,electro-,mechanical ,series ,,gas ,,and ,,petroleum ,,engines ,,translated ,,and ,,adapted ,,from ,,the ,,french ,,of ,,henry ,,de ,,graffigny ,,and ,,edited ,,by ,a4 ,g4 ,,elliott1 ,b4,sc4 ,,london ,,whittaker ,,and ,,co4 #b ,,white ,,hart ,,street1 ,,paternoster ,,square ,,new ,,york3 #ff ,,fifth ,,avenue #ahih ,,richard ,,clay ,,sons1 ,,limited1 ,,london ,,bungay4 ,,preface ,the great and increasing importance of internal combustion motors is perhaps scarcely realized by the general public4 ,for industrial purposes they have for many years been steadily gaining favour1 and now hold an assured position4 ,it is only in the last few years1 however1 that we have begun to recognize the drawbacks of horse-drawn vehicles1 and the immense advantage gained by propelling them mechanically4 ,the suitability of oil engines for the purpose has awakened a widespread interest in them4 ,the ,editor therefore hopes that this little volume will be especially welcome to non-technical readers who like to keep ahead of the times in matters of such universal importance4 ,one chapter deals exclusively with the theory of the gas engine1 but the non-technical mind should have no fear1 for mathematics have been as far as possible avoided4 ,it may also serve to dispel wrongful notions concerning the practical limits of the efficiency of gas engines which1 we are sorry to say1 exist even among persons living in a scientific atmosphere4 ,we have not spoken in the text of the extremely interesting results obtained from the oil engine invented by ,herr ,diesel of ,berlin1 because it has not yet been proved that this motor is strictly practicable4 ,if1 however1 it turns out to be a commercial success1 we hope to add a description of it at some future date4 ,may #ahih4 ,,contents ,,chap4 ,,page ,i4 ,,history ,,of ,,the ,,gas ,,engine #a ,,ii4 ,,the ,,working ,,principles ,,of ,,the ,,gas ,,engine #ac ,,iii4 ,,description ,,of ,,existing ,,gas ,,engines #bc ,,iv4 ,,carburetted ,,air ,,engine #fg ,v4 ,,petroleum ,,engines #gg ,,vi4 ,,gas ,,generating ,,plant #ajc ,,vii4 ,,engines ,,for ,,use ,,with ,,poor ,,gases #aba ,,viii4 ,,maintenance ,,of ,,gas ,,and ,,oil ,,engines #acj ,,index #aci ,,list ,,of ,,illustrations ,,fig4 ,,page #a4 ,early ,lenoir ,motor #bd #b4 ,bisschop ,motor #be #c4 ,bnier ,motor #bf #d4 ,forest ,motor #bg #e4 ,plan of ,dugald-,clerk ,engine #cj #f4 ,benz ,gas ,engine #cb #g4 ,otto ,gas ,engine #cf #h4 0 0 0 7vertical type7 #ch #i4 ,lenoir ,gas ,engine #ci #aj4 ,koerting-,boulet ,motor #dj #aa4 ,niel ,gas ,engine #dd #ab4 ,martini ,motor #de #ac4 ,lablin ,three-cylinder ,motor #df #ad4 ,crossley ,gas ,engine 7,x type7 #dg #ae4 ,crossley ,gas ,engine #dh #af4 ,pygme ,gas ,engine #ej #ag4 ,national ,gas ,engine #eb #ah-ai4 ,de ,forest ,gas ,engines #ed #bj4 ,de ,forest ,double ,piston ,motor #ed #ba4 ,diagram of ,atkinson ,mechanism #eh #bb4 ,section of ,charon ,motor #eh #bc4 ,charon ,motor #ei #bd4 ,roger ,vertical ,gas ,engine #fj #be4 ,vertical ,gas ,engine of the ,compagnie ,parisienne du ,gaz #fb #bf4 ,maurice ,motor 7de ,cadiot7 #fd #bg4 ,durand ,carburetted ,air ,motor #gb #bh4 ,de ,dion ,motor ,tricycle #ge #bi4 ,campbell ,oil ,engine #ha #cj4 ,section of ,grob ,motor #hc #ca4 ,exterior ,view of ,grob ,oil ,motor #hd #cb4 ,capitaine ,gas ,engine #hf #cc4 ,horizontal 8,balance0 ,motor 7,capitaine7 #hg #cd4 ,capitaine ,two-cylinder ,gas ,engine #hh #ce4 ,hornsby-,akroyd ,oil ,engine 7section7 #ia #cf4 ,exterior ,view of ,hornsby-,akroyd ,oil ,engine #ib #cg-ch4 ,sections of ,ragot ,petroleum ,engine #id #ci4 ,carburator of ,ragot ,oil ,engine #if #dj4 ,crossley-,holt ,petroleum ,engine #ii #da-db4 ,griffin ,oil ,engine #aja #dc4 ,dowson ,gas-producing ,plant #ajh #dd4 ,taylor ,gas-producing ,plant #aad #de4 ,simplex ,gas ,engine 7,delamare-,deboutteville7 #abc #df-dg4 ,governor of ,simplex ,engine #abc #dh4 ,combined ,simplex ,engine and ,buire-,lencauchez ,gas-producer #abd #di-ej4 ,bnier ,engine and ,gas ,plant 7sectional plan and elevation7 face p4 #abg #ea4 ,section of ,simplex ,gas-producing ,plant #ace #eb4 ,agricultural ,oil ,locomotive #acg ,,gas ,,and ,,petroleum ,,engines ,,chapter ,i ,,history ,,of ,,the ,,gas ,,engine ,the history of gas engines may be said to date from a time when coal gas and petroleum were unknown4 ,this statement appears at first somewhat paradoxical1 but it arises from the fact that the first gas engine1 invented by the ,abb de ,hautefeuille in #afgh1 used the explosive force of gunpowder as a motive power4 ,the principle of this early gas engine1 however1 is exactly the same as that of its more modern brothers2 that is1 the work is done by the expansion and cooling of a volume of heated gas1 the only difference being that gunpowder contains within its grains the oxygen necessary for its combustion1 while coal gas or petroleum require admixture with the oxygen of the air before they can be made to explode4 ,two years after the ,abb de ,hautefeuille had made public his idea1 in a memoir entitled ,a ,method of ,raising ,water by means of ,gunpowder1 the ,dutch savant ,huyghens published a similar work1 describing an apparatus consisting of a cylinder with two leather exhaust pipes1 forming valves2 to the bottom of the cylinder was screwed a small box in which gunpowder was to be ignited4 ,the effect of the explosion was to drive out a large quantity of heated gas through the valves1 which closed again when it had passed4 ,the gas remaining in the cylinder soon cooled down1 so that the pressure within it fell below that of the surrounding atmosphere1 and caused the piston to be forced down by the excess of atmospheric pressure4 ,this operation was certainly very crude1 and1 as might have been expected1 scarcely came up to the expectations of its inventor4 ,the idea was1 however1 not allowed to rest here1 and ,papin set himself to find out some better agent to replace the gunpowder1 whose action was uncertain and1 to say the least of it1 brutal4 ,the result of his experiments pointed clearly to the condensation of steam as being the most suitable method of producing a space filled with a gas at a lower pressure than that of the atmosphere1 and many inventors1 following in his footsteps1 adopted this process for working pumping engines4 ,in consequence of the great success of the steam engine1 which was due to the genius of ,watt and his successors1 the idea of using combustion to act directly as a motive power was lost sight of for a great number of years1 and it was not till the year #agia that any suggestion was made which was an improvement on the engines of ,de ,hautefeuille and ,huyghens4 ,the inventor1 this time an ,englishman1 by name ,john ,barber1 specified in his patent1 in somewhat laconic language1 the use of a mixture of a hydrocarbon gas and air1 and its explosion in a vessel which he termed an exploder4 ,several years later1 in #agid1 ,robert ,street1 also an ,englishman1 took out a patent for the production of an explosive vapour by means of a liquid and air1 ignited by a flame in a suitable cylinder so as to drive machinery and pumping engines4 ,petroleum or any other inflammable liquid was allowed to drip on to the heated bottom of a cylinder so as to be vaporized and drive up the piston4 ,philip ,lebon1 of ,brachay1 the creator of the coal gas industry in ,france1 took out a patent in #agii1 setting forth very clearly the principle and construction of an engine using the explosion of coal gas as its motive power4 ,lebon1 in fact1 devised his gas-producing plant with the intention of only using the coal gas in his gas engine1 lighting by its means being quite an afterthought4 ,in a second patent two years afterwards he describes a more perfect apparatus1 in which a pump is provided for compressing the mixture of coal gas air1 and also an electric machine worked by the engine itself for igniting the compressed mixture4 ,unfortunately1 the career of this fertile inventor came to an abrupt end by his assassination in #ahjd4 ,it is highly probable1 that if he had lived gas engines would have come into general use at the beginning of the century instead of nearly sixty years later4 ,from #agii up till the year #ahfj1 in which the first really practical gas engine made its appearance1 several schemes were put forward1 some of them not lacking in ingenuity1 of which the most interesting were due to ,welman1 ,wright1 ,johnston1 and ,barnett4 ,wright's machine was particularly well thought out and constructed4 ,the double-acting cylinder was placed in a vertical position and the gases were ignited by a gas-jet4 ,a centrifugal governor regulated the pumps which compressed the explosive mixture in the cylinder1 and at the same time varied the composition of the explosive mixture so as to always be proportional to the work which was required to be done4 ,when we come to consider that this engine was brought out in the year #ahcc1 it is wonderful that it did not meet with greater success1 but this was probably due to the fact that the steam engine was at that period coming greatly into favour1 and for the time being completely eclipsed all other forms of motive power4 ,about this time a double-acting gas engine was devised by ,johnston1 using pure hydrogen and oxygen as the explosive mixture1 in the proportion of two volumes of hydrogen to one of oxygen4 ,after the explosion and driving forward of the piston1 the combined gases being cooled were precipitated as water1 and a partial vacuum obtained which was used during the return stroke4 ,this idea was a highly ingenious one1 but failed owing to the high price of hydrogen and oxygen1 but perhaps some day1 when these obstacles have been removed1 this idea may once more be taken up4 ,in #ahch ,william ,barnett took out a patent for an engine based on the same principle as that of ,lebon4 ,two pumps compressed separately the combustible gas and the air and forced the mixture under pressure into the cylinder4 ,the explosion was caused by a small gas-jet1 communication between it and the cylinder being set up at the right moment by a revolving valve4 ,the gas-jet was situated in the valve itself1 and was so arranged that during half a revolution it was turned towards the outside1 and was then lighted by a second jet1 and during the remainder of the revolution it communicated with the interior of the cylinder and ignited the explosive mixture4 ,this was the first gas motor in which the ignition was from the outside1 and in which the explosive gases were at the same time under pressure4 ,in most modern gases the same result is obtained1 but the original and rather crude method of obtaining it has of course been much modified and improved4 ,during the next few years several patents were taken out relating to the same subject4 ,in #ahdd ,john ,reynolds suggested using a battery which should white-heat a platinum wire in order to ignite the gases1 the ignition taking place at the required moment by means of an automatic switch closing the battery circuit4 ,in #ahej ,stphard recommended a magneto-electric machine driven by the engine itself instead of the primary battery4 ,barsanti and ,matteucci described in #aheg an atmospheric motor1 their arrangement of the parts being afterwards adopted by ,otto and ,langen4 ,a ,bunsen cell supplied current to a ,de la ,rive multiplier1 causing a stream of sparks to pass between two fine points situated within the combustible mixture4 ,in #aheh and #ahei ,degrand explained in two patents a gas engine in which the gases were compressed in the cylinder itself4 ,owing to mechanical difficulties his machine was impracticable1 but the idea forms an important step in the history of gas engines4 ,in #ahfj1 when the ,lenoir motor appeared1 no other existed which was capable of regular and comparatively efficient work4 ,this machine1 devised by ,lenoir and constructed by ,marinoni1 had the appearance of a double-acting horizontal steam engine4 ,the explosive mixture was ignited by an electric spark produced by a ,ruhmkorff coil and a primary battery4 ,the machine ran smoothly and regularly and its cost was moderate3 among the advantages which it possessed at that time over other forms of motive power1 were the absence of a cumbrous boiler and costly foundations1 and the little care and attention necessary to keep it in working order4 ,so great was its success at the time1 that many people prophesied that the steam engine would soon become extinct4 ,in spite of this the ,lenoir motor possessed many defects which engineers were not slow to recognize4 ,the enthusiasm which it had aroused soon cooled down when it became known that for steam and gas engines of equivalent power1 the steam engine was considerably cheaper4 ,it required in fact #cjjj litres of gas to produce one horse-power hour1 and to cool the cylinder of such a motor a volume of water was necessary four times as great as that required to produce the steam of a steam engine of equal power4 ,besides this1 the machine had to be kept flooded with lubricating oil4 ,in consequence of these various defects the ,lenoir motor disappeared almost as rapidly as it had arisen4 ,in spite1 however1 of this apparent failure1 it did some good1 for it once more directed the attention of inventors to the problem of a practical gas engine4 ,among the numerous patents taken out in consequence of this reaction1 the most important1 filed in #ahfj by ,m4 ,hugon1 related to a gas motor with a flame ignition1 and in which the cylinder was cooled by injecting into it a very fine spray of cold water4 ,experiments were made upon it in #ahgf by ,m4 ,tresca1 and it was found that the motor consumed #bdde litres of gas per horse-power hour4 ,the temperature of the exhaust gases was #ahj ,c41 while in the ,lenoir motor they were about #bhj ,c4 ,the diminution in temperature was probably due to the better method of cooling the cylinder1 and was found to be a great improvement1 the cylinder requiring much less lubrication4 ,in #ahfa ,kinder and ,kinsey somewhat modified the existing arrangements of the parts1 but otherwise their motor embodied no new ideas4 ,another motor was devised about this time by ,millon1 once more bringing forward ,lebon's idea of compressing the gases in the cylinder itself4 ,we have now reached the year #ahfb1 which may be considered a memorable one in the history of the gas engine1 for it was in this year that a patent was taken out by ,m4 ,beau de ,rochas1 setting forth from a theoretical point of view the best working conditions for a gas engine4 ,during the forward stroke of the piston the explosive mixture was to be drawn into the cylinder1 during the return stroke this volume of gas being compressed2 at the dead point at the beginning of the second forward stroke the explosion was to take place1 driving the piston forward1 the gases being expelled during the second return stroke4 ,the whole principle will be seen to consist of four distinct operations1 forming what is known as the ,otto cycle1 for reasons which we will presently explain4 ,the peculiar part of the patent was its purely theoretical explanation4 ,whilst giving all the honour due to the inventor1 and recognizing that he fully understood what he was talking about1 we must not forget that there was nothing whatever in the patent indicating how the ideas embodied therein might be carried into practice4 ,no drawings were appended to the text1 explaining how the gases were to be ignited1 or how the exhausted gases were to escape2 it contained nothing1 in fact1 but the plain statement of the most efficient cycle of operations4 ,m4 de ,rochas did not construct a machine on this principle1 and as he omitted to pay his patent fee for the second year1 the idea became public property4 ,for these reasons no attention was drawn to it until ten years afterwards1 when it came to light during some patent litigation undertaken by ,dr4 ,otto in #ahgh4 ,in #ahfg at the ,international ,exhibition at ,paris a vertical atmospheric motor was to be seen working1 based on the primitive principle of the gunpowder pump of ,de ,hautefeuille4 ,this machine was constructed by two ,german engineers1 ,otto1 and ,langen of ,deutz near ,cologne1 and was a perfected form of the ,barsanti and ,matteucci motor invented ten years previously4 ,the explosion of the gases in the cylinder only served to obtain a partial vacuum underneath the piston1 which was therefore forced down by the excess of atmospheric pressure above it4 ,this arrangement had one great advantage over the ,lenoir and ,hugon motors1 it only burnt #acej litres of gas against their #bejj or #cjjj per horse-power hour1 and consequently it rapidly came into favour1 and the lucky inventors were able to sell no less than #ejjj motors in a few years4 ,the motor itself was very rough and had many defects3 the gear-wheels rattled and made a furious noise1 the igniting flame kept up a continuous roar1 and above the noise of clanking machinery the explosion of the gases could be heard like a cannon going off2 in fact1 no one could say that the ideal of domestic motors had been attained2 but as the motors constructed in #ahgb only consumed #hjj litres of gas per horse-power hour1 rendering power produced by this means cheaper than steam1 its success was assured in spite of the defects4 ,the success of these early attempts stimulated ,dr4 ,otto to further efforts1 and in #ahgh he brought out his famous gas engine1 which has earned a world-wide reputation by reason of its incontestable merits4 ,it was based on the principle explained in the ,de ,rochas patent which we have spoken of1 but ,otto undoubtedly knew nothing of this patent1 and his invention was perfectly independent and fresh as far as the world was concerned4 ,the enormous success to which the new motor attained naturally led to many unscrupulous imitations1 and legal proceedings were instituted in ,england and ,france4 ,in this country the validity of ,otto's patents were upheld1 but in ,france the ,de ,rochas patent was for the first time brought to light1 and the verdict went against him4 ,this verdict has been attributed to malice on the part of the ,french judges1 for at that time the ,french nation would have probably conceded as little as possible to a ,german2 but whether that be so or not1 we are indebted to ,dr4 ,otto for having made the gas motor a really practical engine after many years of patient experiment and study4 ,at the same time as the ,otto engine three other motors appeared at the ,exhibition of #ahgh3 the ,bisschop gas engine constructed by ,mignon and ,rouart1 and two others by ,simon and ,ravel4 ,the ,simon motor1 of which only a very small number were constructed1 was very interesting from the economy point of view4 ,the explosion of the mixed gas was not allowed to take place suddenly1 but proceeded gradually as the piston moved forward1 and the heat which in the ,otto engine is carried off by the water jacket1 was made use of1 as in the old ,hugon motor1 to vaporize a spray of cold water1 and thus adding to the total force behind the piston4 ,this process was so effective1 that on shutting off the supply of gas the motor continued to revolve for a considerable period by means of the vaporized water4 ,about #hjj litres of gas were consumed and four litres of water per horse-power hour1 a very good result4 ,the ,ravel motor used even less1 about #ejj or #fjj litres only1 but owing to the bad arrangement of the parts the mechanical efficiency was very low4 ,such was the position of the gas engine in #ahgh4 ,a standard type had been adopted and worked excellently4 ,it merely required to be perfected in detail and simplified in order to make it still more economic1 and capable of holding its own against its powerful rival the steam engine4 ,many modifications of the ,otto gas engine have appeared since that date1 among the most important being those by--,dugald-,clerk1 in #ahgi1 a motor which compressed and exploded the gases once in every revolution2 ,lenoir1 in #ahcc1 the cylinder being cooled by currents of air2 and in the same year appeared the ,griffin gas engine1 with a complete cycle of operations every three revolutions4 ,at the ,antwerp ,exhibition of #ahhd several new types appeared1 among them the ,stockport engine by ,andrews1 and others by ,koerting1 ,bnier1 and ,benz4 ,in the same year a very good motor appeared1 called the ,simplex1 constructed by ,powell of ,rouen 7now ,matter et ,cie471 according to the plans of ,,mm4 ,delamare-,deboutteville and ,l4 ,malandin4 ,this engine was the subject of some litigation1 the ,otto people considering it an infringement of their patents1 but the improvements in the design of the working part and the novelty of several details being apparent1 the ,simplex gas engine gained the day4 ,in #ahhe1 after the appearance of the ,simplex and the new ,lenoir motors1 most makers made use of the ,otto cycle1 and about this time appeared the first carburetted gas motors1 that is to say1 using volatile spirits and products of petroleum for their source of energy4 ,such motors have been devised by ,tenting1 ,koerting-,boulet1 ,diedrichs1 ,gotendorf1 ,nol1 ,forest1 ,ragot1 ,rollason1 ,atkinson1 etc4 ,at the ,international ,exhibition in #ahhi there were thirty-one exhibitors and fifty-three machines1 with a total power of #ajjj horse-power4 ,all except four used the ,otto cycle1 and for the first time a motor was to be seen using a gas other than coal gas1 namely a poor gas produced at a very low cost in a special gas-producing plant4 ,the motor itself was of the single-cylinder ,simplex type of #ajj horse-power1 opening up a new horizon to inventors1 and demonstrating the possibility of using large gas engines supplied with poor gas4 ,this short history of the gas engine will be seen to consist of three distinct periods--firstly1 from #agjj up to #ahfj1 during which time many inventors tried and failed to produce anything practical2 secondly1 from #ahfj to #ahhi1 during which the gas engine became something really practical2 thirdly1 from #ahhi up to the present date4 ,in this period gas engines have grown in size1 and large units of #bjj to #djj horse-power are now constructed1 worked by poor gas produced from special gas plants1 and enabling the gas engine to successfully hold its own against the steam engine1 which it may one day entirely supplant4 ,,chapter ,,ii ,,the ,,working ,,principles ,,of ,,the ,,gas ,,engine ,assuming that the earth once formed part of the sun1 the whole of the energy at our command for commercial purposes can be traced back to the sun as source4 ,this energy we have received from it in the form of heat1 and under certain circumstances the heat is stored up in a latent form in chemical compounds such as coal1 petroleum1 etc4 ,with our present knowledge it is exceedingly difficult to extract the latent energy from coal and petroleum in any other form but heat1 and in order to do so to our greater benefit1 it is necessary to study the laws of heat and heat engines4 ,the law which states the relation between heat and other forms of energy such as electricity1 mechanical work1 is called the principle of the conservation of energy1 and forms the first law of thermodynamics4 ,it is enunciated as follows4 ,whenever a body does work or has work done upon it1 there is a disappearance or an appearance of heat1 and the amount of heat thus produced or used up is always exactly proportional to the work which is done4 ,the ratio of the amount of work which a certain quantity of heat can produce has been therefore termed the mechanical equivalent of heat4 ,it has been found by experiment1 taking the calorie 7,c4,g4,s4 unit7 as the unit of heat and the kilogramme metre as the unit of work or energy1 that the mechanical equivalent is #dbd4 ,that is to say1 the heat necessary to raise the temperature of one kilogramme of pure water at #j ,centigrade through #a ,c4 7the calorie7 is equal to the work done in raising #dbd kilogrammes to a height of one metre4 ,in nearly all commercial heat engines the heat is converted into the energy of movement 7kinetic energy7 