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Precise Leveling in New York City 1909-1914

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Benchmark hunters in New York City are probably aware that the New York City Board of Estimate and Apportionment, basically the political body that ran New York City from 1898 until the US Supreme Court declared it unconstitutional in 1989, commissioned a survey of the entire City in 1909. The survey was headed by Frederick W. Koop, and it covered all five boroughs of New York City, took five years to complete, and resulted in the establishment of 1186 survey marks throughout the City. Upon completing the survey, Koop published a monograph, "Precise Leveling in New York City," which details the precise location of each survey mark.


Copies of the original manuscript are available in some local NYC libraries, but the University of Michigan, apparently the recipient of an original copy in 1916, has published this work in softcover, and I want to let the benchmark hunting community know that this work is available on Amazon.com for a very reasonable price. It is an invaluable guide to the copper bolts, chiseled squares and crosses, and other surviving marks from that epochal survey of New York City.


Only a few of the survey's 1186 marks have been included in the USGS database and have datasheets. Those that have been included in the USGS database usually either have numerical designations from 1 to 1186, or may have "NYBE+A" included in their designation. However, some have become known by the landmark to which the marker was affixed, e.g. "PS 34" in the USGS database is on Public School 34 in Queens, but happens to be Koop Survey mark 590.


One footnote to this survey, however, is that all locations are reckoned, of course, to street names as they were in 1909. Queens County, in particular, underwent an almost complete renaming of its streets in the 1920s, subsequent to the 1909 survey. Fortunately, there is a website with tables of old and current street names, which has, also, proven itself extremely valuable for attempting to find these survey marks. Here is the website link: http://stevemorse.org/census/changes/QueensChanges1a.htm. A similar problem arises, less often, with changes in the numbering of Public Schools, but the street location should be sufficient to find a survey mark, if the 1909 school building survives.


Happy Benchmark Hunting!!

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