II THE PROBLEMS OF THE DEEP SEA 43 



dredging, rapidly increases with the depth at 

 which the operation is performed ; and, until the 

 other day, it is probable that trawling at so great 

 d depth as 100 fathoms was something unheard of. 

 But the first news from the Challenger opens up 

 new possibilities for the traAvl. 



Dr. W3rviUe Thomson writes (" Nature," March 

 20, 1873) :— 



"For the first two or three hauls in very deep water off the 

 coast of Portugal, the dredge came up filled with the usual 

 'Atlantic ooze,' tenacious and uniform throughout, and the 

 work of hours, in sifting, gave the very smallest possible result. 

 We were extremely anxious to get some idea of the general 

 character of the Fauna, and particularly of the distribution of 

 the higher groups ; and after various suggestions for modification 

 of the dredge, it was proposed to try the ordinary trawl. We 

 had a compact trawl, with a 15-feet beam, on Iward, and we 

 sent it down off Cape St. Vincent at a depth of 600 fathoms. 

 The experiment looked hazardous, but, to our great satisfaction, 

 the trawl came up all right and contained, with many of the 

 larger invertebrata, several fishes, . . . After the first attempt 

 we tried the trawl several times at depths of 1090, 1525, and, 

 finally, 2125 fathoms, and always with success," 



To the coral-fishers of the Mediterranean, who 

 seek the precious red coral, which grows firmly 

 fixed to rocks at a depth of sixty to eighty 

 fathoms, both the dredge and the trawl would be 

 useless. They, therefore, have recourse to a sort 

 of frame, to which are fastened long bundles of 

 loosely netted hempen cord, and which is lowered 

 by a rope to the depth at which the hempen cords 

 can sweep over the surface of the rocks and break 