by using some body such as water vapour1 gas1 or air as an intermediary agent4 ,we do not1 however1 know at present how to transform heat into mechanical work without losing a greater part of it in the process4 ,even in the most perfect heat engines at least #gj of the heat is lost1 only about #cj being converted into mechanical energy4 ,this is as yet the most perfect result which engineers have obtained even with the most elaborate precautions4 ,as a rule the loss is greater2 for instance1 many good machines which we consider efficient burn one kilogramme of coal1 giving out #hjjj calories1 equivalent to #c1djj1jjj kilogramme-metres1 and transform only about #djj1jjj kilogramme-metres into work1 the rest1 forming nearly #hj1 is lost4 ,it has been the aim of engineers for many years past to reduce this extravagant waste by every means possible1 and the very fact that such a waste exists1 clearly shows that our vaunted engines are hopelessly wrong in their principle4 ,there is reason1 however1 to hope that one day we may1 by converting the chemical energy of coal direct into electricity1 and thereby avoiding the wasteful heat altogether1 reclaim at least #hj of the latent energy which nature has so bountifully supplied to us4 ,it can be shown mathematically that the ratio of the quantity of heat actually converted into work to the total heat used by an engine depends on the temperature at which the heat was absorbed and on the temperature at which the waste heat was discharged4 ,for instance1 in a gas engine the efficiency depends on the temperature of the gases directly after the explosion1 and on the temperature of the exhaust gases after the work has been done4 ,the exact relation is as follows3 the above stated ratio1 which is called the theoretical or thermal efficiency1 is equal to the difference between the temperature of the hot gases immediately after explosion1 and the temperature of the gases of the exhaust divided by the temperature of the hot gases after explosion4 ,this somewhat cumbrous statement may be expressed more clearly in algebraic symbols-- ,w ,t#b - ,t#a -- -------------------------- ,h ,t#b where ,w is the amount of work done by an engine supplied with a quantity of heat1 ,h1 and ,t#b is the temperature of the heated gases which expand doing work1 and are thereby cooled to the temperature ,t#a1 at which they are exhausted4 ,it is therefore evident1 that to make an engine work perfectly efficiently we must obtain an amount of work from it exactly equivalent to the heat put in4 ,that is to say1 ,w must equal ,h in the above equation4 ,we therefore have the efficiency of such a perfect engine ,t#b - ,t#a ,w -------------------------- -- #a4 ,t#b ,h ,it must not be forgotten that ,t#b and ,t#a are reckoned not in the ordinary scales of temperature such as ,fahrenheit and ,centigrade1 but on the absolute scale1 absolute zero being that temperature at which a body has no molecular motion4 ,calculations based upon various considerations point to the fact that absolute zero corresponds to about -#bgc ,c4 ,we have just pointed out that in a perfectly efficient engine ,t#b - ,t#a -------------------------- #a4 ,t#b ,in order that this may be so1 we must have ,t#a #j1 the absolute zero4 ,in practice it is impossible to make the temperature of the exhausted gases as low as this1 and so the only way to obtain more efficient engines is to make ,t#b as large as possible1 that is to say1 the initial temperature of the gases must be high4 ,it is1 however1 just as possible to turn all the heat supplied to a heat engine into work as it is to use up all the energy of a waterfall in a turbine1 because the level from which the zero of the potential of the energy water is measured is the centre of earth1 which is as inaccessible as absolute zero of temperature4 ,it therefore behoves us to make the ratio of the initial and final temperatures of the gas which does work in a gas engine as large as possible1 and it is for this reason that gas engines can be made more efficient than steam engines1 for in the former a momentary initial temperature of #aejj ,c4 may be obtained by the combustion1 whilst steam at #bjj lbs4 on the square inch is at about #a_/ajth of that temperature4 ,there are practical difficulties which prevent higher initial temperatures being used1 residing chiefly in the fact that at #djj ,c4 iron is red-hot1 so that any lubricant coming into contact with it is decomposed and loses its lubricating properties4 ,even at #cjj ,c4 most lubricating oils in contact with the air become oxidized and destroyed4 ,this difficulty of lubrication1 by limiting the temperature1 at the same time limits the efficiency1 and not till some new lubricant is discovered which defies heat will there be much improvement in this direction4 ,even as it is1 it is necessary to cool the sides of the vessel or cylinder in which the gases expand1 and in doing so we lose a great deal of heat4 ,hot-air engines using ordinary air as the expansible gas have been devised from time to time1 but they have not met with much success owing to their weight and the large amount of space they take up1 neither are they as efficient as a good modern gas engine4 ,we will not1 therefore1 study the theory of hot-air engines1 but further consider the details of gas engines1 whose superiority over all other heat engines we think we have sufficiently pointed out4 ,it seems at the present date almost impossible to conceive anything fresh in the cycle of operation of a motor using explosive gases1 so numerous and varied are the already existing types4 ,all possible combinations appear to have been considered1 and even repeated1 for in many recent patents old ideas have once more been brought forward which date back to the early attempts of ,lebon1 ,barnett1 ,beau de ,rochas4 ,the greater number of existing types are based in principle on two or three fundamental ideas1 and their improvement is rather to be found in their mechanical design than in the conception of a new cycle4 ,this fact enables us to classify gas engines very much more easily1 because1 apart from some perfection of detail1 they fall naturally into several groups1 which will prevent the reader from losing his way in what otherwise might be chaos4 ,we shall therefore1 in describing individual engines later on in this book1 follow a systematic course1 and arrange the different systems into four classes1 which we shall consider in turn4 ,motors using 7#a7 coal gas4 7#b7 carburetted gas4 7#c7 petroleum4 7#d7 water gases4 ,and in order to classify them according to the principles of their cycle of operations1 irrespective of their fuel1 ,m4 ,witz places them in four groups-- 7#a7 ,explosion of the gases without compression4 7#b7 ,explosion of the gases with compression4 7#c7 ,combustion of the gases with compression4 7#d7 ,atmospheric motors4 ,the first group of this second classification is formed by motors which have developed the idea conceived in #ahfj by ,m4 ,lenoir4 ,for the first half of the forward stroke the piston draws in a mixture of gas and air2 the valves being then closed1 and ignition taking place1 the explosion drives the piston to the end of the stroke4 ,the return stroke is made use of to expel the gases through the exhaust4 ,before igniting the gases which have been drawn in they may be compressed either by a separate pump1 or in a chamber forming a continuation of the cylinder4 ,the arrangement is characteristic of the second group4 ,this again can be modified to form the third group1 by allowing the gases to burn under constant pressure throughout the stroke instead of violently exploding at the commencement4 ,engines using this sort of progressive combustion have been designed by ,simon and ,brayton4 ,finally1 in the fourth group the explosion is merely used for obtaining a partial vacuum under the piston1 and the work is done by the excess of atmospheric pressure acting on its external surface4 ,it is almost unnecessary to state that this method has been completely abandoned1 and has been replaced by a sort of combination type1 in which the explosion is used in the forward stroke and atmospheric pressure in the return stroke1 such a motor as the ,bisschop gas engine being therefore practically double-acting4 ,the table on page #bj1 which we have borrowed from ,m4 ,witz's very complete work on gas engines1 shows at a glance the cycle of operations in the cylinders of the different types3 they are arranged in parallel columns1 in order to make it more easy for the reader to compare the operations undergone by the gases before and after their combustion4 ,it is necessary to subdivide the motors of the second group into three1 according as the cycle of operations is completed in one1 two1 or three complete revolutions of the fly-wheel4 ,perhaps this subdivision is somewhat unnecessary1 because the employment of a second cylinder for compressing the gases does not alter the character of the cycle1 but we think that it will make the classification clearer if we proceed in this manner4 ---------------------------------------- ------------------------- ,group ,i4 ,group ,,ii4 ,group ,,iii4 ,group ,,iv4 ,without ,with ,combustion ,atmospheric4 compression4 compression4 and compression4 ---------------------------------------- ------------------------- #a4 ,explosive #a4 ,explosive #a4 ,explosive #a4 ,explosive mixture enters gases enter mixture enters mixture enters the cylinder the cylinder the cylinder the cylinder at at atmospheric at atmospheric at atmospheric atmospheric pressure pressure pressure pressure ---------------------------------------- ------------------------- #b4 ,compression #b4 ,compression of the gaseous of the gaseous mixture mixture ---------------------------------------- ------------------------- #b4 ,explosion #c4 ,explosion at #c4 ,combustion #b4 ,explosion at at constant constant at constant constant volume volume volume pressure ---------------------------------------- ------------------------- #c4 ,expansion #d4 ,expansion #c4 ,piston of gases in of gases driven back by cylinder the pressure of the atmosphere ---------------------------------------- ------------------------- #d4 ,products of #e4 ,products #d4 ,products of #d4 ,products of combustion of combustion combustion combustion expelled from expelled from expelled from expelled from the cylinder the cylinder the cylinder the cylinder ---------------------------------------- ------------------------- ,group ,i4 ,explosion without compression4 ,lenoir ,kinder ,kinsey ,hugon ,ravel ,turner ,bnier ,parker ,hutchinson ,forest ,baker ,economic motor ,crown ,laviornery ,lentz ,group ,,ii4 ,explosion with compression4 7#a7 ,two-cycle type4 ,dugald-,clerk ,koerting-,lieckfeld ,wittig ,hees ,andrews 7,stockport7 ,benz ,ravel ,baldwin ,taylor 7,midland7 ,campbell ,bnier 7#b7 ,four-cycle type4 ,millon ,otto ,linford ,crossley ,maxim ,martini ,lenoir ,simplex ,koerting-,boulet ,lombard ,durand ,daimler ,varchalouski ,atkinson ,tenting ,diedrichs ,adam ,ragot ,forest ,nol ,charon ,niel ,lablin ,poussant ,roger ,letombe ,lacoin ,cronan ,cadiot ,drkopp ,brouhot ,levasseur ,fielding ,delahaye ,acm ,cuinat ,group ,,iii4 ,combustion with compression4 ,brayton ,hoch ,simon1 et fils ,livesay ,crowe ,gardie ,overmand ,group ,,iv4 ,atmospheric motors4 ,otto ,langen ,bisschop ,gilles ,hallevell ,robson ,franois ,carburetted ,air ,engines4 ,lenoir ,forest ,tenting ,daimler ,le ,marcel 7,cadiot7 ,durand ,de ,dion-,bouton ,bolle ,pelloree ,le ,pygme ,klause ,oil ,engines4 ,brayton ,priestman ,ragot ,otto ,crossley-,holt ,niel 7,atlas7 ,hornsby-,akroyd ,grob-,capitaine ,merlin ,knight-,weyman ,griffin ,pinkney ,levasseur ,root ,rationnel ,dawson ,the 8,gnome0 ,on page #ba we give a table embracing all the best known types of gas engines1 which will also help to avoid the confusion arising from the fact that some motors exist which belong to neither one nor another1 but are combinations of one or more groups4 ,such hybrid motors have been devised amongst others by ,schweizer and ,siemens4 ,in the former the power of the explosion is used to compress a considerable volume of air1 which is then used for working a compressed air engine4 ,in the latter the gas heats a quantity of air which drives a hot-air motor4 ,in this table we have also1 specially grouped apart1 engines using carburetted air 7air which has been passed through a volatile spirit such as benzoline7 and petroleum4 ,the list may be found somewhat incomplete1 as more than #bej gas engines have been devised and patented in the last twenty-five years2 but on the other hand1 many of these have been failures1 and we have only included those motors which can undoubtedly be considered commercial successes4 ,these we will now study4 ,,chapter ,,iii ,,description ,,of ,,existing ,,gas ,,engines ,early ,lenoir engine 7#ahfj74--,the motor 7,fig4 #a7 resembled in external appearance a horizontal double-acting steam engine4 ,this design was in great favour at that time1 being copied from the steam engine1 and was to a certain extent suitable for use with an explosive gas instead of steam4 ,the valve chest is cylindrical and the valves themselves flat1 and work off two eccentrics2 ignition is effected by an electric spark from a ,ruhmkorff coil1 which passes through the gas in the cylinder when the piston is commencing the second half of the forward stroke4 ,the exploded gases having done their work are driven out through the exhaust in the return stroke1 during which work is being done by a similar explosion on the other side of the piston4 ,a water jacket prevents the cylinder walls from becoming overheated4 ,this arrangement is therefore double-acting1 but a compression of the explosive gas is not possible without the use of a second cylinder4 ,it has been abandoned because regularity of working is only obtained at the expense of economy1 and by using both sides of the piston as explosive chambers it is found that the quantity of gas used is quite out of proportion to the power developed4 ,illustration3 ,,fig4 #a4--;,early ,lenoir ,motor 7#ahfj74 ,the ,bisschop gas engine4--,this motor 7,fig4 #b71 based on a mixed principle1 uses the explosion to do work during the forward stroke1 and in the return the atmosphere exerts an excess of pressure on the other side of the piston1 as in the ,otto and ,langen atmospheric engine which we have previously mentioned4 ,in its time the ,bisschop gas engine obtained a great measure of success1 but it has now almost completely disappeared4 ,it was1 however1 well thought out and constructed2 the cylinder was vertical1 and relied on longitudinal corrugations1 and the air to keep it cool4 ,above the cylinder was placed a cylindrical guide2 a connecting rod and cross-head formed the attachment between the piston rod and crank4 ,the machine was principally constructed for small workshops requiring small powers of from a quarter to one horse-power1 the cost of fuel for the half horse-power size being about one penny per hour4 ,the inventor received a prize of #ajjj francs from the ,socit d',encouragement for the best small motor applicable to home industries4 ,illustration3 ,,fig4 #b4--;,bisschop ,motor4 ,franois motor4--,this type1 which is now quite obsolete1 was somewhat similar in character to the last1 but rather more complicated and perfect4 ,the crank shaft was not in a line with the cylinder1 and was connected by two connecting rods to the cross-head4 ,two fly-wheels were placed one on each side of the cylinder and connected by toothed wheels4 ,the machine was on the whole too complicated1 and although its consumption of fuel was comparatively small and its speed constant1 it did not succeed in ousting the ,bisschop motor from its position4 ,bnier gas engine4--,this motor was the first conceived by the inventors of the combined gas plant and engine which we will describe later1 and is extremely simple4 ,this piston rod is connected to the crank in a manner similar to a beam engine 7,fig4 #c74 ,both the admission of the gases and their ignition are accomplished by a single spring valve worked by a cam on the crank-shaft4 ,the cylinder1 which is vertical and inverted1 draws in the gases for half the forward stroke1 and then the valve1 which has moved still further forward1 brings a flame opposite the admission port and ignites the mixture2 a small auxiliary gas-jet re-ignites the flame at each stroke4 ,the gases escape from the cylinder by a second port with a special valve and cam4 ,a water jacket for the cylinder is provided to carry off the surplus heat4 ,the consumption is high1 being about #adjj litres per horse-power hour1 but owing to the extreme simplicity of the working parts this motor met with a certain amount of success about #ahhj4 ,illustration3 ,,fig4 #c4--;,bnier ,motor4 ,forest gas engine 7,fig4 #d74--,this motor1 being of the single-acting type without compression1 had at one time a considerable sale1 being used where only a small power was required4 ,the rectilinear motion is changed into a rotary one by means of an ,oliver ,evans beam1 and a connecting rod which returned alongside of the cylinder to the crank-shaft and fly-wheel1 which are placed at the back4 ,ignition is obtained by a burner which is re-lit by a smaller one at each stroke1 and the cylinder is cooled not by a water jacket but by a helical groove1 which increases the surface4 ,this helix is formed by a thin plate cast on the cylinder4 ,the fuel consumed was about #adjj litres of gas per horse-power hour1 which may be considered good for such an engine4 ,illustration3 ,,fig4 #d4--;,forest ,motor4 ,economic motor4--,constructed in ,new ,york4 ,this engine is another example of the early attempts to obtain economy without compression4 ,as a rule they were not constructed of more than half horse-power size1 and the general arrangement is ingenious1 but rather more complicated than those which we have so far spoken of4 ,the piston rod is guided by being attached to one end of a lever1 connected with crank by means of a vertical connecting rod4 ,the cylinder is grooved1 and cooled by the circulation of the air round it1 and constancy of speed is obtained by a centrifugal governor1 which cuts off the supply of gas when the speed is too high4 ,the engine seems to have given some very fair results4 ,lentz gas engine4--,it is difficult to conceive a more simple mechanism than is to be found in this motor4 ,the supply of gas is drawn into the cylinder by an open valve1 and a gas flame situated in this admission port ignites the explosive gases4 ,the force of the explosion closes the admission valve1 and on the return stroke a cam opens an exhaust port situated underneath the cylinder4 ,there is no water jacket1 but the cylinder is formed of two parts connected together by a non-conducting joint4 ,in order to smooth down the jerk of the explosion the head of the connecting rod slides in a groove1 and is kept pressed against the crank-pin by a spring1 the result being that the connecting rod is longitudinally elastic and deadens the shock of the explosion4 ,,group ,,ii41 ,,class ,i4--,,one ,,cycle ,,per ,,revolution4 ,dugald-,clerk gas engine4--,in the ideal motor we should have at least one explosion per revolution of the fly-wheel1 which is not the case in the ,otto cycle4 ,for this reason many inventors have tried to construct gas engines with one cycle per revolution1 but experience has taught us that though they may be mechanically more simple1 they lose in efficiency what they gain in simplicity1 and in spite of many eminent inventors attempting to solve the problem4 ,even the best-designed motors of this type have been unable to hold their own against the ,otto cycle because they are not as efficient4 ,the first attempt was made by ,dugald-,clerk in #ahha4 ,his engine is simple in the extreme1 containing no gear-wheels1 and working steadily and noiselessly at a fairly constant speed 7,fig4 #e74 ,there are two cylinders of equal diameter placed side by side1 and projecting over the end of a cast-iron bed-plate4 ,the first of these is the motive cylinder in which the explosion takes place2 the other is used for compressing the explosive mixture1 this compression taking place in the ,otto cycle in the motive cylinder itself4 ,this secondary cylinder also serves for another purpose2 it draws in a certain volume of air directly after the explosion1 which is afterwards driven through the motive cylinder1 effectively clearing out the waste gases4 ,the advantage which this arrangement of double cylinders has over the ,otto cycle1 lies in the fact that one explosion can take place during each revolution of the crank1 and consequently such very heavy fly-wheels as are used for the ,otto type of engine are not necessary4 ,the great disadvantage which the ,dugald-,clerk motor possesses is the extreme suddenness of the explosion1 which is practically complete before the piston begins to move4 ,in spite of this defect the machines have a fairly high efficiency4 ,the gases are ignited by a gas-jet situated in a sliding valve4 ,a water jacket is used for cooling the cylinder1 and in some of these motors a mechanism is attached for converting the engine from simple to compound4 ,the compression cylinder then becomes double-acting1 and the gases are further expanded in what was previously the motor cylinder only4 ,illustration3 ,,fig4 #e4--,plan of ,dugald-,clerk ,engine4 ,owing to the fact that this motor was not as efficient as those of the ,otto type it never became a commercial success1 and it is doubtful if any are working at the present date4 ,early ,stockport gas engine4--,the working of this motor affords a good example of ,british ingenuity4 ,the compression cylinder is situated behind the motive cylinder1 being a prolongation of it on the same axis2 the two are firmly bolted together end on4 ,the active piston is in front and connected to the crank1 drawing behind it the piston of the compression chamber4 ,each cylinder has a separate sliding valve4 ,the rear cylinder having aspirated and compressed a volume of the explosive gases1 they are passed into the motive cylinder through a sliding valve which also serves to ignite them4 ,the waste gas escapes into the air by a special valve4 ,the aspiration and compression take place in the auxiliary cylinder once in every revolution of the crank1 and besides1 the motive piston also compresses the gases a trifle before the explosion takes place4 ,the exhaust valve is made to open slightly before the piston reaches the end of its stroke4 ,the motor was rather inefficient1 and since its appearance a new type has been brought out with an ,otto cycle which we will describe later on4 ,benz motor 7,fig4 #f74--;,in this motor the inventor attempts to drive out the whole of the exhaust gases before the second half of the backward stroke of the piston is reached4 ,to do this he injects a certain volume of air under pressure1 driving out the burnt gases and substituting itself in their place4 ,before the end of this return stroke a small auxiliary pump introduces the requisite amount of coal gas1 which is then compressed during the rest of the stroke4 ,the ignition is effected by a small magneto machine driven by the engine itself1 the sparks being generated between two fine metallic points in the cylinder4 ,the jet of air required to drive out the product of the combustion is furnished from a reservoir1 pressure in it being maintained by using the other side of the piston as an air-pump4 ,this arrangement is an advantage1 because cold air is being continually drawn into the cylinder which keeps it cool1 and enables the lubrification to take place more effectively4 ,there is also an external cooling apparatus in the form of a water jacket1 which uses about #dj litres of water per horse-power hour1 and keeps the cylinder at about #ge ,c4 ,the ,benz motor is very well known on the ,continent1 and much of its success is due to the fact that it seems to work as well with gasoline as with coal gas6 ,it is constructed by ,m4 ,roger of ,paris1 and in