This is larger than the usual overhead mounted lamp in that it is about 12" long X 6" diam., and made of cast brass.  It was never installed and has not been drilled for wiring.  It was made by Pauluhn, an existing U.S. maker  The bulb fixture has not been used, but it should be renewed.  It came from a Moran Towing tug scrapped in Jacksonville.  It may be hung from the overhead and also mounted upward, such as on a railing.

We have several of these identical lamps