Page 1104 note * Translated and reprinted by kind permission of the Editor of L'Aerotecnica and the author G. Guidi.

Page 1104 note † The expression “ human flight,” as used to indicate flight effected by a man's own energy, has in itself been a theme of discussion : some people insist that it be replaced by the more appropriate term “ muscular flight.” It was not I who invented the phrase “ human flight “ : it was set me by the Central Committee as the theme of a monograph for examination purposes. Obviously the adjective “ human “ can be applied to any kind of flight achieved by man, as it can to any other form of man's activity; but in the generally accepted terms “ mechanical flight “ and “ sailplaning “ reference is clearly made to the source of energy—an engine or the wind: when the source of energy is a man it is perfectly logical to designate the flight by the adjective “ human.” By calling it ” muscular flight “ one would create a confusion with bird-flight, which is truly and solely muscular; therefore, in any case, the phrase used should be: “ human muscular flight.” For example, the present article is concerned exclusively with muscular flight, but not with human muscular flight.

Page 1105 note * Magnan: “ Le vol des oiseaux et le vol des avions.” Bulletin Technique n.74, 1931.

Page 1112 note * R. Giacomelli: Gli scritti di Leonardo da Vinci sul volo, G. Bardi—Roma, 1936, pp. 190-194.

Page 1114 note * R. Giacomelli: as above—p. 194.

Translator's Note.—” Traiettoria “—To avoid confusion I have consistently translated this word as “ flight path “ when referring to the motion of the bird, and as “ trajectory “ when referring to the motion of the wing.

” Volo di arresto “—literally “ stopping flight.” This word is used by the author to signify the “ pulling up “ of the bird preparatory to settling on some object; also apparently in the sense of actual “ hovering “ like a hawk. I have translated it in the text as “ hovering,” but in the diagrams as “ checking,“ which seems to be a more accurate description of the bird's position.