consequence of the extreme constancy of its speed1 it has been successfully applied to driving dynamos1 and also to launches1 motor cars1 etc4 ,illustration3 ,,fig4 #f4--;,benz ,gas ,engine4 ,baldwin gas engine4--,the cycle of this engine is somewhat similar to that of the ,benz motor1 one side of the piston being used for expansion and the other side for compression4 ,part of the bed-plate casting is arranged so as to form a reservoir for the compressed gases4 ,the coal gas is also admitted into this vessel1 so that it contains an explosive mixture4 ,as the vessel is only made of cast-iron this arrangement is rather dangerous4 ,there are three valves1 the admission valve being regulated by the governor4 ,the power developed is1 therefore1 always kept proportional to the demand1 and the constancy of speed is sufficient to warrant the use of these engines for running dynamos for electric light4 ,the ignition is by an electric spark1 and is generally obtained from some extra apparatus1 such as accumulators or batteries1 and an induction coil4 ,the engine is constructed by ,messrs4 ,otis ,bros4 of ,new ,york4 ,de ,ravel motors4--,the first motor constructed by ,m4 de ,ravel was exhibited in ,paris in #ahgh1 and was of the oscillating cylinder type1 with a variable centre of gravity4 ,the explosion drove up a heavy piston whose rod was directly connected to the crank-pin4 ,the revolution of the crank-pin caused the whole cylinder to move in the same manner as that of the early oscillating steam engines4 ,this movement was used as a means of opening and closing the ports4 ,the efficiency of the engine was low1 using some #fjj to #gjj litres of gas per horse-power hour2 and besides the motor had1 owing to faulty mechanism1 the unhappy knack of suddenly stopping dead4 ,these defects caused ,m4 de ,ravel to abandon this type and to bring out a second motor in #ahhe1 performing one cycle per revolution4 ,this new motor only had one cylinder1 whose rear half acted as a compression chamber during the backward stroke of the piston1 whilst the explosion took place in the front end of the cylinder4 ,the consumption of gas was slightly more than an ,otto engine1 and the motor ran exceedingly silently and evenly1 but this advantage was not of much service in the struggle against the all-conquering ,otto motor4 ,midland motor 7,taylor74--,constructed in ,nottingham1 this engine is of the horizontal double-cylinder type4 ,one cylinder compresses the explosive mixture and passes it on to the other1 where it is ignited and does work4 ,the cranks connected to the two pistons are placed #fe apart1 and a complete cycle in the cylinders is performed every revolution4 ,the makers of this engine claim a consumption of only #fjj litres of gas per horse-power hour4 ,campbell gas engine4--,the mechanism of this engine is very much like that of the ,dugald-,clerk motor1 two cylinders being placed side by side4 ,the utilization of the heat is1 however1 far superior1 and only about #ejj litres of coal gas per horse-power hour are required4 ,a result which the inventor of this type of cycle never succeeded in obtaining1 but as far as we know the motor has never had any official trial1 and the above figures are only taken from the makers prospectus4 ,however1 there is only a hardly perceptible shock from the explosion1 and the motor can be safely recommended to anybody requiring a silent gas engine4 ,there still exist gas engines worked on this same cycle per revolution principle1 such as the ,conelly1 ,day1 ,de ,ravel motors1 descriptions of which must be sought elsewhere4 ,the limited space at our disposal prevents us from discussing all those types which have only obtained a very small measure of success4 ,the only remaining engine based on this principle worth mentioning is the ,bnier motor1 which is exceedingly instructive1 but we shall speak of it later under the head of poor-gas engines4 ,we shall at present pass on to the consideration of engines based in principle on the patent of ,beau de ,rochas1 and first practically realized in #ahgg by ,dr4 ,otto4 ,otto gas engine 7,fig4 #g74--,the principle on which this engine is based is known as the ,otto cycle1 named after ,dr4 ,otto1 but first suggested by ,beau de ,rochas4 ,since the patents have expired numerous copies and imitations have been brought out1 but very few surpass or even equal some of the earlier types4 ,illustration3 ,,fig4 #g4--,otto ,gas ,engine4 ,the explanation of the working of the ,otto motor1 which we are about to give1 will save us from returning to it in the descriptions of analogous types brought out after this famous system4 ,the cylinder is continued in a backward direction so as to form a compression chamber1 into which the mixture of gas and air is drawn during the forward stroke of the piston4 ,the mixture is compressed during the return stroke in this chamber1 the pressure rising at the end of the stroke to about #c or #d atmospheres4 ,at this point in the cycle a flame is brought into contact with the compressed gases and they explode4 ,this explosion raises the temperature of the gases to #aejj ,c41 and drives forward the piston under a pressure of about #aej lbs4 to the square inch4 ,during the second return stroke1 corresponding to the latter half of the second revolution of the crank1 the piston drives out the products of the combustion into the air under a pressure of about an atmosphere4 ,the heating of the cylinder is avoided by keeping water automatically circulating through a jacket surrounding it4 ,this is necessary1 because if the cylinder walls became heated1 the oil upon them would become decomposed1 and lose its lubricating properties4 ,dr4 ,otto paid special attention to the efficiency of the engine1 and in order to increase it1 he diluted the air and gas drawn into the cylinder with a portion of the gases already burnt in the previous stroke4 ,consequently the explosion at the beginning of the stroke is less violent1 and the gases continue burning while the piston moves forward4 ,the cause of this slow combustion has been wrongly attributed to stratification of superimposed layers of gas and air1 but it is probably due to the action of the cylinder walls4 ,the ,otto gas engine is a marvel of simplicity from a mechanical point of view1 very much more so than a ,corliss steam engine for instance4 ,the admission and exhaust valves are worked by cams1 and the ignition takes place under pressure4 ,the governor is sometimes of the centrifugal type1 and at others of the inertia type1 but in both it is a case of all or nothing1 the supply being completely shut off if the engine is going too fast4 ,the connecting rod joins the crank to the piston rod by a cross-head running into a bored out-guide4 ,it is necessary to have a heavy fly-wheel1 because1 as only one explosion takes place per two revolutions1 the fly-wheel must store up enough energy during that explosion to carry it through the rest of the cycle4 ,many different types of ,otto gas engines now exist1 some having two cylinders and a single crank1 and others two fly-wheels1 in order to ensure constancy of speed for driving dynamos4 ,dr4 ,otto devised a compound gas engine1 but it did not succeed1 and also a cheaper vertical type 7,fig4 #h71 which is very convenient for small workshops4 ,since the invention of carburetted air the creator of the ,otto cycle has devised another motor for use with gasoline instead of coal gas4 ,otto devised the first practical gas engine and opened up the path for others1 who1 following in his footsteps1 have confined their attention to improvement of detail4 ,some have undoubtedly succeeded1 and by avoiding waste of heat1 and by raising the initial temperature of the gases1 they have considerably reduced the consumption of fuel4 ,we shall now discuss different types of motors which have appeared during the last fifteen years1 confining ourselves to the really successful ones4 ,illustration3 ,,fig4 #h4--,otto ,gas ,engine 7vertical type74 ,second ,lenoir motor4--,twenty-five years separated the appearances of the first and second ,lenoir motors1 and during this time ,m4 ,lenoir gained a great deal of practical experience1 so that if reference be made to ,figs4 #a and #i they will be seen to have very little in common4 ,in the later type the cylinder projects over the back of the bed-plate1 and is provided with deep circular grooves on the outside to increase the cooling surface4 ,ignition is obtained by the spark from a coil supplied by a battery as in the early form4 ,the consumption of gas is about #hjj litres per horse-power hour4 ,later on we shall discuss a petroleum motor for motor cars1 and also a stationary petroleum engine by the same inventor4 ,these engines were originally constructed by ,mignon and ,rouart1 but later by the ,compagnie ,parisienne du ,gaz1 and are very well designed and constructed4 ,illustration3 ,,fig4 #i4--,lenoir ,gas ,engine 7second type74 ,koerting-,lieckfeld motor4--,the first of these motors was constructed in #ahgg1 and was based on the ,dugald-,clerk cycle4 ,the original type has1 however1 been abandoned1 and the firm of ,brl et ,cie4 of ,paris now construct these engines on the ,otto system4 ,all the moving parts are attached to a vertical frame of cast-iron 7,fig4 #aj71 the lower half containing the cylinder4 ,the admission and exhaust valves are situated in front and near the base4 ,the governor is of the centrifugal type and acts directly on the levers of the valves4 ,the flame ignition makes it necessary to occasionally clean out the valves1 but otherwise the motor has few drawbacks1 and is very neat and compact4 ,the consumption of coal gas for engines of #h horse-power and upwards is about #hjj litres per horse-power hour4 ,the crank-shaft is placed horizontally across the top of the frame1 and the cams acting upon the valves are rotated by a bevel gear enclosed in a case1 driving a thin supplementary shaft on which they are placed4 ,the motor is self-lubricating1 and is also constructed as a horizontal gas engine4 ,illustration3 ,,fig4 #aj4--,koerting-,boulet ,motor4 ,andrews' motor4--,the governing apparatus in this engine is exceedingly simple and ingenious1 consisting of a weight fixed to an oscillating lever which controls the admission valve4 ,the position which the weight takes up depends upon the rapidity with which the lever oscillates1 and consequently upon the speed of the engine4 ,if1 therefore1 the engine is running too fast or too slow the weight takes up a new position1 and the effect upon the admission valve is to either slow down or quicken the speed4 ,the gases are ignited by means of a tube kept red-hot by a gas flame4 ,this engine possesses the special advantage of being self-starting1 that is to say1 it is not necessary1 as in many other motors1 to start the engine by giving the fly-wheel a few rapid turns by hand4 ,the motor is stopped with the crank in a position slightly in advance of the point corresponding to ignition4 ,the gas is allowed to enter by a small auxiliary valve1 which closes after the first explosion4 ,this volume of gas entering the cylinder mixes with the air already in it1 forming an explosive mixture4 ,this explosive mixture then begins to escape by similar automatic self-closing valves situated at the top of the red-hot ignition tube4 ,ignition takes place1 and is communicated to the rest of the gas in the cylinder1 closing the two small valves by the force of the explosion4 ,the piston is therefore driven forward1 and the energy of this combustion is sufficient to start the engine4 ,it must be understood that this operation is only performed once at starting1 for immediately afterwards the engine falls into its normal cycle of operations4 ,two fly-wheels are as a rule provided to ensure constancy of speed4 ,the consumption of gas is as low as #ehj litres per horse-power hour in the large units of #ajj horse-power4 ,the ,andrews gas engine is also constructed of a special type for consuming poor gas produced by the ,dowson process1 and gives very good results4 ,as a rule1 about #fjj to #hjj grammes of anthracite are necessary to produce one horse-power hour4 ,in one particular plant generating electricity1 the cost has been certified to be as low as one penny per kilowatt hour1 including lubrication4 ,fielding gas engine4--,the characteristic point in these engines is the extreme simplicity of the valve gear1 only one valve being ever subjected to pressure4 ,even in the small engines of this type all sliding valves are replaced by those of the spring pattern1 in fact1 the valve mechanism consists simply of two spring-valves1 one of which fulfils two functions1 controlling the admission and the escape of the gases4 ,the two valves are moved by a double lever actuated by a single cam4 ,the cycle is that of ,dr4 ,otto4 ,when the piston is starting on the return stroke after an explosion has taken place1 the lever lifts one of the valves1 and the products of the combustion escape into a circular space situated below4 ,in the next forward stroke this valve is still further lifted1 opening the admission port1 while at the same moment the exhaust port is closed by the second valve2 a new charge is therefore drawn into the cylinder4 ,at the end of the admission stroke the valves are released by the lever1 and the compression can now take place during the second return stroke4 ,the movement causing the lifting of the valve continuously throughout one whole revolution is effected by means of a cam with two prominences on it1 which act in succession on the lever4 ,there is only one valve1 therefore1 which is subjected to pressure1 and even this is well provided against risk of leakage by the second valve being placed behind it1 acting as a double seating4 ,a chamber is also provided in which the gases are first mixed1 and this mixing is regulated by a second lever and a special valve4 ,the governor is of the inertia type1 and is attached to the upper side of the double lever4 ,it consists of a straight rod with a ball at one end and a knife edge at the other1 pivoted at its centre to the end of the valve lever4 ,as this lever is thrown forward the knife edge strikes the end of the spring-valve admitting gas to the mixing chamber4 ,if the speed is too great the sudden jerk on the ball at the other end of the knife edge causes it to miss the valve1 and no gas is admitted till the speed is reduced to the normal number of revolutions per minute4 ,this arrangement is very sensitive1 and keeps the speed exceedingly constant4 ,mr4 ,fielding has constructed some large gas engines of #cej horse-power which are started by compressed air1 this air having been previously stored up under pressure when the motor was stopping4 ,niel motor4--,as will be seen from ,fig4 #aa1 the valves are actuated by cams rotating on a supplementary shaft placed parallel to the cylinder4 ,a pair of toothed wheels transmit the rotation of the crank to this valve-shaft1 and it is arranged so as to give one rotation to every two of the crank4 ,the cycle of operations is somewhat similar to the ,otto cycle2 gas is only admitted to the cylinder for two-thirds of the forward stroke1 so that the compression on the back stroke is somewhat lessened4 ,it is doubtful whether there is much advantage in this method1 but the ,niel motors have had a large sale1 which is a sufficient proof of their good qualities4 ,illustration3 ,,fig4 #aa4--,niel ,gas ,engine 7elevation and sectional plan74 ,lombart1 ,martini 7,fig4 #ab71 ,adam1 ,le ,parisien1 and ,le ,kientzy motors4--,all these motors1 each of which is constructed by a different maker1 are based in principle on the ,otto engine1 and except for slight modifications of the working parts1 they do not call for any particular notice4 ,the small amount of space at our disposal only admits of our mentioning them4 ,illustration3 ,,fig4 #ab4--,martini ,motor4 ,lablin motor 7,fig4 #ac74--,m4 ,lablin of ,nantes set himself to produce a motor which should correspond with the ,brotherood and ,westinghouse steam engine1 that is to say1 a motor developing the maximum of power for the minimum of space and weight4 ,this might be termed the dynamic density of the motor1 which ,m4 ,lablin sought to increase4 ,he has succeeded in constructing gas motors of horse-power weighing about #ij lbs41 and of #h horse-power weighing #g cwt4 ,unfortunately they consume a rather large quantity of fuel--about #ajjj litres of coal gas1 or #ejj grammes of gasoline per horse-power hour4 ,there are three cylinders grouped at equal distances round the same shaft1 and all attached to one single crank4 ,by this arrangement a more constant torque or twisting movement on the shaft is obtained1 and consequently the weight of the fly-wheel can be considerably reduced4 ,three explosions are produced during every revolution1 that is to say1 each cylinder performs a complete cycle of operations during every revolution1 a fact which accounts for the low efficiency4 ,ignition is obtained by a platinum tube heated to incandescence when using coal gas1 and by an electric spark when carburetted air is used4 ,the governor is centrifugal1 and controls the admission of gas4 ,illustration3 ,,fig4 #ac4--,lablin ,three-cylinder ,motor4 ,crossley ,bros4 gas engine 7,figs4 #ad1 #ae74--,this engine is from the cycle point of view purely and simply an ,otto gas engine4 ,a light shaft runs parallel to the cylinder1 being driven by a worm-gear of the crank-shaft4 ,on it are situated the cams which force open the four spring-valves1 controlling respectively the admission of air gas and the ignition and exhaust4 ,illustration3 ,,fig4 #ad4--;,crossley ,gas ,engine 7,x type74 ,illustration3 ,,fig4 #ae4--;,crossley ,gas ,engine4 ,the pressure of the gases is raised during compression to about four atmospheres1 and immediately after the explosion it rises to about #ahj lbs4 on the square inch2 during the exhaust it averages about #aj lbs4 per square inch4 ,ignition is obtained by a tube heated to a bright red incandescence by a ,bunsen flame4 ,at the right moment a valve is opened1 placing the explosive mixture in contact with it and causing the explosion4 ,when starting the machine the ignition is retarded or takes place a little after passing the dead point1 so that the machine cannot start the wrong way by mistake4 ,two or three other features call for special notice1 especially the device for lubricating the cylinder4 ,in the illustration 7,fig4 #ad7 will be seen a small bell-shaped receptacle4 ,this vessel contains oil1 and also a small crank inside driven by a belt off the valve-shaft4 ,as this crank rotates it dips into the oil at the bottom of the vessel1 and at the top of its path it wipes off the oil which it has gathered on to a cup which allows it to flow into the cylinder4 ,the water jacket is cast separately from the cylinder1 and not1 as in many engines1 in one piece with it4 ,there is an advantage in this1 because there is less likelihood of flaws or blow-holes in the cylinder wall passing unobserved when the engine is leaving the maker's hands4 ,the governor in some of the sizes is centrifugal1 and in others of the inertia type similar to that described in the ,fielding gas engine4 ,pygme motor 7,lefebvre74--,this motor1 shown in ,fig4 #af1 gives one the idea of solidity and compactness4 ,it possesses the peculiar property of working equally well in any position1 either horizontal or vertical4 ,this is due to the fact that it is particularly well balanced1 and when running does not vibrate at all4 ,easily started1 these engines run at a very constant speed1 and their power in relation to their size is truly remarkable1 hence the name ,pygme4 ,they have been especially designed for self-propelled vehicles1 and are not affected by the worst running conditions1 such as inclement weather or bad roads4 ,in this type they are constructed with two cylinders in order to obtain a more constant torque1 and also have an arrangement by which the speed can be changed4 ,for stationary purposes the motor is mounted on a cast-iron stand 7,fig4 #af74 ,in virtue of their exceedingly small dimensions and reduced weight they are specially suitable where small-power motors are required for home industries or small workshops1 and also for driving private electric installations and pumping water4 ,they have economically replaced steam engines in agricultural operations1 both on a large and small scale4 ,the working parts being entirely enclosed they stand a good deal of rough usage1 and will work in positions in which other motors would be useless4 ,where it is necessary to bring the motor to the work it is required to perform they are bolted to a carriage instead of a cast-iron base4 ,illustration3 ,,fig4 #af4--,pygme ,gas ,engine4 ,the 8,national0 gas engine4--,as a gas engine this machine is constructed in all sizes1 from one horse-power up to large units requiring a gas plant of their own4 ,as petroleum motors they range from one to ten horse-power4 ,they are all provided with two fly-wheels1 which keep them well balanced and steadies their speed4 ,they have besides been especially designed with a view to economy of coal gas or petroleum4 ,an idea of the general arrangement of the parts will be obtained by glancing at ,fig4 #ag4 ,the petroleum motors are provided in addition with a vaporizer and a petroleum lamp placed at the front end of the machine1 and the oil reservoir is situated immediately above the cylinder4 ,m4 ,herckenrath has specially devoted himself to simplifying the mechanism and making it more self-contained and less unsightly4 ,up to #ej horse-power only one cylinder is found necessary1 and for larger powers two are provided4 ,the patent governor is centrifugal and rather novel in construction1 and to it is partly due the high efficiency of these engines4 ,the large sizes are as easily started as the smaller ones1 and the lubrication is perfectly automatic4 ,besides these advantages they require a minimum of attention1 in fact1 a skilled attendant can be dispensed with1 a few explanations and instructions being all that is necessary to enable a boy or labourer to take competent charge of them4 ,illustration3 ,,fig4 #ag4--;,herckenrath ,national ,gas ,engine4 ,forest motor 7,figs4 #ah1 #ai1 #bj74--,we have already described the earlier attempts of ,m4 ,forest to produce a practical gas engine4 ,the idea embodied in the motor depicted in ,fig4 #bj1 if not particularly advantageous1 is none the less highly original4 ,the ends of the single cylinder are open1 and within it are two pistons1 between which the explosive mixture is introduced4 ,the explosion drives these pistons out in different directions1 but by means of a suitable mechanism they are each connected to one of two cranks on the same shaft4 ,the whole forms a very neat and compact arrangement4 ,in another type by the same inventor 7,figs4 #ah1 #ai71 also working on the ,otto cycle1 the cylinders are vertical1 there being one1 two1 or four placed side by side4 ,in the last case two explosions per revolution are obtained1 ensuring a very constant torque throughout4 ,m4 ,forest has1 however1 particularly applied himself in collaboration with ,m4 ,gallice to designing petroleum engines for small boats4 ,these two inventors have conceived a highly ingenious arrangement for reversing the direction of rotation of the engine1 which is absolutely necessary in the propulsion of boats4 ,all the cams which actuate the valves are grouped together on a light shaft1 and by a simple twisting of this shaft from one end by a handle the engine is reversed4 ,the engines are self-starting1 and are so especially suitable for the propulsion of boats that they have been adopted by the ,french navy1 who at the present date have a number of small vessels propelled by this motive power4 ,illustration3 ,,fig4 #ah4 ,,fig4 #ai4 ,de ,forest ,gas ,engines4 ,illustration3 ,,fig4 #bj4--;,de ,forest ,double ,piston ,motor4 ,cuinat gas engines4--,these engines are constructed in four types4 ,the ,a type is vertical with the cylinder