This map is the Fire Place portion of an 1851 nautical chart titled Nautical Chart of Western Part of the Southern Coast of Long Island.  The full chart is available at the National Oceanic and Atmospheric Administration Historical Map and Chart Collection.

Since the map was designed as a nautical chart, the accuracy of the land portions is suspect.  There is evidence that the topographical portion of the map is based on surveys conducted in 1836.  Click on image to see the map full scale -- the quality of the available image is such that it can only be seen clearly at full scale.