If you look rather closely at this image you will see an open style arc light suspended above the middle of the roadway. These were the first style of electrically operated arcs that lit the streets of the America commencing about 1880. These arcs required expensive daily trimming and maintenance. In the mid to later 1890s enclosed arc lights were introduced. Maintanence was "only" once a week to 10 days for carbon rod upkeep and glass globe cleaning/replacement. These lights had a rather large glass globe enclosing the arc and provided improved lighting efficiency. About 1912 a major advancement in tungsten lamps fervered all arc lights for street lighting purposes inferior, inefficient and very expensive to maintain. Thus, the majority of all street lighting arc lights were replaced by tungsten incandescents by c. 1920. The "new" tungsten (incandescent) lamps were revolutionary when introduced. In principle they have not basically changed since 1912!