect is of the diluents in the water gas in preventing the overcracking of the hydrocarbons1 as shown by the increase in the percentage of them present in the finished gas2 while the enormous reduction in the amount of carbon monoxide present is due to the interaction between it and the paraffin hydrocarbons in the presence of red-hot carbon1 a point which makes the ,van ,steenbergh apparatus enormously superior to any of the superheater forms of plant4 ,after all said and done1 however1 the reactions taking place1 although they have an intense fascination for the chemist1 are not the factors which the gas manager deems the most important1 the cost of any given process being the test by which it must stand or fall2 and it will be well now to consider1 as far as it is possible1 the expense of enriching coal gas by the various methods ,i have brought before you4 ,in order to be well above the prescribed limit of illuminating power at all parts of an extended service1 the gas at the works must be sent out at an illuminating power of #ag4e candles and we may1 ,i think1 fairly take it that #af candle coal gas1 as made by the big ,london companies1 costs1 as nearly as can be1 #as4 per #a1jjj cubic feet in the holder1 and the question we have now to solve is the cost of enriching it from #af to #ag4e candle power4 ,when this is done by cannel1 the cost is #b4f pence per candle power1 so that the extra #aa_/b would cost #d;d4 per #a1jjj4 ,carbureting by the vapors of gasoline by the ,maxim-,clarke process costs #ac_/d;d4 per #a1jjj1 so that the extra candle power would mean an expenditure of #b4fb d4 ,unfortunately ,i have no figures upon which to calculate the cost of producing such a gas by the ,dinsmore process1 but with the three important water gas enrichers we can deal4 ,using ,russian fuel oil1 which can be obtained in bulk in ,london at #c;d4 per gallon1 the proprietors of the ,springer plant guarantee #ea_/b candle power per #a1jjj cubic feet of gas per gallon used1 so that1 to produce a #bb candle gas1 #d gallons would be used4 ,the cost per #a1jjj cubic feet may be roughly tabulated1 as the coke used amounts to about #dj lb4 s4 d4 ,oil444444444444444444444444444444444444 #a #j ,coke44444444444444444444444444444444444 #j #c ,labor and purification44444444444444444 #j #b ,charge on plant444444444444444444444444 #j #a ---- #a #f ,twenty five per cent4 of #ab-;candle gas when mixed with #ge per cent4 of the #af-;candle gas gives the required #ag4e candle gas1 which would therefore cost #as4 #aa_/b;d41 or the enrichment would have cost #aa_/b;d4 ,by the ,lowe process1 an increase of #e4c-;candle power is guaranteed for the consumption of a gallon of the same oil1 so that the cost would be a shade higher1 all other factors remaining the same1 while with the ,van ,steenbergh process both grade of oil and consumption of fuel vary from either of these processes4 ,in order to obtain a thousand cubic feet of #bb-;candle gas1 two and a half gallons of the lighter grade oil would be consumed1 and ,i am informed that there is now no difficulty in obtaining oil of the right grade in ,london in bulk at #d;d4 per gallon1 which would make the cost3 s4 d4 ,two and a half gallons of oil44444444444 #j #aj ,thirty pounds of coke4444444444444444444 #j #ba_/d ,labor and purification444444444444444444 #j #b ,charge on plant4444444444444444444444444 #j #jc_/d ------ #a #c ,and the enriched coal gas would1 therefore1 cost #as4 #c_/d;d4 per thousand1 the extra #aa_/b-;candle power having been gained at an expense of #c_/d;d4 or #a_/b;d4 per candle4 ,tabulating these results we have--,cost of enriching a #af-;candle gas up to #ag4e candle power per #a1jjj cubic feet by cannel coal1 #d;d42 by ,maxim-,clarke process1 #b-f_/aj;d42 by ,lowe or ,springer water gas1 #aa_/b;d42 by ,van ,steenbergh water gas1 #c_/d;d4 ,in reviewing this important subject1 and bringing a wide range of experimental work to bear upon it1 ,i have1 as far as is possible1 divested my mind of bias toward any particular process1 and ,i can honestly claim that the fact of the ,van ,steenbergh process showing such great superiority is due to the force of carefully obtained experimental figures1 corroborated by an experienced and widely known gas chemist1 and by the chief gas examiner of the city4 ,in adopting any new method1 the mind of the gas manager must to a great extent be influenced by the circumstances of the times1 and the enormous importance of the labor question is a main factor at the present moment2 with masters and men living in a strained condition which may at any moment break into open warfare1 the adoption of such water gas processes would relieve the manager of a burden which is growing almost too heavy to be borne4 ,combining1 as such processes do1 the maximum rate of production with the minimum amount of labor1 they practically solve the labor question4 ,requiring only one-tenth the number of retort house hands that are at present employed1 the carbureted water gas can be used for enrichment until troubles arise1 and then the gas can be used pure and simple1 with a hardly perceptible increase in expense1 while the rapidity of make will also give the gas manager an important ally in the hour of fog1 or in case of any other unexpected strain on his resources4 ,one of the first questions asked by the practical gas maker will be3 ,what guarantee can you give that as soon as we have erected plant1 and got used to the new process of manufacture1 a sudden rise in the price of oil will not take place1 and leave us in worse plight than we were before8 and the only answer to this is that1 as far as it is possible to judge anything1 this event is not likely to take place in our time4 ,a year ago the prospects of the oil trade looked black1 as the output of ,american oil was in the hands of a powerful ring1 who seemed likely also to obtain control of the ,russian supplies2 but1 fortunately1 this was averted1 and1 at the present moment1 the ,russian pipe lines are flooding the market with an abundant supply1 which those best able to judge tell us is practically inexhaustible1 so that prices may be expected to have a downward rather than an upward tendency4 ,but even should a huge monopoly be created1 ,i think ,i have found a source of light at home which will hold its own against any foreign illuminant in the market4 ,for a long time ,i have felt that in this country we had sources of light and power which only needed development1 and the discovery of the right way to use them1 in order to give an entirely new complexion to the question of carbureting2 and now by the aid of the engineering skill and technical knowledge of ,mr4 ,staveley1 of ,baghill1 near ,pontefract1 ,i think it is found4 ,at three or four of the ,scotch iron works the ,furnace ,gases ,co4 are paying a yearly rental for the right of collecting the smoke and gases from the blast furnaces4 ,these are passed through several miles of wrought iron tubing1 diminishing in size from #f feet down to about #ah inches2 and as the gases cool1 so there is deposited a considerable yield of oil4 ,at ,messrs4 ,dixon's1 at ,glasgow1 which is the smallest of these installations1 they pump and collect about #fj1jjj1jjj cubic feet of furnace gas per day2 and recover1 on an average1 #be1jjj gallons of furnace oils per week1 using the residual gases1 consisting