§ 403. CURRENTS OF THE SEA. I97 



east, sometimes west, but which always lose themselves where they 

 rise, viz., in mid ocean. 



403. Under Currents. — Lieutenant J. C.Walsh, in the U. S. 

 Under cckrents— schooucr "Taney," and Lieutenant S.P.Lee, in the 

 sounding. " U. S. brig "Dolphin," both, while they were carry- 

 ing on a system of observations in connection with the Wind and 

 Current Charts, had their attention directed to the subject of 

 submarine currents. They made some interesting experiments 

 upon the subject. A block of wood was loaded to sinking, and, 

 by means of a fishing-line or a bit of twine, let down to the depth 

 of one hundred or five hundred fathoms, at the will of the exper- 

 imenter. A small barrel as a float, just sufficient to keep the block 

 from sinking farther, was then tied to the line, and the whole let 

 go from the boat. To use their own expressions, " It was wonder- 

 ful, indeed, to see this harrega move off, against wind, and sea, and 

 surface current, at the rate of over one knot an hour, as was gen- 

 erally the case, and on one occasion as much as If knots. The 

 men in the boat could not repress exclamations of surprise, for it 

 really appeared as if some monster of .the deep had hold of the 

 weight below, and was walking off with it."* Both officers and 

 men were amazed at the sight. The experiments in deep-sea 

 soundings have also thrown much light upon the subject of un- 

 der currents. There is reason to believe that they exist in all, 

 or almost all parts of the deep sea, for never in any instance yet 

 has the deep-sea line ceased to run out, even after the plummet 

 had reached the bottom. If the line be held fast in the boat, it 

 invariably parts, showing, when two or three miles of it are out, 

 that the under currents are sweeping against the bight of it with 

 what seamen call a sivigging force^ that no sounding twine has yet 

 proved strong enough to withstand. Lieutenant J. P. Parker, of 

 the United States frigate Congress^ attempted, in 1852, a deep-sea 

 sounding off the coast of South America. He was engaged with 

 the experiment eight or nine hours, during which time a line near- 

 ly ten miles long was paid out. Night coming on, he had to part 

 the line (which he did simply by attempting to haul it in) and re- 

 turn on board. Examination proved that the ocean there, in- 

 stead of being over ten miles in depth, was not over three, and 

 that the line was swept out by the force of one or more under 



* Lieutenant Walsh. 



