September, 2006 - Abandoned mining operation near US-590 between Silverton and Ouray, Colorado.
This is an Ingersoll-Rand "Imperial Type 10" steam-driven air compressor. Actually, it's several tons of 1912-vintage cast iron left behind whenever the mine operator gave up. This thing was huge -- those are full-grown pines in the background; the size 15 hiking boot tracks in the snow are mine.
Nutsy-boltsy engineering info here:
...check the post dated 05-12-2010 - 05:49 PM from "hendeyman". Anything big enough to use 36" to 45" flywheels deserves respect.