From John Whitehurst3
ALS: American Philosophical Society
Derby 20 Oct 1765
I forwarded yesterday by the derby Stage, to the Swan with two necks, Lad-lane,4 a Hare, from Mr. Tunnicliff,5 which he desires the favor of You to accept as a gratful acknowledgment of the favors confer’d upon him.
Since Mr. Ludlams report of Mr. Harrisons Time-keeper,6 has been made public, I have been considering what further improvements are wanting to render such machines of more general Use and flatter myself with Some hopes of contributing towards that end.
First, by reducing the price. Secondly, by reducing the Machinery to a more easie construction, so, as to bring the Executive parts within the Compass [of] any common workman. Thirdley [torn] machine may be taken to peices [and put] together without altering the time [or?] regulation, of it. Fourthly that it shall not be liable to stop, as Mr. Ludlam observes is the Case with Mr. Harrisons. Such are the ends I propose to myself, as improvements but the event must be left to tryal to determine the reallity of them. If I shoud come to town this winter, hope you will be kind enough to spend your Judgment upon it, as I purpose bringing the machine up with me. I am Sir Your most Obedient Servant
P.S. From the little knowledge I have of the Use of time keepers at Sea, I apprehend a seconds Motion needless—that a ⅓ or ¼ of Minute, will be as Small a part of time as can be of any real Use in Navigation.7
Addressed: To / Benj: F[ran]klin Esqr. / at Mrs Stevensons / Craven Street Charing-Cross / London
Endorsed: Mr Whitehurst
3. On Whitehurst, horologer and instrument maker, see above, IX, 42 n; X, 70–1, 226–30; and this volume, p. 109.
4. The Swan with Two Necks in Lad Lane (later part of Gresham Street) was an old inn, tavern, and booking and parcel office, the London headquarters for coaches and wagons to and from the North. Henry B. Wheatley, London Past and Present (London, 1891), II, 353; III, 342.
5. On John Tunnicliff, see above, p. 109 n.
6. William Ludlam (1717–1788), St. John’s College, Cambridge, B.A., 1738; M.A., 1742; B.D., 1749; vicar of Norton-by-Galby, 1749; junior dean of St. John’s College, 1754–57; Linacre lecturer in physic, 1767–69; rector of Cockfield, 1768–88. In 1765 he was one of a committee of three experts appointed to report to the Board of Longitude on the merits of John Harrison’s timekeeper (above, VII, 208–10; X, 179–80 n, 228, 302). DNB. Ludlam’s report was printed in Gent. Mag., XXXV (Sept. 1765), 412–13.
7. Whitehurst seems to have been unaware of the importance of seconds in the timekeeper for the accurate determination of longitude on long sea voyages; see above, VII, 209 and note.