Use this device to demonstrate the phenomenon of thermal convection in liquids caused by temperature variation. It consists of a rectangular-shaped borosilicate glass tube, 6″ x 8.25″, with a funnel-shaped opening at the top for filling with liquids. When this tube is filled with water and heated at 1 corner after adding a dye, potassium permanganate crystals, saw dust, or aluminum powder, the movement of colors or particles illustrates the formation of convection currents. Comes with a Teacher’s Guide and reproducible student handout.