above and fly-wheel and shaft below4 ,this is a more stable arrangement than placing them in the reversed order1 as is more frequently done4 ,for small engines the vertical type is undoubtedly the best1 space1 or rather lack of space1 being very often an important consideration to the purchaser4 ,the ,b type is similar to the previous one1 except that two fly-wheels are provided so as to make it suitable for small electric light installations4 ,the ,c type is horizontal1 having all the valves placed vertically1 which plan seems to work better for engines of power greater than #aj horse-power4 ,the ,d type is also horizontal1 but has two fly-wheels1 having been specially designed for electric lighting purposes4 ,in order to take up as little space as possible the dynamo is situated underneath the projecting cylinder1 both the engine and dynamo being bolted down on to a special bed-plate4 ,this arrangement is more stable than placing them on separate foundations4 ,in the petroleum engines an electric spark is used to ignite the gases1 and in the gas engines both electricity and a gas flame4 ,it is best not to use animal or vegetable oils for lubricating the inside of the cylinder1 because they decompose1 forming fatty acids which have a corrosive action4 ,besides this1 when they have fulfilled their function of lubrication they settle down to a thick paste1 which has a most injurious effect on the working of the engine4 ,it is best1 therefore1 to use nothing but perfectly pure mineral oils and to avoid all others4 ,this does not only apply to the type of engine we have just been describing1 but to all gas engines4 ,the ,cuinat gas and petroleum motors do not mix a portion of their exhausted gases with the fresh charge as is frequently done1 but completely sweep away the products of the explosion before admitting a new charge4 ,the result is1 that combustion is more complete but at the same time rather more violent4 ,an examination of an indicator diagram taken from one of these engines shows that the combustion takes place at once as an explosion1 and that the final expanded pressure is as low as it is possible to get it4 ,these being the conditions necessary for a high efficiency1 it is needless to state that the consumption of fuel in these engines is as low as in any other engine4 ,nol motor4--,this type1 constructed at ,provins1 has the advantage of being exceedingly simple4 ,the entries to the cylinder are controlled by spring-valves1 and the gases are ignited by electricity4 ,from the up to the #b horse-power size the cylinder is not provided with a water jacket1 and the general arrangement is either vertical or horizontal4 ,these engines work equally well with coal gas or carburetted air2 in the latter case the carburator is placed inside the cast-iron frame of the motor4 ,the guaranteed consumption of fuel is about #ijj litres of gas or #ejj grammes of gasoline per horse-power hour1 which is quite satisfactory4 ,tenting motor4--,this is a horizontal motor with the cylinder cooled atmospherically1 and the gases ignited by electricity4 ,the governor acts upon the exhaust valve2 the products of the explosion remain in the cylinder if the speed is too great1 and then the admission valve1 which is automatic1 no longer rises to admit a fresh charge until the speed has once more fallen to the normal4 ,this little motor is one of the most practical small-power engines existing1 partly because of the great simplicity of the mechanism4 ,it works well with carburetted air1 and the vertical type has been successfully applied to the propulsion of small pleasure-boats4 ,atkinson motor 7,figs4 #ba1 #bb74--,this apparatus1 constructed by the ,british ,gas ,engine ,company1 was until recently the most efficient heat engine in existence1 its indicated efficiency being #bbh4 ,mr4 ,atkinson1 the inventor1 has arrived at this result by making the gases burn gradually and by shortening the compression stroke4 ,the discharge of the residual gases is complete1 this being directly opposite to ,dr4 ,otto's procedure1 for he diluted his explosive mixture largely with the exhausted gases4 ,in order1 however1 to make the piston execute two strokes relative to the cylinder of different lengths1 the inventor has had to devise a rather complicated mechanism 7,fig4 #ba74 ,the result1 however1 quite neutralizes this slight disadvantage4 ,illustration3 ,,fig4 #ba4--;,diagram of ,atkinson ,mechanism4 ,illustration3 ,,fig4 #bb4--,section of ,charon ,motor4 ,charon motor 7,fig4 #bc74--,m4 ,charon has attempted to obtain a prolonged combustion without the complicated devices resorted to by ,atkinson4 ,he has obtained the same result by means of a regulator controlling a double cam1 one half of which actuates the admission valve and the other half an auxiliary valve1 which opens into a tube forming a sort of reservoir1 into which part of the explosive mixture passes during the compression4 ,after the explosion this stored-up mixture is gradually allowed to re-enter the cylinder and prolong the combustion4 ,by this means a considerable gain in economy is obtained1 so that engines of this type only use about #ejj litres of coal gas per horse-power hour4 ,in appearance the motor much resembles the ,otto motor1 the crank-shaft and valve-shaft and valves being placed in the same relative positions4 ,although these motors are rather more expensive than others working with the ,otto cycle1 they are nevertheless widely used4 ,this is due to the fact that if cost of coal gas in a particular district is high it is cheaper in the end to pay a higher price for an efficient engine than to buy a less expensive and at the same time less economical machine4 ,illustration3 ,,fig4 #bc4--;,charon ,motor 7latest type74 ,roger motor4--,this excellent little engine 7,fig4 #bd7 was especially designed for small workshops4 ,the extreme simplicity of the working parts in no way lessens the efficiency1 for the two horse-power only burns #gjj litres of gas per horse-power hour4 ,the simple design also keeps the cost of construction low1 and the price averages about #cj per horse-power4 ,illustration3 ,,fig4 #bd4--,roger ,vertical ,gas ,engine4 ,the governor controls the admission valve4 ,ignition is obtained by means of an incandescent tube2 the cylinder is cooled by a water jacket2 the mean speed is about #bjj revolutions per minute1 and this speed is constant enough to allow the engine to drive a dynamo for electric lighting4 ,the motor has been very favourably received abroad1 but is not much known in this country4 ,motor of the ,compagnie ,parisienne du ,gaz 7,fig4 #be74--,owing to its very large consumption of gas the engine can only be used if the price of gas is low1 but it has several advantages which to a certain extent neutralize this defect4 ,it runs at a high speed of #djj revolutions per minute1 and the parts are arranged so as to be easily accessible4 ,illustration3 ,,fig4 #be4--,vertical ,gas ,engine of the ,compagnie ,parisienne du ,gaz4 ,letombe motor4--,constructed by the firm of ,mollet-,fontaine of ,lille1 this engine presents several interesting features which we will briefly enumerate4 ,the cylinder is double-acting1 giving one impulse to the piston during every revolution4 ,the speed is therefore maintained fairly constant4 ,the efficiency is high owing to the gases in the cylinder being made to burn slowly as in the ,charon motor4 ,the machine on the whole works exceedingly satisfactorily and reflects great credit on its inventors4 ,robuste 7,levasseur7 motor4--,the composition1 admission1 and ignition of explosive mixture are regulated by a sliding valve as in the ,otto motor2 in this case1 however1 it is a piston-valve and not a flat one4 ,the valve-chest is at the back of the cylinder4 ,the governor is of the inertia type1 and suppresses the admission if the speed becomes higher than the normal4 ,a double water jacket is provided for cooling the cylinder walls4 ,although not presenting any new features1 this motor fully merits its name1 and its solid construction enables it to withstand a surprising amount of bad handling4 ,richardson and ,norris gas engine4--,yet another high-speed engine1 running at a speed of #bcj revolutions per minute4 ,roby ,co4 construct this machine especially for driving dynamos1 and for this purpose two fly-wheels are provided in order to make it run smoothly without variation of speed4 ,the gases are ignited through a valve with a double seating by means of a red-hot tube4 ,the motor is reversible1 which is an advantage under certain conditions4 ,poor gas can also be used instead of coal gas1 consuming about #eaj grammes of anthracite per horse-power hour for an #hf horse-power engine supplied with ,dowson gas4 ,this works out to a thermal efficiency of #ba1 a result which places this engine above criticism4 ,h4 ,c4 motor4--,this is an enclosed motor for use in mines or dusty places1 the fly-wheel alone of the moving parts being visible4 ,it works equally well with coal gas1 carburetted air1 or petroleum1 and is constructed in sizes from to #fj horse-power4 ,in spite of its original features it has not met with much success up to the present time4 ,le ,marcel and ,le ,maurice motors 7,cadiot7 7,fig4 #bf74--,the smallest types of the ,marcel motors are of one man-power1 and the largest of one horse-power1 so that they are only suitable for small operations4 ,one impulse is given to the piston every two revolutions1 the cycle being that of ,dr4 ,otto4 ,the gas is compressed in a red-hot tube during half of the backward stroke4 ,there are only two valves1 one for the admission and the other for the escape of the gases1 actuated by a single cam on the crank-shaft4 ,the cylinder is cooled by a water jacket4 ,the governor works on the all or nothing principle1 the supply of gas being completely shut off if the speed rises above the normal of #cej revolutions per minute4 ,illustration3 ,,fig4 #bf4--,maurice ,motor 7de ,cadiot74 ,the ,maurice motors are somewhat similar in construction1 but are designed for operating dynamos4 ,for this purpose two fly-wheels are provided4 ,many of these little motors are to be seen about the country working fans1 lathes1 pumps1 etc4 ,various4--,we have described about thirty different sorts of motors1 selected from the best-known and most original types4 ,about one hundred other motors exist in ,europe1 which are similar in one way or another to those already described1 such as the engines of ,drkopp1 ,forward1 ,brouhot1 ,debry de ,soissons1 ,narjot1 ,archat1 ,wertenbruch1 the 8,acm0 motor1 and many others4 ,but we are obliged to limit our descriptions1 and to conclude the chapter by a couple of examples of motors performing one cycle of operations per three revolutions4 ,griffin motor4--,in this engine we have only two explosions over three revolutions1 but as it is double-acting this number is reduced to one explosion per revolution and a half4 ,the different operations are as follows3--7#a7 gases drawn into the cylinder1 7#b7 compression of gases1 7#c7 ignition and expansion1 7#d7 products of combustion driven out of the cylinder1 7#e7 a volume drawn into it to completely sweep away any residue of the exhaust gases1 7#f7 this volume of air drawn out4 ,admission and ignition are obtained by the action of a sliding valve and eccentric4 ,the governor causes the gas admission valve to remain open for a shorter or longer time1 so as to ensure constancy of speed4 ,the exhaust gases escape by two valves actuated by a pair of cams1 opening them at every turn and a half1 so that the gases are alternately discharged from the back and front parts of the cylinder4 ,the consumption of fuel for a #ab horse-power motor was about #gib litres of coal gas per horse-power hour in an official trial4 ,the speed is very constant in spite of the long cycle4 ,rollason gas engine4--,this is also an engine using a long cycle of operations1 the arrangement of the parts being copied off the ,otto motor4 ,the governor is electric1 and acts on the admission valve1 varying the amount of gas admitted to the cylinder in proportion to the demand for power4 ,in the larger size of from #bj to #ajj horse-power a self-starting arrangement has been added4 ,this engine1 like the ,griffin motor1 has proved that it is possible1 by completely getting rid of the products of combustion1 to use a very dilute explosive mixture1 which would be impossible in the ,otto motor4 ,the ,rollason engine is constructed by ,messrs4 ,beck and ,co4 of ,newcastle-on-,tyne4 ,,chapter ,,iv ,,carburetted ,,air ,,engine ,if cold air be saturated with the vapour of volatile spirits such as gasoline1 or distillates of petroleum of about #fe mean specific gravity1 an explosive mixture is formed with similar properties to that produced by coal gas mixed with air4 ,this carburetted air can be used as fuel for heat engines of the explosive type4 ,about twenty different methods of carburating air are in existence1 some of which are more practical than others4 ,we shall proceed to describe the best known of these4 ,mille carburetted gas4--,in this system air is drawn into a reservoir containing a petroleum spirit by the volatilization and fall of the petroleum vapour1 this vapour being heavier than air4 ,the reservoir is placed on a higher level1 and an indiarubber tube connected to its base leads the explosive mixture to the cylinder4 ,the success of this arrangement encouraged inventors to perfect it4 ,one of the earliest carburators by ,lafroque was provided with a tiny hot-air engine1 which helped to obtain a more perfect saturation of the air with the volatile spirit4 ,in the ,eclipse motors1 and also in the ,phbus motors of ,pluyer and ,muller of ,birmingham1 the air and spirit vapour are mixed by an injector4 ,the vapour is first obtained by heating the liquid spirit in a small still2 it then passes by a fine nozzle across a space drawing air with it after the manner of the ,giffard injector4 ,the explosive mixture thus obtained passes into a reservoir4 ,faignot apparatus4--,the air is drawn in by a revolving pump and forced into a vessel1 divided into several compartments1 one above the other1 separated by porous partitions and containing gasoline2 several taps or valves cause the compartments to be alternately opened or closed1 so that the mixture can always be drawn off rich in hydrocarbon vapour4 ,this apparatus appeared in #ahhe at the ,antwerp ,exhibition1 and supplied a ,bnier motor with carburetted air4 ,it is suitable for lighting villages1 country houses1 etc41 in fact1 any places where coal gas is not laid on4 ,the apparatus has been imitated by ,polack of ,hamburg and others4 ,lenoir carburetted air motor4--,carburators for producing fuel for motive power have been carefully studied during the last ten years by reason of the rapidly extended use of gas motors4 ,one of the most ingenious is due to ,m4 ,lenoir1 constructed for a special motor designed by himself and constructed by ,messrs4 ,rouart frres4 ,this carburator consists of a horizontal cylinder rotated by a pinion wheel1 and performing five or six revolutions a minute4 ,vertical perforated partitions divide the cylinder internally into several compartments1 and the interior wall of the cylinder has attached to it a number of small buckets which draw up the spirit like a water-wheel1 and pour it out again when they reach the summit of their path4 ,the air and vapour are thus thoroughly mixed1 and pass from thence into the cylinder4 ,motors supplied by such carburators have been used for agricultural operations1 and also for driving small pleasure vessels1 the cost of maintenance per horse-power hour being about #b;d4 ,schrab carburator4--,the idea of this apparatus is quite original4 ,the jacket for cooling the motive cylinder is filled not with water but with the hydrocarbon to be vaporized4 ,from thence it passes at a temperature of about #ahj ,f4 into a carburator containing several compartments1 and through which pass part of the products of combustion2 these gases passing through the already boiling liquid hydrocarbon become saturated with its vapour1 but require admixture with air before they are capable of being exploded4 ,the inventor states that the waste gases only take up #a_/af part of that which pure air would in passing through the hot liquid fuel1 and thus explains the extraordinary economy of fuel which is obtained by these motors1 only #a_/afth of a litre of gasoline being necessary to produce one horse-power hour4 ,this is a very remarkable result1 and if it is correct places this combined plant in the foremost rank of carburetted air engines4 ,meyer carburator4--,this apparatus has the advantage of allowing heavier and cheaper oils to be used1 at the same time completely volatilizing them4 ,the heavy hydrocarbons are allowed to fall drop by drop into a steel chamber about eight centimetres diameter and four centimetres in height1 heated by a flame4 ,the vapour is produced at a high pressure1 and escapes through a fine nozzle at high speed drawing the necessary air with it4 ,entering a reservoir this explosive mixture is prevented from returning by a check-valve4 ,the apparatus is so arranged1 that when the pressure in the reservoir has reached a certain point1 the flame heating the vaporizer is turned down and prevents further explosive mixture being formed4 ,the apparatus is therefore self-regulating1 the supply of carburetted air being always proportional to the demand4 ,delamare carburator4--,m4 ,delamare-,deboutteville has devised a very compact carburator for use with his ,simplex motor4 ,gasoline is contained in an upper vessel1 from which it flows in a fine stream from a tap on to a horse-hair brush1 and is there met by a similar stream of warm water coming from the water jacket of the cylinder4 ,the heat obtained from this source tends to vaporize the hydrocarbon1 and the two liquids fall together into a closed vessel4 ,the gasoline rids itself of its impurities and floats on the surface of the water1 which is withdrawn from underneath it by a siphon4 ,the hydrocarbon vapour produced during the fall1 and afterwards by the heat of the substratum of water1 passes by a check-valve to the motor4 ,it is found that the cleansing effect of the water renders the cylinder much less liable to become fouled by tarry products4 ,lothhammer carburator4--,experience has shown that vapour of petroleum when mixed with air soon separates out2 the vaporizer must therefore be placed as close to the engine as possible4 ,in this motor it has been the aim of the inventor to obtain an exceedingly perfect mixture of the explosive gases4 ,in order to do this the air enters the vaporizer near its base1 and passes through it in a number of exceedingly fine streams of bubbles4 ,the petroleum spirit is at the same time heated by a flame1 and the result is a very close mixture of the gases4 ,the inventor claims that he thereby obtains much more complete combustion4 ,tenting motor4--,m4 ,tenting has arranged his gas engine1 which we have already described on page #eg1 for use also as an oil engine4 ,the carburator is composed of three superposed vessels1 through each of which the oil flows in turn4 ,the upper vessel acts as a reservoir and will hold a day's consumption of oil1 and the lower one is traversed by the exhaust pipe1 which supplies the heat necessary to obtain the change of state of the oil from liquid to gas4 ,although this carburator is rather crude it gives a very fair practical result4 ,durand carburetted air engine 7,fig4 #bg74--,m4 ,durand has set himself to produce a motor which should work equally well with gas or petroleum1 and which should require a minimum of attention at the same time1 keeping in view such points as regularity of speed1 rigidity1 economy of space1 and above all low price4 ,this ideal he has1 however1 failed to reach1 although his engine has many good points4 ,he fails chiefly because the mechanism is too complicated4 ,the motor works with an ,otto cycle1 and the ignition is by an electric spark generated by a small magneto machine4 ,the regulation of the speed is obtained by throttling the admission1 and the air is drawn through a tube heated by the waste gases2 this arrangement allows a slight economy to be effected4 ,the carburator is automatic1 consisting of a closed cylinder placed vertically over the motor cylinder4 ,within it is placed the oil fuel1 and also a spongy mass of cork which soaks up the heavier impurities found in the oil1 and thereby allows cheaper oils to be used4 ,air is drawn through the spongy mass1 becoming carburetted in the process2 these gases are mixed with a further quantity of pure air in a distributing chamber before entering the cylinder4 ,illustration3 ,,fig4 #bg4--;,durand ,carburetted ,air ,motor4 ,such a ,durand motor sins only by the number of its parts1 the inconvenience of which is noticeable not only by the amount of lubrication they require1 but also by their rapid deterioration4 ,daimler motor4--,this motor1 constructed by ,panhard and ,levassor1 has become especially famous for its application to power-driven road vehicles4 ,it gained nearly all the best prizes in the automobile races organised in #ahid between ,paris and ,rouen1 and again in #ahie between ,paris and ,bordeaux4 ,,mm4 ,panhard and ,levassor also construct their motors as fixed engines1 but except for slight modifications1 the mechanism is the same in both2 we shall therefore describe the automobile type4 ,there are two single-acting cylinders working on the same crank-shaft4 ,a central valve allows compressed air to be admitted which completely drives out the products of combustion4 ,the admission and exhaust valves are enclosed in a chest also containing the incandescent tube which ignites the mixture4 ,the governor on the crank-shaft prevents the exhaust gases from escaping when the normal speed is exceeded4 ,the gases remaining in the cylinder prevent a fresh charge from entering1 and during the next revolution no explosion takes place4 ,the whole mechanism of the engine1 together with the fly-wheels1 are enclosed in an air-tight case communicating with the outside air by a valve opening inwards4 ,the pistons during the backward stroke draw in air through this valve and compress it during the forward stroke2 this forms the supply of compressed air for the explosive mixture4 ,the carburetted air is obtained by the suction of heated air through oil placed in a vaporizing vessel4 ,the motor cylinder is kept cool by a stream of water1 which is itself cooled by travelling through a long annular pipe which runs completely round the carriage4 ,the heat which it has absorbed from the cylinder is rapidly extracted from it by the circulation of the air on both the inside and outside of the tube4 ,brouhot gas and carburetted air engine4--,the firm of ,brouhot of ,vierzon construct an engine capable of working either by coal1 gas1 or petroleum1 and which has been especially designed for agricultural operations4 ,the general appearance of the engine is of the usual type2 the cylinder projects over the bed-plate and is cooled by a water jacket4 ,the explosive mixture is ignited by an electric spark produced from a battery of cells whose charge lasts from #abj to #acj hours1 or by a small magneto machine driven by the motor itself4 ,when working with petroleum a carburator is attached filled with a very volatile mineral spirit4 ,the air is carburetted by being sucked through it directly into the cylinder4 ,a second vessel is provided1 which serves as a reservoir for oil feeding the carburator automatically1 and keeping the oil in it at a constant level4 ,the whole machine1 though not presenting any novel features1 is strongly constructed and thoroughly suitable for the work it has to perform4 ,carburetted air motors for horseless carriages4--,although not to such a great extent in ,england1 self-propelled vehicles have within the last two years come rapidly into favour on the ,continent1 and the success which has attended them has caused inventors and makers to concentrate