September i, 1904] 



NA TURE 



435 



inventions have been the result of long training and 

 laborious research and long-continued labour. Generally, 

 what is usually called an invention is the work of many 

 individuals, each one adding something to the work of his 

 predecessors, each one suggesting something to overcome 

 some difficulty, trying many things, testing them when 

 possible, rejecting the failures, retaining the best, and by 

 a process of gradual selection arriving at the most perfect 

 method of accomplishing the end in view. 



This is the usual process by which inventions are made. 



Then after the invention, which we will suppose is the 

 successful attempt to unravel some secret of Nature, or some 

 mechanical or other problem, there follows in many cases 

 the perfecting of the invention for general use, the realisa- 

 tion of the advance or its introduction commercially ; this 

 after-work often involves as great difficulties and requires 

 for its accomplishment as great a measure of skill as the 

 invention itself, of which it may be considered in many 

 cases as forming a part. 



If the invention, as is often the case, competes with or is 

 intended to supersede some older method, then there is a 

 struggle for existence between the two. This state of 

 things has been well described by Mr. Fletcher Moulton. 

 The new invention, like a young sapling in a dense forest, 

 struggles to grow up to maturity, but the dense shade of 

 the older and higher trees robs it of the necessary light. 

 If it could only once grow as tall as the rest all would be 

 easv, it would then get its fair share of light and sunshine. 

 Thus it often occurs in the history of inventions that the 

 surroundings are not favourable when the first attack is 

 made, and that subsequently it is repeated by different 

 persons, and finally in different circumstances it may 

 eventually succeed and become established. 



We may take in illustration almost any of the great in- 

 ventions of undoubted utility of which we happen to have 

 the full history — for instance, some of the great scientific 

 discoveries, or some of the great mechanical inventions, 

 such as the steam-engine, the gas-engine, the steamship, 

 the locomotive, the motor-car, or some of the great chemical 

 or metallurgical discoveries. Are not most, if not all, of 

 these the result of the long-continued labour of many 

 persons, and has not the financial side been, in most cases, 

 a very important factor in securing success? 



The history of the steam-engine might be selected, but 

 I prefer on this occasion to take the internal-combustion 

 engine, for two reasons — firstly, because its history is a 

 typical one ; and secondly, because we are to hear a paper 

 by that able exponent and great inventor in the domain of 

 the gas-engine, Mt. Dugald Clerk, describing not only the 

 history, but the engine in its present state of development 

 and perfection, an engine which is able to convert the 

 greatest percentage of heat units in the fuel into mechanical 

 work, excepting only, as far as we at present know, the 

 voltaic battery and living organisms. 



The first true internal-combustion engine was undoubtedly 

 the cannon, and the use in it of combustible powder for 

 giving energy to the shot is strictly analogous to the use 

 of the explosive mixture of gas or oil and air as at present 

 in use in all internal-combustion engines: thus the first 

 internal-combustion engine depended on the combination 

 of a chemical discovery and a mechanical invention, the 

 invention of gunpowder and the invention of the cannon. 



In 1680 Huygens proposed to use gunpowder for obtain- 

 ing motive power in an engine. Papin, in 1690, continued 

 Huygens's experiments, but without success. These two 

 inventors, instead of following the method of burning the 

 powder under pressure, as in the cannon, adopted, in ignor- 

 ance of thermodynamie laws, an erroneous course. They 

 exploded a small quantity of gunpowder in a large vessel 

 with escape valves, which after the explosion caused a partial 

 vacuum to remain in the vessel. This partial vacuum was 

 then used to actuate a piston or engine and perform useful 

 work. Subsequently several other inventors worked on the 

 same lines, but all of these failed on account of two causes 

 which now are very evident to us. Firstly, gunpowder was 

 then, as it still is, a very expensive form of fuel, in pro- 

 portion to the energy liberated on explosion ; secondly, the 

 method of burning the powder to cause a vacuum involves 

 the waste of nearly the whole of the available energy, 

 whereas had it been burned under pressure, as in the cannon, 

 a comparatively large percentage of the energy would have 



NO. 1818. VOL. 70I 



been converted into useful work. But even with this alter- 

 ation, and however perfect the engine had been, the cost 

 of explosives would have debarred its coming into use, 

 except for very special purposes. 



