340 POPULAR LECTURES AND ADDRESSES. 



30 lb. sinker hauled on board. I scarcely think any 

 one but myself believed the bottom had been 

 reached until the brass tube with valve was un- 

 screwed from the sinker and showed an abundant 

 specimen of soft grey ooze. The length of wire and 

 cod-line which had been paid out was within a few 

 fathoms of being exactly 2,700 fathoms. The wire 

 was so nearly vertical that the whole length of line 

 out cannot have exceeded the true depth by more 

 than a few fathoms. The position was accurately 

 determined by two Sumner lines observed at nh. 

 23m. a.m. and ih. 5m. p.m. Greenwich apparent 

 time, and found by their intersection to be latitude 

 44 32', longitude 5 43' west. 



That one trial was quite enough to show that the 

 difficulties which had seemed to make the idea of 

 sounding by wire a mere impracticable piece of 

 theory have been altogether got over. 



The great merit of wire compared with rope is the 

 smallness of the area and the smoothness of the 

 surface which the wire presents, in contrast with 

 the greatness of the surface and its roughness, when 

 rope with a comparable degree of strength is used. 



