DEEP-SEA SOUNDING. 629 



was despatched in June, 1862, and Mr. Hoskyn, R.N., made a very careful 

 examination of the edge of the bank of soundings, between the parallels of 

 51° and 54° N., as well as of that between Iceland and Rockall. It will be 

 needless to recapitulate this work — the charts are by far the best guide ; 

 but it may be said that no such sudden dip or abrupt precipice was found, 

 the steepest incline being a difference of level of 3,060 feet in 2f miles, or 

 about 19 feet in 100 feet. 



Several other expeditions were afterwards organised with a view to 

 obtaining an exact knowledge of the nature of the sea-bed, and of the 

 depth of the ocean. The voyage of H.M.S. Hydra, Capt. P. R. Shortland, 

 and that of H.M.S. Lightning (one of the first two steam-vessels built in 

 1825 for the Eoyal Navy), in 1868, with Dr. Carpenter and Dr. Wyvilla 

 Thomson on board, may be cited as the most prominent. Besides these, 

 there were the Gannet and Valorous, and the Swedish vessels Sophia 

 and Josephine. 



In 1869, H.M.S. Porcupine was sent out to continue these interesting 

 researches, and under the masterly seamanship of Captain Calver, the 

 apparatus used was brought much more nearly to perfection. The im- 

 portant results of this expedition in the seas N.W. of the British Isles 

 will be briefly alluded to presently, but the topic is too wide for full 

 notice here.* 



In 1870, the U.S. vessel Yantic took numerous soundings in the West 

 Indies, and in the following year the Mercury gained a series of 15 sound- 

 ings between Sierra Leone and Havana. In 1872, the Telegraph Works 

 Company took a series of soundings between the Lizard and Bilbao, steel 

 wire being successfully used in place of hemp line. In 1873, the United 

 States Government despatched the Tuscarora to the Pacific Ocean, under 

 Commander Belknap, when a large series of soundings was successfully 

 made with wire. 



Up to now, the most extensive deep-sea exploring expedition was con- 

 ducted on board H.M.S. Challenger, between December, 1872, and May, 

 1876, a period of three years and five months, three years of which were 

 spent between lat. 40° N. and 40° S. Elaborate investigations were made 

 in each of the great Oceans of the globe, and it may be interesting to 

 record, that during this lengthened voyage, the ship sailed and steamed 

 over upwards of 68,000 miles, and nearly 400 deep soundings were taken, 

 of which two were over 4,000 fathoms, nine between 3,000 and 4,000 

 fathoms, 168 between 2,000 and 3,000 fathoms, 124 between 1,000 and 

 2,000, the remainder being under 1,000 fathoms. There were 360 ob- 

 serving stations established, at each of which, as far as circumstances 

 would permit, the exact depth was determined ; samples of the bottom 

 from 1 oz. to 1 lb. were obtained ; samples of water from the bottom and 

 from various depths were procured for physical and chemical examina- 

 tion ; the bottom and intermediate temperatures were determined ; at 

 most stations a fair sample of the bottom fauna, and of that of inter- 

 mediate depths, was obtained by the dredge or trawl variously adjusted ; 



• See " Proceedings of the Royal Society," vol. xviii,, No. 181, for a full report of 

 the voyage. 



