² Dr. Marshall Dale's Medical Biographies (1952) (University of Oklahoma Press, 1987), p. 47.

³ These mathematical proofs were "probably not understood in his own day by more than a dozen people." See Hoyle's preface in his biography of Nicolaus Copernicus (London: Heinemann, 1973).

⁴ Bernal's Science in History (1954) (Cambridge, Mass.: MIT Press, 1981), p. 485.

⁵ Dale, op. cit., p. 52.

⁶ John Flamsteed (1646-1719), the first astronomer-royal of England, the man who set up the Greenwich Observatory, and who complied the first trustworthy catalogue of the fixed stars; as quoted by Dale, op. cit., p. 52.

⁷ Fletcher, op. cit., p. 33.

⁸ Dale, op. cit., p. 51.

⁹ Sir David Brewster wrote the standard biography on Newton, Memoirs of Newton (1855).

¹⁰ Bernal's Science in History, op. cit., p.482.

¹¹ Bernal's Science in History op. cit., p. 484.

¹² Fletcher, op. cit., p. 31.

¹³ See Hoyle's biography of Nicolaus Copernicus, op. cit., preface.

¹⁴ Chambers Biographical Dictionary.

¹⁵ See, for example, Adam Smith.

¹⁶ See James Clerk-Maxwell (1831-79).

¹⁷ Op. cit., p. 487.

¹⁸ Principia, Preface.

¹⁹ From Brewster's biography, op. cit., vol. II, ch. 27.

²⁰ Letter to Robert Hooke, February 5, 1676.

²¹ As quoted by Professor Morris Kline, in his book, Mathematics and the Search for Knowledge (Oxford University Press, 1985), pp. 107,121.