MARK SYKES / SCIENCE PHOTO LIBRARY MARK SYKES / SCIENCE PHOTO LIBRARY
Steam engine indicator in its box. This portable instrument was used to measure the cylinder pressure and piston movement in a steam engine. This information could be used to calculate horsepower ratings as well as to diagnose mechanical problems. This indicator was manufactured by The Crosby Steam Gauge and Valve Company.
Model release not required. Property release not required.