Subaqueous heater apparatus

摘要

A subaqueous heater apparatus of simple construction adapted for use by a human diver who in underwater activities needs to maintain his vital warmth. The apparatus contains uncombined calcium which under the gradual, controlled supply of water effects chemical reaction with evolution of heat. The supply of such water into the apparatus by capillary action is so controlled that the apparatus serves as an optimum body-warmer to the diver.