"Our invention relates to the class of gas-heaters used in torpedo-boats for preventing the congealing of the compressed carbonic-acid by the rapid decrease in temperature caused by the change from the liquid to gaseous state. Our object is to provide a device and means for the automatic mixing of the chemicals used to heat and expand the gas; and our invention consists in the heating-chamber containing one of the chemicals, as sulphuric acid and a similar chamber with means for holding the latter closed, and also for automatically opening it so that its contents - usually lime - is dumped into the acid, and in details of the construction and combination of the several parts as more particularly hereinafter described…"