Page:Popular Science Monthly Volume 78.djvu/254

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244
THE POPULAR SCIENCE MONTHLY.
PSM V78 D254 Dredging winch of the albatross.png
The Dredging Winch on the Forward Deck of the "Albatross."
(Photograph by DeLong.)

several models of dredges, those designed by Captain Z, L. Tanner, the first captain of the Albatross, and by Professor Alexander Agassiz, have been used most frequently. These consist of a pair of heavy iron running frames at the sides of the mouth of the dredge, connected with one cross bar ten or twelve feet long in the Tanner model, and by two such bars in the Agassiz type. Lashed to this frame is a cone-shaped bag, twenty or thirty feet long, made of heavy webbing, with much finer meshes near the tail than near the mouth, and with a lining of fine webbing in the after part of the bag, the end being closed by a lashing. An extra-heavy, six-foot dredge, fitted with strong teeth on the lower beam, was also built for raking over the pearl oyster beds in the southern part of the archipelago, and this small dredge has also been used to good advantage in collecting over other unusually rough bottoms.

During the Philippine cruise, the largest beam-trawl ever used by the Albatross was made by connecting the usual iron runners with twenty-five-foot spars, and lashing to these a bag over sixty feet long. This net was handled with great success on a smooth ocean floor until, while dredging in Batangas Bay on Washington's Birthday, 1909, the dredge caught on some obstruction and, after a moment of severe tension, gave way. When the wreck was brought to the surface, it was found that both of the heavy pine spars had been snapped in two, and that only a few shreds of the long bag were left hanging to the remains of the frame. This, indeed, is the fate of many a good, deep-sea dredge.

Two models of nets have been used for trawling between the surface