70 EXPEDITION OF THE " CHALLENGER " m 



has hitherto been yielded by her exploration of 

 the nature of the sea bottom at great depths, a 

 full scientific equivalent of the trouble and ex- 

 pense of her equipment would have been obtained. 

 In order to justify this assertion, and yet, at the 

 same time, not to claim more for Professor Wyville 

 Thomson and his colleagues than is their due, I 

 must give a brief history of the observations which 

 have preceded their exploration of this recondite 

 field of research, and endeavour to make clear 

 what was the state of knowledge in December, 

 1872, and what new facts have been added by the 

 scientific staff of the Challenger. So far as I have 

 been able to discover, the first successful attempt 

 to bring up from great depths more of the sea 

 bottom than would adhere to a sounding-lead, was 

 made by Sir John Boss, in the voyage to the 

 Arctic regions which he undertook in 1818. In 

 the Appendix to the narrative of that voyage, 

 there will be found an account of a very ingenious 

 apparatus called " clams " a sort of double scoop 

 of his own contrivance, which Sir John Eoss 

 had made by the ship's armourer ; and by which, 

 being in Baffin s Bay, in 72 30' N. and 77 15' W., 

 he succeeded in bringing up from 1,050 fathoms 

 (or 6,300 feet), " several pounds " of a " fine green 

 mud," which formed the bottom of the sea in this 

 region. Captain (now Sir Edward) Sabine, who 

 accompanied Sir John Boss on this cruise, says of 

 this mud that it was " soft and greenish, and that 



