Born Bishop Auckland, Durham, England, 27 July 1733
Died Cockfield, Durham, England, 22 January 1779
Jeremiah Dixon was a surveyor and astronomer who, with Charles Mason , surveyed the Mason-Dixon Line delineating the boundary between Maryland and Pennsylvania, USA. Dixon was born to well-to-do Quaker parents, George and Mary Hunter Dixon; his father owed a coal mine that was believed to have drawn coal as far back as the fourteenth century. Dixon was educated in private schools, where he excelled in mathematics and astronomy.
With the transit of Venus of 1761 impending, Astronomer Royal James Bradley chose Mason to lead an observatory expedition to Bencoolen, Sumatra. On the voyage, he was accompanied by Dixon. They departed in November 1760 aboard HMS Seahorsewith orders to proceed to Bencoolen unless it was in the hands of the French, in which case they would divert to Batavia. While still in the English Channel, the Seahorsewas attacked by the French frigate Le Grand. After a violent battle, which lasted barely an hour, the captain was able to return the ship back to Plymouth. However, upon witnessing the casualties and damage to both the ships and some of the astronomical equipment, Mason and Dixon wrote of their desire not to go to Bencoolen. Instead, Mason suggested the eastern portion of the Black Sea, where they would be able to observe first contact, but not the planet leaving the face of the Sun.
The Royal Society not only denied their request but also threatened them with a lawsuit, so the voyage to Bencoolen was recommenced. However, by the time they were rounding the Cape of Good Hope, they received news that Bencoolen had been taken by the French. Arriving at the Cape in April 1761, Mason and Dixon prepared to observe the transit from there. As luck would have it, their observations at the Cape of Good Hope were the only successful ones for the South Atlantic region – others were clouded out.
Afterward, Mason and Dixon joined Nevil Maskelyne on the island of Saint Helena, assisting him in various measurements such as tides, longitude, and the gravitational constant.
In 1763, as a result of the successful collaboration with respect to the transit of Venus, Mason and Dixon were charged with the responsibility of surveying what is still referred to as the Mason-Dixon Line. The language of the original land grants to William Penn (later the state of Pennsylvania) and to Lord Baltimore (later Maryland) were sufficiently vague that by the mid-eighteenth century the argument between their respective heirs required the appointment of a commission in 1760 to adjudicate the border dispute. Three years later, Mason and Dixon were hired to survey and establish the boundary. Arriving in America in November 1763, they set up their equipment – two transits, two reflecting telescopes, and a zenith sector. Within a month, they had measured the southernmost latitude of Philadelphia – 39° 56′ 29.1″ N – and began the survey proper.
During the first few months, Mason and Dixon followed the old “Temporary Line” surveyed in 1739 by Benjamin Eastburn. This brought them through small townships such as Darby, Providence, Thornbury, West Town, and West Bradford. From there they continued to travel westward, as they were directed, along the parallel of latitude as far as the country was inhabited. The two continued until September of 1767 where, at Dunkard Creek, their Indian guide informed them it was the will of the Six Nations that the survey be stopped. They returned to England a year later in September 1768.
Because of their experience and their quality observations in 1761, Mason and Dixon were again asked to participate in an expedition for the 1769 Venus transit. Mason did not wish to participate; at the last minute, he grudgingly agreed to travel to County Donegal in Ireland. Only Dixon was willing, and he observed from the island of Hammerfest, off the Norwegian coast.
After the transit, Dixon’s life was very quiet with a local surveying practice. He returned home to Cockfield, where he died, unmarried. Dixon was buried at the Friends’ Burial Ground, Staindrop.