I am trying to figure out why someone would do this.
A gas line in case that wasn’t obvious, there may have been a basement space heater at one time. That may an old time gas control valve for a space heater or coal fired converted to gas octopus, it is obviously not doing anything anymore. That is my WAG, other opinions appreciated. Possibly galvanized pipe, but may also be painted. There used to be a gravity furnace judging by the location of the return and supply vents, but house was 1959.