This journal was written during the survey of the Mason and Dixon line. Also on this reel are minutes from the Joint Commissioners of Lord Baltimore and the Penns (1760-1768), and field notes and journal of the surveys of Lord Baltimore and the Penns (1761-1763).

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).