A Warning Concerning the Peace-Time Use of Army Gas Masks

1922 Scientific American  
Left : Small boat equipped to chlorinate the water of a large swimming pool. The engine exhaust i s used to counteract the refrigerating effect of the released gas. Right: A small amount of water is pumped through the chlorinator, is charged, and � then flows off at the stern How Washington, D. C., keeps its immense new swimming pool fit to swim in
doi:10.1038/scientificamerican0522-327 fatcat:w4ekspi7s5ecvhw7isrgrykf4i