Surveyor, Astonomer, Mathematician. With little formal scientific education, he gained acclaim when he and fellow Englishman, Charles Mason dutifully carried out their Royal assignment to survey the boundary between the Pennsylvania and Maryland colonies beginning in 1763. The work was halted by Indian wars in 1767 but later was continued. The Mason-Dixon line which was finally marked in 1784 set a precedent for the precise measurement and mapping of vast land distances. In addition to surveying 325 miles of boundary lines, Mason and Dixon measured the first degree of latitude and took the first scientific gravity measurements ever recorded in America. In 1773, for his outstanding contributions to science, he was elected a Fellow of the Royal Society of London.
Bio by: Edmond Spaeth