The next time I visited the laboratory, a few days later, Edison was up again and talking cheerfully. But he had grown five years older in five months. "I shall succeed," he said to me, "but it may take me longer than I at first supposed. Everything is so new that each step is in the dark; I have to make the dynamos, the lamps, the conductors, and attend to a thousand details that the world never hears of. At the same time I have to think about the expense of my work. That galls me. My one ambition is to be able to work without regard to the expense. What I mean is, that if I want to give up a whole month of my time and that of my whole establishment to finding out why one form of a carbon filament is slightly better than another, I can do it without having to think of the cost. My greatest luxury would be a laboratory more perfect than any we have in this country. I want a splendid collection of material--every chemical, every metal, every substance in fact that may be of use to me, and I hardly know what may not be of use. I want all this right at hand, within a few feet of my own house. Give me these advantages and I shall gladly devote fifteen hours a day to solid work. I want none of the rich man's usual toys, no matter how rich I may become. I want no horses or yachts--have no time for them. I want a perfect workshop." In the last twelve years Edison has seen his dream fulfilled. His electric light has not displaced gas, by any means, but it has been the foundation of a business large enough to make the inventor sufficiently rich to build the finest laboratory in the world, in the most curious room of which are to be found the three hundred models of machinery and apparatus of various kinds devised by Edison in the last twenty years and made by himself or under his eye. He is still a gaunt fellow, with a slight stoop, a clean-shaven face, and a low voice. His hands are still soiled with acids, his clothes are shabby, and there is always a cigar in his mouth. [Illustration: The Home of Thomas A. Edison.] [Illustration: Edison's Laboratory.]