Most will recognize the photo at right as that of the William Penn Statue which sits atop of the City Hall in Downtown Philadelphia, but what most do not realize is that the hat sitting atop of Williams head has been a survey control station since late 1800.
In 1933 the U.S. Coast and Geodetic Survey established and occupied a specific survey control point a copper bolt set on the observation platform. It was not until 1961 that the U.S. Coast and Geodetic Survey occupied the station again. At this time the triangulation party was establishing control for Penn DOT and the control for the Interstate Highway System through Philadelphia.
The station City Hall 2 was established and ties made to the center of the statue making it possible for the local land surveyors to have a specific point on the statue to perform surveys. At this time City Hall 2 West Ecc 1961 was occupied for control purposes. This was a scribed X in the copper sheeting covering the floor of the observation platform.
The Coast Survey party under the leadership of Raymond W. Tomlinson was moved in September, 1961 to Dover Delaware to start the Steel Tower Triangulation survey of the Mason-Dixon Line between Maryland and Delaware. T.J. Mills and I were transferred to Dover from the Triangulation Part y in Mount Vernon, Illinois. During that Fall and Winter the Survey Party built Bilby Towers over all but two original Mason-Dixon Monuments. The two we did not build over were being used as door steps on some old abandoned shacks out in the woods.
A note about the Mason-Dixon Survey: These monuments are only a mile apart but in order to perform triangulation to see from one tower to the other the towers had to be built to a height of 103 feet. The entire network had only one 77 foot tower and one four foot stand. Most of these stations were in less than desirable building sites. Brush, woods and swamps were the order of the day.
In the Winter of 1962 the party was ordered to return to Philadelphia to complete setting additional control for the Department of Transportation. This is when I had my chance to see Philadelphia from the observation deck at the top of City Hall.
Marvin Larabee and I were to occupy City Hall and establish another eccentric Point on the East side of the monument this was to be called City Hall 2 East Ecc. 1962 and tied to City Hall 2.
Marvin and I had dropped of one of our Light keepers at Station SHARESWOOD at Second Street and Wolf in Southeast Philadelphia. We had built a 77 foot tower over this station and it was located inside the Shareswood School property fence. The light keeper unloaded the lights and batteries and we proceeded on to City Hall. We unloaded our equipment and took the elevator to the observation deck and proceeded to scribe another point in the copper flooring then set up and secure a 4 foot wooden stand, This is where I discovered that you can monitor car phone signals with a Tellurometer.
Accident at Shareswood
I cannot talk about City Hall or Philadelphia without relating this story. Marvin and I left City Hall and drove back to pickup the Light Keeper once the observation was finished. We arrived at the Station and could not get him to respond. We checked the Bar across the street and I told Marvin I would go up and check the tower and retrieve the lights and batteries.
As I started up the tower and had climbed above the street lights I could see the Light Keepers legs extending over the side of the floor boards on the opposite side of the tower from the ladder leg I was climbing. As I got near the top and started across to where he lay he rolled over on his stomach and went over the side feet first 77 feet where he struck the 10 foot Iron picket school yard fence. He was severely injured having lost a leg but he lived through it having excellent emergency treatment at Einstein Medical Center there in Philadelphia. The William Penn Statue there at City Hall has been a constant reminder of a survey control point and the near death of fellow surveyor.
Of the thousands of survey control points that I have established throughout the word—many with GPS and many by conventional survey methods—each of them has a story. City Hall Philadelphia is only one.
Note: The author can be reached at Gpsprice@aol.com