Here is a closer look at the pole on the right of the full image (click "Previous"). A series street lighting circuit operated along this roadway. The old incandescent fixture seen here dates back to the early 1900s. Most of these lights operated in a simple electrical series, just like a string of Christmas lights. A provision was made within the lightbulb's socket to automatically and electrically bypass in the event a bulb burned out or was broken. This kept the rest of the lights within the series loop lit. A cast iron "break-arm" bracket as seen here was often used for deadending each of the circuit's wires. This allowed for the two wires that led to the fixture. Transposition insulators and guy-wire "Johnny ball" insulators also were commonly employed for this purpose.