This simple and ingenious device quickly and graphically shows students how different metals conduct heat at different rates. It consists of four identically-sized bars of common metals - steel, brass, aluminum, and copper - mounted parallel to one another in a plastic support. Attached to each bar is a liquid crystal thermometer. When the ends of the bars are immersed in hot water, the thermometers quickly show the progress of heat along each bar. Students can measure the time for the tops of the bars to reach the top display temperature (42C) and discover how well each metal conducts heat.