[2] "Aero," May 3, 1910.

[3] Part of this retardation was, of course, "increased resistance."

[4] Personally I do not recommend aluminium.—V.E.J.

[5] "Aeronautical Journal," January 1897, p. 7.

[6] Vide "Invention," Feb. 15, 22, and 29, 1896.

[7] Really aerofoils, since we are considering only the supporting surface.

[8] I.e., to express it as a decimal fraction of the resistance, encountered by the same plane when moving "face" instead of "edge" on.

[9] If the width be not uniform the mean width should be taken.

[10] This refers, of course, to transverse stability.

[11] See ch. vi.