IOWA ACADEMY OF SCIENCES. 
23 
abstruse problems as the specific volume of steam and its 
law of tension under varying temperatures. And the 
improvements in the steam engine, which since the fifties 
have more than doubled the speed of the piston, while 
saving at least one fourth of the fuel, have been made 
under the guidance of Joule and the mechanical theory of 
heat. In the matter of the advantage of super-heated 
steam and high pressure, theory still seems to outrun 
practice. 
In electricity the mere mechanician can take no impor- 
tant step beyond the scientific discoverer. How happy 
was the thought which designated the various units of 
electricity by the illustrous names of the masters of 
research, — volt, in honor of the professor in the University 
of Pavia who one hundred years ago gave the world in his 
crown of cups its first effective reservoir of the new power; 
ampere, the name of the professor of physics in the College 
of France, founder of the science of electro dynamics; 
ohm, in memory of the professor of experimental physics 
in the University of Munich, discoverer of the law of the 
strength of the electric current; and farad, in honor of the 
greatest of them all, Michael Farady, professor of Chem- 
try in the Institution of England, the prince of experi- 
menters, whose researches, resulting in the dynamo, con- 
nected up the industries of the world to the first economical 
source of electrical energy. 
Illustrations of the dependence of industry on pure 
science are everywhere at hand. When as an amateur in 
photography, I take up a package of eikonogen or hydro- 
quinon, the label with the name of one of the great ani- 
line factories of Germany, at Elberfield, Mannheim, or 
Berlin, reminds me of the debt of the Farbenfabriken to 
men of research. To the chemist is not only due the dis- 
covery of developers, of such bye products as antipyrine, 
cocaine, saccharine and vanilline, — it was he who, in the 
black amorphous coal tar, the former refuse of the gas 
works, first found there brilliant crystalline dyes which 
have so largely replaced all other colors in the dye vats of 
the world. So far as I am aware, no monument has been 
