A 1997 study by the New York City Landmarks Preservation Commission found that approximately 100 historic, cast-iron lamp posts are known to survive in New York City. In all likelihood, even fewer survive today. Their extinction is mainly the result of age and construction. Often they are left alone until the Department of Transportation, or other agency, conducts work in their vicinity.
New York City’s first ornamental street lamps were installed in September 1892 on Fifth Avenue between Washington Square Park and 59th Street and the Edison Illuminating Company provided the electricity. Beginning in 1913 the twin lamp post began appearing throughout the City. The last of the Type 24 Twin Lamp Post can be found in Johnny Hartman (formerly Alexander Hamilton) Square, which is located at the intersection of Amsterdam Avenue, Hamilton Place and West 143rd Street.
I would like to thank Kevin Walsh at Forgotten NY for his help in determining what this symbol is. Contrary to my initial beliefs that this image was a globe surmounted by a crown, Kevin Walsh noted that it is actually an illuminating light bulb, the symbol of the Edison Illuminating Company which likely manufactured the lamp post. (The light bulb can be seen more clearly on the base of this lamp post located in City Hall Park.)