Brooklyn Heights Coal Chute Cover
The Adam Happel foundry was located at First Ave and E 93rd St. from 1897 until 1943, this example seems to be from about 1915 or later, after the company started being known as Adam Happel Inc. (Adam Happel died in 1926)
The design of this cover differed from the earlier star & studs designs, but used tropes that were used by other foundries on the Upper Ease Side at that time (see below).
This particular cover found in Brooklyn Heights appears to be a replacement for a slightly larger predecessor.
Happel covers can be found in a number of places in Manhattan, but this one is the only one I have seen in Brooklyn.