(b. Bishop Auckland, Durham, England, 27 July 1733; d. Cockfield, Durham, England, 22 January 1779)
The fifth child of George Dixon, a well-to-do Quaker, Dixon was educated at John Kipling’s school at Barnard Castle, where he displayed interest in mathematics and astronomy. An acquaintance with John Bird, an instrument maker in London and a native of Bishop Auckland, led to Dixon’s appointment as assistant to Charles Mason, whom the Royal Society proposed to send to Sumatra to observe the transit of Venus on 6 June 1761. An encounter with a French man-of-war prevented the party from reaching Bencoolen; they observed the transit instead at the Cape of Good Hope, taking so many other measurements that the astronomer royal declared a few years later: “It is probable that the situation of few places is better known.”
In 1763 Mason and Dixon were employed to survey the long-disputed boundary between Pennsylvania and Maryland. They were engaged in the delicate and laborious task for nearly five years, hiring local surveyors to assist in observations and calculations and local laborers to cut “vistoes” and set boundary stones. At Dixon’s suggestion, and with the approval of the Royal Society, the surveyors calculated the length of a degree of latitude (363, 763 feet, or 470 less than the currently accepted figure). The Mason and Dixon survey put a stop at once to quarrels between the two colonies; in political and social significance the line became and remains the most famous boundary in the United States. Dixon was elected a member of the American Society for Promoting Useful Knowledge (later merged with the American Philosophical Society) in 1768.
He was hardly home when the Royal Society sent him—without Mason—to Hammerfest to observe another transit of Venus on 3 June 1769. While there he prepared “A Chart of the Sea Coast and Islands near the North Cape of Europe.” Thereafter Dixon lived comfortably at Cockfield, only occasionally resuming his profession. He never married.
I. Original Works. Reports from Dixon’s three expeditions are in Philosophical Transactions of the Royal Society, 52 (1762), 378–394; 58 (1768), 274–323; and 59 (1769), 253–261. The journal of Mason and Dixon in America, 1763–1768, has been edited from the original manuscript in the National Archives, Washington, by A. Hughlett Mason, in Memoirs of the American Philosophical Society, 76 (1969).
II. Secondary Literature. See H. W. Robinson, “Jeremiah Dixon (1733–1779)—A Biographical Note,” in Proceedings of the American Philosophical Society, 94 (1950), 272–274; Report on the Resurvey of the Maryland-Pennsylvania Boundary Part of the Mason and Dixon Line, Maryland Geological Survey, vol. VII (1908); and Harry Woolf, The Transits of Venus (Princeton, 1959), pp. 84–93.
Whitfield J. Bell, Jr.