Pitz Foundry, established in 1910, was located on Scholes Street between Williamsburg and Bushwick. Walter Grutchfield has some cool info on the foundry and the Baier Patent.
I like this understated manhole design with the stars on each side, in place on lower Fifth Avenue. The Petroleum Heat & Power Co. dates to at least 1920.
There still is a company called Petroleum Heat & Power Co. Could it be the same one? It’s in Queens now, not at 511 Fifth Avenue—as the cover states.