A NOTED inventor once said at the end of a lifetime of fighting to defend his rights, that he found there were three stages in all great inventions: the first, in which people said the thing could not be done; the second, in which they said anybody could do it; and the third, in which they said it had always been done by everybody. In his central-station work Edison has had very much this kind of experience; for while many of his opponents came to acknowledge the novelty and utility of his plans, and gave him unstinted praise, there are doubtless others who to this day profess to look upon him merely as an adapter. How different the view of so eminent a scientist as Lord Kelvin was, may be appreciated from his remark when in later years, in reply to the question why some one else did not invent so obvious and simple a thing as the Feeder System, he said: "The only answer I can think of is that no one else was Edison." Undaunted by the attitude of doubt and the predictions of impossibility, Edison had pushed on until he was now able to realize all his ideas as to the establishment of a central station in the work that culminated in New York City in 1882. After he had conceived the broad plan, his ambition was to create the initial plant on Manhattan Island, where it would be convenient of access for watching its operation, and where the demonstration of its practicability would have influence in financial circles. The first intention was to cover a district extending from Canal Street on the north to Wall Street on the south; but Edison soon realized that this territory was too extensive for the initial experiment, and he decided finally upon the district included between Wall, Nassau, Spruce, and Ferry streets, Peck Slip and the East River, an area nearly a square mile in extent. One of the preliminary steps taken to enable him to figure on such a station and system was to have men go through this district on various days and note the number of gas jets burning at each hour up to two or three o'clock in the morning. The next step was to divide the region into a number of sub-districts and institute a house-to-house canvass to ascertain precisely the data and conditions pertinent to the project. When the canvass was over, Edison knew exactly how many gas jets there were in every building in the entire district, the average hours of burning, and the cost of light; also every consumer of power, and the quantity used; every hoistway to which an electric motor could be applied; and other details too numerous to mention, such as related to the gas itself, the satisfaction of the customers, and the limitations of day and night demand. All this information was embodied graphically in large maps of the district, by annotations in colored inks; and Edison thus could study the question with every detail before him. Such a reconnaissance, like that of a coming field of battle, was invaluable, and may help give a further idea