In 1827 a valuable improvement was made to the machine of civilization by Ohm, who announced the now famous Ohm's Law, that the strength of an electric current in any circuit is equal to the difference in potential of the ends of the circuit, divided by its resistance. This is usually expressed by writing C = E/R. Can anything be less inspiring than C = E/R? Yes:--few things have been more inspiring. Few things have inspired more zeal for work than that simple formula. That simple formula evolved order out of chaos in the little but super-important world, in which physicists and chemists were trying to solve the riddles that the utilization of electric currents presented. It gave them a basis from which to start, and a definite rule to work by. No oration of Demosthenes, Cicero or Webster has imparted more inspiration, or supplied a greater stimulus to high effort, or done more for human kind than C = E/R. In 1827 Walker in the United States invented friction matches. It seems strange that someone had not invented matches before. The usual way of getting light was with the flint and steel and tinder-box,--a most inconvenient contrivance. It was quite well known that certain substances would ignite when rubbed, and yet men waited until 1827 to utilize the fact in matches! In the following year Wöhler succeeded in reducing aluminum, thus contributing a valuable new factor to human knowledge and a valuable new metal to human needs. In the same year Neilson took out a patent in England for "an improved application of air to produce heat in fires, forges and furnaces," in which he proposed to pass a current of heated air through the burning fuel. His invention met with opposition of all kinds, but eventually proved its usefulness. Another invention produced in the same year was Woodworth's machine for planing wood. Still another, was the tubular boiler for locomotives. In 1829 the first steam locomotive was put into use in the United States. No especial invention seems to have been expended on this device; but there was considerable invention of the kind that I have ventured to call "opportunistic" involved in conceiving the idea of getting the locomotive, and then in actually getting it, and then putting it to work. In the following year Braithwaite and Ericsson in London brought out the first portable fire-engine. There was a great deal of invention of the practical kind involved in the design, construction, production and successful employment of this novel device; and an important step was taken in the means of protecting life and the material products of civilization from destruction by fire.