lar area of about face of the target and passed entirely two feet in diameter. The outer plate through the backing. These bolts are in- was sprung from the bolts at each eud. dicated in the figures by numbers. Be- The outer pair of plates separated about a fore this target was constructed, 265… … Fig. 3. uninjured. An old crack in the middle pounds, were exploded against plates upright, due to checking, had widened fastened to this same structure without . slightly. The whole structure had sprung materially damaging it. back two inches, but had recovered itself The No. 1 kisselguhr dynamite…
Engineering
Internet Archive · Smithsonian Libraries · Public domain (published before 1931). Free to use for anything.
