Skip to main content

Star Gazers' Stone - Chester County, Pennsylvania

  


One of the most important surveying markers in the United States, and perhaps, the world, is located in an otherwise unassuming field at Embreeville in Newlin Township in Chester County, Pennsylvania. That marker is the Star Gazers' Stone, which is the land marker that was used in 1764 by 18th century astronomers Charles Mason and Jeremiah Dixon to determine the true boundary between Pennsylvania and Maryland.

At the time, the colonies of Maryland and Pennsylvania had a disputed border thanks to competing royal charters of the time. Maryland and Pennsylvania both claimed the land between the 39th and 40th parallels according to the charters granted to each colony, and this would have included the City of Philadelphia. The issue was unresolved until the British Crown intervened in 1760, ordering Frederick Calvert, 6th Baron Baltimore to accept a border agreement signed in 1732. As part of the settlement, the Penns and Calverts commissioned the team of English astronomers Charles Mason and Jeremiah Dixon to survey the proper boundaries between Pennsylvania, Maryland, Delaware and parts of Virginia.

The Mason-Dixon Line (the northern boundary of Maryland) was to be 15 miles south of the southernmost house in Philadelphia. On January 7, 1764, after finding the latitude of the house, they picked out a location 31 miles west of Philadelphia at John Harlan's farm in modern day Embreeville, Pennsylvania at the same latitude of the forks of the Brandywine Creek. Moving their delicate but heavy equipment took two days. They moved westward because surveying 15 miles directly south from Philadelphia would have involved a difficult crossing of the Delaware and would have landed them in New Jersey from which they would have to cross the Delaware again on the way west. It made more sense for Mason and Dixon to set up their base of operations for astronomical observations to the west of Philadelphia. A reference point in the garden of the Harlan property, now known as Star Gazers' Stone, was placed to mark the astronomical meridian line north of their observatory.

Using a device with a 6 foot long brass telescope that allowed them to establish their position relative to the stars, Mason and Dixon spent the winter nights charting the sky from the Star Gazers' Stone. In spring 1764, they ventured due south from the farm with a team that cleared a wide swath through the dense forests. Using chains and levels, they surveyed in straight, 12 mile segments, then made detailed astronomical calculations to adjust to the exact latitude. As miles were measured differently in the 18th century, the majority of the original stones were not actually placed a mile apart by today's standards. While many of the 230 original crown stones have been lost over time, the Stargazers’ Stone, the starting point of the boundary survey, is located in exactly the right place.

Today, you can visit the Star Gazers' Stone by taking a short hike in the ChesLen Preserve off of PA 162 in Embreeville, near the intersection with the aptly named Stargazers Road. There is a parking lot and a trail that leads to the Star Gazers' Stone, along an easement surrounded by a privately owned property. I enjoyed this short journey to this widely overlooked, but very important piece of our history.

Along the trail to the Star Gazers' Stone

Star Gazers' Stone historical plaque.

Star Gazers' Stone keystone marker located on Stargazers Road.

The Star Gazers; Stone is protected by a stone encasement.


How to Get There:



Sources and Links:
Landmarks - The Star-Gazers' Stone
Historical Marker Database - The Star Gazers' Stone
Natural Lands - Star Gazers’ Stone More Accessible to Visitors
Town of Rising Sun, Maryland - History of the Mason-Dixon Line
Scott's ODDySEEy (YouTube) - Stargazers Stone | A Line Drawn in the Sand...stone
Vista.Today - Most Important Stone Along Mason-Dixon Line Has Survived Centuries in Newlin Township

Crossposted to Quintessential Pennsylvania - https://quintessentialpa.blogspot.com/2022/10/star-gazers-stone.html

Comments

Popular posts from this blog

Ghost Town Tuesday; Mannfield, FL and the stairway to Hell

Back in 2015 I went searching the Lecanto Sand Hills for the original Citrus County Seat known as Mannfield.  Unlike Centrailia in Hernando County and Fivay in Pasco County I did find something worth seeing. Mannfield is located in the Lecanto Sand Hill section of Withlacoochee State Forest somewhat east of the intersection of Citrus County Route 491 and Mansfield Road. Mannfield was named after Austin Mann and founded in Hernando County in 1884 before Citrus County Split away.  In 1887 Citrus County was split from northern Hernando County while Pasco County was spun off to the south.  Mannfield was selected as the new Citrus County seat due to it being near the county geographic center.  Reportedly Mannfield had as many as 250 people when it was the County Seat.  The town included various businesses one might include at the time, even a sawmill which was common for the area.  In 1891 Citrus County voted to move it's seat to Inverness which set the s...

Interstate 40's Tumultuous Ride Through the Pigeon River Gorge

In the nearly 60 years Interstate 40 has been open to traffic through the Pigeon River Gorge in the mountains of Western North Carolina, it has been troubled by frequent rockslides and damaging flooding, which has seen the over 30-mile stretch through North Carolina and Tennessee closed for months at a time. Most recently, excessive rainfall from Hurricane Helene in September 2024 saw sections of Interstate 40 wash away into a raging Pigeon River. While the physical troubles of Interstate 40 are well known, how I-40 came to be through the area is a tale of its own. Interstate 40 West through Haywood County near mile marker 10. I-40's route through the Pigeon River Gorge dates to local political squabbles in the 1940s and a state highway law written in 1921. A small note appeared in the July 28, 1945, Asheville Times. It read that the North Carolina State Highway Commission had authorized a feasibility study of a "...water-level road down [the] Pigeon River to the Tennessee l...

The mystery of Hawaii Route 144 and temporary Hawaii Route 11

The 1959 Gousha Road map of Hawaii features two largely unknown references in the form of Hawaii Route 144 and Temporary Hawaii Route 11.  Both corridors are shown running from the boundary of Hawaii Volcanoes National Park east to Glenwood via Volcano Village.  At the time Hawaii Route 11 was using the so-called "Volcano Road" which was constructed as a modernization of Mamalahoa Highway during 1927-1928.  This blog will examine the two map references and will attempt to determine what they might indicate.  The mystery of Hawaii Route 144 and Temporary Hawaii Route 11 Hawaii Route 11 is part of Mamalahoa Highway (the Hawaii Belt Road) and is the longest Hawaiian State Route at 121.97 miles.  The highway begins at the mutual junction of Hawaii Route 19 and Hawaii Route 190 in Kailua-Kona.  From Kailua-Kona the routing of Hawaii Route 11 crosses the volcanic landscapes of southern side of the Big Island.  Hawaii Route 11 terminates at Hawaii Route 19/Ka...