The 



" Albatross. 



12 DEPTHS OF THE OCEAN 



distribution of temperature in that ocean and of the deep-sea 

 deposits covering its floor. Piano wire was first used for 

 oceanic sounding work on board the " Tuscarora," though for 

 some years previously Sir WilHam Thomson (Lord Kelvin) 

 had been experimenting with it on board his yacht. 



Also contemporaneous with the "Challenger" Expedition 

 was the circumnavigating cruise of the German ship "Gazelle," 

 during which many 

 valuable oceanograph- 

 ical observations were 

 recorded. 



In 1876 the U.S.S. 

 "Gettysburg" took a 

 series of deep - sea 

 soundings in the North 

 Atlantic, and in the 

 years 1876 to 1878 

 the Norwegian North 

 Atlantic Expedition on 

 board the S.S. " Vorin- 

 gen " made important 

 physical and biological 

 observations in the seas ; 

 between Norway and 

 Greenland, making thus 

 the first survey of the 

 Norwegian Sea ; the 

 scientific results were 

 published in English 

 and Norwegian. 



From 1877 to 1880 

 the United States Coast Survey steamer " Blake" explored the 

 Caribbean Sea, the Gulf of Mexico, and the coasts of Florida, 

 under the direction of Alexander Agassiz, who published in 

 1888 a general account of the results. At the same time the 

 U.S. Fish Commission steamer "Albatross" was engaged in 

 making observations along the Atlantic coast of the United 

 States, and later, in 1891, explored the Panamic region of the 

 Pacific under the direction of Alexander Agassiz. 



During the " Challenger" Expedition the naturalists became 

 convinced, as a result of their observations in different parts 

 of the world, that a ridge must separate the bodies of cold 

 and warm water found by the "Lightning" and "Porcupine" 



Dr. Alexander Agassiz. 



