458 ANNUAL, REPORT SMITHSONIAN INSTITUTION, 1910. 



on board until April, 1878, exploring the Gulf of Mexico and adja- 

 cent regions. Admiral, then Lieut. Commander C. D. Sigsbee, 

 United States Navy, was in command, and his ingenious inventions 

 of sounding apparatus, trawls, etc., enabled the expedition to accom- 

 plish unprecedented results. 



The second cruise of the Blake started from Washington on No- 

 vember 27, 1878, with Capt. J. R. Bartlett, United States Navy, in 

 command, and throughout the winter of 1878-79 they cruised among 

 the Windward Isles of the West Indies and over the Caribbean Sea, 

 visiting Habana, Jamaica, Haiti, Porto Rico, St. Thomas, Santa 

 Cruz, Montserrat, St. Kitts, Guadeloupe, Dominica, Martinique, St. 

 Lucia, St. Vincent, Granadines, Grenada, and Barbados, and gath- 

 ering an immense collection of animals from the depth^of the ocean. 



The third and last cruise of the Blake was for the purpose of sound- 

 ing the depths of the Gulf Stream. They started from Newport in 

 June and cruised until August, 1880, running seven lines of sound- 

 ings off the coast between Charleston and George's Bank, which led 

 to the discovery that a plateau covered by water not more than GOO 

 fathoms deep extends from the Bahamas northward to Cape Hat- 

 teras, forming a vast triangular area of shallow water, the outer edge 

 of which is from 300 to 350 miles out in the ocean from the coast of 

 the Southern Atlantic States. The Gulf Stream flows across this 

 area on its course between the Straits of Bernini to Cape Hatteras, 

 and the outer edge of this shallow bank is where the North American 

 Continent rises abruptly from the depths of the flat floor of the ocean. 

 The name " Blake Plateau " was most appropriately given by Alex- 

 ander Agassiz to this extensive area of shallow water. 



During her three cruises the Blake made 355 soundings, deep-sea 

 temperature observations, and trawl hauls yielding a phenomenally 

 rich harvest of new and interesting marine animals. Among other 

 things, the second cruise led to the discovery of a vast submarine 

 valley, the " Bartlett Deep," extending for nearly 700 miles along the 

 southern coast of Cuba toward Honduras. Twenty miles south of 

 Grand Cayman this great depression is 3,100 fathoms deep, so that 

 the summits of the mountains of Cuba only 50 miles away are 28,000 

 feet above its somber trough. 



This experience upon the Blake was the most momentous event in 

 Alexander Agassiz's scientific life, for it gave him a taste for marine 

 exploration which was to dominate his future career. Without this 

 he might have continued to be an embryologist and systematic zoolo- 

 gist, but he was destined to more conspicuous achievements as an 

 explorer. 



Its effect upon the history of the museum at Cambridge was also 

 profound, for the output of museum publications had been so slow 

 that at the end of 1877 only three volumes of the " Bulletins " and 



