Hero's Engine

A functional glass model of the earliest form of steam turbine. Comprising borosilicate glass bulb 70 mm diameter, with side arms bent at right angles and formed into jets at their tips. The bulb is carried upon a metal stand which leaves it free to rotate about its horizontal axis. With 25-30 mL of water put into the bulb and boiled, the increased pressure ejects steam, which causes rapid rotation as per Newton's third law. Supplied complete on stand but without burner.