land. Large charges are made by hy- is so lowered that it is slung immediately inside the draulic pressure in a single homogeneous block, in- crib, and between it and the crib a stout rubber tube stead of being built up of a number of small seg- is provided which, being connected with the… … banksman has_ im- vertical cylinder made finely-perforated properly signalled for lowering. The motive sheet metal sur- The principal merits of this system are the follow- rounded by a strong casing. Here all air that may power for driving the apparatus is compressed air. ing: First, simplicity of…
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