The first volume is minutes of the commissioners for determining the line between Pennsylvania and Maryland, which was copied by George M. Justine in 1842 from an "authenticated" copy owned by Ferdinand R. Hassler. The second volume contains receipts (62 items) for money spent by the Penn family for the survey.

Correspondence from Charles Mason and Jeremiah Dixon to Thomas Birch, and Nevil Maskelyne to Charles Mason, relating to the survey, and the transits of Venus (1761,1769).

These letters relate principally to provincial business and comment on the Indians of Pennsylvania, the French and Indian War, a survey of the Maryland-Pennsylvania boundary, and the Stamp Act. Correspondents include James Burd, Jeremiah Dixon, Joseph Galloway, Humphry Marshall, Charles Mason, Edward Shippen of Lancaster, and Edward Shippen, Jr.