The Star-Gazers’ Stone Erected in 1764 by Mason and Dixon in locating the Pennsylvania-Maryland Boundary Line Being 15 miles North thereof and 31 miles due West of Philadelphia. Here they also measured a degree of Latitude on the Earth’s surface southward, and made other Astronomical observations; Hence the name Enclosed and marked by The Chester County Historical Society

Marker is on Star Gazers Road, on the right when traveling north.

Courtesy hmdb.org

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