chiefly of carbon monoxide1 as fuel for distilling and other purposes1 while a considerable yield of sulphate of ammonia is also obtained4 ,in the same way a small percentage of the coke ovens are fitted with condensing gear1 and produce a considerable yield of oil1 for which1 however1 there is a very limited market1 the chief use being for lucigen and other lamps of the same description1 and for pickling timber for railway sleepers1 etc42 the result being that1 four years ago1 it could be obtained in any quantity at #a_/b;d4 per gallon1 while since that it has been as high as #ba_/b;d4 a gallon1 but is now about #b;d41 and shows a falling tendency4 ,make a market for this product1 and the supply will be practically unlimited1 as every blast furnace and coke oven in the kingdom will put up plant for the recovery of the oil1 and as with the limited plant now at work it would be perfectly easy to obtain #d1jjj1jjj or #e1jjj1jjj gallons per annum1 an extension of the recovery process would mean a supply sufficiently large to meet all demands4 ,many gas managers have1 from time to time1 tried if they could not use some of their creosote for gas producing1 but on heating it in retorts1 etc41 they have found the result has generally been a copious deposit of carbon1 and a gas which has possessed little or no illuminating value4 ,now1 the furnace and coke oven oils are in composition somewhat akin to the creosote oil1 so that at first sight it does not seem a hopeful field for search after a good carbureter1 but the furnace oils have several points in which they differ from the coal tar products4 ,in the first place1 they contain a certain percentage of paraffin oil1 and in the next1 do not contain much naphthalene1 in which the coal tar oil is especially rich1 and which would be a distinct drawback to their use4 ,the furnace oil as condensed contains about #cj to #ej per cent4 of water1 and in any case this has to be removed by distilling2 and ,mr4 ,staveley has patented a process by which the distillation is continued after the water has gone off1 and by condensing in a fractionating column of special construction1 he is able to remove all the paraffin oil1 a considerable quantity of cresol1 a small quantity of phenol1 and about #aj per cent4 of pyridine bases1 leaving the remainder of the oil in a better condition1 and more valuable for pickling timber1 which is its chief use4 ,if the mixed oil so obtained1 which we may call phenoloid oil1 is cracked by itself1 no very striking result is obtained1 the #dj percent4 of paraffin present cracking in the usual way1 and yielding a certain amount of illuminants1 but if this oil be cracked in the presence of carbon1 and be made to pass over and through a body of carbon heated to a dull red heat1 then it is converted largely into benzene1 the most valuable of the illuminants1 and also being the one to which coal gas owes the largest proportion of its illuminating power1 it is manifestly the right one to use in order to enrich it4 ,on cracking the phenoloid oil1 the paraffins yield ethane1 propane1 and marsh gas1 etc41 in the usual way1 while the phenol interacts with the carbon to form benzene-- ,phenol4 ,benzene4 ,c#f;,h#e;,,ho ,c ,c#f;,h#f ,,co4 ,and in the same way the cresol first breaks down to toluene in the presence of the carbon1 and this in turn is broken down by the heat to benzene4 ,a great advantage of this oil is that the flashing point is #aaj1 and so is well above the limit1 thus doing away with the dangers and troubles inseparable from the storage of light naphtha in bulk4 ,in using this oil as an enricher1 it must be cracked in the presence of carbon1 and it is of the greatest importance that the temperature should not be too high1 as the benzene is easily broken down to simpler hydrocarbons of far lower illuminating value4 ,this fact is very clearly brought out by a series of experiments ,i have made1 in which the phenoloid oil was cracked by passing it through an iron tube packed with coke and heated to various temperatures1 the hydrocarbons being much more easily broken up under these conditions than if mixed with diluents1 such as water gas3 ,,results ,,obtained ,,on ,,cracking ,,phenoloid ,,oil4 ,i4 ,,ii4 ,,iii4 ,temperature4 #fjj ,c4 #hjj ,c4 #a1jjj ,c4 ,volume of gas per gallon4 #da4f c4f4 #gf4h c4f4 #aba4f c4f4 ,,composition ,,of ,,the ,,gas4 ,hydrogen4 #cd4j #cf4j #cg4j ,methane4 #bj4j #bf4j #di4j ,olefines4 #aa4j #e4j ,nil4 ,ethane4 #af4j #i4j ,nil4 ,carbon monoxide4 #ac4j #ae4j #ab4j ,carbon dioxide4 #b4j #d4j #b4j ,oxygen4 #b4j #a4j ,nil4 ,nitrogen4 #b4j #d4j ,nil4 ,this analysis shows that if the temperature is allowed to reach a cherry red1 complete decomposition of the illuminating hydrocarbons is taking place1 and a gas of practically no illuminating value results4 ,the power of regulating the temperature and the body of carbon as a cracking medium in the ,van ,steenbergh water gas plant especially fits it for using this oil1 and removes the objections which could have been urged against the lighter naphthas4 ,this oil is at present not in the market1 but given a demand1 it can be produced in four months1 at the latest1 in very large quantities1 as the apparatus is very easy and cheap to erect1 and the crude material can be plentifully obtained4 ,if this oil becomes1 as ,i think it will1 an important factor in the illumination of the future1 it will mark as important an era in the history of our industries as any which the century has seen1 as1 by using it1 you are giving smoke a commercial value1 and this will do what the ,society of ,arts and the ,county ,council have failed in--that is1 to give us an improved atmosphere4 ,if ,i were lecturing on an imaginary ,hygeia1 ,i should point out that the smoke of ,london contains large quantities of these oils1 and they1 by coating the drops of mist on which they condense1 give the fog that haunts our streets that peculiar richness which is so irritating and injurious to the system1 and1 further1 by preventing the water from being again easily taken up by the air1 prolong the duration of the fog4 ,make this oil a marketable commodity1 and another twenty years will see ,london without a chimney2 underground shafts will be run alongside the sewers2 into these shafts by means of a down draught all the products of combustion from our fires will be sucked by local pumping stations1 and the oil condensing in the tubes will serve in turn to illuminate our streets1 instead of performing its former function of turning day into night and ruining our health2 but as ,i am not at all sure of the engineering possibilities of such a scheme1 ,i will leave its discovery to some other abler prophet than myself4 7,to be continued47 99 99 99 99 99 ,,electrical ,,laboratory ,,for ,,beginners4 ,,by ,,geo4 ,m4 ,,hopkins4 ,it is only when theory and practice1 study and experiment1 go hand in hand that any true progress is made in the sciences4 ,a head full of theory is of little value without practice1 and although the student may apply himself with all his energies for years1 his time will1 to a great extent1 have been spent in vain1 unless he by experiment rivets the ideas he gains by his study4 ,in the study of electricity1 for example1 let the student try to remember the position a magnetic needle will take when placed below or above a conductor carrying