OK, I thought we ought to have at least one thread in this subject area so I'm tossing this one in.
When scrounging street lights sometimes the best deals on really old ones are the old series street lights. That's because most people don't know how to make them work on 110v without changing out the socket, which is a lot of hassle.
So here's the down and dirty mod for anyone looking at scoring an old series light but who isn't sure how to wire it up.
The series light has a removable socket that fits between two jaws. If the socket is removed, the jaws close together, keeping the circuit alive.
In the 50s a kid skilled with a baseball could knock a socket loose and the rest of the lights would stay on. (OK, so I was a juvenile delinquient. I did eventually grow up.)
The socket had two contact blades that touched at the end. The blades were separated by a cutout disc that would overheat and short out if the bulb burned out, again keeping the rest of the lights in the circuit lit.
So the simple modification here is to install a thin piece of plastic where the cutout disc would normally go, and position it so that it won't fall out when the socket is jacked back into the luminaire. You might need to add a mogul to Edison (medium) base socket adapter to put a conventional sized bulb in the fixture, but the conversion to 110v is fast and simple.
":O) Willis