A Field Guide to New York City Manhole Covers



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This emergent coal hole cover, it was once completely covered with cement, is from the "manufactory" of Thaddeus Hyatt. Hyatt has several patents to his name but made his fortune from two of them, both concerning sidewalk vaults. Many buildings to this day have extended basement spaces underneath the sidewalk, or in this case, just beyond the exterior wall of the building. Dark and dank in the days before electric lighting, Hyatt developed a method of illuminating these spaces with small glass cylinders embedded in large metal plates. Hyatt's patents were for the raised studs surrounding each glass, to protect the glass from hooves and falling objects, and for the buffering placed around each glass to protect it from expansion of the metal in warm weather. More about glass vaults, Thaddeus Hyatt, and the radical abolitionist movement can be found here: Walter Grutchfield!
Consistent with the dates on the cover, the Landmarks Preservation Commission dates the construction of the building at this location in Brooklyn Heights to 1856.


Hyatt was apparently a litigious fellow and vigorously protected his patents, thus the two patent announcements on the cover. The design forms a natural hexagonal honeycomb with 6 studs surrounding the internal glass plugs (only 5 on the outer). Whether the studs protected the glass is unclear, as after only 150 or 160 years, all have disappeared.


The glass vaulted coal hole cover, was the domesticated version of the larger sidewalk vault covers. It developed as the home delivery of coal (rather than wood) for heating was first undertaken, and the delivery of the dirty rocks directly to the basement through a hole in the sidewalk made eminent sense.


The cover shown here is part of a group of 5 coal holes along the Willow St. side of a building on Pierrepont St. All 5 have a hexagonal stone bases. One has a plain, unmarked steel cover (1), one has a cover identical to this one but modified with piping for heating oil delivery (2). One has a strange, sarcophagus-like rectangle of stone covering it (3) and one has a burial mound-like lump of cement covering it. (4). It is this last one that may echo the history of this cover, as the concrete ring around the cover may be the remains of a similar mound. It appears that this cover has emerged only recently, as earlier, intrepid lid chroniclers (Diana Stuart & Walter Grutchfield) don't seem to have spotted this rather accessible cover. Immediately against the building wall are sections of vault-lighting that still retain many glass lenses (5).
Please Note: These covers are clearly visible from the sidewalk but are on private property.

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Don Burmeister -- Photographs