THE ATLANTIC TELEGRAPH. 377 



The materials used for this map* and profile were the deep-sea 

 soundings already mentioned as made by Walsh, Taylor, Lee, and 

 Barron, together with others which had been received from the 

 Congress, Commodore M'Keever; the Portsmouth, Captain Dor- 

 nin ; the Cyane, Captain Paine ; the St. Louis, Captain Ingraham ; 

 the Plymouth, Captain Kelly ; the Grermantown, Captain Knight; 

 the Susquehanna, Captain Inman ; and Lieutenant Warley, of the 

 Jamestown, Captain Downing. These were the first maps of the 

 kind ever attempted for " blue water." Their object was to show 

 the depressions of the solid crust of our planet heloiL\ as geogra- 

 phers seek to represent its elevations ahove the sea-level.f The 

 "telegraphic plateau" is there delineated on Plate XIY., very much 

 as the subsequent deep-sea soundings have shown it to be. This 

 attempt to map out the bottom of the deep sea was regarded with 

 exceeding interest by the learned. Humboldt gave it high praise ; 

 it opened the freshest and most interesting field that remained to 

 him for contemplation in the domains of science. 



Up to this time, however, nothing had ever been brought up 

 from the deep sea. The plummet was a cannon ball, and the 

 sounding-line a bit of small twine which was broken off when the 

 cannon ball reached the bottom, so that ball and twine remained 

 behind; consequently, every cast of the deep-sea plummet in- 

 volved the loss of a shot and of as much twine as it took to reach 

 the bottom. It was desirable to bring up soundings, not only 

 that we might learn what the bottom and bed of the ocean were 

 made of, but that we might know of a verity and have the proof 

 that the bottom had been reached. 



Under these circumstances, the attention of Lieutenant J. M. 

 Brooke, who was at the time stationed at the Observatory, was 

 called to the subject, when he made, for hringing up specimens 

 from the bottom^ the beautifiil and simple contrivance known as 

 "Brooke's deep-sea sounding apparatus." 



When the Dolphin returned from the Tagus, which she did in 

 March, 1853, arriving at Norfolk on the 7th of that month, she 

 was ordered to sea again under Berryman, to assist still farther 

 ^'in perfecting the discoveries made by Lieutenant Maury in the 



* See Plates XIV. and XV., Maury's Sailing Directions, 5th edition, 

 t See p. 239, 240, 5th ed. Maury's Sailing Du-ections, printed by C. Alexander, 

 Washington, and published in February, 1853. 



