Explorations and field-work of the Smithsonian Institution in .. . r 20 minutes, and in its tangled threads many bottom-livingforms were enmeshed. When it was possible, we used a dredge consisting of a heavy ironframe with the long sides slightly flaring, from the rear end of whichwas suspended a net protected on the outside with a canvas sleeve. Wesoon learned that nothing larger than a 4-foot element could safelybe employed on account of the roughness of the bottom. Samples ofbottom mud, made up largely of the skeletons of minute creatures,were preserved undisturbed. On very rough bottom we
Explorations and field-work of the Smithsonian Institution in .. . r 20 minutes, and in its tangled threads many bottom-livingforms were enmeshed. When it was possible, we used a dredge consisting of a heavy ironframe with the long sides slightly flaring, from the rear end of whichwas suspended a net protected on the outside with a canvas sleeve. Wesoon learned that nothing larger than a 4-foot element could safelybe employed on account of the roughness of the bottom. Samples ofbottom mud, made up largely of the skeletons of minute creatures,were preserved undisturbed. On very rough bottom we found the Chesapeake oyster dredge withits linked chain bag very serviceable. On smoother bottom we usedthe 6-foot or the 9-foot reversible beam trawl, which consists of twoU-shaped steel runners 4 inches wide and 4 feet long held apart bytubes of the desired length. To the four open ends of the loops isattached the long net with its lead line at the mouth end. The bag iskept open by hollow glass spheres suspended on the inside. SMITHSONIAN EXPLORATIONS. I933 13.
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectscienti, bookyear1912
