Brownstoner Queens has some awesome photos and history of what 5Pointz was way before it was the beloved graffiti hotspot. It was built in 1892 as the headquarters of the Thomson Meter Company, later the Neptune Meter Company, which are dials that look like this that measured water usage.
As Mitch Waxman writes, “Water meters were a ‘new thing’ at the end of the 19th century, and ‘paying for what you use’ was a very popular thing as NYC entered into the 20th century.”
Neptune vacated the property in 1972 and 5Pointz set up in 1993. Neptune Meter Company still exists as the Neptune Technology Group, having branched out into utility management systems as well as hardware.