. The depths of the sea; an account of the general results of the dredging cruises of SS. 'Porcupine' and 'Lightning' during the summers of 1868, 1869 and 1870, under the scientific direction of Dr. Carpenter, J. Gwyn Jeffreys, and Dr. Wyville Thomson. Porcupine (Ship); Lightning (Ship); Ocean; Marine animals; Deep-sea temperature; Marine sediments. 252 THE DEPTHS OF THE SEA. [chap. VI. out. The weight of the frame of this dredge, the largest we ever used, was 225 lbs.; it was forged by Messrs. Harland and Wolff of Belfast of the best Lowmoor iron. The dredge-bag was double—the outer of s
. The depths of the sea; an account of the general results of the dredging cruises of SS. 'Porcupine' and 'Lightning' during the summers of 1868, 1869 and 1870, under the scientific direction of Dr. Carpenter, J. Gwyn Jeffreys, and Dr. Wyville Thomson. Porcupine (Ship); Lightning (Ship); Ocean; Marine animals; Deep-sea temperature; Marine sediments. 252 THE DEPTHS OF THE SEA. [chap. VI. out. The weight of the frame of this dredge, the largest we ever used, was 225 lbs.; it was forged by Messrs. Harland and Wolff of Belfast of the best Lowmoor iron. The dredge-bag was double—the outer of strong twine netting, the inner of bread- bag. Three sinkers—one of 1 cwt., the other two of 56 lbs. each—were attached to the dredge-rope at 500 fathoms from the dredge. The operation of sounding at a depth of 2,435 fathoms in the Bay of Biscay on the 22nd of July, 1869, has already been described in detail. When the depth had been accurately ascertained, about the dredge was let go, the vessel drift- ing slowly before a moderate breeze (force = 4) from the The 3,000 fathoms of rope were all out at The diagram (Fig- 50) will give an idea of the various relative positions of the dredge and the vessel according to the plan of dredging adopted by Captain Calver, which End Of the workcd admirably, and which ap- gSe3f\^":^^^^^^^^ pears, in fact, to be the only mode of the Bag. which would answer for great depths. A represents the position of the vessel when the dredge is let go, and the dotted line a b the line of descent of the dredge, rendered oblique by the tension of the rope. While the dredge is going down the vessel drifts gradually to leeward ; and when the whole (say) 3,000 fathoms of rope are out, c, Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Thomso
Size: 826px × 3026px
Photo credit: © Paul Fearn / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1870, booksubjectmar, booksubjectocean
