4 THE OCEAN WORLD. 



Thouars, during his scientific voyage in the frigate Venus, took some 

 very remarkable soundings in the Southern Pacific Ocean : one, 

 without finding bottom at 2,411 fathoms ; another, in the equinoctial 

 region, indicated bottom at 3,790. 



In his last expedition in search of a north-west passage, Captain 

 Ross found soundings at 5,000 fathoms. Lieutenant Walsh, of the 

 American Navy, reports a cast of the deep-sea lead, not far from 

 the American coast, at 34,000 feet without bottom. Lieutenant 

 Berryman reported another unsuccessful attempt to fathom mid ocean 

 with a line 39,000 feet in length. Captain Denman, of H. M.S. Herald, 

 reported bottom in the South Atlantic at the depth of 46,000 feet ; 

 and Lieutenant J. P. Parker, of the United States frigate Congress, on 

 attempting soundings near the same region, let go his plummet, after 

 it had run out a line 50,000 feet long, as if the bottom had not been 

 reached. We have the authority of Lieutenant Maury for saying, 

 however, that " there are no such depths as these." The under- 

 currents of the deep sea have power to take the line out long after 

 the plummet has ceased to sink, and it was before this fact was 

 discovered that these great soundings were reported. It has also 

 been discovered that the line, once dragged down into the depths of 

 the ocean, runs out unceasingly. This difficulty was finally overcome 

 by the ingenuity of Midshipman Brooke. Under the judicious 

 patronage of the Secretary to the United States Navy, Mr. Brooke 

 invented the simple and ingenious apparatus (Fig. i), by which 

 sound ngs are now made, in a manner which not only establishes the 

 depth, but brings up specimens of the bottom. The sounding line 

 in this apparatus is attached to a weighty rod of iron, the lower 

 extremity of which contains a hollow cup for the reception of tallow 

 or some other soft substance. This rod is passed through a hole in 

 a thirty-two pound spherical shot, being supported in its position by 

 slings A, which are hooked on to the line by the swivels a. When 

 the rod strikes the bottom, the tension on the line ceases, the swivels 

 are reversed, the slings B are thrown out of the hooks, the ball falls 

 to the ground, and the rod, released from its weight, is easily drawn 

 up, bringing with it portions of the bottom attached to the greasy 

 substance in the cup. By means of this apparatus, specimens of the 

 bottom have been brought up from the depth of four miles. 



The greatest depth at which the bottom has been reached 

 with this plummet is in the North Atlantic between the parallels 

 of 35 and 40 north, and immediately south of the great bank 

 of rocks off Newfoundland. This does not appear to be more 

 than 20,000 feet deep. " The basin of the Atlantic," says Maury, 



