[15] Aëronat, an airship of the lighter-than-air kind.

[16] Hearne, Airships in Peace and War.

[17] Over Sea by Air-Ship, MacMechen and Dienstbach, The Century, May, 1910.

[18] A mathematical argument against this device is presented in Appendix I.

[19] It is commonly reported by navigators that the albatross “sports in the tempest” on unbeating pinions; but it may be questioned whether any bird can make headway against the swiftest winds.

[20] The “drift” and “lift” are the components of surface wind-pressure respectively in the direction of flight and at right angles to it.

[21] The tandem monoplane, or two lifting planes arranged in tandem, was invented by D. S. Brown and exhibited to the Aëronautical Society of Great Britain in 1873.

[22] This gasoline aëroplane model was previously tested in private many times, both with single surface wings, and with superposed surfaces.

[23] Abbe, Helicopters for Aërial Research, Aëronautics, Feb. 1909.

[24] L’Empire de l’Air.