A silver, unpainted M-400 containing an ancient clear 400 watt mercury lamp that still works.
In 1957, GE introduced a 400 watt mercury vapor streetlight that comes with an intergral ballast. It was a modifed version of the remote ballasted Form 400 with an greatly enlarged neck that allows the ballast to be included. But this orginial luminaire was shortlived, as it was superseded in 1959 by the M-400 cobrahead luminaire shown here. Like the smaller M-250, the M-400 line retained the orginial cobrahead style other than a few updates through around 1970 or 1971, when it was replaced by a simplifed version of the M-400A PowrDoor with the ballast in the fixture's upper housing, not on the door. That luminaire was also called the M-400. Several photos of the orginial M-400 can be seen here, enjoy!
Another silver M-400 with remote mounted photocontrol on the crossbar.
Another silver M-400, a dayburner with old 1960s photocontrol. Lamp is not as green as it appears in the photo.
A later, updated version with grey finish and thumb door latch for easier door opening for servicing.
A mid 1960s version with silver finish and thumb door latch, equipped with a glaresheild. Likely a 250 watt mercury, at western end of I-Street Bridge, West Sacramento, CA
