Benjamin Franklin Papers

From Benjamin Franklin to John Winthrop, 10 July 1764

To John Winthrop

ALS: Harvard College Library

Philada. July 10. 1764


I received your Favour of the 12th. past,3 and congratulate you on the Recovery of Mrs. Winthrop and your Children from the Small Pox.4

Mr. Stiles return’d Æpinus to me sometime since.5 I must confess I am pleas’d with his Theory of Magnetism. Perhaps I receive it the more readily on Account of the Relation he has given it to mine of Electricity. But there is one Difficulty I cannot solve by it quite to my Satisfaction, which is that if a Steel Ring be made magnetical by passing Magnets properly round it, and afterwards broken into two Semicircles, each of them will have strong N. and S. Poles, in whatever Part the Ring is broken. I have not try’d this, but have been assur’d ’tis so: and I know that a magnetic Bar broken has after Breaking 4 Poles, i.e. it becomes two compleat Bars. I think with him that Impermeability to the El. Fluid, is the Property of all El[ectric]s per se; or that, if they permit it to pass at all, it is with Difficulty, greater or less in different El[ectric]s per se. Glass hot permits it to pass freely; and in the different degrees between hot and cold may permit it to pass more or less freely.

I shall think of the Affair of your unfortunate College, and try if I can be of any Service in procuring some Assistance towards restoring your Library.6 Please to present my respectful Compliments to Dr. Chauncy, Mr. Elliot and Mr. Cooper;7 and believe me with sincere Esteem, Sir Your most obedient humble Servant

B Franklin

My Respects to the President, and to Mr. Danforth.8

J. Winthrop Esqr

Endorsed: Dr Franklin 10 July 1764 [and on another page:] Recd July 23.

[Note numbering follows the Franklin Papers source.]

3Not found.

4Boston experienced a smallpox epidemic in 1764 after inoculation had been prohibited because it spread infection. The town lifted the ban in February 1764. John Duffy, Epidemics in Colonial America (Baton Rouge, [1953]), pp. 64–6.

5On BF’s lending of a volume of Aepinus” writings to friends in New England and its return, see above, X, 267, 351, 389; and this volume, pp. 230, 246. For a summary of Aepinus” theories of magnetism and electricity, see I. Bernard Cohen, Franklin and Newton (Phila., 1956), pp. 538–43.

6On the night of Jan. 24, 1764, during a snowstorm, Harvard Hall, then being used by the Mass. General Court because of the smallpox in Boston, was destroyed by fire and the library and philosophical apparatus in it were completely lost. The members of the General Court, joined actively by Governor Bernard, assisted in saving the nearby college buildings. The General Court voted two days later to rebuild the hall, and the authorities hoped that the contents would be replaced by private generosity. Pa. Gaz., Feb. 23, 1764, had printed an account of the catastrophe. See also F. Apthorp Foster, “The Burning of Harvard Hall, 1764, and Its Consequences,” Col. Soc. Mass. Publications, XIV (1911–13), 2–43.

7These friends were: Charles Chauncy (1705–1787), minister of the First Church in Boston, an outspoken opponent of the emotionalism of the Great Awakening and later a leader in the movement towards Unitarianism (DAB); probably Andrew Eliot (1718–1778), pastor of the New North Church in Boston, who took an active part in seeking replacement of the books and apparatus lost in the Harvard fire, and for whom BF later tried to get a Scottish honorary degree (Sibley’s Harvard Graduates, X, 128–61); and Samuel Cooper (1725–1783), minister of the Brattle Square Church (above, IV, 69–70 n; DAB).

8Edward Holyoke (1689–1769) was president of Harvard College, 1737–69 (Sibley’s Harvard Graduates, V, 265–78); and Samuel Danforth (1696–1777), an early advocate of inoculation, was a judge and member of the Mass. Council, 1739–74. In 1773 BF called him a friend of half a century’s standing (ibid., VI, 80–6; BF to Danforth, July 25, 1773, Lib. Cong.).

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