38 A Retrospect of Oceanography 



practice. It had been brought so far in 1872 as to have emerged 

 from the tentative experimental stage, and was ready for being 

 tried on a large scale. Had the "Challenger" been going 

 to run a line of soundings across the Atlantic for the purpose 

 of selecting a bed for a telegraph cable, it would have been 

 perfectly reasonable that she should be fitted with wire sounding- 

 apparatus and a large supply of wire. She would, no doubt, 

 have got to the other side of the ocean with wire to spare, 

 and by filling up again with fresh wire, she might have con- 

 tinued similar work. But such was not the work that the 

 "Challenger" was fitted out for. Determining the depth of 

 the ocean was only a small part of her work at the 354 stations 

 which mark her course round the world. Each of these 

 stations marks, on an average, ten to twelve hours' work. 

 Had wire been equally trustworthy with hemp sounding- 

 line, then about one hour of this time would have been saved. 

 So far from wire being equally trustworthy with hemp, it 

 is the very emblem of treachery, and had the leaders of the 

 expedition allowed themselves to trust thermometers and other 

 precious instruments to wire, the store of instruments would 

 soon have been exhausted, and the physical and chemical 

 work would have been at a standstill. Wire rope had 

 not been proposed for dredging until some years after the 

 "Challenger's" return. In the first year of the cruise the 

 sounding-line carried away nine times. After August 16, 

 1873, and until the "Challenger" reached home in May, 1876, 

 ,it only carried away once, namely, on June 14, 1874. Con- 

 sequently, after the first six months of the cruise there was 

 no loss of instruments ; and deep-sea temperatures, for instance, 

 were, station after station, taken with the same thermometers. 

 How different the conditions are when wire has to be depended 

 on alone I experienced in the "Buccaneer," where, in spite 

 of every precaution which care and practice could suggest, 

 and an abundant supply of instruments, the stock of thermo- 

 meters was almost completely exhausted before the work 

 was done. I never attached a thermometer to the wire without 

 feeling that I was guilty of a form of cruelty cruelty to 

 instruments. 