a current which flows in a known direction4 ,without experiment there are nine chances of forgetting to one of remembering2 but let the student try the experiment1 and he will ever afterward be able to determine the direction in which the current is flowing by the position taken by the needle relative to the conductor4 ,in the matter of ampere turns1 as another example1 it is quite simple to assert that a ten ampere current carried once around a soft iron bar produces the same result as a one ampere current carried ten times around the bar1 but how much more strongly is this fact stamped upon the memory when its truth is established by experiment8 ,reading about a fact1 or commiting to memory the literature of a subject1 is desirable and even necessary1 but knowledge of this character partakes more of the nature of faith than that gained by actual experience4 ,let the reader learn first all that can be learned by the aid of this simple apparatus1 then branch out to allied things1 making each step as thorough as possible1 and before long he will be congratulating himself on having gained at least an elementary knowledge of electricity4 ,very little can be done in the way of electrical experiment without an electrical generator of some sort1 and nothing at present known can excel a battery for this purpose4 ,although not the most desirable battery for all purposes1 that shown in ,fig4 #a is the most desirable for the amateur who desires a strong current for a short time4 ,it is formed of two plates1 a1 of carbon arranged on opposite sides of an amalgamated plate1 b1 of zinc1 and separated from the zinc by strips of wood4 ,bars of wood are placed outside of the carbon plates1 and the four bars are fastened together by two common wood screws1 thus clamping all the bars and the zinc and carbon plates securely in the position of use4 ,illustration3 ,,fig4 #a4--,,simple ,,battery4 ,between the zinc plate and the wooden bar adjoining it is inserted a strip of copper1 c1 for leading away the current from the zinc pole of the battery1 and between the carbon plates and the wooden bars is inserted a doubled strip of copper1 d1 forming a connection between the two carbon plates1 and at the same time serving as a conductor for conveying away the current from the carbon pole of the battery4 ,this element is to be plunged into a tumbler of sufficient depth to allow the wooden bars to rest on the upper edge of the tumbler1 while the lower ends of the plates are one-half or three-quarters inch above the tumbler bottom4 ,,the ,,solution4 ,in the tumbler is placed a solution consisting of two-thirds of a tumblerful of water1 two ounces of bichromate of potash1 and two ounces of sulphuric acid4 ,the bichromate of potash should be dissolved first1 then the acid should be slowly and carefully added4 ,as the solution heats1 it is well to prepare it in an earthen vessel1 which is not liable to break4 ,these materials should be used with great caution1 as they are poisonous1 and the solution is very corrosive1 destroying almost everything with which it comes in contact4 ,with proper care1 however1 there is no danger in using the solution4 ,it gives off no poisonous vapors4 ,of course it is advisable to make the solution in quantities of a gallon or so when convenient4 ,the battery compound known as the ,c and ,c battery compound1 sold in tin cans at most electric stores1 is very convenient4 ,it is only necessary to place two or three ounces of it in the tumbler and add the amount of water above mentioned1 stirring the solution with a glass or rubber rod until the crystals are dissolved4 ,a caution is necessary here4 ,if only a portion of the contents of the can are to be dissolved1 it will be necessary to place the remainder in a glass or earthen jar1 as it will absorb moisture and rapidly eat its way through the can4 ,the zinc plates should be amalgamated by plunging them into the bichromate solution1 then sprinkling on a minute quantity of mercury1 rubbing it about by means of a swab1 until the entire exposed surface is covered with mercury4 ,,conventional ,,sign ,,for ,,the ,,battery ,,and ,,galvanometer4 ,in making electrical diagrams it is necessary to frequently represent a battery4 ,it requires too much time to make a sketch or drawing of a battery4 ,besides this1 the drawing of any particular kind of battery might be misleading4 ,a sign representing the galvanic battery has been universally adopted4 ,it consists of a long1 thin mark or dash1 representing the carbon electrode1 and a shorter1 thick mark representing the zinc electrode1 thus3 ,illustration ,where more cells are required1 this sign is repeated once for each cell1 thus3 ,illustration ,the galvanometer is represented thus3 ,illustration ,by the use of the battery and a few articles such as may be found anywhere1 in addition to the pieces shown in ,fig4 #b1 all the experiments here described may be performed4 ,as these pieces are shown half size in the diagrams1 ,fig4 #b1 and about full size in the perspective views1 it will be unnecessary to give dimensions4 ,the bobbins1 ,a ,a1 are wound with ,no4 #bd double cotton-covered magnet wire1 the terminals being soldered to eyes formed of pieces of spring wire bent so as to form helical coils of two turns each1 with the ends inserted in holes drilled in heads of the spools4 ,these coiled wires answer a good purpose in making electrical connections4 ,the magnet frame1 ,b1 consisting of the cores and the yoke formed integrally of a single soft gray iron casting1 is adapted to receive the bobbins1 ,a ,a1 to form an electro-magnet4 ,the yoke of the magnet is provided with a thumb-screw1 e1 for securing the magnet to the motor frame1 ,c4 ,the latter is furnished with a base piece1 f1 a slotted standard for receiving the clamping screw1 e1 of the magnet1 and the standards1 g1 in which is journaled the armature1 h1 on a wire extending through both the standards and the armature4 ,the armature1 h1 consists of an oblong rectangular soft iron frame having at one end a small pulley and at the other end an elliptical boss1 i1 which is arranged obliquely to form in conjunction with the spring1 j1 a circuit closer and opener1 which closes the circuit twice during each revolution of the armature1 just as one of its side bars is approaching the poles of the magnet and breaks it as the bar comes opposite the poles of the magnet4 ,the spring1 j1 is bent into a loop and its lower end is inserted in a wooden plug driven into a hole in the base piece1 f4 ,in the upper part of ,fig4 #b are shown two telegraph instruments less the bobbins4 ,each instrument 7,fig4 #ad7 consists of a wooden base1 k1 a right angled soft iron bar1 l1 having the central part of its upper end brought to an obtuse angle1 an armature1 m1 fitted loosely to the angled end of the bar1 a notched brass standard1 n1 for limiting the movement of the armature1 a retractile spring for lifting the armature1 a spring key1 o1 pivotally secured to the base by a common wood screw1 and a contact point projecting from the base under the key4 ,besides these there is a ,d shaped block1 to answer as a frame to the galvanometer1 a common pocket compass1 ,e1 fitted to a circular cavity in the top of the block1 ,d1 a permanent ,u magnet1 ,f1 a bundle of soft iron wires1 ,g1 and two copper strips1 ,h4 ,illustration ,,decomposition ,,of ,,water4 ,to illustrate the decomposition of water1 connect the copper strips1 ,h ,h1 to the poles of the battery by means of wires1 as shown in ,fig4 #c1 and insert them in a tumbler of water acidulated with a few drops of sulphuric acid4 ,instantly bubbles will rise from the copper strips1 showing that gas is being disengaged from the water4 ,the strip connected with the carbon plate will disengage oxygen1 while the strip connected with the zinc plate will disengage hydrogen4 ,illustration3 ,,fig4 #c4--;,,decomposition ,,of ,,water4 ,,solenoid4 ,by connecting one of the coils1 ,a1 with the battery by means of the wires1 the action of a helix or solenoid is shown4 ,when so connected1 the helix will draw up with itself a barrel pen1 or any light iron or steel object4 7,see ,fig4 #d47 ,this is not a true solenoid1 but it is generally known by that name4 ,in a true solenoid one of the terminals is passed back through the center of the coil4 ,illustration3 ,,fig4 #d4--,,solenoid4 ,,magnetization ,,of ,,steel4 ,by inserting in the solenoid a knitting needle1 or any bar of hardened or tempered steel1 and sending a current through the coil1 the steel will become permanently magnetized4 ,,electromagnet4 ,by placing the two coils1 ,a1 upon the magnet frame1 ,b1 and connecting one terminal of each with the battery1 the remaining terminals being connected together1 as shown in ,fig4 #e1 an electromagnet is formed which will lift several pounds4 ,illustration3 ,,fig4 #e4--;,,electromagnet4 ,,electric ,,motor4 ,by placing the magnet thus formed upon the motor base1 ,c1 in front of the armature1 h1 as shown in ,fig4 #f1 and connecting one terminal of the magnet with the battery and the other with the clamping screw1 e1 of the magnet1 and by connecting the commutator spring1 j1 with the remaining pole of the battery1 the motor will be made to rotate rapidly4 ,,compass ,,and ,,magnetic ,,experiments4 ,by placing one end of the bar magnetized by the solenoid near the compass contained by the cabinet 7,fig4 #g7 it will be seen that one end of the compass needle is attracted4 ,when the opposite end of the bar is presented to the same end of the needle1 that end of the needle will be repelled and the opposite one attracted1 showing that like poles repel each other while unlike poles attract4 ,illustration3 ,,fig4 #g4--,,magnetic ,,experiment4 ,,galvanometer4 ,by placing one of the coils1 ,a1 in the block1 ,d1 then placing in the cavity in the top of the block the compass1 with the line marked ,n ,s arranged at right angles to the axis of the coil1 a serviceable galvanometer will be formed 7,fig4 #h74 ,by turning the galvanometer so that the needle will point north and south without the current passing1 with ,n underneath one end of the needle1 and then connecting the poles of the battery with the terminals of this galvanometer1 a deflection of the compass needle will be produced1 the direction of which depends upon the direction of the current4 ,,experiments ,,showing ,,the ,,effects ,,of ,,resistance4 ,by placing the galvanometer in the circuit of the battery1 as shown in ,fig4 #i1 and noting the deflection of the needle1 it will be ascertained that a certain amount of current is flowing4 ,now1 by placing in the circuit1 in addition to the galvanometer1 the remaining coil of the magnet1 thus introducing considerable resistance1 the current will be diminished1 as shown by a smaller deflection of the needle4 ,,resistance ,,of ,a ,,fluid ,,changed ,,by ,,the ,,addition ,,of ,,another ,,fluid4 ,a very pretty and instructive experiment may be performed by arranging the apparatus as shown in ,fig4 #aj1 with the copper strips1 ,h ,h1 inserted in clean water and the galvanometer placed in the circuit4 ,the deflection of the galvanometer needle will be very slight1 showing that the resistance of clean water is considerable4 ,a few drops of sulphuric acid or even vinegar will increase the conductivity of the water so as to produce a marked deflection of the galvanometer needle4 ,common salt added to the water will produce the same effect4 ,,magnetic ,,electric ,,induction4 ,by placing one of the coils1 ,a1 on the magnet frame1 ,b1 and connecting it by the wires with the galvanometer1 arranged as before described1 and bringing the permanent magnet1 ,f1 suddenly against the poles of the magnet1 as shown in ,fig4 #aa1 a current will be induced in the coil1 which1 in passing through the galvanometer1 causes the needle to be deflected in one direction1 and when the permanent magnet is suddenly removed from the electro-magnet1 a current will be set up in the opposite direction1 which will cause a deflection of the needle of the galvanometer in the opposite direction4 ,,induction ,,coil4 ,by placing both coils1 ,a1 upon the bundle of soft iron wires1 ,g1 connecting one of them with the terminals of the battery1 as shown in ,fig4 #ab1 and holding the terminals of the other coil in the moistened thumb and fingers of the two hands1 when the battery circuit is opened and closed by touching one of the wires to the battery1 and removing it1 a slight shock will be felt from the coil which is disconnected from the battery4 ,by placing a coarse file in the circuit and drawing one of the terminals along the file the circuit will be rapidly interrupted4 ,this shock is due to the current induced in the detached coil by the magnetism of the bundle of wires4 ,illustration3 ,,fig4 #aa4--,,magneto-,,electric ,,induction4 ,,extra ,,current4 ,an experiment showing the extra or self-induced current consists in arranging the motor as shown in ,fig4 #f1 and connecting wire with each conductor leading from the battery to the motor1 as shown in ,fig4 #ac4 ,if these wires are grasped one in each hand while the motors is in motion1 a slight shock will be felt1 providing the hands are moistened4 ,,telegraph ,,sounders ,,and ,,keys4 ,the cabinet contains material for two telegraph sounders and keys which will enable the user to establish a short telegraph line with a single cell of battery4 ,the armature1 m1 may be lifted from its pivot so as to permit of slipping one of the coils1 ,a1 on to the round magnetic core of the sounder4 ,the armature is then replaced1 as shown in ,fig4 #ad1 and the small retractile spring at the rear of the instrument is arranged to draw down the shorter arm of the armature lever4 ,one of the terminals of the coil1 ,a1 is connected with the turned up pivoted end of the telegraph key1 o1 on the same base4 ,the other terminal is connected with one pole of the battery and the contact point of the key is connected with the other pole of the battery1 as shown4 ,by swinging the key laterally1 so as to remove it from the contact point1 it will be found that every touch of the key produces a movement of the sounder lever4 ,to connect the two instruments together upon a line1 it is only necessary to connect the two keys with one wire and the terminals of the two coils with another wire1 cutting one of these wires and inserting the battery4 ,illustration3 ,,fig4 #ae4--,,magnetic ,,figures4 ,as soon as the operator ceases to work his instrument he should place the key in contact with the contact point1 and cause it to remain there by slipping the end of the key under the head of the screw provided for that purpose4 ,the other operator can then proceed to send his message4 ,those who