[48] In the place above-cited.
[49] These experiments are described in § 73.
[50] Book II. Chap. 5.
[51] Chap. 1. § 25, 26, 27, compared with § 15, &c.
[52] Book II. Chap. 5. § 3.
[53] See Euclid’s Elements, Book XII. prop. 13.
[54] Archimed. de æquipond. prop. 11.
[55] Ibid. prop. 12.
[56] Lucas Valerius De centr. gravit. solid. L. I. prop. 2.
[57] Idem L. II. prop. 2.