SOUNDING 203 



various types of wire sounding machines, such as the 

 Le Blanc, the Sigsbee, and the Lucas. The Lucas 

 machine (Fig. 198, p. 282) is the one most frequently in 

 use, and is extremely satisfactory. It seems unnecessary 

 to describe these various instruments in detail ; their 

 great advantage is that they indicate at once when 

 the weight strikes the bottom. In well-appointed 

 cable ships soundings in 2,000 fathoms can be made 

 in an hour from start to finish, but in order to do this 

 the wire must be hove in as fast as possible, and 

 breakages of the wire frequently occur. One cannot, 

 therefore, work at this rate with any regard to the 

 safety of instruments attached to the wire. With 

 hempen line the maximum rate of working can be 

 observed, even when the line carries instruments. 

 On cable ships there is usually plenty of old or damaged 

 wire, and where the depth only is required, this old wire 

 is sometimes used and cut adrift when the bottom has 

 been reached in order to save the time of heaving 

 it in. 



A great many arrangements have been used with the 

 sounding apparatus to bring up samples of the deposits 

 forming on the bottom in deep water. The "arming " 

 of the hand-lead with lard and tallow has already been 

 mentioned ; snappers, cups, and tubes with valves are 

 also used for this purpose. Experience alone can 

 show the best appliance to adopt in special circum- 

 stances. On board the " Challenger," when sounding 

 over Red Clay areas, the Baillie sounding tube, 2J 

 inches in diameter, without butterfly valves, has been 

 forced from 18 inches to 2 feet into the deposit, and has 

 brought up a section of that depth, the total quantity 

 of clay being more than enough to fill a quart bottle. 

 So far as obtaining a sample of the bottom is con- 

 cerned when sounding, this is the most successful 