desire to practice telegraphy should learn the ,morse telegraphic code4 ,,magnetic ,,figures4 ,by arranging the coil so as to form an electro-magnet1 as before described1 and holding the magnet under a plate of glass sprinkled with fine iron filings1 as shown in ,fig4 #ae1 and then sending a current through the magnet1 at the same time jarring the glass by striking it with a lead pencil1 a magnetic figure will be formed which is sometimes called the magnetic spectrum4 ,by connecting the terminals of the coils diagonally with each other1 and connecting the remaining terminals with the battery1 two like poles will be formed1 and the magnetic figures will have an entirely different appearance1 owing to the repulsion between the two like polarities4 ,different figures may be produced by using the solenoids without the iron cores4 ,,experiment ,,showing ,,the ,,current4 ,by removing the coil1 ,a1 from beneath the compass1 ,e1 and connecting the ends of the transverse wire1 a' a'1 with the battery ,fig4 #af1 then lifting the plates of the battery out of the solution and allowing the needle to come to rest1 it will be found upon inserting the plates of the battery in the solution1 very gradually1 that the deflection of the needle will increase with the increase of plate surface submitted to the action of the battery fluid2 and if1 when the greatest deflection is reached1 the coils or solenoids are introduced into the circuit1 one after the other1 it1 will be found that each added coil diminishes the current1 as will be shown by the diminished deflection of the needle4 ,illustration3 ,,fig4 #af4--;,,experiment ,,showing ,,the ,,current4 ,,microphone ,,and ,,telephone4 ,take two small carbon rods1 p p1 if procurable1 if not1 use two ordinary nails1 and connect them up in the circuit of the battery2 lay them upon a thin box so that the rods or nails cross each other1 as in ,fig4 #ag2 insert the electromagnet in the circuit2 move the coils out a little beyond the ends of the cores1 lay a thin iron plate over the ends of the coils1 then jar the box upon which the bars1 p p1 are laid1 or drop a pin upon it1 or scratch it with a piece of paper1 and the sound will be heard by placing the ear against the iron plate resting upon the coils of the magnet4 ,,electro ,,metallurgy4 ,dissolve an ounce of sulphate of copper in a half pint of water2 add a few drops of sulphuric acid2 connect with the zinc pole of the battery the object to be coppered4 ,to the wire connected with the carbon attach a small plate of copper4 ,hang the object and the copper plate in the solution a short distance apart4 ,a deposit of copper will be quickly formed4 ,,the ,,heating ,,effect ,,of ,,the ,,current4 ,with a piece of very fine platinum wire 7,no4 #cf or #dj71 placed in the circuit of the battery1 the heating effect of the current may be shown4 ,a half inch of ,no4 #cf platinum wire will serve for the experiment4 ,if the battery is in good condition it will heat from #a_/h to #a_/d inch of the wire red hot4 ,this is sufficient to light gas or an alcohol lamp1 also to ignite powder or gun cotton4 ,a short piece of a watch hair spring1 or a piece of very fine iron wire1 if placed in the circuit will be made very hot4 ,,duplication ,,of ,,batteries4 ,should the experimenter desire to go more deeply into the effects of the current1 he will need a more powerful battery4 ,the battery described has been made on a very simple plan1 to enable the amateur to copy it without difficulty or great expense4 ,there is no mystery about the battery4 ,any one can make it4 ,all that is required is a plate of zinc1 two plates of carbon1 some strips of wood and copper1 and two common wood screws for each cell4 ,the tumblers may be had anywhere4 ,although it is advisable to use insulated wire for making the electrical connections1 bare wires may be used if care is taken in arranging them1 so that they will not touch each other or other metallic objects which would complete the circuit4 ,it will be found convenient if the elements of the battery are arranged upon a frame of some sort1 by means of which they may be raised or lowered all together1 and supported at any desired height4 99 99 99 99 99 ,,the ,,action ,,of ,,the ,,silent ,,discharge ,,on ,,chlorine4 ,arguing from the fact that oxygen gas1 when subjected to the silent discharge1 partially undergoes condensation into ozone1 it seemed possible1 says ,mr4 ,h4,m4 ,vernon1 in the ,chemical ,news1 that other elementary gases1 as chlorine and bromine vapor1 might undergo an analogous change when subjected to the same treatment4 ,a glass tube1 with a ,u-shaped index of fine bore glass tubing1 was filled with purified and dried chlorine4 ,after passing a current of the gas through the tube for some time1 the end was sealed in the blowpipe flame4 ,the tube was then warmed slightly1 and a few bubbles of gas thus driven out4 ,the end of the index tube dipped under strong sulphuric acid saturated with chlorine gas1 so that1 on cooling1 a short column of the acid was drawn up4 ,this served as an index for any changes of volume which might take place in the chlorine in the tube4 ,a silent discharge of electricity was then passed4 ,the volume of the gas was observed to increase slightly1 but afterward it remained quite constant1 even after the discharge had been passed for several hours4 ,we may therefore conclude that no allotropic change takes place when chlorine gas is subjected to the silent discharge of electricity1 the initial increase of volume being merely due to the heating effect the discharge has upon the gas4 ,into another similar tube1 filled with chlorine1 was introduced a small quantity of liquid bromine4 ,the tube thus contained chlorine saturated with bromine vapor4 ,the silent discharge on being passed through this tube did not produce any different effect than for chlorine alone4 ,so we may conclude that bromine vapor also does not undergo any allotropic condensation when subjected to the influence of a silent discharge of electricity4 ,the fact that oxygen gas is capable of undergoing condensation while chlorine and bromine are not is easily explained4 ,the oxygen atom1 being divalent1 is capable of uniting itself to two other atoms of oxygen or other elements1 and thus with oxygen forming ozone4 ,the atoms of chlorine and bromine1 however1 being only monovalent1 have all their affinity satisfied when they are united to a single other atom of chlorine and bromine4 ,it is not possible1 therefore1 that condensation can take place if the atoms remain monovalent4 ,hydrogen gas and iodine vapor are in a similar manner debarred from undergoing condensation4 ,mr4 ,vernon1 therefore1 comes to the conclusion that it is most improbable that any other element but oxygen will be found capable of undergoing molecular condensation when in the gaseous state and subjected to the silent discharge4 99 99 99 99 99 ,,estimating ,,carbon ,,in ,,organic ,,substances4 ,,by ,j4 ,,messinger4 ,this is an improvement on the author's method of two years ago4 ,the method is now applicable to compounds with which previously low results were obtained4 ,the substance is weighed into a small tube #bd mm4 long and #aa mm4 wide1 and is then introduced into the decomposition flask1 which contains #f to #h grms4 of chromic acid1 care being taken that the chromic acid does not come into