Deep-sea sounding and dredging; a description and discussion of the method and appliances used on board the Coast and Geodetic Survey Steamer, "Blake." . r place. On the first dredging cruise tow-nets had been used only at or nearthe surface, because Professor Agassiz had but little confidence in the valueof the tow-net as it had generally been worked in deep waters—i. e., withthe mouth wide open during the several processes of lowering, dragging,and hauling back. The exact habitat of specimens brought to the surfacein this way was thought to be very much in doubt. The desirability ofhaving a
Deep-sea sounding and dredging; a description and discussion of the method and appliances used on board the Coast and Geodetic Survey Steamer, "Blake." . r place. On the first dredging cruise tow-nets had been used only at or nearthe surface, because Professor Agassiz had but little confidence in the valueof the tow-net as it had generally been worked in deep waters—i. e., withthe mouth wide open during the several processes of lowering, dragging,and hauling back. The exact habitat of specimens brought to the surfacein this way was thought to be very much in doubt. The desirability ofhaving a tow-net which could be kept closed in lowering and hauling back,and yet be kept open when dragging, was several times the subject of con-versation on board. I suggested something of this kind: the net to befastened to the dredge-rope and lowered with the mouth closed; whendragging, a weight to be sent down on the rope, which would open the tow-net and at the same time detach itself and fall clear; when ready to haulback, a second weight to be sent down to close the mouth of the net. This DEEP- SEA SOUNDING AND S COAST SURVEY. ,. PLANS OF THE DECK AND APPARATUS OE THE BLAK-E ,^2. DURING THE FIRST DREDGING DURING THE SECOND DREDGING EXPEDITION. DREDGING AND TEAWLING—APPARATUS AND METHODS. 145 is a vague suggestion, but it might perhaps be put in mechanical shape.*On the second dredging cruise an open-mouth tow-net was tried in deepwater, but not with much success in getthig specimens. Another device, called the tangle-bar drag, for dragging along thebottom, was used on the second cruise. It was towed by a bridle, andhad sAvabs secured along its whole length. This apparatus brought upspecimens in great profusion. GENERAL REMARKS. The advantages gained by the use of wire rope for dredging purposesare chiefly in the following particulars: compactness, strength, durability,neatness, facility of handling with a small force, celerity of o
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