CHAP, v.] DEEP-SEA SOUNDING. 231 



have been prosecuting a most careful and elaborate 

 survey of their coast-line ; and latterly the Coast 

 Survey, under the late Professor Bache and the pre- 

 sent energetic head of the Bureau, Professor Pierce, 

 has pushed its operations into deep water, particu- 

 larly in the Gulf- stream region north-westwards of 

 the Strait of Florida. Dredging operations have 

 been conducted most successfully under Count Pour- 

 tales, and it will be seen hereafter that his results 

 are a valuable complement and corroboration of our 

 own. The Swedish Government has- twice executed 

 careful soundings in the sea between Spitzbergen and 

 Greenland and to the south-west of Spitzbergen ; in 

 1860 under the direction of Otto Thorell, and in 

 1868 through the Swedish Arctic Exploring Expe- 

 dition under Captain Count von Otter of the Royal 

 Swedish steamer ' Sophia.' In 1869 the Swedish 

 corvette ' Josephine ' sounded and dredged in the 

 North Atlantic, taking soundings to the depth of 

 upwards of 3,000 fathoms, and discovered the ' Jose- 

 phine Bank/ with a minimum depth of 102 fathoms, 

 in lat. 36 45' N., long. 14 10' W. to the north-west 

 of the Strait of Gibraltar. The North-German Polar 

 expeditions greatly increased our knowledge of the 

 Spitzbergen and the Greenland Seas ; and finally, 

 on December 20th, 1870, the American nautical 

 school-ship 'Mercury/ Captain P. Giraud, crossed the 

 Tropical Atlantic to Sierra Leone, which she reached 

 on the 14th of February, 1871. She left Sierra 

 Leone on [February 21st, and soundings and other 

 observations were continued till she reached Havan- 

 nah on the 13th of April. The object of this ex- 

 pedition and the character of the observers are 