We come a century later to the first real gas-engine. 

 Street, in 1794, proposed the use of vapour of turpentine 

 in an engine on methods closely analogous to those success- 

 fully adopted in the Lenoir gas-engine of eighty years later, 

 or thirty years ago. But Street's engine failed from crude 

 and faulty construction. Brown, in 1823, tried Huygens's 

 vacuum method, using fuel to expand air instead of gun- 

 powder, but he also failed, probably on account of the 

 wastefulness of the method. 



Wright, in 1833, made a really good gas-engine, having 

 many of the essential features of some of the gas-engines 

 of the present day, such as separate gas and water pumps, 

 and water-jacketed cylinder and piston. 



Barnett, in 1839, further improved on Wright's design, 

 and made the greatest advance of any worker in gas-engines. 

 He added the fundamental improvements of compression of 

 the explosive mixture before combustion, and he devised 

 means of lighting the mixture under pressure, and his 

 engine conformed closely to the present-day practice as re- 

 gards fundamental details. No doubt Barnett 's engine, so 

 perfect in principle, deserved commercial success, but either 

 his mechanical skill or his financial resources were inade- 

 quate to the task, and the character of the patents would 

 seem to favour this conclusion, both as regards Barnett and 

 other workers at this period. Up to 1850 the workers were 

 few, but as time went on they gradually increased in 

 numbers ; attention had been attracted to the subject, and 

 men with greater powers and resources appear to have 

 taken the problem in hand. Among these numerous 

 workers came Lenoir, in i860, who, adopting the inferior 

 type of non-compression engine, made it a commercial 

 success by his superior mechanical skill and resources. Mr. 

 Dugald Clerk tells us: "The proposals of Brown (1823), 

 Wright (1833), Barnett (1838), Bansanti and Matteucci 

 (1857), show gradually increasing knowledge of detail and 

 the difficulties to be overcome, all leading to the first 

 practicable engine in 1866, the Lenoir." This stage of the 

 development being reached, the names of Siemens, Beaude 

 Roches, Otto Simon, Dugald Clerk, Priestman, Daimler, 

 Dowson, Mond, and others, appear as inventors who have 

 worked at and added something to perfect the internal- 

 combustion engine and its fuel, and who have helped to 

 bring it to its present state of perfection. 



In" the history of great mechanical inventions there is 

 perhaps no better example of the interdependence of the 

 engineer, the physicist, and the chemist than is evinced in 

 the perfecting of the gas-engine. The physicist and the 

 chemist together determine the behaviour of the gaseous 

 fuel, basing their theory on data obtained from the experi- 

 mental engines constructed by the mechanical engineer, 

 who, guided by their theories, makes his designs and im- 

 provements ; then, again, from the results of the improve- 

 ments fresh data are collected and the theory further 

 advanced, and so on until success is reached. But though 

 I have spoken of the physicist, the chemist, and the engineer 

 as separate persons, it more generally occurs that they_ are 

 rolled into one, or at most tv/o, individuals, and that it is 

 indispensable that each worker should have some consider- 

 able knowledge of all the sciences involved to be able to act 

 his part successfully. 



Now let us ask. Could not this very valuable invention, 

 the internal-combustion engine, have been introduced in a 

 much shorter time by more favouring circumstances, by 

 some more favourable' arrangement of the patent laws, or 

 by legislation to assist the worker attacking so difficult 

 a' problem? I think the answer is that a great deal might 

 be done, and I will endeavoyr to indicate some changes 

 and possible improvements. 



The history of this invention brings before our minds two 

 important considerations. Firstly, let us consider the 

 patentable matter involved in the invention of the gas- 

 engine, the utilisation for motive-power purposes of the 

 then well known properties of the explosive energy of gun- 

 powder or of mixtures of gas and oil with air. Are not 

 these obvious inferences to persons of a mechanical tu^i- 

 of mind and who had seen guns fired, or explosions Jh 

 bottles containing spirits of turpentine when slightly heal'ed 



