382 



SCIENCE. 



[N. S. Vol. XV. No. 375. 



energy which should be transformed into 

 work escapes transformation simply be- 

 cause of the low terminal pressures of the 

 engine at the lowest temperatures of its 

 range. It is this loss which is sought to be 

 reduced by the series-fluid engines and 

 which, so far as the thermodynamic and 

 the dynamic questions are concerned, may 

 be actually saved in large degree. The 

 uncertainty remaining is that regarding 

 costs, safety and convenience. 



Du Trembley, about two generations 

 ago, built binary-vapor engines, with ether 

 as the secondary fluid, for a line of trans- 

 oceanic steamers and 'broke the world's 

 records ' for his time in economy of power- 

 production ; but the compound engine came 

 in and his secondary fluid proved danger- 

 ously inflammable. He lost one of his 

 ships, Randolph & Elder bettered his rec- 

 ord and the matter dropped out of sight. 

 Later, many inventors have gone through 

 the same experience in one way or another. 

 Ether, chloroform, alcohol, ammonia, ear- 

 bon-disulphide and sulphur-dioxide, among 

 other volatile substances, have been tried, 

 usually with some apparent gain but never 

 yet with permanent success. 



Recently, however, Professor Josse, at 

 Berlin, has again 'broken the world's rec- 

 ord ' in heat-engine operation by produc- 

 ing the horse-power with an expenditure 

 of less than eight and a half pounds of 

 moderately superheated steam per hour. 

 The experiment has been made with the 

 utmost care and repeated under varying 

 conditions, until there can remain no doubt 

 of the fact. He further states that the 

 steam and sulphur-dioxide, binary-vapor 

 system adopted by him can be constructed 

 at no greater cost than the standard triple- 

 expansion engine which it rivals, that, 

 properly cared for, it is not subject to in- 

 jury by corrosion as had been anticipated 

 by engineers generally, and that it can be 

 safely insured against loss or accident 



through leakage. If experience confirms 

 this claim, this means that the long-sought 

 utilization of the waste heat of the steam- 

 engine may be practically accomplished. 



Time and experience will confirm or re- 

 fute these expectations and it is for time 

 and experience to settle the ultimate ques- 

 tions of the engineer relative to cost, re- 

 liability, safety and 7iet gain or loss by the 

 substitution of the series-vapor engine for 

 the compound, the single-fluid, series- 

 engine. 



R. H. Thurston. 



WHAT ARE THE REQUIREMENTS OP A 



COURSE TO TRAIN MEN FOR WORK 



IN TECHNICAL CHEMISTRY.* 



The subject before us may be discussed 

 in two parts ; first, what sort of instruction 

 in chemistry should be given to men who 

 are to become technical chemists, and, sec- 

 ond, what work in other subjects should 

 be required? Our consideration of the 

 question will perhaps be more definite if 

 we have before us a list of the occupations 

 followed by a number of young men who 

 have received training of this sort. 



During the past twelve years twenty- 

 three men have graduated from the chem- 

 ical course of the Rose Polytechnic Insti- 

 tute. These have been employed as fol- 

 lows: One is inspector of coke for a large 

 steel company, three are chemists in 

 iron or steel laboratories, two are assayers, 

 two are teachers, three chemists in soap 

 factories, two employed by a firm manu- 

 facturing liquid carbon dioxide, two are 

 draftsmen, one is superintendent of a gas 

 company, one chemist for a firm manu- 

 facturing photographic supplies, one chem- 

 ist for a paint oil company, one chemist 

 for an electrical company, one manager of 

 the paint department for a wholesale 

 * Read at the meeting of the Indiana College As- 

 sociation, December 27, 1901, and also at the 

 Philadelphia meeting of the American Chemical 

 Society. 



