"For all that I am something of a boy still myself," says the inventor. "You see I could work for the present generation to make money. Of course that's all right, but I don't care what the present generation thinks of me. It is the growing generation--the boys of to-day that I want to work for, because they will live in an age when the world has advanced far enough in science to understand some of the deeper mysteries of electricity. The boys of to-day are the great scientists of to-morrow, and it is to them that I dedicate my greatest efforts." All his life Tesla has been working with an eye to the future as well as to the present, and some of his inventions probably will be far better appreciated in twenty years than they are now, although to Tesla we owe our thanks for some of the most important electrical machinery in use at the present time. As an inventor Tesla is best known as a pioneer in high tension currents. It was he who introduced to the world the great principle of the alternating current, as up to the time he carried out his experiments only the direct current was used. Indeed, more than four million horsepower of waterfalls are harnessed by Tesla's alternating current system. That is the same as forty millions of untiring men working without pay, consuming no food, shelter or raiment while labouring to provide for our wants. In these days of conservation, it is interesting to note that this electrical energy derived from water power saves a hundred million tons of coal every year. Our trolley roads, our subways, many of our electrified railroads, the incandescent lamps in our homes and offices, all use a system of power transmission of this man's invention. As said before Tesla is a naturalized American citizen. He was born in Smiljan, Lika, on the Austro-Hungarian border, in 1857. He came by his scientific and inventive turn of mind naturally, for his father was an intellectual Greek clergyman, and his mother, Georgia Mandic, was an inventor herself as was her father before her. The boy attended the public schools of Lika and Croatia, where he was a leader among his playmates in sports where imagination and mechanical skill were required. There are marvellous tales of the ingenuity of Tesla while a schoolboy, but with all his play he was a serious-minded student, and went through the Polytechnic in Gratz and the University of Prague in Bohemia with honours. While in the Polytechnic, Tesla saw the defects of some of the machinery that was used in the laboratory, and made suggestions for its improvement.