B for B LIne?
This honeycomb cover may have a date stamped on it "1900" but certainly comes from that era, right after consolidation of Brooklyn and New York City. The meaning of the "B" is uncertain, There is a string of similar covers in Windsor Terrace with a "C" in the center, and Diana Stuart in her book "Designs Underfoot" suggests these may be line designations.
DESIGN:
This is an early example of the ring of six vent holes around the middle ring of cells, that is widely seen in later examples.
UTILITY:
Sewer
RANGE:
This cover with the letter B was seen on Stratford Rd between Church and Albemarle Rd in Brooklyn. A few others with a different style B can be seen in Bensonhurst.