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Historical Note: In 1909, the New York City Board of Estimate and Apportionment (abbreviated NYBE+A) commisioned a survey of all five boroughs of New York City. This was the first city-wide survey to be done after the consolidation of the five boroughs into the City of New York in 1898. The survey would replace numerous incompatible systems in use by many city agencies, such as the highway department, the water department, the Department of Docks, etc. There were over 1000 benchmaks set in all, and the marks in Brooklyn go from #178 (at Fort Hamilton) to #504 (at the bulkhead on Newtown Creek at Manhattan Avenue, across from Queens), or 327 marks in all for Brooklyn. Of these, just 23 (that I know of) were put into the NGS database in 1952. You can tell if you get one of these Brooklyn marks if the designation is a number between 178 and 504. The whole project and descriptions of each mark can be found in the volume Precise Leveling in New York City by Frederick W. Koop, published in 1914 and available in the New York Public Library. Mr. Koop was head of the surveying team that set the marks. A number of these historic marks are lost, but many are still around if you just know where to look. Three of the bench marks from this original 1909 survey survive just across Flatbush Avenue from this station. Two (#381, a disk, and #382, a chiseled cross) are on the arch (the Soldiers and Sailors Monument) in the center of the Plaza and the third (#387, a copper bolt) is on the step of the round granite structure directly across the street. #381 is particularly noteworthy. It is a 2 inch brass disk inscribed "BD. OF EST. & AP.". There were fewer than 20 of these disks used in the entire city, and this one is in the best condition of any I have found. These are the only bench marks used that are what we would immediatly recognize as a "Bench Mark Disk". I have included pictures and directions to these marks. They're not in the NGS database, so if you find them, you get "extra credit" or you can waymark them. Have fun!
[This entry was edited by Papa-Bear-NYC on Thursday, March 23, 2006 at 1:39:42 PM.]
Photos:
 NYBE+A #381 & #382, Grand Army Plaza, Brooklyn NY
View of the Soldiers and Sailors Monumental Arch from the southwest on the Prospect Park side of Grand Army Plaza. #381 is on the west face and #382 is on the east face (out of site).
NYBE+A #381, Grand Army Plaza, Brooklyn NY
View of the west face of the arch showing the location of the mark.
NYBE+A #381, Grand Army Plaza, Brooklyn NY
There were less than 20 of these disks set and this one is in the best condition of any I have found.
NYBE+A #382, Grand Army Plaza, Brooklyn NY
This is the door on the east face of the arch. The mark is a chiseled cross on the door sill.
NYBE+A #382, Grand Army Plaza, Brooklyn NY
The chiseled cross on the door sill.
NYBE+A #387, Grand Army Plaza, Brooklyn NY
This is the circular granite structure on the left side (east) of the main entrance to Prospect Park at Grand Army Plaza. It is right across Flatbush Avenue from the Library (visible in the background). The mark is a 7/8" copper bolt in front of the granite column on the left side of the entrance to the structure.
NYBE+A #387, Grand Army Plaza, Brooklyn NY
The 7/8" copper bolt on the step of the structure.
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