A device for performing boiling experiments consist of a copper bar (k = 400 W/m · K), which is exposed to a boiling liquid at one end, encapsulates an electrical heater at the other end, and is well insulated from its surroundings at all but the exposed surface. Thermocouples inserted in the bar are used to measure temperatures at distances of x 1 = 10 mm and x 2 = 25 mm from the surface.