134 



SCIENTIFIC THOUGHT. 



many, and Hirn^ in France, studied the most important 

 of all machines then in use, the steam-engine, in the light 

 of the new discoveries. It became possible to define 

 clearly what was meant by the efficiency of an engine, 

 and to distinguish between those losses of the energy of 

 heat or temperature which were dependent on the use of 

 steam as the working substance, and therefore inherent 

 and unavoidable, and those losses which depended upon 

 the mechanism and upon the carrying out of the process 

 employed. The older teachings contained in treatises 

 written before a knowledge, or even an idea, of the 



largely based upon the scientific 

 training afforded in the excellent 

 chemical laboratories and poly- 

 technic schools of Germany, it 

 assisted in giving to German in- 

 dustrial enterprise that scientific 

 character which was at first ridi- 

 culed and has latterly been ex- 

 tolled in unbounded measure, and 

 which — combined with the organis- 

 ing ability inherited from English 

 ancestry — seems to be one of the 

 distinctive features of the great 

 industrial progress of America. 

 First among writers on the Contin- 

 ent Zeuner gave such a connected 

 exposition of the principles de- 

 veloped by Clausius, Thomson, and 

 Rankine as met the requirements 

 of practical engineers ; attached to 

 them applications referring to the 

 steam-engine ; criticised the views 

 adopted by Watt and later writers, 

 notably de Pambour, with reference 

 to the behaviour of saturated va- 

 pour in the steam-cylinder during 

 expansion and compression ; and 

 largely prepared the way for the 

 great improvements in steam, air, 

 and refrigerating engines which 

 have been brought out on the Con- 

 tinent by those trained in his 

 school. Through Clausius, Zeuner, 



and others, Dingler's * Poly- 

 technic Journal ' became the 

 organ by which the many discus- 

 sions on the new mechanical theory, 

 and notably the second law of ther- 

 mo - dynamics, gradually forced 

 themselves upon the attention of 

 practical men. 



^ Equally important were the 

 labours of Adolph Hiru (1815-90). 

 He was a self-made man who had 

 grown up in the midst of the im- 

 portant textile industry of Alsace. 

 With a naturally inquiring dis- 

 position he combined the scientific 

 and artistic accomplishments for 

 the manifestation of which the 

 chemical and mechanical products 

 of that country have long been 

 renowned. He approached some 

 of the great theoretical problems 

 connected with practical engin- 

 eering, such as those of heat, 

 steam, lubrication, and superheat- 

 ing, by a long series of carefully 

 planned experiments. A very in- 

 teresting account by several authors 

 is given in a publication by Faudel 

 and Schwoerer (' G. A. Hirn, sa Vie, 

 sa Famille, ses Travaux,' Paris, 

 1893). Hirn, like Rankine, was not 

 only an engineer, but also an artist 

 and a philosopher. 



