[348] Discovery of Subterraneal Treasure. London, 1639, p. 48.

[349] Laplace, System of the World, translated by Harte, vol. ii. p. 322.

[350] Principia, bk. ii. sect. 6, Prop. xxxi. Motte’s translation, vol. ii. p. 108.

[351] Essayes of Natural Experiments, &c. p. 117.

[352] Hooke’s Posthumous Works, p. 182.

[353] Principia, bk. iii. Prop. vii. Corollary 1.

[354] Keill’s Introduction to Natural Philosophy, 3rd ed., London, 1733, pp. 48–54.

[355] Discovery of Subterraneal Treasure, 1639, p. 52.

[356] Elements of Inductive Logic, 1st edit. p. 175.

[357] Philosophical Transactions, vol. li. p. 138; abridgment, vol. xi. p. 355.