When I was down in Austin this year for the South-by-Southwest Interactive festival, we drove around looking at the city’s old moon towers. The concept of these old towers is that they were used to augment street lighting, which was made of gas at the time (late 1800’s), and could be employed when regular street lighting was way too expensive.
The moonlight towers, as they are officially called, were once carbon arc sources, but now sport mercury vapor HIDs. Once incandescent lighting started to get really popular, moonlight towers sorta went by the waysite. Austin, however, still has 17 original towers that have been refurbed all the way down to the hardware back in 1993. Supposedly they provide enough light for you to read a watch for a 1500 foot radius. It was very hard to discern these onsite due to all of the other street lighting, but the towers certainly provide a presence around the city. You can see them for miles.
I took a few crappy shots of the moonlight tower I checked out – there are 16 more to explore!