Scientific American. relation of the parts. The principle consists By removing the lower portion of the tubes, Helo Inventions, in providing a balance puppet valve of large dimensions, which can be lifted from its seat by a comparatively small force, and so ar- ranging and connecting this that by… … portion of the latter, for purposes which will affect thera in the discharge of their duties. protect firemen from the injurious effects of appear below. For further information, address the inventor smoke and heated air upon the lungs, by When the pressure rises to such an extent as above; or,…
Internet Archive · Public domain (published before 1931). Free to use for anything.
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