Report of the Secretary of Internal Affairs of the Commonwealth of Pennsylvania : containing reports of the surveys and re-surveys of the boundary lines of the commonwealth, accompanied with maps of the same. Prepared in compliance with a resolution of the General Assembly, approved the 7th day of May, 1885
"Field notes and astronomical observations of Charles Mason and Jeremiah Dixon. Made by them in their surveys of the boundary lines between the provinces of Pennsylvania, Delaware, and Maryland. 1763-68. Transcribed from the original autograph manuscript of Mason and Dixon, now in the possession of the Historical Society of Pennsylvania": p. [59]-281.
