Connecticut - DigitalSorceress
Some kind of single-piston steam engine. I think these small ones were actually being powered by compressed air though. 

Taken at Antique Engine and Tractor Show - Somers, CT, US

Some kind of single-piston steam engine. I think these small ones were actually being powered by compressed air though.

Taken at Antique Engine and Tractor Show - Somers, CT, US

2008AntiquesCTEnginesEventsOutdoorsScantic Valley Antique Engine ShowSomers

From Scantic Valley Antique Engine Show 2008