The street arc lamp street light had a metal cone above it to protect its electrical arc from the rain, snow and nature's other elements that didn't exactly agree with electricity...

The arc light in this photo was of the "open arc" type which required arc rod trimming maintenance every day or so. These were among the first electrically operated street lights used in America. About 1900 "enclosed" type arc lights were introduced and were more energy efficient, requiring arc-rod trimming approximately once a week.