Head of Water unit

4 stroke One cylinder, 4 cycled and double valve system gas engine, to show operations like intake, compression, explosion, exhaust, spark and others, mounted on wooden base with spark plug and battery.

GRAVESANDE – Ring and Ball with Chain. An apparatus for demonstrating thermal expansion, comprising a captive brass ball secured to a mounted brass ring by a chin, Ring mounted on rod with a wooden handle. The ball passes through the ring when cold but will not pass through after being heated