A trifling incident revealed to an Italian savant the fact that when two metals and the leg of a frog came into contact the muscles of the leg contracted. The galvanic battery resulted. Years later another observer discovered that if a wire carrying a current of electricity was wound around a piece of soft iron the latter became a magnet. Out of these simple discoveries have arisen the telegraph, the telephone, and a host of inventions depending upon electricity. And to-day, with all the wonders accomplished in this field, we are yet upon the threshold of the enchanted palace that electricity is about to open to us. Through its aid we shall one day enjoy light, heat, and power almost as freely as we now enjoy air. The crops will be planted, watered, cultivated, gathered, and transported to the uttermost ends of the earth by electricity. The steam-engine is said to do the work of two hundred million men, and to have been the chief agent in reducing the average working hours of men in the civilized world in this century from fourteen hours a day to ten. But electricity, according to even conservative judges, will accomplish infinitely more. It will make possible the harnessing of vast forces of nature, such as the falls of Niagara, because the electric current can be transported from place to place at small cost and it is easily transformed into light or power or heat. Within a few months we shall see the first results of the great work at Niagara. Before many years the power of the tides is certain to be used along the seaboard for producing electricity. Here is a force equal to that of a million Niagaras going to waste. [Illustration: Charles F. Brush.]