Note that this span-wire street light fixture has several lightbulbs clustered within it. This was a fairly uncommon street lighting practice since it was more economical to use a single, larger lamp. At any rate, I bet this fixture looked priceless at night especially when illuminating the snow in the winter.

A four-crossarm, 10-pin telephone open wire pole proudly stands in the background ;-)

Added note: That is a pulley that is mounted above the fixture. Its purpose was for conveniently (and safely) relamping the fixture, lowering it to the ground for maintenance. A winch on a nearby pole controlled this maneuver. Many arc lights were installed with this provision. It is very possible an arc light once existed here and was replaced by this fixture employing incandescent bulbs. The latter lasted longer and were a bit more energy efficient.