car because it was built by the people who built the cable cars. >> safer: our tour guide is rick laubscher a non-profit group that keeps the city's vintage trolleys rolling. >> laubscher: this is the main artery of san francisco and always has been. >> safer: market street is three miles long, 120 feet wide-- the beating heart of the city since the days of the gold rush. >> laubscher: this is where the original film started, right here, about 8th street. >> safer: right here is where the past comes alive, thanks to a camera mounted on the front of a cable car a century ago, catching glimpses of fashion, faces, and the helter-skelter of city traffic-- horses, trolley cars, and that new devil's own invention, the motor car. >> laubscher: you can see when people turn to look at the camera, it was really the shock of the new. can you imagine? here comes this contraption down the street with these guys hand- cranking this camera furiously. >> safer: others had made films of san francisco, starting in the 1890s. but this cameraman had the good sense to simply turn it on and leave it on. when you