366 POPULAR LECTURES AND ADDRESSES. 



six men have a heavy haul to bring up a lead in 

 soundings of 50 or 60 fathoms, if the ship is under 

 way ; but by the wire process a cabin boy can 

 bring a 34 Ibs. sinker with ease from a depth of 150 

 fathoms the ship all the time going on her course, 

 at from four or five knots (to which the speed may 

 have been reduced for a couple of minutes for the 

 sounding) up to full speed. 



An important merit of wire for deep-sea sounding 

 is the setting of the ship in motion again, which it 

 permits almost as soon as the bottom is reached. 

 Suppose the depth found 3,000 fathoms, by the 

 time you have got about 500 fathoms of wire in, 

 you steam slightly ahead ; when 1,500 fathoms is 

 in, you may steam at five or six knots without 

 injury ; and by the time you have only about 1,000 

 fathoms out, you may steam at 10 knots ; and, if 

 the speed of the ship is equal to it, you may steam 

 at 12 knots with 700 or 800 fathoms of line out. 

 In fact, the time spent in deep-sea soundings will 

 be reduced to a small fraction of what it is by the 

 process of our own Admiralty. Mr. Siemens has 

 asked, how quickly a sounding of 2,000 fathoms can 



