There are multiple of these fixtures on a bridge in the town I live in. I can't find any information about them. They are currently hps. I don't know if they were retrofitted with hps or not due to not knowing how old they are. The bridge was built around 1912. This is located in southern ontario, canada. Thanks in advance 

That is a McGraw-Edison Resilite, made sometime in the 1980's. It is more than likely HPS from the factory.

Thanks. I had a feeling it might have been a mcgraw Edison due to the fact that our town had lots of unidors most hps and a few mv. But i didn't know on this one. Thanks so much