president's address — SECTION J. 195 



disclosed, and a vast amount of learning and mechanical 

 ingenuity has been devoted to it. For many purposes, such 

 as lighting, chemical reactions, concentration of intense heat 

 on small surfaces, small motive powers, and telegraphic com- 

 munication, it has a world of its own. In my opinion many 

 people expect too much of it, their mistake appearing to be 

 in their conceiving electricity to be a new ])ower. This con- 

 ception is evidently wrong, for electricity has its existence 

 only in the old powers of heat and gravity — the steam engine 

 or the waterfall. Electricity has its own sources of waste 

 and loss of efficiency, which are always in addition to those 

 of the machinery employed to generate it. For this reason 

 electricity is seldom profitably used directly in substitution of 

 steam or water power. 



For conveying power to long distances it has certain 

 advantages which, according to the circumstances of the 

 case, may or may not be counterbalanced by the erection of 

 a steam engine on the sj^ot. 



It is impossible to foresee what the future has in store for 

 electricity as a means of utilising the power derived from coal 

 or other forces of nature, therefore we cannot tell what part 

 engineering will take in its use and development. My own 

 impression is that as long as coal lasts it will always be found 

 the best and handiest source of power, as in no known form is 

 power contained in so small a compass. Thus, to compare the 

 ])ower of coal to that of falling water, which seems to be the 

 next best source of power : — In engines burning 2^ pounds 

 of coal per horse-power per hour, the mechanical effect of 

 one pound of coal is equal to that of 40 tons of water falling 

 12 feet, and some engines burn less than 2^ pounds per horse- 

 ]>ower per hour; yet this effect, developed in the best engmes, 

 is only about one-eighth of the total energy given out by coal 

 during its combustion. 



Now, although in many cases water may be had for nothing, 

 yet for large powers the quantity of water, or the height of fall 

 required is so great, and the necessary appliances so costly, 

 that people prefer to use steam whenever coal is to be had at 

 a reasonable cost. For heating and for portable power, such 

 as steamships require, I do not think we have any evidence 

 that coal can ever be dispensed with, and ranch less that 

 electricity can take its place. Notwithstanding modern dis- 

 coveries, I believe the warning given us by Professor Huxley 

 thirty years ago still holds good. His warning was against 

 the common assertion that it does not signify if coal is used 



