10 president's address. 



then it is not too much to say that the whole future of our race would be 

 altered. 



The whole progress of the human race has indeed been due to 

 individual members discovering means of concentrating energy, and of 

 transforming one form into another. The carnivorous animals strike 

 with their paws and crush with their teeth; the first man who aided 

 his arm with a stick in striking a blow discovered how to concentrate 

 his small supply of kinetic energy; the first man who used a spear 

 found that its sharp point in motion represented a still more concen- 

 trated form; the arrow was a further advance, for the spear was 

 then propelled by mechanical means; the bolt of the crossbow, the 

 bullet shot forth by compressed hot gas, first derived from black 

 powder, later, from high explosives ; all these represent progress. To 

 take another sequence : the preparation of oxygen by Priestley applied 

 energy to oxide of mercury in the form of heat; Davy improved on 

 this when he concentrated electrical energy into the tip of a thin wire 

 by aid of a powerful battery, and isolated potassium and sodium. 



Great progress has been made during the past century in effecting 

 the conversion of one form of energy into others, with as little useless 

 expenditure as possible. Let me illustrate by examples : A good 

 steam engine converts about one-eighth of the potential energy of the 

 fuel into useful work ; seven-eighths are lost as unused heat, and useless 

 friction. A good gas-engine utilises more than one-third of the total 

 energy in the gaseous fuel; two-thirds are uneconomically expended. 

 This is a universal proposition; in order to effect the conversion from 

 one form of energy into another, some energy must be expended 

 uneconomically. If A is the total energy which it is required to con- 

 vert; if B is the energy into which it is desired to convert A; then a 

 certain amount of energy, 0, must be expended to effect the conversion. 

 In short, A = B + C. It is eminently desirable to keep C, the useless 

 expenditure, as small as possible; it can never equal zero, but it can 

 be made small. The ratio of C to B (the economic coefficient) should 

 therefore be as large as is attainable. 



The middle of the nineteenth century will always be noted as the 

 beginning of the golden age of science ; the epoch when great generalisa- 

 tions were made, of the highest importance on all sides, philosophical, 

 economic, and scientific. Carnot, Clausius, Helmholtz, Julius Bobert 

 Mayer abroad, and the Thomsons, Lord Kelvin and his brother James, 

 Bankine, Tait, Joule, Clerk Maxwell, and many others at home, laid 

 the foundations on which the splendid structure has been erected. That 

 the latent energy of fuel can be converted into energy of motion by 

 means of the steam engine is what we owe to Newcomen and Watt; 

 that the kinetic energy of the fly-wheel can be transformed into elec- 

 trical energy was due to Faraday, and to him, too, we are indebted 



