San Francisco, Days Before the Great Earthquake
From the Better Late Than Never department:

The segment was about an 11-minute reel of film, shot from the front of a cable car on Market Street. It captured everyday activity on the street – as well as a lot of mugging for the camera, then still a newfangled contraption although film of the city had been made as early as the 1890s.
The wonder of the segment was not just that footage, but the story of how it has recently been dated thanks to painstaking detective work by movie historian David Kiehn. Using evidence in the film, including the license plates of the then-few cars on the roads and water puddles on the road, he crosschecked against motor-vehicle licensing records, meteorological reports, and other information to pinpoint the exact date on which the film was very likely made.
The whole 11-minute film, along with the 60 minutes report and other material, is available freely online.
Previous Post: Media Art History 2011 - REWIRE
Next Post: CPB Job Posting