sentences:  The reheater bubbled air through a hot water tank, picking up hot water vapor to improve the engine's range.An improved engine contained a high-pressure cylinder of 5 inches operating at 50-150 lb/sq.in and a low-pressure cylinder of 8 inches, with an 8-inch piston stroke.The system was promoted as being suitable for use in congested streets and in tunnels, as compressed air produced no smoke or flames, and thus would not disturb horses or fill the carriage with soot and sparks like a steam engine.