their efforts on building the motors as light and as practicable as possible1 as much for purposes of locomotion as for a host of other uses4 ,we have already spoken of the ,daimler motor1 which is used to drive several different types of motor cars2 we will now speak of more recent developments in the same direction4 ,among many of the same character1 the most noticeable is the high-speed motor of ,,mm4 de ,dion and ,bouton1 who have applied them with great success to the propulsion of tricycles 7,fig4 #bh74 ,illustration3 ,,fig4 #bh4--;,de ,dion ,motor ,tricycle4 ,the cooling is effected by radiating cast-iron ribs offering a considerable surface to the air4 ,the ignition is obtained by an induction coil and accumulator with a contact mechanism1 invented by ,captain de ,place4 ,the rotation of the crank-shaft is transmitted to the wheel-shaft of the tricycle by a reduction gear4 ,among other motors we must mention the benzoline engines for self-propelled vehicles of ,lepape1 ,gautier1 the ,gladiateur tricycles and quadricycles constructed by the ,socit des ,voitures sans ,chevaux2 also the exceedingly light motors of the ,kane-,pennington type2 and lastly1 the voiturette-tandem of ,m4 ,leon ,bolle1 some of whose vehicles have shown a remarkable speed with a very small consumption of fuel4 ,a few monstrosities have also appeared in the shape of a five-cylinder motor driving a bicycle called the 8bicyclette ,soleil ,millet10 and a heavy and complicated mechanism by ,wolfmller1 also driving a bicycle and using petroleum4 ,these motors have not1 however1 obtained any success1 nor will they at a future date1 by reason of their complication and weight4 ,it is almost unnecessary to state1 that any of the above types may be equally well used for driving a dynamo and producing electric energy or light4 ,,chapter ,v ,,petroleum ,,engines ,there is a great deal of difference1 from an economic point of view1 between spirit or carburetted air engines which we have just described and motors using ordinary commercial petroleum oil4 ,as a rule such oil is much less dangerous1 having a lower flashing-point1 while at the same time it is cheaper than the more artificial products such as benzoline1 naphtha1 etc4 ,we shall presently give a table comparing the cost of power produced by various systems of motors1 and which will explain why the petroleum engine is gradually ousting the carburetted air motor from its place4 ,the first motor using ordinary petroleum was brought out twenty-six years ago by ,brayton in #ahgb1 and may be said to be the father of the large family of motors which consume oils varying from naphtha to others which have boiling-points as high as #aej ,c4 ,ready motor 7,brayton74--,this motor belongs to the third group of the table on page #ba 7combustion and compression74 ,there are two cylinders1 one motive the other auxiliary1 and used for compressing air4 ,the compressed air passes through a space filled with some absorbent material such as felt1 and kept saturated with petroleum injected into it by a special pump4 ,the carburation of the air proceeds as follows3 the high-pressure jet of air causes the petroleum to froth up1 and in passing through it draws along a quantity of oil in the shape of finely-divided particles4 ,this petroleum mist passes on to the cylinder4 ,the advantage of this method of obtaining an explosive mixture is that it matters not what oil is used1 in fact1 the heavier oils are even to be preferred1 as their partial condensation in the cylinder helps to lubricate it4 ,one volume of petroleum will by this process produce #bd1jjj of explosive mixture4 ,the motor is constructed in both the horizontal and vertical form1 the auxiliary being superposed upon the motor cylinder4 ,the admission of the pulverized petroleum lasts for one-third of the forward stroke1 and the return stroke expels the burnt gases4 ,the engine is double-acting1 using both sides of the piston4 ,a reservoir of compressed air is used for starting the engine1 and saves the trouble of turning the heavy fly-wheel round by hand to give it the necessary impetus4 ,the ,brayton motors are constructed by an ,american firm from #a to #aj horse-power4 ,the cost of maintenance and fuel is moderate1 rendering them exceedingly practicable where coal gas or the lighter petroleum are unobtainable4 ,a later type than the one we have just described appeared in #ahij which is slightly more economic1 single-acting1 and uses the ,otto cycle4 ,the process for obtaining a spray of oil is also much improved4 ,both the auxiliary and the motor cylinders are connected by a beam and connecting rods to the shaft4 ,a red-hot platinum tube ignites the explosive mixture4 ,scurit petroleum motor4--,this engine was patented in #ahhg by ,,mm4 ,belmont ,chabout and ,diedrichs1 and appeared at the ,paris ,exhibition of #ahhi4 ,an ,otto cycle is used1 and ignition is obtained by a platinum capsule heated to incandescence by a jet of carburetted air which passes through a spiral coil warmed by the waste heat of the cylinder4 ,this ignition tube is situated at the back of the cylinder1 and is placed in communication with it by a port and valve1 which determines the exact instant at which the explosion takes place4 ,the petroleum is vaporized by passing through pipes coiled up in a vessel traversed by the heated products of combustion4 ,the vapour thus formed has a high enough pressure to draw air along with it as it passes across an air space between two nozzles2 an explosive mixture is therefore formed4 ,the motor is started by carburating a small quantity of air by means of a reservoir containing a light oil1 and this supplies sufficient energy to work the motor until the spiral coils are hot enough to vaporize the petroleum4 ,the whole apparatus is rather complicated1 especially as there are two separate vaporizers using different oils4 ,this disadvantage1 combined with only a moderate efficiency and a high prime cost1 has severely handicapped the engine4 ,priestman oil engine4--,the first patent of this interesting engine was taken out in #ahhf by ,messrs4 ,dent and ,priestman4 ,the engine as a whole represents probably the highest point of perfection which it is possible to attain to in this class of motor1 and the general arrangement is somewhat similar to that of ,dr4 ,otto's engines1 but in addition there is a very ingenious apparatus for working with heavy petroleum oils4 ,a single-stroke pump1 driven by an eccentric keyed to an auxiliary shaft turning half as fast as the main shaft1 compresses the air to a standard pressure 7depending in value1 on the size of the engine7 in a reservoir supplied with a governing valve and placed near the front of the engine4 ,this reservoir contains petroleum1 and the pressure of the air forces it up into a spray-maker1 where it is pulverized4 ,from thence the petroleum spray passes to a vaporizer heated by the waste gases1 and becomes mixed with a certain volume of air forming an explosive mixture1 which is admitted to the cylinder by an automatic valve4 ,compression and ignition take place in the cylinder1 and the waste gases escape through a valve worked by the same eccentric which drives the air-pump4 ,the number of parts of the mechanism is by this means reduced to a minimum1 and it is found that this peculiar vaporizing process completely prevents the cylinder from being fouled1 as is usual when petroleum is heated to such a high temperature1 often decomposing it4 ,the ,priestman engine gave a fresh lease to the life of oil motors1 which had at one time been almost abandoned by engineers4 ,it is well adapted for all kinds of industrial operations requiring powers of from #a to #ej horse-power1 and large vertical engines have been constructed for marine purposes up to #ajj horse-power1 and have always given complete satisfaction to persons using them4 ,a few minutes are required for the apparatus to become sufficiently heated to be able to start1 after which the consumption of fuel is about #chj to #ejj grammes of petroleum per horse-power hour1 or about #he lb4 ,the six-horse size weighs about #a tons4 ,ignition can be had either electric or by a flame1 according to the wishes of the purchaser4 ,campbell gas engine4--,fig4 #bi shows a very compact engine1 built by the ,campbell ,gas ,engine ,co4 ,there are only three valves2 the admission valve is regulated by a centrifugal governor4 ,the petroleum is gasified in a vaporizer heated by a lamp4 ,the speed is very constant and the motor easily started4 ,illustration3 ,,fig4 #bi4--;,campbell ,oil ,engine4 ,grob motor4--,this engine is constructed in ,leipzig and uses the ,otto cycle1 and1 like the motors already described1 works well with ordinary petroleum4 ,the arrangement 7,fig4 #cj7 is vertical2 the cylinder and valve gear are supported on a hollow cast-iron column1 which in turn is bolted to a circular bed-plate4 ,the shaft has on one side a fly-wheel and on the other a pulley4 ,the working valve parts are all situated on the outside so as to be easily got at4 ,the oil-pump marked in the figure drives1 the petroleum into a vaporizer1 where it is broken up into very minute drops4 ,this oil spray becomes mixed with air1 and passes through a vaporizing tube heated by a flame4 ,in the state of vapour the explosive mixture passes into the cylinder1 where it is ignited at the right moment by a red-hot tube4 ,in consequence of the compression during a quarter of the cycle1 the combustion is very rapid1 the power of these engines being very great for their size4 ,ignition1 and therefore the explosion1 only takes place when the speed falls below the normal4 ,this regulation is obtained by a pendulum governor1 and ensures a very constant speed4 ,the cylinder walls are warm enough to make sure of ignition happening4 ,illustration3 ,,fig4 #cj4--,section of a ,grob ,motor4 ,all heat engines based on the principle of the explosion of a volume of gas require an arrangement for drawing superfluous heat from the cylinder1 otherwise it would soon become red-hot4 ,this cooling is obtained in small engines by the circulation of air about a large surface especially attached to the cylinder walls1 but in larger engines this means is insufficient1 and it becomes necessary to use water as a cooling agent4 ,if water is laid on there is no difficulty about this1 but it occasionally happens that water is too expensive1 or that it is unobtainable2 in such cases it is usual to erect a large cylindrical reservoir of galvanized iron holding about ten litres of water per horse-power of the engine4 ,this reservoir is connected by two pipes from the top and bottom to the water jacket of the engine cylinder1 and circulation takes place by the difference of density of hot and cold water4 ,in the ,grob motor a somewhat different device is resorted to4 ,the water arriving from the jacket at a temperature of about #gj ,c4 is divided into a number of fine streams1 which pass up through a network inside the reservoir4 ,at the same time a small centrifugal pump driven by the engine forces in addition a stream of air through the water2 the effect is to cool the water before it returns to the jacket to a temperature of from #hj to #ij ,fahrenheit4 ,the ,grob motor is built in the same manner as the ,capitaine engine1 which we shall describe next1 but it does not work either as smoothly or efficiently as the latter engine4 ,it possesses1 in addition1 other faults which are objectionable4 ,the vaporizing apparatus is particularly troublesome1 for the result of gasifying petroleum at such a high temperature is very often to decompose it1 and thereby foul the cylinder and valve mechanism4 ,illustration3 ,,fig4 #ca4--;,exterior ,view of ,grob ,oil ,motor4 ,capitaine petroleum motor 7,figs4 #cb1 #cc1 #cd74--,more than seventeen years have elapsed since ,emile ,capitaine1 already well known for his experiments on gas engines1 first tried his hand at oil motors4 ,his first patent dates from the year #ahgi1 and since that time he has continuously worked at the subject1 expending much patience and money in order to produce a high-speed motor capable of using ordinary petroleum of #hh specific gravity4 ,the result of his labours is a machine which is excellent in all respects1 requiring no igniting or heating apparatus4 ,in the earlier type it was found that the motor would not work at less than three-quarters of its full load1 because when it was doing less work the vaporizer became cooled in the intervals which occurred between the rarer explosions4 ,this motor could only work under certain conditions1 and after further trials and experiments ,capitaine brought out a motor which worked at small loads as well as full loads1 and which only consumed fuel in proportion to the power developed4 ,this machine was considered too complicated1 and a fresh type was brought out4 ,illustration3 ,,fig4 #cb4--;,capitaine ,gas ,engine4 ,illustration3 ,,fig4 #cc4--;,horizontal 8,balance0 ,motor 7,capitaine74 ,this third engine has a vaporizer which is in permanent communication with the cylinder1 and is so constructed that even if it became red-hot there would be no risk of pre-ignition or the formation of tarry oils which would foul the cylinder4 ,the vaporizer only draws in sufficient petroleum at a time for one explosion1 and then only during the aspirating stroke of the piston4 ,at the end of this stroke the whole of the petroleum in the vaporizer is gasified4 ,the first motor on this plan was built by ,capitaine in #ahhi1 and many of them are still constructed at the present date by ,m4 ,louis ,herlicq of ,paris4 ,illustration3 ,,fig4 #cd4--;,capitaine ,two-cylinder ,gas ,engine4 ,capitaine came to an agreement with ,grob et ,cie4 in order to exploit his inventions in a wider field4 ,unfortunately differences arose1 and in #ahia the agreement was cancelled4 ,a lawsuit followed1 lasting till ,march #bf1 #ahic1 when it was brought to an end by ,grob et ,cie4 agreeing to pay ,capitaine the sum of #abe1jjj francs in consideration for permission to use his name and patents in connection with their motors4 ,after breaking up the partnership with ,grob et ,cie41 ,capitaine continued to build engines1 and has since then taken out several patents1 which have considerably enhanced the value of his previous inventions4 ,in the #ahib-ic type a lamp is used for starting which can afterwards be dispensed with1 the heat of the compression being sufficient to maintain the temperature of the vaporizer4 ,this is1 however1 only if the motor is developing more than three-quarters of its full power4 ,when it was found that the same shaped indicator diagram could be obtained from these motors even when they were giving only #ge of their full power1 it became obvious that it was only necessary to keep the vaporizer as warm as possible by covering it with non-conducting jackets1 in order to get the engine to run at quite a small fraction of its full power4 ,capitaine has1 by carefully observing this condition1 obtained a motor which will run at all loads without any external heating apparatus4 ,the vaporizer forms part of the combustion chamber1 and is carefully covered with non-conducting material4 ,only hot gases are allowed to pass through it4 ,it must be started by heating for a few minutes with a small hand-lamp1 and the engine is then ready for work4 ,merlin motor4--,this motor is of the vertical type1 and resembles the ,capitaine motor in some respects4 ,the oil is stored in a reservoir in the bed-plate2 this receptacle is in communication with an air-pump driven by the motor1 and also with an oil-pump4 ,the pressure of air generated by the former forces the petroleum up into the oil-pump1 which in its turn passes it drop by drop through a pulverizer1 after which the spray of oil enters a vaporizer and becomes gasified4 ,the vaporizer is heated by a special petroleum lamp4 ,ignition takes place when the explosive mixture comes into contact with the heated walls of the vaporizer1 their temperature being always high enough to ensure ignition taking place4 ,the consumption of fuel is regulated by a governor acting on the oil-pump1 preventing it from supplying more oil than is absolutely necessary to keep up the speed4 ,the governor regulates the exhaust valve as well1 so that the speed1 which is pretty high1 is kept quite constant4 ,hornsby-,akroyd oil engine 7,figs4 #ce1 #cf74--,this interesting machine was invented by ,messrs4 ,akroyd1 ,stuart and ,binney2 it works with ordinary petroleum1 and without the help of a carburator uses oils varying greatly in specific gravity4 ,the reservoir of fuel is situated in the bed-plate4 ,the ignition is automatic1 and an electric spark is unnecessary1 in fact1 the whole engine is of the simplest construction1 in order that there may be no inconvenience due to breakdowns4 ,referring to ,fig4 #ce1 ,l is a special petroleum lamp situated at the back of the cylinder ,a4 ,when starting this lamp is supplied with air from a rotary fan turned by hand2 in a short space of time1 by the help of this stream of high-pressure air1 the cartridge ,c becomes sufficiently heated to ensure the ignition of the explosive mixture4 ,this cartridge ,c is provided on its interior with radiating ribs1 which greatly increase the surface4 ,during the back-stroke of the piston it becomes filled with compressed air from the cylinder1 and towards the end of this stroke a quantity of petroleum1 exactly sufficient for the explosion1 is squirted into it4 ,to do this a small pump is provided1 which is actuated by a cam driving the oil into the cartridge and brought back by a spring4 ,the centrifugal governor ,g acts on the admission valve from this pump4 ,the sudden injection of the oil into the middle of the heated chamber completely vaporizes it1 forming with the air already present the necessary explosive charge1 which immediately ignites in contact with the heated walls4 ,illustration3 ,,fig4 #ce4--;,hornsby-,akroyd ,oil ,engine 7section74 ,when the vaporizing cartridge has been sufficiently heated a rapid turn of the fly-wheel by hand1 so as to produce the first explosion1 is sufficient to start it1 after which the vaporizer keeps itself warm4 ,the pump which keeps up the supply of oil will be seen in the right-hand bottom corner of ,fig4 #ce4 ,it is of the plunger pattern1 and at every stroke of the piston draws in the right quantity of oil and injects it into the vaporizer through a valve4 ,the illustration on page #ia shows the other side of the engine with the valve-shaft1 which revolves once for every two revolutions of the crank1 also driving the centrifugal ,porter governor4 ,if the speed should happen to exceed the normal1 a steel finger moved by the governor closes the valve admitting oil to the vaporizer1 which then returns to the reservoir1 having failed to accomplish its object4 ,as the ordinary ,otto cycle is used1 a heavy fly-wheel is necessary to maintain the speed constant between the explosions4 ,after being once started very little attention is necessary1 everything working automatically4 ,a water jacket ,w cools the cylinder4 ,illustration3 ,,fig4 #cf4--;,exterior ,view of the ,hornsby-,akroyd ,oil ,engine4 ,the specific gravity of the oil is usually about #hed1 and of this the engine consumes about one pint per hour per ,b4,h4-,p41 at a cost of #a;d4 ,an additional advantage of the high speed is1 that there is less chance of the cylinder becoming fouled by tarry products4 ,vulcan motor4--,this engine is in many respects a counterpart of the ,akroyd motor4 ,the cylinder is horizontal1 and projects over the end of the bed-plate4 ,two fly-wheels are provided if very steady running is required4 ,the lamp which vaporizes the petroleum at starting is removed when once the normal speed is attained4 ,a water jacket prevents the cylinder from getting too hot4 ,the most noticeable feature is the rather curious arrangement for governing by means of bent oscillating levers1 which control both the admission and escape valves4 ,the governor itself is situated inside the transmission pulley and keeps the speed within #a of the normal2 #fjj grammes of petroleum per hour per horse-power is the usual consumption4 ,the motor is rather too complicated1 and can scarcely be said to have justified the expectations formed of it4 ,ragot petroleum motor 7,figs4 #cg1 #ch74--,this engine1 like the preceding ones1 uses heavy petroleum and particularly schistic oil1 which has a flashing-point above #gg ,fahrenheit1 and which may be bought very much more cheaply than naphtha1 benzoline1 or other artificial products of petroleum4 ,several different patterns of the engines are on the market1 of which certain ones are of great value for electric lighting purposes1 not only because of their steady running1 but also because1 by burning cheap oil1 they allow the cost per horse-power to be reduced to a minimum4 ,one high-speed pattern has been especially designed for coupling direct to dynamos1 forming a very neat and compact plant4 ,the latest developments in the construction of these engines tend to the simplification of the parts1 and they are now so free from unnecessary mechanism1 that persons with little or no knowledge of mechanics are quite capable of looking after them1 and even taking them to pieces and putting them together again if a breakdown should occur1 which is unlikely4 ,illustration3 ,,figs4 #cg1 #ch4--,sections of the ,ragot ,petroleum ,engine4 ,by a special arrangement in the carburator all constituents of the petroleum which might foul the cylinder are removed before the oil is allowed to enter the cylinder1 and therefore it seldom requires cleaning out4 ,the carburator 7,fig4 #ci7 is very ingeniously arranged2 it consists of a cast-iron cylinder smooth on the inside1 but provided with a spiral rib on its outer surface1 and heated by an oil lamp4 ,the spiral rib is itself enclosed by a covering1 so that it forms a spiral tube4 ,the petroleum is allowed to enter at the top1 and gradually winds its way down1 passing over a continually warmer and warmer surface as it approaches the lamp4 ,the more volatile portions of the oil are therefore vaporized first1 and the heavier oil passes on and is not vaporized till near the base1 where the temperature is high enough to gasify the heavy residue4 ,the air is heated in a jacket surrounding the base of the spiral1 and is afterwards mixed with the oil vapour4 ,root motor4--,these engines work with the ordinary four-cycle1 and are interesting because of the double-ignition apparatus4 ,a lateral chamber is attached to the cylinder1 communicating with it by an orifice situated at the back end1 which is covered when the piston is at the beginning of its stroke4 ,during the compression stroke a portion of the mixture is enclosed in this chamber and separated from the rest of the charge1 which is compressed and ignited in the ordinary way4 ,the explosion drives forward the piston1 and when it has moved forward some distance it unmasks the above-mentioned orifice1 igniting the gas contained in the lateral chamber1 and helping to maintain the pressure behind the piston4 ,this addition to the pressure is noticeable in a diagram taken from the cylinder1 by sudden rise of pressure4 ,we don't quite see the utility of this arrangement1 which seems to merely complicate matters4 ,the first ignition is effected by a red-hot tube4 ,the ,root vaporizer utilizes the heat of the exhaust gases2 the air is heated in a spiral coil wound round the tube through which the vaporized oil passes4 ,the two become mixed in a small vessel1 and the vaporizer is supplied by a chamber placed directly round the exit of the exhaust gases4 ,strictly speaking1 there is no oil pump1 but a plunger in a small auxiliary cylinder serves to direct the flow of oil into the right channels4 ,admission takes place through an automatic valve4 ,the escape valve is actuated by the same mechanism which drives the piston governing the flow of oil4 ,illustration3 ,,fig4 #ci4--;,carburator of the ,ragot ,oil ,engine4 ,koerting-,boulet motor4--,in this four-cycle