"A Map of that Part of America where a Degree of Latitude was Measured for the Royal Society: By Cha. Mason, & Jere. Dixon", Anon.

Shows the Delaware peninsula north to Philadelphia with only a few cities and roads including Annapolis, Baltimore, and Greenwich. The Mason-Dixon Line (as it was to become known) was the boundary between Maryland and Pennsylvania, surveyed in 1763 to 1767 by two British astronomers, Charles Mason and Jeremiah Dixon, in order to settle a dispute between the Calvert and Penn families. Published in the December issue. Very nice fleur-de-lys and simple cartouche.

References: Jolly GENT-199.

Condition: A

Three marginal punctures well away from map image. Image near mint.