August 27, 1886.] 



SCIEl^CU. 



183 



built an engine that worked ; and between 1705 

 and 1758 quite a number were erected. These 

 engines had a duty of only 5,500,000 foot-pounds 

 per pound of coal, the improvements of James 

 Watt, an instrument maker, increasing the duty 

 to 60,000,000. 



My object in giving this sketch is to call your 

 attention, first, to the gradual evolution of an in- 

 vention by the process of exclusion, by finding out 

 what would not do ; and second, the aj)parent 

 chain of connection, running for over a century, 

 through several generations of inventors, each 

 evidently profiting by the failures of his predeces- 

 sors, to the extent, at least, of avoiding their 

 repetition. Is it not evident that the earlier in- 

 ventors would have accomplished greater results 

 had they had a larger range of scientific experi- 

 ments and advice ; and that Watt triumphed be- 

 cause he had the whole faculty of the University 

 of Glasgow at his back, to give him knowledge of 

 natural principles, and information as to what had 

 been done? So with other inventions ; the steam- 

 boat was being developed from 1760 to 1807 ; the 

 locomotive, from 1802 to 1829 ; the telegraph from 

 1729 to 1844 ; the sewing machine, with its two 

 thousand patents, from 1790 to 1860 ; the reaping 

 raachine, for seventy-five years, and so on, — the 

 last successful man adding generally but little to 

 what had been done before. The rule is, that 

 " the basis of success lay in a thorough acquaint- 

 ance with what had been done before, and in set- 

 ting about improvement in a thoroughly scientific 

 way." 



My own observation has acquainted me with 

 the development of the ice-making machine. The 

 economical production of cold by the combustion 

 of fuel was a matter of theory when, in 1755, Pro- 

 fessor CuUen experimented in Glasgow with 

 'quick-lime and spirits of sal-ammoniac' as the 

 best volatile substance for producing cold. His 

 discoveries remained as laboratory experiments 

 until Jacob Perkins, in 1834, obtained a partial 

 success in producing ice by the evaporation of 

 ether. Then came Professor Twining, of New 

 Haven, Leslie, Valance, Harrison, Pontifex Seibe, 

 Windhausen, Tellier, Carre, and Pictet, with 

 more or less doubtful success. Up to 1869, the 

 machine was in the experimental or unsuccessful 

 stage. Then came an experimenter who delibe- 

 rately read up the whole subject in a library, and 

 made himself master of what patent-attorneys call 

 'the state of the art,' and of the scientific prin- 

 ciples concerned, working, according to his own 

 account, 'harder than he ever had before in his 

 life.' He discarded the usual working fluids, and 

 adopted anhydrous ammonia. After various 

 struggles and successes, the machine was adapted 



to the difficulties of the case, and put in success- 

 ful operation in 1874, since which time it has be- 

 come of immense practical importance in warm 

 climates, for making ice, cooling breweries, etc., 

 though giving an efficiency of but seventy per 

 cent. In 1877, another inventor set himself de- 

 liberately to improve the machine. He put a prac- 

 tical mechanic, a chemist, and a patent-attorney to 

 work, and in 1878 built a machine, which, how- 

 ever, gave no improved results. He did not let 

 the matter rest here, however, but persevered, and 

 in 1880 built an entirely successful machine, which 

 did the work for which seven thousand tons of 

 ice had been required. So rapid has been the in- 

 troduction of refrigerating machines, that there are 

 now several hundred of various makes at work in 

 the United States. They produce as much cold 

 for each ton of coal consumed as would be ob- 

 tained by the melting of twenty tons of ice, at 

 which rate natural ice is worth only seventy-five 

 to eighty cents per ton, or less than the usual cost 

 of harvesting and storing it. 



In comparing this development with that of the 

 steam-engine, we see the difference between the 

 scientific way of working out an invention and 

 the former disjointed way, when each man had to 

 rely chiefly upon his own experiments ; and also 

 the difference between ancient facilities and the 

 modern advantages offered by experts, technical 

 publications, scientific societies, etc. 



Ordinary technical societies usually discourage 

 speculative papers and discussions, and prefer to 

 hear of accomplished facts ; but the busy men 

 who are developing this country need something- 

 more, — they need to keep up with discovery before 

 it is reduced to practical account, and they need 

 that personal contact and sympathy with men of 

 science which nothing can replace. Engineers, as 

 well as other practical men, owe it to themselves, 

 to come to these meetings, bringing accounts of 

 what they have done and hope to do, and es- 

 pecially of what they have failed to do, and why ; 

 and some speculative papers may well be allowed 

 providing always that they are on a sound basis, 

 and stick to facts ; for how often is it that the 

 imagined things of to-day become the accom- 

 plished results of to-morrow ! 



To encourage good work in the preparation of 

 papers, might there not be established, by friends 

 of the association and section, prizes for the best, 

 papers on a number of important subjects? I 

 hope to see something done in this direction be- 

 fore the close of the meeting. I hope also to see 

 the practice inaugurated for members, during the 

 year or meeting, to propound queries upon sub- 

 jects about which they wish information or dis- 

 cussion. I should like also to see published annu- 



