Constant Level Tank

Heavy cast iron base with 4 uprights, on one end of which is fitted a hand nut, the other drilled with holes to carry a cast iron rod bearing against narrow flats with 12 cast iron breaking rods to show force of contraction or expansion

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.