5O A Retrospect of Oceanography 



in warm latitudes. After every sounding it has to be thoroughly 

 dried before being used for the next one, and it has to be 

 constantly surveyed in case of chafes or weaknesses. It was 

 partly to the goodness of the material, but very much more 

 to the unremitting care and watchfulness of those who had 

 charge of it, that after the first beginning only one sounding- 

 line was lost. Fortunately, the novelty of the single wire 

 for sounding purposes has worn off, and the safety of instru- 

 ments is thought more of. The principal advantage possessed 

 by the wire was that a great length of it occupied very little 

 space, and in small vessels operating in deep waters this is 

 of some importance. A small wire cable is now manufactured ; 

 it takes up very little more room than the single wire, and is 

 comparatively trustworthy. H.S.H. the Prince of Monaco 

 has a cable of this kind only 2-25 millimetres in diameter, 

 for work on board the "Princesse Alice," and with it several 

 water-bottles can be used at once, enabling the great bulk 

 of the deep water of the ocean to be studied physically and 

 chemically. 



We owe, however, to the single wire and the free use which 

 has been made of it, chiefly in the interests of the submarine 

 cable industry, the pretty detailed knowledge which we now 

 have of many portions of the ocean bed. Its usefulness as 

 a means of obtaining many soundings was shown in the clearest 

 way by the performance of the U.S. S. "Tuscarora" in the 

 Pacific, on a line from California by the Sandwich islands 

 to Japan, in the course of which the astonishing depths of 

 over 4000 fathoms were first discovered; and all this work 

 was done by hand. In the "Challenger" the distance between 

 the soundings varied from 100 to 300 miles. In the "Tuscarora" 

 they were taken at intervals of 30 miles, and they revealed 

 differences of relief in the bottom of the ocean which had 

 not been suspected. The report .of the soundings of the 

 "Tuscarora" was received with the greatest interest on board 

 the "Challenger" when at Hong-Kong. 



Although at the date of the sailing of the "Challenger" 

 the chart of the ocean was almost a blank as regarded deep 

 soundings, there were studded over it numerous shallow 



