See: Jonathan Williams, Jr., "Memoir on the use of the thermometer in discovering banks, soundings, &c," American Philosophical Society, Transactions, vol. 3, copy 1, opposite p. 84. One copy presented by Jonathan Williams, Jr., 19 November 1799.Wheat: 725
See: Franklin Bache, "Where is Franklin's first chart of the Gulf Stream?" American Philosophical Society, Proceedings, vol. 76, p. 731, 1936; and Benjamin Franklin, "A letter from Dr. Benjamin Franklin to Mr. Alphonsus Le Roy . . . August 1785," American Philosophical Society, Transactions, vol. 2. Philadelphia: 1786.