The Edison Electric Iluminating Co of Brooklyn was founded in 1887, 6 years after the first Edison electric grid centered on Pearl St. in lower Manhattan was established. It merged with its rival the Kings County Electric Light and Power Co. to form Brooklyn Edison in 1919.
During its 32 year run the EEI Brooklyn installed thousands of manholes. The covers were generally square or rectangular, with variations of the two-stranded basket weave pattern, often with rings or squares of vent holes, and usually with "E E I Co" in a badge at the center. Note also the careful triangular borders on the lid and on the rim of the cover seat.
Originally the EEI supplied DC current to its customers, but because of the advantages of the Westinghouse/Tesla AC current system for long distance transmission, it often converted AC from it's (and other companies) generators in DC at points closer to the final customer. Thus the need for the prominent ventilation holes. Later, after the AC systems became universal, and presumable now, these sites are used for voltage regulation before final distribution.
This cover is on W 1st St. between W Brighton Ave and Sea Breeze Ave in Coney Island. The design was widely used by both the EEI Co and others throughout the borough.