engine we shall only describe the vaporizer and spray-maker4 ,the oil is stored in a reservoir placed about six feet from the ground1 and a pipe conducts it into a space between two discs with a valve at the top4 ,this circular space1 about half a millimetre in thickness1 is traversed by the air which pulverizes the oil2 the spray thus formed is vaporized by the high temperature developed by a lamp situated underneath the tube which conducts the carburetted air to the cylinder4 ,in addition1 this lamp is used for igniting the gases through a porcelain tube kept at red heat by it4 ,an auxiliary spirit-lamp is used for starting the engine1 which takes about fifteen minutes to acquire a sufficiently high temperature4 ,knight gas engine4--,in his endeavour to completely drive out the products of combustion from the cylinder1 ,mr4 ,knight has had recourse to the ,griffin cycle and to a double-acting cylinder3 we have already discussed the relative merits of this system1 and think it is sufficient to point out the greater constancy of speed obtained by it4 ,the vaporizer is placed behind the motor-cylinder1 and is separated from it by a steel plate1 so that it is maintained at a high temperature2 this vaporizer is made of bronze1 and is provided with radiating ribs4 ,a pump injects oil into it1 and it is also supplied with compressed air by a special pump1 which furnishes in addition a jet for producing a blow-pipe flame4 ,this flame white-heats a platinum wire1 which ignites the gases4 ,the wire is situated in an opening in the ignition valve2 the valve moves forward1 and the white-hot wire is brought into contact with the explosive mixture at the right moment4 ,the admission valve is automatic1 and situated in the steel plate separating the vaporizer from the cylinder4 ,the other organs of the motor are not of any special interest4 ,crossley-,holt oil engine 7,fig4 #dj74--,this is practically the same engine which we described in the chapter on gas engines2 a vaporizer is added in the oil motor to enable it to work with petroleum4 ,it consists of a chamber divided into four channels by vertical partitions1 and heated by a lamp placed underneath4 ,the flame traverses these channels before reaching the chimney placed at the top4 ,the petroleum is converted into a spray1 and drawn off by a jet of air warmed by passing it through a spiral coil placed round the lamp chimney4 ,this jet of air is supplied by a small pump worked by a lever4 ,the oil lamp has no wick1 which is rather a novel arrangement3 it is supplied by a small pump similar to that which provides the air4 ,since its first appearance this engine has undergone certain changes which have considerably improved it4 ,messrs4 ,crossley ,bros4 have especially devoted themselves to shortening the length of time necessary to heat and start the engine4 ,besides this they have paid great attention to simplicity of the working parts4 ,illustration3 ,,fig4 #dj4--;,crossley-,holt ,petroleum ,engine4 ,trusty oil engine4--,this motor was devised by ,mr4 ,knight1 and is constructed by ,messrs4 ,weyman and ,hitchcock4 ,there is no spray-maker1 the liquid oil being directly converted into vapour4 ,the vaporizer is heated by the waste gas from the cylinder1 and the oil falls drop by drop on to the hot metal walls and becomes vaporized4 ,the engine is of the ordinary four-cycle type1 the most noticeable feature being the governing arrangement2 a governor of the inertia pattern regulating the admission valve and the oil-pump4 ,if the speed becomes too great the action of the governor on the valves ceases1 and oil is no longer supplied to the vaporizer from the pump and the admission valve remains closed4 ,ignition is obtained by a red-hot tube heated by an oil lamp2 a layer of asbestos on the outside prevents the tube from cooling1 and keeps the tube at a high temperature4 ,it takes twenty minutes before the vaporizer becomes sufficiently heated to enable a start to be made1 and the cylinder is very liable to become fouled by tarry products from the oil4 ,these serious disadvantages are scarcely neutralized by the variety and small quantity of oils which the engine will burn4 ,an engine of this type with two cylinders consumed in certain trials only half-a-pint of oil1 which speaks for itself4 ,griffin oil engine 7,figs4 #da1 #db74--,yet another ,otto cycle engine provided with a pump reservoir and vaporizer4 ,the latter is hidden in the bed-plate1 and is heated by the gases from the exhaust4 ,the pump is driven by an eccentric on the main shaft1 and compresses the air to about #h lbs4 on the square inch in a reservoir also situated in the bed-plate4 ,the compressed air passes from this chamber into a needle pulverizer1 along with a quantity of oil which it has gathered in a small ante-chamber4 ,this pulverized oil arrives in the vaporizer at the same moment as the air for the explosive mixture4 ,a portion of the vaporized oil and air is used for the lamp1 which red-heats the ignition tube4 ,at starting1 a small quantity of air is compressed in a hand pump1 and in ten minutes the vaporizer is hot enough to gasify the oil4 ,the ,griffin engine is very economical1 and only uses about a pint of petroleum per horse-power hour4 ,illustration3 ,,figs4 #da1 #db4--;,griffin ,oil ,engine4 ,niel petroleum engine4--,in these motors1 the general arrangement of whose parts is similar to that of the gas engines constructed by the same firm1 the principal part is the vaporizer4 ,it consists of a small cast-iron chamber1 provided with radiating ribs in its interior so as to increase the surface2 the petroleum1 coming from a reservoir placed at a height of about six feet1 passes through a regulating valve1 and is dispersed in fine drops over the surface of the radiating ribs2 the vaporization is consequently very steady4 ,an automatic valve allows air to pass into this chamber from the outside1 forming an explosive mixture with the vaporized oil4 ,a special tube coming from the reservoir supplies a lamp with oil for heating the ignition tube and also the vaporizer at the same time4 ,a methylated spirit lamp is used for warming them up to the right temperature before starting the engine4 ,the governor acts on both the admission and the exhaust1 and the supply of oil is indirectly regulated by the closing of the exhaust valve4 ,the whole mechanism is ingenious1 giving excellent results2 the speed is very constant1 and the consumption of oil is within wide limits proportional to the demand for power4 ,about a pound of oil is consumed per horse-power hour1 including that necessary for the lamp4 ,two patterns of this engine are built1 one vertical and the other horizontal4 ,in the latter1 called the ,atlas engine1 the consumption per hour is slightly greater4 ,the governor is also different4 ,the compression in the cylinder rises to about two atmospheres1 and the quantity of water necessary for the water jacket varies from seven to ten gallons per horse-power hour1 according to the size of the motor4 ,,chapter ,,vi ,,gas ,,generating ,,plant ,we have so far followed1 step by step1 the various improvements undergone by internal furnace engines1 from their first practical realization thirty-seven years ago by ,m4 ,lenoir4 ,this improvement has continually tended1 as one might naturally expect1 to cheapen the cost of the motors themselves1 and lessen the cost of the fuel consumption so that they might successfully compete against the steam engine1 over which they have many advantages4 ,as a rule1 coal gas is pretty expensive1 in some particular districts ruling as high as #ds4 or #es4 per #ajjj cubic feet4 ,this price would be prohibitive were it not for the extreme economy which has been obtained in gas engines by such devices as compression and the lengthening out of the combustion4 ,inventors have sought to still further lessen the cost of power by replacing the expensive coal gas by other gases of lower illuminating power1 produced by special gas plants attached to the engine1 and which can be used in places where there is no coal gas laid on4 ,other engines have been devised1 as we have already shown1 which get over the difficulty by consuming petroleum oil or distillates of same1 such as benzoline and other light hydrocarbons4 ,gas companies are1 as a rule1 heavily taxed1 and if it were not for a vast amount of idle capital buried in the streets in the form of gas mains1 they would probably supply gas at a very low price1 especially as the sale of bye-products practically covers the cost of production4 ,some companies have even reduced the price of gas if used for driving gas engines1 and have therefore slightly decreased the cost of production of power by this means4 ,in ,france1 the home of the oil motor1 they are severely handicapped by having to pay double duties on all petroleum entering1 first the country itself1 afterwards the towns4 ,inventors have therefore sought a method of getting round these difficulties by producing a cheap gas1 which would answer the same purpose as coal gas4 ,first of all many manufacturers tried to cut down the expense by erecting their own coal gas plants1 so as to be independent of arbitrary taxation4 ,the system1 although fairly satisfactory1 had many drawbacks1 and further experiments were made with a view to simplifying the process of production4 ,the result has been to give us water gas and also poor gases1 whose great practical value we shall presently demonstrate4 ,in order to produce what is called water gas1 the process essentially consists of placing in contact with one another red-hot carbon and superheated steam4 ,the result is to form a mixture of gases according to the following chemical equation-- #c ,h#b,o #b ,c ,,co ,,co#b #c ,h#b4 ,for those not understanding the above it will be as well to explain1 that on the left-hand side of the equation are placed the compounds brought into contact1 water 7,h#b,o7 and carbon 7,c71 and on the right the products of the chemical action1 carbon monoxide 7,,co71 carbonic acid gas 7,,co#b71 and hydrogen 7,h#b74 ,the resulting water gas contains #fj of hydrogen and #bj of carbon monoxide1 both of which are combustible gases4 ,the proportions of the gases evolved can be varied at will by admitting more steam or using an excess of carbon2 by this process a richer gas can be obtained-- ,c ,h#b,o ,,co ,h#b1 and #e ,h#b,o #c ,c #b ,,co#b ,,co #e ,h#b4 ,with #ah parts of steam and #ab parts of carbon we can obtain by the former equation #bh parts of carbon monoxide and #b parts of hydrogen4 ,this forms an extremely calorific mixture4 ,there are several processes for preparing water gas which give good practical results1 and the gas produced has been used in ,america and ,germany for lighting towns on the incandescent gas-burner system4 ,the ,strong and ,lowe processes consist of a furnace lined with fire-bricks1 and in which is placed coal or coke4 ,when this mass of carbon has reached a state of bright incandescence by playing upon it a stream of air1 steam is admitted at high temperature1 and is decomposed by the carbon forming oxides and liberating hydrogen4 ,the gaseous products pass from the furnace to a reservoir4 ,when the chemical action ceases1 due to cooling of the carbon1 the steam is shut off and the stream of air turned on till it becomes incandescent once more4 ,the process of admitting steam is then repeated4 ,about #b lbs4 of coke are necessary to produce #bj cubic feet of water gas4 ,analysis of the gas reveals the following parts by volume of the constituents4 7#a7 ,water gas produced by the ,strong process3-- ,hydrogen #ec volumes ,carbon monoxide #ce 0 ,hydrocarbons #d 0 ,other gases #h 0 ------ #ajj volumes 7#b7 ,lowe process3-- ,hydrogen #cj volumes ,carbon monoxide #bh 0 ,hydrocarbons #cd 0 ,other gases #h 0 ------ #ajj volumes ,it is possible to entirely get rid of the cooling effect of the steam1 by using instead a jet of air which passes up through the carbon4 ,first of all carbon dioxide 7,,co#b7 is formed near the bottom of the mass1 but this gas passing upwards through it is reduced to carbon monoxide 7,,co7 by the excess of carbon1 and a mixture is obtained consisting of #cd parts by volume of carbon monoxide and #fe of nitrogen4 ,this gas has been named after its inventor1 ,siemens gas4 ,by proceeding for ten minutes with this air process1 and then stopping it and generating water gas1 two different mixtures are obtained1 which can be combined together forming a gaseous product containing #aj parts of hydrogen1 #bj of carbon monoxide1 and #ej of nitrogen4 ,one kilogramme of coal produces #de cubic metres of this mixture4 ,instead of performing the operations of producing ,siemens gas1 or producer gas1 as it is sometimes termed1 and water gas alternately and separately1 it is possible to so arrange the furnace and apparatus1 that both are generated at the same time1 and continuously instead of intermittently4 ,the combination of the two is called poor gas4 ,the invention of gas-producing plant is due to two ,frenchmen1 ,thomas and ,laurens1 who studied deeply the question of the economic generation of poor gas1 and constructed the first working plant4 ,these two inventors stood1 however1 in the same position relative to the production of poor gas that ,beau de ,rochas had held relative to the gas engine1 and it was not till ,siemens came forward1 and showed how they might most economically be generated1 that poor gases were generally adopted4 ,siemens adapted them especially to metallurgy and the manufacture of glass4 ,we shall now describe the most interesting processes which have been brought out since the time of the appearance of the ,siemens plant4 ,dowson gas-producer 7,fig4 #dc74--,this process was the first to appear after the ,siemens process1 and the gas produced by it is used in a large number of manufacturing operations4 ,it consists of a generator1 a boiler for producing superheated steam1 an hydraulic box1 the scrubbers and the gasometer4 ,the generator is simply a gas retort lined internally with fire-bricks1 and placed vertically in position4 ,it will be seen in front on the left-hand side of the illustration4 ,the fuel is usually anthracite coal1 and is supported on a grate4 ,it is fed in through a hopper placed at the top of the generator4 ,by an arrangement of valves the anthracite enters without direct communication being ever established between the interior of the generator and the exterior atmosphere1 which would result in explosions4 ,the steam which is to be decomposed by the heated coal is generated in the small boiler1 seen in front on the right1 at a pressure of #ej lbs4 per square inch1 and superheated in a spiral coil inside4 ,the steam passes into the retort through an injector1 drawing a quantity of air along with it whilst passing from a nozzle across an air space4 ,the air enters the generator along with the steam and causes the coal to burn1 and the steam is decomposed1 forming a mixture of producer gas and water gas4 ,the quantity of gas produced is therefore regulated by the injector4 ,the gases generated by the combustion of the anthracite are conveyed by a pipe into a flat hydraulic box seen behind the generator1 and divided into two parts and half filled with water4 ,the gases are washed by this water and then pass on to the scrubbers1 where they are cooled and washed by passing through a mass of coke moistened by fine streams of water4 ,to further cleanse them they are passed through saw-dust and thence pass to the gasometer4 ,a number of analyses made by ,m4 ,witz show that ,dowson gas consists on the average of #be hydrogen1 #af to #be carbon monoxide1 and #ej of nitrogen4 ,the heat of combustion of one litre varies according to the quality of coal used1 but averages about #adjj calories4 ,one kilogramme of anthracite will produce about four cubic metres of ,dowson gas1 the cost being one-tenth of a penny per cubic metre4 ,it must not be forgotten that this gaseous mixture is only a quarter as rich as coal gas1 but it costs about one-tenth to produce1 and is therefore cheaper on the whole4 ,at some future date this type of apparatus may1 to a great extent1 replace the boiler of the steam engine4 ,that ,mr4 ,emerson ,dowson's process has succeeded beyond his most sanguine expectations goes without saying4 ,his apparatus is in use in every corner of the globe1 and1 to quote his own words1 8still better results can and will be obtained when an engine is really designed to give the best effect with this gas40 ,illustration3 ,,fig4 #dc4--;,dowson ,gas-producing ,plant4 ,buire-,lencauchez gasogene4--,the analysis of the gas produced on this system shows that it contains #bj volumes of carbon dioxide1 #aae of carbon monoxide1 #ff of hydrogen1 and #agh of nitrogen2 its percentage composition is therefore the following3-- ,carbon monoxide #bid ,carbon dioxide #ei ,hydrogen #agf ,nitrogen #dga ------ #ajj ,theoretically one kilogramme of coal should develop #ebf cubic metres of gas1 having a heat of combustion at #j ,c41 and atmospheric pressure of #acfj calories4 ,these figures enable us to calculate the efficiency of a gas-producing plant and the value of the gas obtained4 ,very good results have been obtained by gas generated by the latest ,lencauchez process1 with improvements added by the firm of ,buire of ,lyons1 who construct the apparatus4 ,the chief point to be noticed in these plants is the suppression of the steam boiler1 which requires constant attention and stoking4 ,the hearth of the generator is made of refractory bricks surrounded by a layer of sand to keep in the heat4 ,the fuel enters through a hopper1 which by means of a bascule and counterpoise never allows any direct communication between the interior of the retort and the surrounding atmosphere4 ,the fuel is either coke or anthracite1 and is spread over a grate situated over an ash-pit4 ,this ash-pit forms an important part of the apparatus1 for it is fed with water which evaporates from the heat striking down on to it from the incandescent coke4 ,the steam generated by this novel process passes together with air up through the heated mass of fuel1 forming a mixture of producer and water gases in the generator above4 ,the supply of air is regulated by a centrifugal fan driven by the gas engine which the plant is supplying4 ,the necessity of having to use this fan very often more than destroys the advantage gained by the absence of a boiler4 ,the gases produced pass by a pipe into the scrubbers after first surmounting the pressure of a water valve1 which prevents them from returning to the generator4 ,the scrubbers are filled with coke1 with a continual stream of water flowing down over it4 ,the gases in passing up are therefore thoroughly cleansed1 so much so that they are fit to pass straight to the gasometer4 ,when the gasometer is full and has reached its top position1 it acts on a lever connected by a wire rope with a tap regulating the air supply of the generator4 ,the centrifugal fan ceases to act1 and the coke in the generator soon cools down1 and the production of gas ceases4 ,as the gasometer falls again the process is re-started1 but not before the coke or anthracite in the generator has been re-lit automatically4 ,the whole plant1 therefore1 only produces gas in proportion to the demand made on it1 which is a necessary condition when driving gas engines4 ,the coke is automatically re-lit by a small jet at the side of the generator1 and fed by gas from the gasometer4 ,a plant producing gas sufficient for #fj horse-power1 or about #bjj cubic metres per hour1 uses up about #ajj litres of water for vaporization1 and about #ejj for cooling the scrubbers4 ,the water used for cooling the cylinder of the engine which the plant is supplying may be used for vaporizing purposes1 and requires the addition of a small pump4 ,matter et ,cie4 of ,rouen uses the ,buire-,lencauchez gasogene for supplying their ,simplex engine1 which we have already described4 ,altogether about #cjjj horse-power have been supplied by them on this system1 and have given repeated proof of the value of this process of generating poor gas1 especially in ,france1 where poor ,french coal1 which can be used1 is cheaper than imported ,english anthracite4 ,gardie gas-producing plant4--,this apparatus is characterized by the use of high-pressure air at about #hj lbs4 per square inch1 mixed with steam at the same pressure2 this arrangement being more concentrated only requires small plant4 ,the generator is of peculiar construction1 without any grate1 the coke being held up on shelves4 ,the air and steam enter the generator by a ring of twyers1 and a small window is pierced at the side through which the attendant can see if the proper degree of incandescence is maintained4 ,the fuel is poured in through a hopper in a similar manner to other generators already described4 ,the gas is produced at a high temperature1 and is made to heat a coil through which the steam passes1 which is thus economically superheated4 ,after accomplishing this duty the gases pass on to a scrubber1 formed by two concentric tubes of different heights1 and travel on straight to the gasometer4 ,the air is compressed in a reservoir by a special pump1 and is heated by the waste gases from the cylinder of the motor4 ,these various heating arrangements1 therefore1 prevent as much as possible any loss of waste heat4 ,some of the operations described are novel and interesting1 and the gas produced is very rich1 having a heat of combustion of over #adjj calories1 and very little ammonia is produced4 ,the result of this is that only rudimentary scrubbers are required1 other systems requiring elaborate methods of cleansing the gases4 ,the only drawback to the apparatus is the reservoir of compressed air1 which necessitates a pump using up power4 ,taylor gas-producing plant 7,fig4 #dd74--,the future of gas engines1 especially large units1 is intimately connected with production of poor gases at low cost1 for they would be far from economical if coal gas were used at the price at which it is usually sold4 ,for this reason many inventors have attempted to devise apparatus which should produce gases suitable for being used in a gas engine1 by the decomposition of steam by red-hot carbon4 ,the ,taylor system is one of the best of those which have appeared in the last few years4 ,it has been thoroughly tested in practice4 ,the plant consists of a generator and boiler1 a series of cleansing and washing towers1 and a gasometer4 ,the most important feature is the automatic manner of getting rid of the coke ash from the generator by a moving hearth1 which enables it to be cleaned out without stopping the production of gas4 ,by this system cheap coal can be used instead of anthracite1 which is more expensive4 ,the steam boiler is placed on the generator1 and is heated by the gases coming from it4 ,the steam passes first of all through a superheater consisting of a number of tubes round which circulate the gases from the generator4 ,the high temperature of the mixture of steam and air ensures a good efficiency4 ,the gases produced in the generator pass through vertical tubes1 exposing them to a large cooling surface1 where they are chilled2 they then pass through scrubbers lined with coke and so into the gasometer4 ,illustration3 ,,fig4 #dd4--,taylor ,gas-producing ,plant4 ,the gaseous mixture1 consisting of hydrogen1 carbon monoxide1 etc41 produced in the generator has a heat of combustion of from #adjj to #aejj calories4 ,the relative heating power compared with coal gas is therefore two-sevenths4 ,a motor consuming #gjj litres of coal gas would require #bejj litres of the poor gas produced by this system to develop the same power1 and #eej grammes of anthracite would be consumed in the process4 ,the cost per horse-power hour varies according to the price of materials4 ,supposing we have an eight horse-power motor consuming #be cubic feet of coal gas per horse-power hour1 at #bs4 #f;d4 per #ajjj cubic feet1 and working for #aj hours1 the cost per day would be #h #be #cj #aj;d4 ---------------------------------------- #es4 or d4 #ajjj per horse-power hour4 ,if1 on the other hand1 it were supplied with poor gas generated from anthracite costing #bes4 a ton1 it would burn about #a lbs4 per horse-power hour1 costing #af;d41 which is about one-fifth the cost1 and using cheap coal this cost can be still further reduced4 ,these figures clearly show how much cheaper it is to burn poor gases than coal gas4 ,bnier gasogene4--,since the #ahhi ,exhibition1 where a ,simplex engine was to be seen working with poor gas generated on the ,dowson system1 engineers and others have fully recognized the advantages of this cheap motive power4 ,in the last few years a very large number of these plants have been erected1 and the experience gained by practice has shown1 that in spite of the extreme cheapness there are serious faults to be found with this class of apparatus4 ,the gases are produced under pressure and are of an exceedingly poisonous nature1 carbon monoxide being the same gas which is principally evolved from burning charcoal4 ,great care has therefore to be taken that there are no leaks1 which might have fatal results if inhaled by the persons attending to the plant4 ,the chemical operation of the production of the gas is a very delicate one1 and requires skilled attendants if constancy in the quality of the gas is required4 ,the ,bnier gasogene has been designed to eradicate or circumvent these grave drawbacks4 ,it presents many novel features1 the most interesting of which is the device for absolutely ensuring no leaks4 ,this is done by generating the gas below the pressure of the atmosphere4 ,this low pressure is maintained throughout the plant right up to the valve which admits the explosive mixture to the motor cylinder4 ,the only places in which the pressure is raised are surrounded by vacuum jackets leading to the gas reservoir4 ,the gas-producing plant can therefore be installed anywhere1 even in dwelling-houses or cellars1 without running any risk of poisoning the inmates4 ,the irregularity of the qualities of the gas produced by other generators is due to the difficulty of always admitting the air and steam in the same proportions to the generator4 ,this difficulty is got over in the ,bnier gasogene1 indirectly as the result of the low pressure in the interior3 the air and steam enter under atmospheric and therefore constant pressure1 and their proportions can be regulated to a fine degree of accuracy by varying the size of the orifices through which they are admitted4 ,so regular is the production of the gas in quality that diagrams taken from an engine at intervals of several hours showed no appreciable difference4 ,the functions of attendant can be thoroughly fulfilled by an unskilled labourer or boy1 the operation of emptying a quantity of coke once every half-hour being sufficient to keep the plant working steadily4 ,this apparatus is also an economic one1 partly because of the invariable qualities of the gas produced1 but chiefly owing to air and steam being heated before entering the hearth4 ,a rotating grate is also provided1 so that the generation of gas is in no way interfered with by the clearing out of ash and clinkers4 ,a special engine is constructed for use with this plant1 which we shall describe in the next chapter4 ,taylor gas-producing plant modified by ,wimand4--,there exist a number of systems of gas-producers which are not so well known as those which we have already described1 but which are none the less interesting4 ,the most important of these is a modification by ,wimand of the ,taylor system1 in which the boiler is discarded1 and replaced by a jacket or vessel surrounding the generating plant and heated by the waste gases4 ,the hot water trickles down over a column of coke1 and meets at the base the current of air passing towards the generator2 the air is therefore heated1 and becomes saturated with water vapour4 ,this device can be applied to any generator4 ,kitson gas-producer4--,a rotating hearth is provided1 as in other systems already described4 ,the air is driven by a steam injector through holes in it1 and the steam is supplied from a spiral coil situated in the fire-brick lining of the generator4 ,a second tube through which the steam passes acts as a superheater4 ,the steam enters a reservoir chamber at the side of the generator1 from which it passes out again to fulfil its functions4 ,there is therefore no fan needful1 and the generating furnace is not liable to become fouled4 ,the price of the plant is moderate4 ,loomis gasogene4--,this apparatus aspirates its air and draws it completely through a layer of carbon from top to bottom4 ,the generator is open at the top1 and instead of the usual grate at the bottom it is provided with a cone-shaped base instead4 ,the air drawn in combines with the carbon during its downward journey1 and then passes through a cooling tower surrounded by a water jacket which acts as a boiler4 ,the heat extracted from the gas is therefore used to produce steam1 which drives an engine working the pump which aspirates the air4 ,the exhaust steam from this engine passes into the incandescent fuel and is decomposed1 forming hydrogen and carbon monoxide4 ,the valves which govern the supplies of air and steam are so arranged that producer gas or water gas1 or both at once1 may be generated at will4 ,one particular plant is known to have worked unceasingly for two years without stopping1 but in this case it did not supply a gas engine1 in fact1 we believe that this system has not been applied for driving motors at all as yet4 ,wilson gas-producer4--,the generator is broader than it is high1 and it is possible to use in it all sorts of cheap coal and coke4 ,a window is provided1 so that the attendant can see if the fuel is sticking and not settling down properly4 ,the air is blown into the centre of the hearth by a steam injector at a low pressure of about two inches of water or less4 ,stoking is effected by turning spiral grate bars which rid the fire of clinkers and ashes4 ,the air is heated by waste gases from the motor1 a process which gives a slight gain in economy4 ,longsden process4--,we have mentioned that water gas generated by various processes has been used for lighting towns in ,america on the incandescent system4 ,the drawback of the system is the exceedingly poisonous nature of carbon monoxide even when very dilute1 and it is all the more dangerous because it is odourless4 ,many accidents have in consequence occurred1 some of them terminating fatally4 ,mr4 ,longsden has attempted to produce a gas entirely free from carbon monoxide1 so as to avoid this difficulty4 ,he first attempted to rid water gas of the monoxide1 but not being able to find a cheap enough solvent for it he tried other means4 ,his present process consists of adding a sodium salt to the carbon in the generator4 ,the gas produced has then the following composition3-- ,hydrogen #fbb volumes ,carbonic acid gas #bfd 0 ,carbon monoxide #ab 0 ,hydrocarbons #fe 0 ,nitrogen #bb 0 ,oxygen #ae 0 ---------- #ajj 0 ,this very rich gas1 which might easily be ridded of its carbonic acid by passing it through lime1 is very suitable for supplying motive power through the medium of the gas engine4 ,gayon and ,mtais process4--,this process1 which1 as far as we know1 has not been put into practice1 was intended by its inventors to diminish the price of coal gas4 ,instead of allowing coke to be deposited in the gas retorts1 as it usually is1 and selling it as a bye-product1 their intention was to use it there and then for the production of water gas1 which was to be mixed with the coal gas and increase its heat of combustion1 while diminishing its cost of production4 ,one ton of coal would produce #dej cubic metres of gas instead of #cjj2 the idea has1 however1 never been put into practical shape4 ,,chapter ,,vii ,,engines ,,for ,,use ,,with ,,poor ,,gases ,simplex motor 7,fig4 #de74--;,although this motor works equally well with coal gas and oil1 we have put off the description of it until now because it has become associated particularly with the production of poor gases1 and by their help forms one of the most formidable rivals of the steam engine4 ,the ,simplex was invented in #ahhd by ,,mm4 ,edouard ,delamare-,deboutteville and ,lon ,malandin4 ,in appearance it is of the usual four-cycle type4 ,a lateral shaft transmits the rotation of the crank-shaft to a small crank which actuates the sliding valve4 ,this sliding valve forms one of the principal features of the engine1 and consists of a sliding iron plate pierced with two holes1 one oblique regulating the ignition1 and the other straight forming the admission valve4 ,the piston having completed its first forward stroke comes back to compress the explosive mixture1 and the sliding valve having advanced puts it in communication with a chamber containing two metallic points1 between which a continuous stream of electric sparks is made to flow4 ,after the explosion this cavity and the passage leading to it are filled with burnt gas1 which must be driven out to prevent a miss-fire at the next stroke4 ,this is effected by a small purging hole1 through which they are driven by a fresh charge entering the cylinder4 ,in earlier patterns of this engine an ingenious air governor was used1 but it has now been replaced by a fresh arrangement of a different pattern4 ,this governor 7,figs4 #df and #dg7 consists of a double pendulum1 which takes up a vertical position because of the lower ball1 seen in the illustration1 being the heaviest4 ,the whole pendulum is pivoted on a fixed bearing4 ,the variation in the speed is obtained by a weighted knife blade acting on the gas-valve4 ,the sliding valve is provided with a knife blade square at one end and pointed at the other1 which catches in a notch on the pendulum1 and is held by it in position so that the square end hits the end of the gas-valve and admits gas4 ,if1 however1 the speed of the engine be too great the sliding valve carries its knife blade forward too soon and it does not catch in the notch1 with the result that no gas is admitted as the square end is too low4 ,the speed of the engine1 therefore1 tends to remain adjusted to the rate of vibration of the pendulum1 which is a fixed quantity4 ,a self-starting arrangement is provided by stopping the engine half-way back along the compression stroke1 so that it is only necessary to pass an electric spark across for an explosion to occur and give it the necessary starting impetus4 ,illustration3 ,,fig4 #de4--,simplex ,gas ,engine 7,delamare-,deboutteville74 ,illustration3 ,,figs4 #df1 #dg4--;,governor of the ,simplex ,engine4 ,,mm4 ,delamare-,deboutteville and ,malandin were the first to construct units of very great power4 ,at the ,havre ,exhibition in #ahhi they exhibited a ,simplex engine using ,dowson gas1 and in #ahhi they exhibited at the ,paris ,exhibition a #ajj horse-power single-cylinder motor4 ,their latest achievement in this direction is the erection of a #cbj horse-power engine supplied by two ,buire-,lencauchez gasogenes with poor gas4 ,this is the largest single-cylinder gas engine in the world4 ,the ,simplex engine was the pioneer of motors using poor gas4 ,the machine we described was for use with coal gas1 and some modification has to be made in the parts when the motor is required to use gases of the ,dowson type4 ,the economy is very good1 only #ehj litres of coal gas or #eej grammes of anthracite being used per horse-power hour4 ,illustration3 ,,fig4 #dh4--;,combined ,simplex ,engine and ,buire-,lencauchez ,gas-,producer4 ,gardie motor4--,we have shown how poor gases are1 beyond a shadow of a doubt1 cheaper than coal gas for the production of power4 ,many makers have therefore attempted to use it by simply adding a gas-producing plant to existing engines4 ,sometimes these motors were totally unsuited for these cheaply produced gases1 and the result has been failure from miss-fire or irregular speed4 ,the ,crossley1 ,niel1 and ,andrews motors are exceptions1 and a few others have also given fairly good results4 ,we described in the previous chapter the ingenious gasogene devised by ,m4 ,gardie of ,nantes2 the motor which is constructed for use with it is rather novel4 ,it has two cylinders placed side by side1 a compressing pump and reservoir for compressed air4 ,the gaseous mixture arriving at a high temperature from the gasogene passes into the cylinders1 and is mixed with a volume of air coming from the reservoir2 these gases are compressed to about #ajj lbs4 on the square inch4 ,at the entrance to the cylinders are placed two igniters of platinum heated to a white heat by an electric current at starting1 but the temperature is afterwards maintained by the combustion4 ,during the admission the gaseous mixture burns without any explosion and without raising the pressure1 but considerably increasing in volume4 ,at the commencement of the stroke the pressure in the cylinder is therefore the same as in the compressor1 but it soon decreases by virtue of the expansion and driving forward of the piston4 ,after having exhausted themselves in doing work the gases pass out into a regenerator1 which communicates their heat to the air for admission4 ,the valves are actuated by a horizontal shaft placed above the cylinders2 the cams are three in number corresponding to three valves1 of which two regulate the admission of gas and air to a chamber in which they are mixed4 ,the third valve opens the exhaust4 ,this arrangement is not unlike that adopted by ,,mm4 ,forest and ,gallice for their marine oil engines4 ,the cylinders are surrounded by water jackets for cooling purposes1 aided by air which can enter the front end when the piston is moving in its backward stroke4 ,the hottest portion is therefore that situated at the valve end1 and in which the explosion takes place4 ,this portion is surrounded by a closed chamber forming a boiler1 where steam is formed for use in the gas plant2 the steam is superheated in a spiral coil placed on the top of the gasogene4 ,as we have already stated1 this system of gas production avoids the ammoniacal products1 which are a constant source of trouble in other engines4 ,the drawback lies in the compressor1 which uses up about one-third of the indicated power1 but the speed is exceedingly constant1 and averages about #age revolutions per minute4 ,the consumption of gas is not very high1 probably owing to the amount of heat which is absorbed from the waste gases1 usually lost4 ,a number of other engines exist of a similar type to the ,gardie motor1 such as the ,shaw1 ,woodburg1 ,crowe1 ,buchett1 and others1 which cannot1 however1 consume poor gases1 and which have not any distinguishing features worth mentioning4 ,bnier motor gasogene 7,figs4 #di and #ej74--,we have described the ,bnier gasogene1 and we will now complete the description by a short notice of the motor associated with it4 ,this motor works on the ,dugald-,clerk cycle1 and in general arrangement is not unlike the ,dugald-,clerk motors4 ,a special compressing cylinder is provided cast in one with the motor cylinder1 and the cranks are set at #ij degrees apart from one another4 ,the pump is double1 with two pistons coupled tandem-wise in the same cylinder4 ,one of these draws in the air and the other forces the gas into the gasogene4 ,the air and gas thus conducted by different paths reach the mixing chamber placed behind the motor cylinder and provided with a valve4 ,the motor cylinder has exhaust ports perforating the walls1 and which are uncovered by the piston when it has moved through five-sixths of the forward stroke4 ,it remains open during the remaining sixth and the first sixth of the return stroke4 ,at this moment the two piston pumps have forced into the cylinder the air and gas which they contain4 ,the mixture enters through a valve and a perforated plate1 which thoroughly mixes them in the cylinder4 ,during the return stroke the piston1 having closed the exhaust ports1 compresses the explosive mixture till the end of the stroke4 ,ignition then takes place1 and the explosion drives the piston forward1 and the products of combustion escape to the air directly the exhaust ports are uncovered by the piston4 ,illustration3 ,,figs4 #di1 #ej4--;,bnier ,engine and ,gas ,plant 7sectional plan and elevation74 ,by this arrangement it might happen that the explosive mixture introduced into the cylinder might escape by the open exhaust valves4 ,m4 ,bnier has obviated this difficulty by a novel device4 ,pure air is first admitted1 driving out the products of combustion2 the explosive mixture which follows is only admitted when the ports are closed4 ,this result is obtained by properly regulating the supply of air and gas from the pump4 ,one explosion therefore occurs in every revolution4 ,the ,bnier engine is constructed in sizes up to #ajj horse-power1 and also smaller ones of a few horse-power4 ,a #e horse-power motor consumes #hjj grammes of anthracite per horse-power hour3 this result is very remarkable1 because great difficulty has been found in working these small engines at all with poor gas2 the gas generator seems to work badly when its dimensions are so small4 ,a #ae horse-power motor only consumes #fjj grammes per horse-power hour4 ,the ,bnier combined plant shown in ,figs4 #di and #ej has received a most flattering reception on the ,continent1 and there is good reason to believe that it will be very much more widely used in the future4 ,we close this chapter with a table setting forth the relative merits and economy of a number of motors4 ---------------------------------------- ---------------------------------- ,cost ,nature ,power ,consumption per ,trials ,type of ,engine4 of of the ,consumption per horse-conducted ,fuel4 ,engine4 of ,fuel4 horse-power power by hour4 hour1 pence4 ---------------------------------------- ---------------------------------- ,lenoir 7#ahfj7 ,coal gas #i #bdjj litres #bgjj litres #i ,tresca ,hugon 7#ahff7 0 #bjg #edjj 0 #bfjj 0 #he 0 ,langen and ,otto 0 #df #ffj 0 #achj 0 #de 0 7#ahfg7 ,wittig and ,hees 0 #d #difj 0 #abdj 0 #ce ,brauer 7#ahha7 ,koerting- 0 #bah #bgjj 0 #abge 0 #cg ,schettler ,lieckfeld ,otto 0 #hcd #iejj 0 #iae 0 #bh ,allard and ,potier ,dugald-,clerk 0 #aaf #igjj 0 #hgg 0 #be ,sterne 7#ahhd7 ,lenoir 7#ahhe7 0 #b #acbj 0 #fee 0 #ai ,tresca ,simplex 7#ahhe7 0 #ida #eehj 0 #eic 0 #aa ,witz 0 0 ,dowson #cff #fjdj 0 #ccjj 0 #g 0 gas ,lenoir 7#ahhe7 ,carburet- #dae #bg 0 #fe 0 #de ,tresca ted air 7petroleum7 ,benz 7#ahhe7 ,coal gas #ea #cfjj litres #gjg 0 #ad 0 ,atkinson 7#ahhh7 0 #idh #fjjj 0 #fah 0 #ac ,society of ,arts ,crossley7#ahhh7 0 #adgd #aj1hjj 0 #gfe 0 #ae 0 0 ,griffin 7#ahhh7 0 #abea #iejj 0 #ghf 0 #ae 0 0 ,charon 7#ahhi7 0 #dag #bbaj 0 #ecj 0 #aa ,witz ,forest 7#ahij7 ,petroleum #affg #g kilg4 #djj #deh grms4 #c ,martin spirit ,niel 7#ahia7 ,coal gas #cge #abej 0 #djb litres #h ,witz ,simplex 7#ahhi7 ,poor gas #ge #aia cub4 met4 #bcgj 0 #g 0 0 7#ahic7 0 #bbj #aaj kilg4 #ejj grms4 #c ,leblan 7anthracite7 ,lenoir 7#ahia7 ,coal gas #f #dbfj #gaj litres #ae ,lencauchez ,charon 7#ahib7 0 #ge #dchj #ehf 0 #ab ,chauveau ,priestman 7#ahij7 ,daylight #gg #c kilg4 #che grms4 #ag ,unwin oil 0 7#ahia7,russoline #fg #b kilg4 #gjj #dbh 0 #ai 0 ,crossley 7#ahib7 ,dowson #adh #dae kilg4 #bhj 0 #b ,dowson gas 7anthracite7 ,atkinson 7#ahib7 0 #afg #ff kilg4 #dee 0 #c ,tomlinson ,schleicher-,schum ,poor gas #ib #ee 0 #eif 0 #cb ,spanglon ,trusty ,petroleum #dc #ahc 0 #ddj 0 #bb ,beaumont 7ordinary7 ,delamare- ,lencauchez #fb #cg 0 #fjc 0 #b ,bourdon ,deboutteville gas 7cheap coal7 7#ahid7 ,campbell 7#ahie7 ,petroleum #f #bd 0 #djj grms4 #be 0 7ordinary7 ---------------------------------------- ---------------------------------- ,the price of fuel has been calculated from prices current at the dates given4 ,,chapter ,,viii ,,maintenance ,,of ,,gas ,,and ,,oil ,,engines ,gas engines are in most cases mounted on a metal bed-plate1 and for small engines the weight of the machine is very often sufficient to keep it in place2 it is more satisfactory1 however1 to bolt it firmly down to a bed of concrete or stone4 ,plenty of room must be allowed round about to enable cleaning and repairs to be executed2 space is also necessary for turning the fly-wheel round if no self-starting mechanism is provided4 ,above two or three horse-power water must be used for cooling the cylinder1 mere cooling by air circulation being insufficient for carrying off the waste heat except in very small motors4 ,it occasionally happens that water is laid on1 which can be used for the water jacket1 the heated water being simply allowed to run to waste4 ,unless the water is exceedingly cheap this arrangement is far too expensive1 and it becomes necessary to erect a separate circulating system1 in which the water is used over and over again4 ,makers provide for this purpose galvanized iron tanks1 which are connected by two pipes to the water jacket4 ,the tank being filled with water1 and the engines started1 circulation takes place in a manner similar to the ordinary household hot-water systems4 ,the lower opening of the water jacket is connected to the lower pipe from the tank1 and the second pipe1 starting from a point near the top of the tank1 is connected to the upper opening of the cooling jacket4 ,the difference of density between hot and cold water causes the former to rise and flow back to the reservoir along the upper pipe1 and cold water rushes in to take its place4 ,about #djj to #ejj litres of cold water are required per horse-power1 but it largely depends on the rate at which the tank cools2 in some cases only #bjj litres being found quite sufficient4 ,the temperature of the water leaving the jacket should be about #fj ,c4 ,it is more economical to let it rise to #hj ,c41 but in this case very good lubricating oil is required for the cylinder4 ,a tap in the lower pipe1 and a thermometer placed against the upper one1 will enable the attendant to adjust this temperature4 ,starting and stopping4--,starting is an operation requiring a little practice4 ,first of all the igniting burner must be lit1 and time allowed for it to red-heat the ignition-tube2 if electricity is used this wait of a few minutes is obviated4 ,the lubricating arrangements are then attended to1 so as to make sure of them being in satisfactory working order4 ,if no self-starting arrangement is provided1 the supply of gas to the cylinder is partly turned on1 and a few quick turns of the fly-wheel by hand are sufficient to set the engine in motion4 ,having attained the normal speed the gas can be turned full on4 ,if the motor refuses to start1 the tap regulating the gas supply should be examined as it may be too full on2 the ignition apparatus must then be inspected4 ,sometimes the reason of the refusal to start lies in the exhaust-valve which leaks2 in this case no compression takes place4 ,this can easily be verified by turning the fly-wheel backwards1 and seeing whether the piston tends to resist the motion1 which it would do if the compression was taking place properly4 ,when running it is a mistake to flood the engine with oil2 a barely sufficient quantity of good mineral oil is all that is required4 ,if the valves require cleaning1 then of course plenty of oil should be used to wash away the deposit1 but they should be well wiped before starting4 ,many persons have become erroneously imbued with the idea that a gas engine requires a skilled mechanic to attend to it4 ,as a matter of fact any person without previous knowledge is1 with a few days' practice1 competent to take charge of a motor provided that he is intelligent and careful4 ,under these conditions a gas engine will last as long as a steam engine1 and will be generally found much more satisfactory4 ,to stop the machine1 the self-starting mechanism must first be allowed to operate1 and then the supply of gas is shut off4 ,after this the burner or electric ignition must be cut off1 and the cooling water too1 if it is not a circulating system4 ,if the machine is to remain stopped for some considerable