THE NATURAL HISTORY OF THE SEA. 383 



Cook, on the conclusion of his voyages, left little to be 

 done in the way of discovering new lands, and gradually 

 attention came to be given more particularly to the scientific 

 study of the sea. Just as Banks was the first notable 

 observer of animal and plant life on the high seas, so the 

 physical study of the sea may be said to spring from 

 Cavendish's self-registering thermometer, first made about 

 1757. He suggested that it might be applied to ascertain- 

 ing " the temper of the sea at great depths". Irvine, who 

 accompanied Lord Mulgrave to the Arctic regions, so applied 

 it in 1773 (two year after the return of the Endeavour\ and 

 he also seems to have invented a water-bottle. On this 

 voyage, also, one of the earliest attempts at deep-sea sound- 

 ing was made, the greatest depth reached being 683 fathoms. 

 Improvements in apparatus were made, and many experi- 

 ments were tried in the succeeding years. Franklin, Sir 

 John Ross, and among naturalists the great Ehrenberg 

 were conspicuous by their labours. Sir James Clark Ross's 

 Antarctic Expedition (1839-43), and at the same time 

 Captain Wilkes, who commanded the first purely scientific 

 expedition sent out by the United States, made notable 

 advances. The one expedition was fortunate in carrying 

 Sir Joseph (then Dr.) Hooker, the other Dana, as natural- 

 ist. However, after all was done, there was still lacking^ 

 the material for any important generalisation. Edward 

 Forbes, Captain Spratt, Maury, and many others continued 

 to amass observations and to attract attention to the study 

 by theoretical views of profound interest. Captain Dayman, 

 who sounded across the North Atlantic in H.M.S. Cyclops 

 {1857), brought home soundings in which Huxley discovered 

 the Coccoliths. It was not, however, until submarine tele- 

 graphy came to be a necessity that any great opportunities 

 came for a systematic study of the deep sea, just as ocean 

 commerce has led to the careful charting of coasts and 

 shallow seas. In i860 H.M.S. Bulldog made a survey 

 for a telegraph route between England and America. It 

 was on this voyage that Dr. G. C. Wallich made his cele- 

 brated observations on the existence of a special deep-sea 

 fauna. Many of his opinions have been confirmed by 



