270 ANNUAL OF SCIENTIFIC DISCOVERY. 



and rivers from the land. The waters of Lake Titicaca, which receives 

 the drainage of the great inland basin of the Andes, are only brackish, 

 not salt. Hence we may infer that this lake has not been standing 

 long enough to become brine, like the waters of the Dead Sea ; conse- 

 quently it belongs to a more recent period. On the other hand, it will 

 also be interesting to hear that my friend, Captain Lynch, informs me, 

 that in his exploration of the Dead Sea he saw what he took to be the 

 dry bed of a river, that once flowed from it. And thus we have two 

 more stout links, and strong, to add to the circumstantial evidence 



foing to sustain the testimony of this strange and fickle witness, which 

 have called up from the sea to testify in this presence concerning the 

 works of nature, and to tell us which is the older, the Andes watching 

 the stars with their hoary heads, or the Dead Sea sleeping upon its 

 cubic beds of crystal salt. 



DEEP-SEA SOUNDINGS. 



THE system of deep-sea soundings, instituted some years since, by 

 Lieut. Maury, and since carried out to some extent by our national 

 vessels, has been prosecuted with success during the past year.* Capt. 

 Platt, in the sloop of war " Albany," has run a line of deep-sea sound- 

 ings across the Gulf of Mexico, from Tampico to the Straits of Florida. 

 The basin which holds the waters of this gulf has thus been ascertained 

 to be a mile deep, and the Gulf Stream in the Florida Pass about 3,000 

 feet deep. In like manner the " John Adams," Capt. Barron, has made 

 a step in giving us the shape of the great Atlantic basin between the 

 Capes of Virginia and the Island of Madeira, showing it to be at least 

 five miles and a half deep. The method of measurement now pursued 

 is the suggestion of Prof. Guyot, and consists of ordinary packing- 

 twine attached to a thirty-two-pound shot, which is allowed to run out 

 until the shot strikes bottom, when the uncoiling is of course suspended. 

 The length of the twine is previously ascertained, and the depth at- 

 tained is known by measurement of the quantity remaining upon the 

 reel. Improvements have been made upon this system by waxing the 

 twine and timing its rate of descent. 



In order to promote the schemes of Lieut. Maury, the Navy Depart- 

 ment has ordered the commanders of all national vessels to make deep- 

 sea soundings whenever it is practicable, in whatever part of the ocean 

 they may happen to be cruising; The following is a specimen of the 

 soundings made by the "John Adams" in the North Atlantic, as 

 reported to the department : 



" May 3, 1851. Latitude 33 50' North ; longitude 52 34' West ; 

 temperature of the air 64, water C5. Had a fair " up and down " 

 sound with (2,600) twenty-six hundred fathoms of line. Time of run- 

 ning out, 1 hour 23 minutes 10 seconds one 32-pound shot on the 



1 A 



line. 



"May 9. Latitude 32 06', longitude 44 47' West; temperature 

 of the air GG, water 68. Got bottom with (5,500) five thousand five 

 hundred fathoms of line out. Time of running out, 2 hours 44 min. 



*See Annual of Scientific Discovery, for 1851, p. 264. 