contact with the substance under analysis4 ,the decomposition flask is fitted with a thistle funnel1 and is connected to the reversed condenser and apparatus shown in the figure4 ,fifty c4c4 of concentrated sulphuric acid are run into the flask4 ,during the whole of the operation a gentle current of air 7free from carbon dioxide7 is passed through the apparatus4 ,the asbestos plate underneath the flask is then warmed1 and thus the flask and contents are warmed by radiant heat from the plate alone until the sulphuric acid darkens4 ,at this point1 where decomposition of the organic substance begins1 the flame is entirely removed4 ,the carbon dioxide 7with some carbon monoxide7 passes through the condenser and then over a heated mixture of copper oxide and lead chromate contained in a tube #ae cm4 long4 ,the gas 7,,co#b7 then passes through a ,u-tube1 in one limb of which is sulphuric acid1 in the other glacial phosphoric acid4 ,illustration3 ,,apparatus ,,for ,,the ,,estimation ,,of ,,carbon ,,in ,,organic ,,substances4 ,thus dried it passes through weighed potash bulbs1 after which is placed for safety a small tube containing soda lime and phosphoric acid4 ,after the lapse of about twenty minutes1 warming may be once more proceeded with in the same manner as before1 and after about two and one-half hours the asbestos plate may be placed directly below the flask1 and more strongly heated4 ,the whole operation is very easily carried out1 and needs no watching4 ,with substances containing halogens1 it is advisable to place1 after the copper oxide tube1 a small washing flask containing potassium iodide solution4 99 99 99 99 99 ,,new ,,race ,,of ,,dwarf ,,dahlias4 ,the dahlia has held a prominent place among garden flowers for many years1 and it has received new life in the acquisition of a section little expected by cultivators1 but peculiarly welcome4 ,this class is the outcome of much patient work on the part of ,mr4 ,t4,w4 ,girdlestone1 the well known secretary of the ,national ,dahlia ,society1 who has for some time past devoted much time to the improvement of the single varieties4 ,we had the pleasure a short time since of receiving a photograph of this dwarf section of dahlias from ,messrs4 ,j4 ,cheal ,sons1 of ,crawley1 who have purchased the stock1 and this we have had engraved1 as it conveys an excellent idea of the height of the plant and the profusion with which the flowers are produced4 ,the photograph was also of interest as containing a portrait of ,mr4 ,girdlestone1 which we are sure will be welcome to many of our readers4 ,the plants of this race are very dwarf1 not exceeding twelve inches in height1 bushy1 spreading and exceedingly free in flowering1 the range of varieties being at present limited to twelve4 ,the blooms are of medium size1 and the colors are distinct and rich1 more particularly the scarlet and crimson shades1 which can be employed to immense advantage in the flower garden4 ,the heavy formal show varieties are of little value for planting in trim beds and borders4 ,many of the decorative or cactus varieties are too coarse in growth to be of much value in the flower garden4 ,therefore1 this ,liliputian race should find favor with those who wish for showy and novel effects in the garden during the summer months4 ,illustration3 ,,tom ,,thumb ,,single ,,dahlias4 ,there are no peculiarities of culture to contend with1 and the unusually dwarf habit of the plants specially fits them for comparative small beds and borders4 ,one good way would be to fill a single bed with one or more decided colors1 as is now done with the tuberous begonia1 for the reason that these dahlias have flowers similar in size to those of the tall-growing single varieties1 and bear them on stiff stalks well above the stems4 ,a mass of the crimson variety would produce a rich glow of color infinitely finer than a mixture of undecided hues4 ,we anticipate a high degree of popularity for these dwarf single or ,tom ,thumb dahlias1 and there is a possibility of double varieties equally dwarf which would be also welcome4 ,the great fault of the majority of dahlias already in cultivation is the tall habit of the plants1 but here we have dwarfness1 a profusion of finely formed flowers1 and varied and attractive colors4--,the ,gardeners' ,magazine4 99 99 99 99 99 ,,some ,,winnebago ,,arts4 ,in the ,proceedings of the ,new ,york ,academy of ,sciences an abstract is given of a paper on the above1 read by ,dr4 ,frederick ,starr3 ,it is well known that a tribe may have peculiarities in speech1 in manners1 in arts1 that distinguish it at once from its neighbors4 ,the ,haida carves slate as no other tribe does4 ,the elegant blankets of mountain sheep wool from ,chilcat are characteristic4 ,the ,hebrews tested the enemy with the word shibboleth1 and found that he could only say sibboleth4 ,a twist of the tongue in pronouncing a word is a small matter1 but1 small as it is1 it may be perpetuated for ages4 ,such a perpetuation of a tribal peculiarity has been aptly called an ethnic survival4 ,some of the advanced linguists of the present day are beginning to query whether the group of modern languages of the ,aryan family are not examples of such ethnic survival2 whether the differences between ,french and ,italian and ,spanish1 ,latin1 ,greek and ,slavonic1 are not due to the difficulty various ancient tribes found in learning to speak the same new and foreign language4 ,to draw an example of ethnic survival from another field of science1 consider the art of the ,french cave men4 ,the archologist finds in the caverns bones of various mammals1 teeth of cave bear1 and antlers of reindeer carved with animal figures4 ,the art is good for a barbarous people1 but it is certainly barbarian art4 ,the range of designs is quite great3 horses1 bears1 mammoths1 reindeer1 are among the figures4 ,the people who did this work were an artistic people4 ,to carve and represent animal forms was almost a mania with them4 ,an ethnic impulse seems to have driven them on to such work1 just as a similar impulse drives the ,haida slate carver to-day2 just as a similar impulse has driven the ,bushman to cover the walls of his caves in ,south ,africa with pictures whose boldness and fidelity are the amazement of all who see them4 ,we have1 then1 in the ,french cave dwellers a people who had a well defined art1 and who1 as art workers1 were isolated and unlike all neighbors4 ,an eminent ,english scientist believes that neither they nor their art are gone4 ,there is a people who to-day lives much as a cave man of ,france lived so long ago1 who hunts and fishes as he did1 who dresses as he did1 who builds houses in whose architecture some think they can see evidence of a cavern original1 who above all still carves batons from ivory1 and implements from bone1 adorning them with skillfully cut figures of animals and scenes from the chase4 ,this people is the ,eskimo4 ,if ,dawkins' view is true1 we have in the ,eskimo carvings of to-day a true ethnic survival--an outcropping of the same passion which displayed itself in the mammoth carving of ,la ,madelaine4 ,scarcely anything in the range of ,american antiquities has caused more wonder and led to more discussion than the animal mounds of ,wisconsin4 ,we do not pretend to explain their purpose4 ,perhaps they were village guardians2 perhaps tribal totems