Page:Popular Science Monthly Volume 59.djvu/151

Rh

N 1800, Galvani and Volta had sewed the seed, and since has sprung up the whole science and art of electrical physics. Ten years ago we had about 700 miles of electric railway; to-day about 15,000 miles are in operation in the United States alone; a thousand millions of dollars are invested in the stock, and an army of two hundred thousand men is employed by them, mainly in the great cities, but with steady growth towards all sections and into all aggregations of population. Two thousand millions of dollars are reported to be now invested in apparatus of electrical distributions of energy, converted ultimately into light and power. About two-thirds of a billion of dollars are invested in the property of the electric light companies. We have between one and two million miles of telephone wire, and can talk from Boston to Chicago; from Chicago to San Francisco will soon be found an easy conversational distance. The Bell Company alone owns a million miles of wire, a million and a half instruments, and receives six millions of dollars a year from its business. The world, outside the United States, utilizes not quite as much capital in this most wonderful of the inventions of the century as does our own country, having about a half-million exchanges to our six hundred thousand and over on the Bell system alone.

Of steam power, about twenty millions of the engineers' 'horsepower,' the equivalent of perhaps seventy-five, or even possibly more nearly a hundred, millions of horse-power developed by animal forces, move the fleets of the world, merchant and naval, and drive our ships across every sea. It even has been found practicable to apply steam-power to the sewing machine, and of the million or more manufactured in the United States and the fifty per cent, added to the total by other nations, a very considerable fraction are operated by steam-power, and of the hundred thousand people engaged in its manufacture and the millions engaged in its use, a corresponding proportion are aided by this mighty engine of civilization. Steam supplies the power for driving the machinery which produces a quarter of a million mowers and reapers in the United States—an unknown industry a century ago—and thus, with the help of the steam-plow and other machinery of agriculture, all inventions of the century, secures for the nation a foreign market for