Parking lots around town sometimes feature ancient streetlamps that were never part of the streetlighting mix employed by the Department of Traffic, later Department of Transportation in NYC, such as this clutch of General Electric Form 400 clamshell lights found in a supermarket/pharmacy parking lot at Francis Lewis Blvd. and 35th Avenue.
The Form 400s were only produced between 1955 and 1960, and were quickly succeeded by the General Electric M400s, which battled for supremacy in NYC streets with the Westinghouse OV-25 between 1960 and about 1972. All these lamps were lit by mercury vapor and shone a greenish white. When new, they were quite bright, but when the bulbs were about to go, they were a dim green, especially when the glass reflector disks were dirty.
Though the Form 400 can be found in a few parking lots around NYC they never found general street use here, unlike their cousins the GE Form 109, which briefly found a home along 6th Avenue (Avenue of the Americas) in the 1950s. I remember both of them in service in Boston in the 1980s, which some making it as far as my last visit there in 2006.