[24] Cf. Hans Przibram, Anwendung elementarer Mathematik auf Biologische Probleme (in Roux’s Vorträge, Heft III), Leipzig, 1908, p. 10.
[25] The subject is treated from an engineering point of view by Prof. James Thomson, Comparisons of Similar Structures as to Elasticity, Strength, and Stability, Trans. Inst. Engineers, Scotland, 1876 (Collected Papers, 1912, pp. 361–372), and by Prof. A. Barr, ibid. 1899; see also Rayleigh, Nature, April 22, 1915.
[26] Cf. Spencer, The Form of the Earth, etc., Phil. Mag. XXX, pp. 194–6, 1847; also Principles of Biology, pt. II, ch. I, 1864 (p. 123, etc.).
[27] George Louis Lesage (1724–1803), well known as the author of one of the few attempts to explain gravitation. (Cf. Leray, Constitution de la Matière, 1869; Kelvin, Proc. R. S. E. VII, p. 577, 1872, etc.; Clerk Maxwell, Phil. Trans. vol. 157, p. 50, 1867; art. “Atom,” Encycl. Brit. 1875, p. 46.)
[28] Cf. Pierre Prévost, Notices de la vie et des écrits de Lesage, 1805; quoted by Janet, Causes Finales, app. III.
[29] Discorsi e Dimostrazioni matematiche, intorno à due nuove scienze, attenenti alla Mecanica, ed ai Movimenti Locali: appresso gli Elzevirii, MDCXXXVIII. Opere, ed. Favaro, VIII, p. 169 seq. Transl. by Henry Crew and A. de Salvio, 1914, p. 130, etc. See Nature, June 17, 1915.
[30] So Werner remarked that Michael Angelo and Bramanti could not have built of gypsum at Paris on the scale they built of travertin in Rome.
[31] Sir G. Greenhill, Determination of the greatest height to which a Tree of given proportions can grow, Cambr. Phil. Soc. Pr. IV, p. 65, 1881, and Chree, ibid. VII, 1892. Cf. Poynting and Thomson’s Properties of Matter, 1907, p 99.
[32] In like manner the wheat-straw bends over under the weight of the loaded ear, and the tip of the cat’s tail bends over when held upright,—not because they “possess flexibility,” but because they outstrip the dimensions within which stable equilibrium is possible in a vertical position. The kitten’s tail, on the other hand, stands up spiky and straight.
[33] Modern Painters.