One of the earliest authenticated devices of this kind was the invention of Blanchard, described by him in the Journal de Paris, August 28, 1781, nearly two years before the invention of the hot-air balloon, of which he became later an enthusiastic votary. As his device is but one of a large number that appeared before the close of the nineteenth century, and the advent of light motors, the reader who wishes fuller acquaintance with man-driven airships may be referred to Mr. Chanute’s book, entitled Progress in Flying-Machines, which describes a large variety of such inventions, and discusses the merit and weakness of each.