Ice is melted by electrical heat supplied to a constant-temperature calorimeter. The amount of ice melted is obtained by observing the change in volume of the system at constant pressure. The determination of the latent heat is precise to within ±1%. In a less precise variation, supercooled water is allowed to freeze and the latent heat is determined from the expansion of the system and the amount of warming which occurs. Students react to the phenomenon with surprise; although the precision is poor, the supercooling experiment is a very effective teaching device.