Here is what is written in one of my books.
"A chemical appliance could be for example, a 60 gallon drum of water that could be used on the spot without the need for a pump. The water was expelled by carbon dioxide gas created by the action of sulphuric acid with a bicarbonate solution. The result was a reasonably powerful jet, which was an effective front line of attack until the heavier jets of the main pumps could be brought to bear on the fire. The downside to these appliances is once they had been turned on, they could not be stoppeduntil they had completelyemptied themselves."
Hope this helps as to there purpose. Where you'd find any to do a restoration is beyond me. Good luck.