marking territorial limits2 some may have been of use as game drives2 some may even have served as fetich helpers in the hunt1 like the prey gods of ,zui4 ,we may never know their full meaning4 ,it is sufficient here for me to remind you what they are and where4 ,they are nearly confined to a belt of moderate width stretching through ,wisconsin and overlapping into ,minnesota and ,iowa4 ,within this area they occur by hundreds4 ,dr4 ,lapham published a great work on the effigy mounds in #ahee1 in which he gave the results of many accurate surveys and described many interesting localities4 ,since his time no one has paid so much attention to the effigies as ,stephen ,d4 ,peet1 editor of the ,american ,antiquarian1 whose articles have during this year been presented in book form4 ,mr4 ,peet has paid much attention to the kind of animals represented1 and has1 it seems to us1 more nearly solved the question than any one else4 ,he recognizes four classes of animals--land animals or quadruped mammals1 always shown in profile2 amphibians1 always shown as sprawling1 with all four feet represented2 birds1 recognized by their wings2 and fishes1 characterized by the absence of limbs of any kind4 ,the land animals are subdivided into horned grazers and fur bearers4 ,of the many species he claims to find1 it seems to us the most satisfactorily identified are the buffalo1 moose1 deer1 or elk2 the panther1 bear1 fox1 wolf and squirrel2 the lizard and turtle2 the eagle1 hawk1 owl1 goose and crane2 and fishes4 ,one or two man mounds are known1 although most of those so-called are bird mounds--either the hawk or the owl4 ,sometimes1 too1 composite mounds are found4 ,nor are these mounds all that are found4 ,occasionally the same forms are found in intaglio1 cut into the ground instead of being built above it1 but just as carefully and artistically made4 ,notice1 in addition to the form of these strange earth works1 that they are so skillfully done that the attitude frequently suggests action or mood4 ,nor are they placed at random1 but are more or less in harmony with their surroundings4 ,remember1 too1 their great number and their large size--a man #bad feet long1 a beast #afj feet long1 with a tail measuring #cbj feet1 a hawk #bdj feet in expanse of wing4 ,they are unique4 ,to be sure1 there are in ,ohio three effigies1 in ,georgia two1 and in ,dakota some bowlder mosaics in animal form4 ,none of these1 however1 are like the ,wisconsin type4 ,the alligator and serpent of ,ohio are different in location and structure from the ,wisconsin mounds1 and are of designs peculiar4 ,the bird mound in the ,newark circle is more like a ,wisconsin effigy1 but is associated with a type of works not found in the effigy region4 ,the birds of ,georgia are different in conception1 in material1 and in build4 ,the mosaics of ,dakota are simply outlines of loose bowlders4 ,it seems to us that the effigy builders of ,wisconsin were a peculiar tribe1 unlike their mound-building neighbors in ,ohio or the ,south2 that they were a people with a passion for representing animal figures4 ,this passion worked itself out in these earth structures4 ,that a single tribe should be thus isolated in so remarkable a custom is no more strange than that the ,haida should carve slate or the ,bushman draw his pictures on his cavern walls4 ,who were the effigy builders8 ,this is a question often asked and variously answered4 ,some writers would refer them to the ,winnebagoes1 or1 if not to them directly1 to some ,dakota stock from which the ,winnebagoes have descended4 ,formerly ,i was a frequent visitor to the ,sac and ,fox ,reservation in ,iowa4 ,about #djj of the tribe are left4 ,to an unusual degree they retain the old dress1 language1 arts and dances4 ,with them lived a few ,winnebagoes4 ,in general the lives of the two peoples are similar4 ,certain arts common to both of them particularly interested me4 ,they are the making of sacks of barks and cords1 and the weaving of bead bands for legs and arms1 upon the ci-bo-hi-kan4 ,of the bark sacks there are several patterns1 the simplest being made of splints of bark passing alternately over and under each other4 ,another kind1 far more elaborate in construction1 is before you4 ,yet more elaborate ones are made entirely of cords4 ,the first of these ,i saw was in old ,jennie ,davenport's wikiup4 ,it was of white and black cords1 and the black ones were so manipulated as to form a pattern--a line of human figures stretching across the sack4 ,jennie would not sell it1 as she said1 ,it is a ,winnebago woman's sack2 ,fox woman not make that kind4 ,i found afterward a large variety of these ,winnebago sacks1 and all were characterized by patterns of men1 deer1 turtles1 or other animals4 ,not one ,fox sack of such pattern was to be found1 though many elaborate and beautiful geometrical designs were shown me4 ,the most beautiful work done on this reservation is the bead weaving on the ci-bo-hi-kan--woven work1 not sewed1 remember4 ,in appearance the result is like the ,iroquois wampum belts1 but the management of the threads is dissimilar4 ,the ,sac and ,fox patterns are frequently complex and beautiful1 but always geometrical4 ,we have seen hundreds of them1 but none with life forms4 ,the ,winnebago belts1 made in exactly the same way1 frequently1 if not always1 present animals or birds or human beings4 ,this1 it seems to us1 is very curious4 ,here are people of two tribes living side by side1 with the same mode of life and the same arts1 but in their art designs so diverse4 ,it is a case parallel to that of the old effigy builders1 a people who have a passion for depicting animal forms--a passion not shared by their neighbors4 ,if this were the only evidence that the ,winnebagoes built the effigy mounds1 or that their ancestors did so1 it would have no great weight4 ,but the claim has been made already on other grounds4 ,this being the case1 we think that this adds something to the testimony1 and we ask1 ,have we here an ethnic survival8 ,at the close of the paper ,dr4 ,starr exhibited a number of fine specimens of ,indian handiwork1 including woven work1 bags1 belts1 etc4 ,dr4 ,newberry explained that these mounds were not sepulchral1 like many others in the ,ohio and ,mississippi valleys4 ,geologically speaking1 man is very recent4 ,the early inhabitants of ,america may have originally come from the ,east1 but1 if so1 they were cut off from that part of the world at a very early date4 ,the development of the tribes in ,america was complete and far-reaching4 ,copper and lead mines were worked1 the forests removed1 and large tracts given over to the cultivation of corn1 grain1 etc4 ,this was the mound age1 and the constructions were certainly abandoned over one thousand years since4 ,the ,pueblo ,indians now existing in ,arizona and ,new ,mexico took their origin from ,central ,america1 and spread as far north as ,salt ,lake1 ,utah1 and south as far as ,chili4 ,their structures were permanent stone buildings1 many of which still exist in a good state of preservation4 ,professor ,munroe found rocks on the ,ohio river1 near the ,pennsylvania line1 inscribed with figures of men1 horses and other animals4 ,at low water these figures can be distinctly observed4 99 99 99 99 99 ,,the ,,philosophy ,,of ,,consumption4 ,by ,dr4 ,j4,s4 ,,christison1 ,chicago4 ,a proclamation