Identifier: deepseasoundingd00usco (find matches)
Title: Deep-sea sounding and dredging; a description and discussion of the method and appliances used on board the Coast and Geodetic Survey Steamer, "Blake."
Year: 1880 (1880s)
Authors: U.S. Coast and Geodetic Survey Sigsbee, Charles D. (Charles Dwight), 1845-1923
Subjects: Blake (Ship) Deep-sea sounding Dredges
Publisher: Washington, Gov't Print. Off.
Contributing Library: The Library of Congress
Digitizing Sponsor: The Library of Congress

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gle of the outer two hundred fathoms of the dredge-rope,which happened in this wise: The rope had been payed out rapidly, thevessel backing slowly meanwhile and drawing the rope ahead; the large,insufficiently-weighted dredge having met with more resistance than thecompact and heavy steel rope, the bight of the latter had landed first, andthe outer two hundred fathoms of the rope, still descending, had gonedown upon its own parts in confused coils. This we afterwards came to consider a most fortunate and timely acci-dent, for, it having taught us how to lower the dredge, we did not againmeet with a like trouble during the whole progress of the work. There-after the dredge, more heavily weighted, was lowered with the submergedrope kept vertical and under strong tension until the bottom had beenapproached to about fifty fathoms, when the rate of paying out was dimin-ished and the vessel slowly backed until the dredge took ground, after DEEP- SEA SOUNDING AND DREDGING. \l S COAST SURVEY.
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FjGIPLAN of trawl as FTKSI VSll ON BOAT-li! TME ■BLAKE.FIG.2.PLAK OF TRAWL AS l-MPROVED BY PROFESSOR ACASSIZ. LJFUI. COMDR. SXGSBE.E AND ITEUT . DREDGING AND TRAWLING—APPARATUS AND METHODS. 139 Avhich the rate of paying out was increased and the vessel backed accord-ing to circumstances, the rope always heing kept well taut. The extent to which the boom was topped up for work is shown onPkites 24 and 30. A sounding, and an observation for bottom tempera-ture, preceded the dredging operations at each station occupied. For lowering the trawl, with its heavy iron frame and long, pendentbag, a different method was adopted, as suggested by consideration ofthe unequal resistances encountered by the parts mentioned in passingthrough the water, it being necessary to guard against the bag gettingup over the frame-work. With the end of the bag well weighted, thetrawl w^as payed out cautiously, the vessel backing slowly to keep therope tending slightly ahead. As the trawl neared bottom the r

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