I am fascinated by the remnants of the 19th century in our area. Prime examples are the quarries along the Potomac River from Sprout Run to Chain Bridge. The old muscular steam boilers are a reminder of early engineering back when the fastest most powerful thing on earth was a steam engine. There are two boilers at this place marked on Google Maps. There is a third boiler in the river at the waterfall on Gulf Branch.
Old boiler from a mining operation