period1 turn the fly-wheel round till the piston is in its most forward position2 this will prevent dust and grit from getting into the cylinder1 and scoring the inside when the engine is re-started4 ,these are the general rules which must be obeyed in the maintenance of the gas engine4 ,the attention they require is therefore small1 and this quality has contributed not a little to their success4 ,no stoker or engine-driver is required2 any person can1 with very little instruction1 take charge of them4 ,if the engine is properly erected by skilled workmen1 and has been running sufficiently long to have arrived at a condition of regular lubrication1 etc41 a person in constant attendance can be dispensed with1 and it is sufficient to look in occasionally and see that everything is all right1 that there is a sufficient supply of oil1 and that the cylinder is cool1 because if it became overheated it might bind and destroy the interior4 ,every month a complete cleaning should be undertaken1 the valve mechanism and cylinder being washed with mineral oil to dissolve the deposit of carbon and tarry substances in them4 ,every six months the valves should be re-adjusted1 and if necessary re-ground into their seatings4 ,the time and trouble necessary for these periodical cleanings will be amply repaid by the satisfactory working of the engine2 nothing is more annoying than a breakdown due to accumulation of dirt1 and to the continual postponement of the cleaning out4 ,maintenance of oil engines4--,these machines require the same careful treatment as gas engines1 but they have in addition a carburator or a vaporizer which require special attention1 and render the cylinder particularly liable to become fouled by the heavier products of the vaporized oil4 ,we have already described the principal systems of vaporizers and carburators1 and we shall only return to them to state1 that for efficient working they should be cleaned out once a week4 ,at the very outside not more than a month should elapse between the removals of incrustations and deposits of carbon4 ,the lamps used for supplying heat to the vaporizer should also be attended to from time to time1 and occasionally thoroughly cleaned out4 ,ignition of the explosive mixture4--,as we have already seen1 several different methods exist of setting fire to the explosive gases1 and each of them has its advantages and drawbacks4 ,ignition by an incandescent tube of iron or porcelain seems to be the most simple1 and works as well as any other system2 the sliding valve containing the igniting jet is somewhat more complicated4 ,electric ignition1 if effected by a magneto generator driven by the engine1 is certain in its operation1 but it is awkward at starting4 ,for petroleum and carburetted air motors batteries both primary and secondary are better1 especially when the motors are used for propelling vehicles4 ,looked at from the economy point of view1 it is very hard to decide which is the best system of ignition3 red-hot tubes require gas1 accumulators require electric energy to be put into them1 magneto machines are expensive and use up power1 in fact1 they are all about the same as far as cost is concerned4 ,in ,france electric ignition is in much greater vogue than in this country1 where hot tubes reign supreme4 ,the electric system requires a few words concerning batteries and induction coil4 ,if primary batteries are used the chromic acid type is the best4 ,these are manufactured in a large number of varieties2 some of the ,french makers1 ,trouv1 ,gurot1 ,radiguet1 and others1 have paid special attention to their application to gas and petroleum engines4 ,the induction coil should have a rather thicker secondary winding than usual2 it is necessary to have as hot a spark as possible to ignite the gas1 and this is not obtained if the spark is of exaggerated length4 ,illustration3 ,,fig4 #ea4--,section of the ,simplex ,gas-producing ,plant4 ,the spark-gap also requires occasional attending to4 ,it consists usually of a porcelain rod with two points between which the sparks pass1 either intermittently or governed by an automatic switch1 or else continuously4 ,in either case the points often become coated with a deposit of carbon1 which decreases their efficiency4 ,they must therefore be wiped clean about once a week4 ,maintenance of engines using poor gas4--,these engines differ very little from the ordinary coal-gas engine4 ,the arrangement of valves which will do for the one is also suitable for the other4 ,we shall therefore only give a few hints on the management of the gas-producing plants which forms their only point of difference2 to do this we shall consider a 8,simplex0 plant4 ,the firm of ,matter et ,cie4 have received many letters from other firms to whom they have supplied their apparatus1 replacing existing steam engines1 in which they state that the whole management and maintenance of their new source of power is much more simple than the old4 ,this is not to be wondered at1 because the whole plant is perfectly automatic4 ,there are no pressure or water gauges to attend to1 because no more gas is ever produced than is absolutely wanted4 ,a steam boiler may require to be stoked once every quarter of an hour1 whilst a poor gas generator only requires charging about once every six hours1 according to demand for power4 ,the ,simplex motor itself requires very little attention1 and all bearing surfaces are made as large as possible to avoid the risk of heating4 ,fig4 #ea shows a complete plant in section4 ,a is the generator filled with coke or anthracite2 the opening of the hopper1 ,n1 and the door1 ,d1 of the hearth are closed4 ,air arrives from the centrifugal pump through a stop-valve1 ,i1 and water through ,w4 ,the air passes through the mass of incandescent carbon forming carbonic acid gas1 which is again reduced by the excess of carbon to carbon monoxide4 ,the water becomes vaporized1 and is dissociated by the action of the heated carbon forming hydrogen and oxygen1 which combines with the carbon forming more carbon monoxide4 ,the gas produced consists therefore of carbon monoxide1 hydrogen1 nitrogen1 and a small proportion of hydrocarbons and carbonic acid gas4 ,passing by the pipe ,s to the base of the washing-tower the gases meet in their ascent water from the pipe ,z1 which cleanses them of all impurities1 after which they pass by the pipe ,y to the gasometer1 and from there to the engine4 ,we close this description of gas and oil engines1 hoping that we have said enough to put before electrical engineers who are thinking of making use of this economic form of motive power1 the exact state of affairs1 what results have been obtained1 and especially the considerations which govern the choice of an engine4 ,illustration3 ,,fig4 #eb4--;,agricultural ,oil ,locomotive4 ,we further hope that this systematic examination of all engines which have received the sanction of practical experience1 will prove of some service to those who wish to become better acquainted with the numerous existing types1 and to understand their relative advantages and faults1 in order that they may select a gas engine which is suitable to the particular requirements of each individual case4 ,,index ,buire-,lencauchez ,gas1 #aaj ,carburator1 ,schrab1 #fi 0 ,delamare1 #gj 0 ,lothhammer1 #gj 0 ,meyer1 #fi ,carburetted ,air ,engine1 ,brouhot1 #gd 0 ,daimler1 #gc 0 ,de ,dion-,bouton 7,tricycle71 #ge 0 ,durand1 #ga 0 ,lenoir1 #fh 0 ,tenting1 #ga ,carburetted ,gas1 ,faignot1 #fh 0 ,mille1 #fg ,de ,dion-,bouton ,motor ,tricycle1 #ge ,dowson ,gas1 #ajg ,efficiency of ,heat ,engines1 #ae ,gas ,engine1 ,andrews1 #da 0 ,atkinson1 #eg 0 ,baldwin1 #cc 0 ,bnier1 #bf 0 ,benz1 #ca 0 ,bisschop1 #bd 0 ,cadiot1 #fc 0 ,campbell1 #cd 0 ,charon1 #ei 0 ,compagnie ,parisienne1 #fa 0 ,crossley1 #dg 0 ,cuinat1 #ee 0 ,dugald-,clerk1 #bi 0 ,economic1 #bh 0 ,fielding1 #db 0 ,forest1 #bg1 #ec 0 ,franois1 #be 0 ,griffin1 #fe 0 ,h4 ,c41 #fc 0 ,koerting-,lieckfeld1 #ci 0 ,lablin1 #de 0 ,lenoir1 #bc1 #ch 0 ,lentz1 #bh 0 ,letombe1 #fb 0 ,martini1 #de 0 ,midland1 #cd 0 ,national1 #ea 0 ,niel1 #dd 0 ,nol1 #ef 0 ,otto1 #ce 0 ,pygme1 #di 0 ,richardson and ,norris1 #fc 0 ,robuste1 #fb 0 ,roger1 #fa 0 ,rollason1 #fe 0 ,simplex1 #aba 0 ,stockport1 #ca 0 ,tenting1 #eg1 #ga ,gas-producer1 ,bnier1 #aae1 #abf 0 ,gardie1 #aab 0 ,kitson1 #aah 0 ,loomis1 #aah 0 ,taylor1 #aac 0 ,taylor-,wimand1 #aag 0 ,wilson1 #aai ,history of ,gas ,engine1 #a ,longsden process1 #aai ,lowe 0 #aje ,maintenance of ,gas ,engines1 #aca ,otto ,cycle1 #h ,oil ,engine1 ,brayton1 #gg 0 ,campbell1 #hb 0 ,capitaine1 #he 0 ,crossley-,holt1 #ih 0 ,griffin1 #ajj 0 ,grob1 #hb 0 ,hornsby-,akroyd1 #ij 0 ,knight1 #ih 0 ,koerting-,boulet1 #ig 0 ,merlin1 #hi 0 ,niel1 #aja 0 ,priestman1 #gi 0 ,ragot1 #id 0 ,root1 #ie 0 ,scurit1 #gi 0 ,trusty1 #ii 0 ,vulcan1 #ic ,siemens ,gas1 #ajg ,strong process1 #aje ,working ,principles of ,gas ,engine1 #ac ,richard ,clay ,sons1 ,limited1 ,london ,bungay4 ,pott #hvo1 limp roan1 gilt edges1 #es4 ,,whittaker',s ,,mechanical ,,engineer',s ,,pocket-,,book ,,by ,,philip ,r4 ,,bj,,rling4 ,,contents4 ,,water--,,wind ,,engines--,,air--,,steam--,,manual ,,power--,,animal ,,power--,,pipes--,,tanks--,,crabs1 ,,winches ,,and ,,cranes--,,gearing--,,rope ,,driving--,,belting--,,shafting--,,beam s--,,gravity ,,of ,,falling ,,bodies--,,accelerated ,,motion--,,centrifugal ,,force--,,pendulum--,,thermometers--,,m ining ,,machinery--,,hydraulic ,,gold ,,mining--,,elevators1 ,,conveyers ,,and ,,picking ,,tables--,,chain ,,belting--,,centrifugal ,,fans--,,speeds ,,of ,,machinery ,,and ,,tools--,,tables4 #8,it contains information not often found in similar works4'--,english ,mechanic4 #8,the book is evidently framed with a thorough appreciation of the most modern needs of the engineer4'--,marine ,engineer4 #8,there is little that any mechanical engineer is likely to require to be informed on--as to formul and data--that is not afforded in greater or lesser degree by the pages of this pocket-book4'--,electrician4 #8,literally packed with concrete data on all matters connected with practice of mechanical engineering1 and every engineer will be much the better practical craftsman in having the work constantly at hand4'--,building ,industries4 #8,we welcome it as a valuable vade mecum to the engineer be he mechanical or civil4'--,indian and ,eastern ,engineer4 ,with #aab ,illustrations4 ,cr4 #hvo1 #bej pp41 #es4 ,,auto-,,cars4 ,,by ,d4 ,,farman1 ,m4,i4,e4,e41 ,,mechanical ,,engineer4 ,,sole ,,authorised ,,translation ,,from ,,the ,,french1 ,,with ,,appendices ,,of ,,the #8,,auto-,,car' ,,bill1 ,,latest ,,developments1 ,,etc4 ,,by ,,lucien ,,serraillier4 ,,contents4 ,,general ,,and ,,historical--,,theory ,,of ,,various ,,types ,,of ,,motors--,,description ,,of ,,the ,,various ,,systems ,,of ,,steam ,,traction--,,compressed ,,air ,,auto-,,cars--,,petroleum ,,auto-,,cars--,,electric ,,auto-,,cars--,,report ,,on ,,the ,,auto-,,cars ,,which ,,entered ,,for ,,the ,,race ,,organised ,,by ,,the #8,,times ,,herald' ,,of ,,chicago--,,lubrication--,,tyres--,,bea rings--,,springs--,,axles--,,carburators -- ,,ignition--,,starting--,,vibration4 #8,a handy little treatise1 both practical and theoretical4'--,times4 #8,a book of interest to those who require general information on the subject4'--,engineer4 #8,this excellent book is simply full of every kind of information on motor-cars4'--,electrical ,review4 #8,amongst works on motor-cars1 that by ,mr4 ,farman is in many respects the best4'--,english ,mechanic4 ---------------------------------------- ---------------------- ,,whittaker',s ,,electro-,,mechanical ,,series ,adapted from the ,french of ,,henry ,,de ,,graffigny by ,a4 ,g4 ,,elliott1 ,b4,,sc4 ,,being ,,an ,,elementary ,,and ,,popular ,,series ,,of ,,books ,,on ,,the ,,theory ,,and ,,practice ,,of ,,electricity4 ,in crown #hvo1 cloth1 #bs4 #f;d4 each4 ,vol4 ,i4--,,industrial ,,electricity ,vol4 ,,ii4--,,gas ,,and ,,petroleum ,,motors ,vol4 ,,iii4--,,distribution ,,of ,,electricity ,vol4 ,,iv4--,,electro-,,chemistry ,others preparing4 99 99 99 99 99 ,in small crown #hvo1 illustrated1 cloth1 #es4 each volume4 ,,elementary ,,electro-,,technical ,,series ,by ,,edwin ,j4 ,,houston1 ,ph4,d41 and ,a4 ,e4 ,,kennelly1 ,sc4,d4 ,alternating ,electric ,currents ,electric ,heating ,electromagnetism ,electricity in ,electro-,therapeutics ,electric ,arc ,lighting ,electric ,incandescent ,lighting ,electric ,motor ,electric ,street ,railways ,electric ,telephony ,electric ,telegraphy 99 99 99 99 99 ,,london3 ,,whittaker ,,and ,,co4 ---------------------------------------- ---------------------- ,whittaker's ,electro-,mechanical ,series4 ,crown #hvo4 #bs4 #f;d4 a volume4 ,,volume ,i4 ,,industrial ,,electricity4 ,,contents4 ,,nature ,,of ,,electricity--,,electric ,,units--,,magnetism ,,and ,,induction--,,practical ,,measurements ,,of ,,electrical ,,quantities--,,chemical ,,generators ,,of ,,electricity--,,accumulators--,,dynamo ,,electric ,,machinery--,,electric ,,light--,,electricity ,,as ,a ,,motive ,,power--,,electro-,,chemistry ,,and ,,electro-,,plating--,,bells ,,and ,,telephones--,,telegraphs1 ,,etc4 #8,the neatness of mind with which all this technical matter is expounded makes the work unusually attractive1 and the series has every prospect of success4'--,scotsman4 #8,the arrangement of the work is excellent1 the illustrations good1 the explanations clear4'--,reynolds' ,newspaper4 #8,the work is commendably free from mathematical language1 and on that account should be welcome4'--,daily ,telegraph4 #8,as these works explain in clear and non-mathematical language many of the various applications of electricity1 they undoubtedly meet the requirements of many readers who wish to grasp the principles underlying the applications of electricity now becoming so general4'--,engineers' ,gazette4 #8,the author and compiler has given a useful and popular account of the present state of the knowledge in regard to electricity and of its application to the service of man4'--,marine ,engineer4 ,,other ,,volumes ,,of ,,series-- ,,vol4 ,,ii4 ,,gas ,,and ,,petroleum ,,engines4 ,,vol4 ,,iii4 ,,distribution ,,of ,,electricity4 ,,vol4 ,,iv4 ,,electro ,,electricity4 ,others in preparation4 99 99 99 99 99 ,,whittaker',s ,,library ,,of ,arts1 ,sciences1 ,manufactures and ,industries4 ,illustrated4 ,in ,square ,crown #hvo4 ,cloth4 #8,messrs4 ,whittaker's valuable series of practical manuals4' ,electrical ,review4 ,by ,w4 ,,perren ,,maycock1 ,m4,i4,e4,e4 ,,first ,,book ,,of ,,electricity ,,and ,,magnetism4 ,second ,edition1 ,revised and ,enlarged1 with #ajg ,illustrations4 #bs4 #f;d4 #8,students who purchase a copy1 and carefully study it1 will obtain an excellent groundwork of the science4'--,electrical ,review4 ,by ,,the ,,same ,,author4 ,,electric ,,lighting ,,and ,,power ,,distribution--,an ,elementary ,manual of4 ,for ,students preparing for the ,preliminary and ,ordinary ,grade ,examination of the ,city and ,guilds of ,london ,institute1 and general readers4 ,third ,edition1 ,revised and ,enlarged1 in two volumes4 ,vol4 ,i41 #dcj pp41 with #bca ,illustrations4 ,crown #hvo4 #fs4 #8,the work will no doubt become a standard text-book for schools and classes on this subject2 as such1 it has few equals4'--,electrical ,review4 ,,the ,,alternating ,,current ,,circuit4 ,an ,introductory and ,non-,mathematical ,book for ,young ,engineers and ,students4 ,by ,w4 ,,perren ,,maycock1 ,m4,i4,e4,e4 ,with #df ,illustrations4 ,small crown #hvo1 cloth4 #bs4 #f;d4 ,,fitting1 ,,the ,,principles ,,of4 ,for ,engineer ,students4 ,by ,j4 ,,horner1 ,m4,i4,m4,e4 ,illustrated with about #bej ,engravings1 and containing an ,appendix of ,useful ,shop ,notes and ,memoranda4 #es4 #8,calculated to aid and encourage the most useful set of handicraftsmen we have amongst us4'--,daily ,chronicle4 ,,the ,,principles ,,of ,,pattern ,,making4 ,written specially for ,apprentices1 and for ,students in ,technical ,schools4 ,by ,j4 ,,horner1 ,m4,i4,m4,e4 ,illustrated with #aja ,engravings1 and containing a ,glossary of the ,common ,terms employed in ,pattern ,making and ,moulding4 #cs4 #f;d4 #8,the book is well illustrated1 and for its size will be found one of the best of its kind4'--,industries4 ,,practical ,,ironfounding4 ,by ,j4 ,,horner1 ,m4,i4,m4,e41 #8a ,foreman ,pattern ,maker4' ,illustrated with over #ajj ,engravings4 ,second ,edition4 #ds4 #8,every pupil and apprentice would find it1 we think1 an assistance to obtaining a thorough knowledge of his work4 ,the book1 however1 is not intended merely for the student1 but contains much useful information for practical men4'--,industries4 ,,metal ,,turning4 ,by ,j4 ,,horner1 ,m4,i4,m4,e4 ,with #ha ,illustrations4 #ds4 ,,contents3--,the ,lathe--,tools and ,tool ,angles--,chucks--,chucking--,general ,remarks on ,turning--,hand ,turning--,slide ,rest ,turning--,boring--,screw ,cutting1 etc4 #8,an exceedingly useful publication to have at hand4'--,machinery4 ,by ,g4 ,e4 ,,bonney4 ,,electrical ,,experiments4 ,with #add ,illustrations4 ,second ,edition4 #bs4 #f;d4 #8,this is an excellent book for boys4'--,electrical ,review4 ,,induction ,,coils4 ,a ,practical ,manual for ,amateur ,coil-makers4 ,with a ,new ,chapter on ,coils for ,radiography4 ,with #aja ,illustrations4 #cs4 #8,in ,mr4 ,bonney's useful book every part of the coil is described minutely in detail1 and the methods and materials required in insulating and winding the wire are fully considered4'--,electrical ,review4 ,by ,g4 ,e4 ,,bonney4 ,,the ,,electro-,,plater',s ,,handbook4 ,a ,practical ,manual for ,amateurs and ,young ,students in ,electro-,metallurgy4 ,with ,full ,index and #fa ,illustrations4 ,second ,edition1 ,revised and ,enlarged1 with an ,appendix on ,,electrotyping4 #cs4 #8,an ,amateur could not wish for a better exposition of the elements of the subject4'--,electrical ,review4 ,by ,h4 ,,orford4 ,,lens ,,work ,,for ,,amateurs4 ,with numerous ,illustrations4 ,small crown #hvo4 #cs4 #8,the book is a trustworthy guide to the manufacturer of lenses1 suitable alike for the amateur and the young workman4'--,nature4 ,,modern ,,optical ,,instruments4 ,by the same ,author4 #bs4 #f;d4 ,by the late ,j4 ,,traill ,,taylor1 ,editor of the ,british ,journal of ,photography4 ,,the ,,optics ,,of ,,photography ,,and ,,photographic ,,lenses4 ,with #fh ,illustrations4 #cs4 #f;d4 #8,personally we look upon this book as a most valuable labour-saving invention1 for no questions are so frequent1 or take so long to answer1 as those about lenses4'--,practical ,photographer4 ,by ,,joseph ,,poole1 ,a4,i4,e4,e4 7,wh4 ,sc4 #ahge71 ,chief ,electrician to the ,new ,telephone ,company1 ,manchester4 ,,the ,,practical ,,telephone ,,handbook4 ,with #bbh ,illustrations4 ,second ,edition4 ,revised and considerably ,enlarged4 #es4 #8,this essentially practical book is published at an opportune moment4 ,it contains readable accounts of all the best-known and most widely used instruments1 together with a considerable amount of information not hitherto published in book form4'--,electrician4 ,by ,,sydney ,f4 ,,walker1 ,m4,i4,e4,e41 ,a4,m4,inst4,c4,e4 ,,electricity ,,in ,,our ,,homes ,,and ,,workshops4 ,a ,practical ,treatise on ,auxiliary ,electrical ,apparatus4 ,third ,edition4 ,revised and ,enlarged4 ,with #adc ,illustrations4 #fs4 #8,it would be difficult to find a more painstaking writer when he is describing the conditions of practical success in a field which he has himself thoroughly explored4'--,electrician4 ,by ,d4 ,,denning4 ,,the ,,art ,,and ,,craft ,,of ,,cabinet ,,making4 ,a ,practical ,handbook to the ,construction of ,cabinet ,furniture1 the ,use of ,tools1 ,formation of ,joints1 ,hints on ,designing and ,setting ,out ,work1 ,veneering1 etc4 ,with #bai ,illustrations4 #es4 #8,a carefully-considered and well-written book4'--,work4 ,by ,f4 ,c4 ,,allsopp1 ,author of #8,the ,telephones and their ,construction4' ,,practical ,,electric-,,light ,,fitting4 ,a ,treatise on the ,wiring and ,fitting-up of ,buildings deriving current from ,central ,station ,mains1 and the ,laying down of ,private ,installations1 including the latest edition of the ,phnix ,fire ,office ,rules4 ,with #bbd ,illustrations4 ,second ,edition1 revised1 #es4 #8,a book we have every confidence in recommending4'--,daily ,chronicle4 ,by ,j4 ,,hopkinson1 ,d4,sc41 ,f4,r4,s4 ,,dynamo ,,machinery1 ,,original ,,papers ,,on4 ,with #ih ,illustrations4 #es4 #8,must prove of great value to the student and young engineer4'--,electrical ,review4 ,by ,s4 ,r4 ,,bottone4 ,,electrical ,,instrument-,,making ,,for ,,amateurs4 ,a ,practical ,handbook4 ,with #gh ,illustrations4 ,sixth ,edition1 ,revised and ,enlarged4 #cs4 #8,to those about to study electricity and its application this book will form a very useful companion4'--,mechanical ,world4 ,by ,s4 ,r4 ,,bottone4 ,,electro-,,motors3 ,how ,made and ,how ,used4 ,a ,handbook for ,amateurs and ,practical ,men4 ,with #gj ,illustrations4 ,third ,edition1 ,revised and ,enlarged4 #cs4 #8,we are certain that the knowledge gained in constructing machines such as described in this book will be of great value to the worker4'--,electrical ,engineer4 ,by ,s4 ,r4 ,,bottone4 ,,electric ,,bells1 ,,and ,,all ,,about ,,them4 ,a ,practical ,book for ,practical ,men4 ,with more than #ajj ,illustrations4 ,fifth ,edition1 ,revised and ,enlarged4 #cs4 #8,any one desirous of undertaking the practical work of electric bell-fitting will find everything1 or nearly everything1 he wants to know4'--,electrician4 ,by ,s4 ,r4 ,,bottone4 ,,the ,,dynamo3 ,how ,made and ,how ,used4 ,tenth ,edition1 with additional matter and ,illustrations4 #bs4 #f;d4 ,,how ,,to ,,manage ,a ,,dynamo4 ,by the same ,author4 ,second ,edition1 ,revised4 ,illustrated4 ,pott #hvo1 cloth4 ,pocket size4 #as4 #8,this little book will be very useful4'--,electrical ,engineer4 ,by ,sir ,,david ,,salomons1 ,bart41 ,m4,a41 ,vice-,president of the ,institution of ,electrical ,engineers1 etc4 ,,electric-,,light ,,installations1 ,,and ,,the ,,management ,,of ,,accumulators4 ,a ,practical ,handbook4 ,sixth ,edition1 ,revised and ,enlarged1 with numerous ,illustrations4 #fs4 #8,to say that this book is the best of its kind would be a poor compliment1 as it is practically the only work on accumulators that has been written4'--,electrical ,review4 ,by ,j4 ,,gray1 ,b4,sc4 ,,electrical ,,influence ,,machines3 containing a ,full ,account of their ,historical ,development1 their ,modern ,forms1 and their ,practical ,construction4 #ds4 #f;d4 #8,this excellent book4'--,electrical ,review4 ,by ,,edwin ,j4 ,,houston1 ,a4,m41 ,professor of ,natural ,philosophy and ,physical ,geography in the ,central ,high ,school of ,philadelphia1 ,professor of ,physics in the ,franklin ,institute of ,pennsylvania1 etc4 ,,advanced ,,primers ,,of ,,electricity4 ,vol4 ,i4--,,electricity ,,and ,,magnetism4 #cs4 #f;d4 ,vol4 ,,ii4--,,electrical ,,transmission ,,of ,,intelligence4 #es4 ,vol4 ,,iii4--,,electrical ,,measurements4 #es4 ,,the ,,metric ,,system ,,of ,,weights ,,and ,,measures ,,compared ,,with ,,the ,,imperial ,,system4 ,by ,w4 ,h4 ,,wagstaff1 ,m4,a41 ,professor of ,geometry at ,gresham ,college4 ,crown #hvo1 cloth4 #as4 #f;d4 ,,engineer ,,draughtsmen',s ,,work4 ,hints for ,beginners4 ,by a ,,practical ,,draughtsman4 ,with #hj ,illustrations4 ,small cr4 #hvo1 cloth4 #as4 #f;d4 #8,will be found of practical value to the beginner in the drawing office4'--,engineer4 ,,practical ,,electrical ,,measurements4 ,an ,introductory ,manual in ,practical ,physics for ,students and ,engineers4 ,by ,e4 ,h4 ,,crapper1 ,lecturer in ,electrical ,engineering at the ,sheffield ,technical ,school4 ,with #ef ,illustrations4 ,crown #hvo1 #bs4 #f;d4 ,london3 ,,whittaker ,,co41 #b ,white ,hart ,street1 ,paternoster ,sq4 ,transcriber's ,notes3 - ,text enclosed by underscores is in italics 7italics74 - ,text enclosed by equals is in bold 7bold74 - ,blank pages have been removed4 - ,silently corrected typographical errors4 - ,spelling and hyphenation variations made consistent4 - ,front advertisements moved to the back4 - 80 is used to enclose a subscripted number1 such as 8,h#b04