Golden Gate stamp mill

Ore crushing device, in which cams on a turning shaft raised and then dropped piston-like hammers, the "stamps", onto ore. They were notorious for making a tremendous racket, particularly since they tended to run 24/7. This one processed ore from the Golden Gate mine in extreme eastern California (not by the actual Golden Gate!), which was brought down by a tramway. The mine was active in the early 20th century--a bit late for stamp mills, which by then were being displaced by newer technology like cone crushers. This mill has been the object of some attempts at preservation: it's been stabilized by the cables attached to the posts in front, and has also had a lot of debris cleared off. Inserts are (1) an interpretive plaque, courtesy of E Clampus Vitus; (2) a close-up of the stamps; (3) a close-up of one stamp hopper, showing the manufacturer's name, based in San Francisco(!); and (4) the pulley in the middle of the camshaft. (3) and (4) are on the areas magnified.