A functional glass model of the earliest form of steam turbine. Comprising a borosilicate glass bulb 70 mm diameter approx. 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. If about 25 to 30 ml of water introduced into the bulb and boiled the issuing steam causes rapid rotation. Supplied complete on stand but without burner. Clearance under the bulb is 5 to 6.5 for the Bunsen burner Please exercise caution while using this unit as it involves flames hot vapors and glass.