SCIENCE AND PRACTICE. 



389 



and as liigli as the room of the ship will allow between the 

 bottom of the tank and the deck ; they are made of plates of 

 iron, riveted together, caulked, and painted with red lead to 

 prevent rusting. There are usually two such tanks, the 

 forehold and afterhold, on board a cable ship. In the centre 

 of each tank a hollow cone of iron is erected (see Fig. 178), 

 and above this a series of rings of 2 7/ round iron, which are 

 lowered in the tank as the cable is paid out, are suspended 



Fig. 178. 



for guiding the cable as . it leaves the tanks, and preventing 

 it flying out by centrifugal force and going into kinks. On 

 leaving the tanks the cable passes through the rings in the 

 circular space between them and the top of the cone, which 

 it rubs against continually. A V- wheel, d, is put upon deck 

 over the middle of the tank, over which the cable is led ; 

 it then passes over the Y-wheel e, before the break, takes 

 three or four turns round the drum, /, goes over the Y-wheel 

 g, under the jockey- wheel h of a dynamometer, and finally 

 over the stern-pulley i into the sea. When the tank is at 

 a distance from the break it is usual to let the cable run in 

 a wooden trough from d over the tank to e in front of the 

 drum. The friction which the cable exerts against the sides 

 and bottom of the trough assists the breaks in preventing its 

 too rapid egress from the ship. 



A wheel-work with a counter is turned by the axle of the 

 drum /for indicating the length paid out, and, by a simple 



