The 1919 Canister
Just before the Armistice, the Gas Defense Long Island Laboratory brought out the so-called “1919 Canister,” which consisted of an oval section, perforated metal, war gas material container with a central, flat, perforated breathing tube connected to a nozzle at one end. ([See also page 228].) After this inner container is packed with the war gas chemicals, a filter jacket is slipped over it and the top edge sealed to the inner container.
Fig. 105.—1919 Felt Filter Canister.
Attempts were made to put paper filters on this canister by wrapping it with layers of paper. In some cases, layers of coarse burlap or mosquito netting were applied between the layers of paper to give mechanical strength and air space. The fact that many filters gave good protection showed that a filter of this type and material is possible, but the operations of wrapping and sealing require careful work in production and inspection and even with the greatest skill and care, imperfections are almost impossible to avoid. This chance of defects, together with the labor involved, makes the process undesirable.