CHAP. v.J DEEP-SEA SOUNDING. 



229 



and currents, and filling up hollows by drift ino- about 

 and distributing their materials. 



The first careful surveys of the Atlantic, in which 

 great depths were determined with considerable accu 

 racy, are the cruises of Lieut. -Commanding Lee, in 

 the U.S. brig ' Dolphin ' (1851-52), and of Lieut- 

 Commanding O. H. Berryman, in the same vessel 

 in 1852-53 ; but the sounding voyage in which 

 modern appliances were first employed with perfect 

 accuracy with a practical object was that of Lieu 

 tenant Berryman in 1856, in the U.S. steamer 

 'Arctic,' in which twenty-four deep-sea soundings 

 were taken with the Brooke's and Massey's sounding 

 machines on a great circle between St. John's, New 

 foundland, and Valeiitia in Ireland, with a view 

 to the laying of the first cable. The same ground 

 was gone over by Lieutenant Dayman, in H.M.S. 

 'Cyclops,' in June and July 1857, and thirty-four 

 soundings were taken, the depth being estimated by 

 Massey's sounding-machine and a modification of 

 Brooke's machine already described. The next im 

 portant sounding expedition was that of Commander 

 Dayman, in H.M.S. ' Gorgon,' from Newfoundland to 

 the Agores, and thence to England. The depths 

 were taken in this case with a lead usually 188 Ibs. 

 in weight which was lost at each cast, and alba- 

 core line with a breaking strain of 420 Ibs. Only 

 on one occasion, about a third of the way from the 

 Acores to England, a cup-lead was let go, attached 

 to a stronger line, in 1,900 fathoms, and came up half 

 filled with grey ooze. 



Another route for a telegraph cable having been pro 

 posed, H.M.S. < Bull-dog ' started in July 1860, under 



