Harlan House | |
 Star Gazers' Stone | |
   | |
| Location | Embreeville, Pennsylvania, Rt. 162 at Star Gazer Road |
|---|---|
| Coordinates | 39°56′21″N 75°43′57″W / 39.9392°N 75.73245°W |
| Built | 1724 |
| NRHP reference No. | 85001004[1] |
Star Gazers' Stone located on Star Gazers' Farm near Embreeville, Pennsylvania, USA, marks the site of a temporary observatory established in January 1764 by Charles Mason and Jeremiah Dixon which they used in their survey of the Mason-Dixon line. The stone was placed by Mason and Dixon about 700 feet (213 m) north of the Harlan House, which was used as a base of operations by Mason and Dixon through the four-and-a-half-year-long survey. Selected to be about 31 miles (50 km) west of the then southernmost point in Philadelphia, the observatory was used to determine the precise latitude of its location. The latitude of the Maryland-Pennsylvania border was then set to be 15 miles (24.1 km) south of the point in Philadelphia. The farm, including the house and stone, were listed on the National Register of Historic Places on May 9, 1985. In 2013 construction was completed on a parking area to allow public access to Star Gazers Stone.[2]
Built c. 1724 near the forks of the Brandywine, the Harlan House was enlarged c.1758, and is likely the first house built in Newlin Township. The Harlan family lived in the house until 1956, and carefully preserved the location of the stone through the generations.[3]
- ^ "National Register Information System". National Register of Historic Places. National Park Service. March 13, 2009.
- ^ "New ChesLen Preserve parking area provides access for visitors". The Times of Chester County. August 2, 2013.
- ^ Roby