It is indeed a great moment when an inventor comes to the announcement of a new and epoch-making achievement. He has been working for years, perhaps, in his laboratory, struggling along unknown, unheard of, often poor, failing a hundred times for every achieved success, but finally, all in a moment, surprising the secret which nature has guarded so long and so faithfully. He has discovered a new principle that no one has known before, he has made a wonderful new machine--and it works! What he has done in his laboratory for himself now becomes of interest to all the world. He has a great message to give. His patience and perseverance through years of hard work have produced something that will make life easier and happier for millions of people, that will open great new avenues for human effort and human achievement, build up new fortunes; often, indeed, change the whole course of business affairs in the world, if not the very channels of human thought. Think what the steam-engine has done, and the telegraph, and the sewing-machine! All this wonder lies to-day in the brain of the inventor; to-morrow it is a part of the world's treasure. Such a moment came on an evening in January, 1902, when Peter Cooper Hewitt, of New York City--then wholly unknown to the greater world--made the announcement of an invention of such importance that Lord Kelvin, the greatest of living electricians, afterward said that of all the things he saw in America the work of Mr. Hewitt attracted him most.