From John Whitehurst3
ALS: The Royal Society
Derby 15 Feby 1767
We experienced a much greater degree of Cold at derby, in the late Frost, than perhaps was ever observed in England, and the quick transitions, were no less remarkable.
On Sunday the 18 of last month, at 7 o Clock in the evening. My thermometer stood at 20. At half an hour after Nine, nearly one degree below 0. At seven the next Morning 30. External Air.4 I hope to hear by Mr. Burdett,5 the bearer, hereof, that you are perfectly well and purpose honouring derbyshire with another Visit before you leave England. I beg my respectfull Compliments to Mrs. Stevenson and I am Sir your most Obedient Servant
Addressed: To/Docr. Franklin/at Mrs. Stevensons Craven/Street. Strand/London
Endorsed: No. 1
3. For John Whitehurst, horologer and maker of philosophical instruments, see above, X, 70 n. In 1762 he had written BF of his interest in changes in the temperature of the atmosphere; see ibid., 228, 302.
4. There is a notation above the salutation of this letter that it was communicated to the Royal Society by its secretary, Charles Morton (above, X, 71 n), received April 9, 1767, and read May 14. The letter, up to this point, was printed in Phil. Trans., LVII (1767), 265.
5. Not identified.