The Dock 5 sign at track level. Probably as an aid to sailors reboarding their vessels.
I’ve been in a lot of different mines. Some on tours, some not. If you pass through Howardsville, Colorado without going on the Old Hundred Mine Tour, you’re missing out. This is what Santiago Tunnel looked like in the 1940s when it was near the end of its life.
Looking at the concrete headframe from street level. Acros 100 in Pentax 67
Pipes to channel nitrose (think nitro glycerine) infused acid through the building.
Note the rails in the floor that guided cars to the coating line, the side of which is lined with the windows in the center of the image.
This miner locker room has probably never been so clean.
Looking up to the second floor of the Nitrating House, where cotton would be soaked in nitric acid. These brought cotton into the building.
The end of the heating line allowed glass to cool slowly, and thus be stronger.