FOOTNOTES:
[28] Sämmtliche Werke, Bd. VI., pp. 5-12, 1839.
[29] G. H. Darwin, Encyclopædia Britannica, article on 'Tides.'
[30] Dynamik des Himmels, p. 49.
[31] Darwin, Philosophical Transactions, vol. clxxii., p. 528.
[32] Philosophical Transactions, vol. clxxi., p. 876.
[33] Harvard Annals, vol. liii., p. 58.