Deep-sea sounding and dredging; a description and discussion of the method and appliances used on board the Coast and Geodetic Survey Steamer, "Blake." . purpose, but the circular form was adopted as the simplest, and, perhaps, theleast liable to become caught among the rocks. Inpractice we have found the tangle-frame hithertoused too light for use on the larger vessel now em-ployed, for when rocks are encountered the chain-bar often comes up badly bent. In constructingnew ones, I should recommend a round or squarebar of iron at least twice as heavy as the one wehave hitherto used. Our present
Deep-sea sounding and dredging; a description and discussion of the method and appliances used on board the Coast and Geodetic Survey Steamer, "Blake." . purpose, but the circular form was adopted as the simplest, and, perhaps, theleast liable to become caught among the rocks. Inpractice we have found the tangle-frame hithertoused too light for use on the larger vessel now em-ployed, for when rocks are encountered the chain-bar often comes up badly bent. In constructingnew ones, I should recommend a round or squarebar of iron at least twice as heavy as the one wehave hitherto used. Our present size was firstdevised for use on a steam-launch. It was alsoused on the Bluelight, a tug of eighty tons, withgood success. We have used tangles of this formwith profit on the roughest cod-fishing ledges offthe coasts of Maine and Massachusetts, where thedredge could not be used with safety. It is par-ticularly useful in capturing starfishes and sea-urchins, which frequent rocky bottoms. Severalyears ago the writer suggested the use of tanglesof this or similar form to capture star-fishes onoyster-beds, where they so often prove very I.—The Tangle-Bar. DIMENSIONS OF TANGLES, Diameter of wheels outside Breadth of rim of wheels Thickness of rim of wheels Width of cross-bar of wheels Thickness of cross-bar of wheels Length of chain-bar Width of chain-bar Thickness of chain-bar Size of rings for drag-rope Size of iron of rings Size of iron of chains Length of iron chains , Length of hemp tangles design. 12 inches. 1i inch, i2 inches. |I inches. 2 inch. 3 inch. i feet. 14 inches. 2^ inches. I ^ inches. f inch. I feet. The drag-rope for the tangles should be very strong, to resist the frequent andsudden strains when using them on rough bottoms. 166 DEEP-SEA SOUNDING AND DEEDGING. THE CHECK-STOP. This arrangement was devised by Oapt, L. A. Beardslee, for use on
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