and stared at it meditatively. Monson, guided perhaps by a photographic study of the flight of birds, and by Lilienthal's methods, had gradually drifted from Maxim's shapes towards the bird form again. The thing, however, was driven by a huge screw behind in the place of the tail; and so hovering, which needs an almost vertical adjustment of a flat tail, was rendered impossible. The body of the machine was small, almost cylindrical, and pointed. Forward and aft on the pointed ends were two small petroleum engines for the screw, and the navigators sat deep in a canoe-like recess, the foremost one steering, and being protected by a low screen, with two plate-glass windows, from the blinding rush of air. On either side a monstrous flat framework with a curved front border could be adjusted so as either to lie horizontally, or to be tilted upward or down. These wings worked rigidly together, or, by releasing a pin, one could be tilted through a small angle independently of its fellow. The front edge of either wing could also be shifted back so as to diminish the wing-area about one-sixth. The machine was not only not designed to hover, but it was also incapable of fluttering. Monson's idea was to get into the air with the initial rush of the apparatus, and then to skim, much as a playing-card may be skimmed, keeping up the rush by means of the screw at the stern. Rooks and gulls fly enormous distances in that way with scarcely a perceptible movement of the wings. The bird really drives along on an aërial switchback. It glides slanting downward for a space, until it has gained considerable momentum, and then altering the inclination