by an eminent physician that he has discovered a specific cure for consumption in its most prevalent and insidious form1 known as tuberculosis1 might well create a deep and universal interest1 since there are comparatively few of us that do not have this deadly enemy within the limits of our cousin kinship4 ,and if ,german slaughter house statistics are to be taken as representative1 no less than ten per cent4 of our domesticated horned cattle are a prey to the same disease1 though seldom discovered during life4 ,this fact would suggest that tubercular consumption is still more prevalent in the human family than has yet been supposed1 and that many carry it under the cover of other maladies4 ,but unfortunately for any hope for a specific remedy1 the preponderance of evidence points to the fact that consumption is much more a product of individual habits and social and climatical conditions than a resultant of any one agency4 ,indeed1 the causative evils may vary not only in their degree1 but also in their number and order of action in the period of its evolution4 ,if it were hereditary in the sense that it is transmitted by the blood as a specific germ or virus1 then the offspring of consumptives would have an attenuated form of the disease1 which1 by reasoning from analogy1 ought to secure them exemption from any further danger along that line4 ,such1 however1 is not the case4 ,but if we say a special fitness is inherited1 then we can understand how the offspring of consumptives are prone to develop it1 since they are not only born with hereditary qualifications1 but not infrequently they are cradled amid the very agencies which fostered the evil in their parents1 if1 indeed1 they were not primarily causative4 ,that the contribution of heredity to consumption is great is undoubtedly the case1 and1 more than any other factor1 it would seem to have a directing power in the army of inducing evils4 ,but the fact that the greater number of the offspring of consumptives escape the disease1 even where the general family resemblance is quite pronounced1 is readily explained by the difference in personal habits1 the circumstances of different periods or the domestic regulations instituted by medical counsel4 ,also the fact that consumptives so frequently spring from neurotic parentage and the victims of dissipation1 especially alcoholic1 still farther goes to show that the hereditary element is essentially a reduced power of resistance to formative evils1 and that as a negative condition it may hold the balance of power in focusing the forces4 ,thus1 heredity1 in disease1 can be understood as in no sense implying a specific force1 but rather an atonic or susceptible condition1 varying in its precise character and producing a pars minoris resistenti--a special weakness in a special way4 ,that the germ bacillus does not originate consumption there can be no doubt1 unless consumption is not to be regarded as a disease until it is full fledged1 for otherwise the germ would be present in the earlier formations1 as well as the later1 which1 according to good authority1 is not the case4 ,but that this parasite has a special affinity for consumptive tissue there is no question1 and that it thrives therein with great rapidity1 hastening retrogressive changes1 is also to be granted4 ,but1 as yet1 this is all we are entitled to believe4 ,we thus see that the lines of successful treatment must be both constitutional and local2 that the constitutional cannot be specific1 and the strictly local cannot be curative4 ,the constitutional must be of a negative and positive character1 having regard to the support of the healthy remnant1 and which will require correction of any deficiency whatsoever in order to remove the morbid constitutional habit4 ,the local will be cleansing of the affected organs from the germs and morbid products4 ,the evident selective affinity of ,koch's lymph for tuberculous tissue may enable it1 in certain cases1 to effectually seal the arterial capillaries about the affected parts1 owing to the intense vaso-motor disturbance produced4 ,this would starve the germs1 which1 with the tubercular matter1 may be expectorated through the moisture and motion of the lungs4 ,in incipient cases the tubercles might be as readily absorbed as catgut ligature1 and the germs1 if any1 fall to phagocytic prey4 ,the ,koch lymph is evidently not a poison to the germs1 and probably has no other action on the affected organs than that of an irritant1 having a selective affinity by virtue of the kinship with its contents4 ,this theory of its action is supported by our common knowledge of the power of pyogenic agents to awaken old or slumbering inflammations1 and the fact that septic fevers1 such as small-pox1 have been known to leave the consumptives with the last stages free from every symptom4 99 99 99 99 99 ,,the ,,scientific ,,american ,,architects ,,and ,,builders ,,edition4 #b4ej a ,year4 ,single ,copies1 #be cts4 ,this is a ,special ,edition of the ,,scientific ,,american1 issued monthly--on the first day of the month4 ,each number contains about forty large quarto pages1 equal to about two hundred ordinary book pages1 forming1 practically1 a large and splendid ,magazine ,of ,architecture1 richly adorned with elegant plates in colors and with fine engravings1 illustrating the most interesting examples of modern ,architectural ,construction and allied subjects4 ,a special feature is the presentation in each number of a variety of the latest and best plans for private residences1 city and country1 including those of very moderate cost as well as the more expensive4 ,drawings in perspective and in color are given1 together with full ,plans1 ,specifications1 ,costs1 ,bills of ,estimate1 and ,sheets of ,details4 ,no other building paper contains so many plans1 details1 and specifications regularly presented as the ,,scientific ,,american4 ,hundreds of dwellings have already been erected on the various plans we have issued during the past year1 and many others are in process of construction4 ,architects1 ,builders1 and ,owners will find this work valuable in furnishing fresh and useful suggestions4 ,all who contemplate building or improving homes1 or erecting structures of any kind1 have before them in this work an almost endless series of the latest and best examples from which to make selections1 thus saving time and money4 ,many other subjects1 including ,sewerage1 ,piping1 ,lighting1 ,warming1 ,ventilating1 ,decorating1 ,laying out of ,grounds1 etc41 are illustrated4 ,an extensive ,compendium of ,manufacturers' ,announcements is also given1 in which the most reliable and approved ,building ,materials1 ,goods1 ,machines1 ,tools1 and ,appliances are described and illustrated1 with addresses of the makers1 etc4 ,the fullness1 richness1 cheapness1 and convenience of this work have won for it the ,largest ,circulation of any ,architectural publication in the world4 ,a ,catalogue of valuable books on ,architecture1 ,building1 ,carpentry1 ,masonry1 ,heating1 ,warming1 ,lighting1 ,ventilation1 and all branches of industry pertaining to the art of ,building1 is supplied free of charge1 sent to any address4 ,,munn ,,co41 ,,publishers1 #cfa ,,broadway1 ,,new ,,york4 99 99 99 99 99 ,,building ,,plans ,,and ,,specifications4 ,in 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