In a paper read at the last annual meeting of this Society, treating of, and advocating steam avitation, I enumerated those qualities which appear to me to be indispensable in a practicable flying engine or avitor.

As appropriate to the opening of this paper, I will quote these remarks :— “First, the ability to raise itself and its “freight from, level ground, by its inherent power solely; “and to propel itself in any desired direction by the same “means:” “to offer but comparatively small obstructive “surface to the air or wind:” “to be so constructed and “balanced, that it cannot capsize, nor fall precipitately.” “Steam being the agent used, the furnace to be so enclosed, “and under control, as regards fuel and air supply, that the “fire can be regulated to a nicety, or if necessary, instantly “extinguished: and lastly, to be capable of a speed, at least “favorably comparable with the fastest land vehicles.”

Assuming the principle adopted is that of “Vertical Screw–Action,” (and I believe that an Avitor of less total weight can be constructed on this principle, than on any other,) I will first describe generally, and then in detail, two types of steam motor adapted to this; and next, a type adapted to Mr. Brearey’s “Wave–Action” principle.