MAKING AND LA YING SUBMARINE CABLES . 163 
stop the ship, and in some operations the cable has to be trans¬ 
ferred from the stern to the fore-part of the ship. In such eases 
there are many additional risks of accidents. And not only has 
the cable to be laid sufficiently strong to ensure its duration, 
but that strength must after a lapse of years be great enough 
to allow the cable to be grappled and brought up for repairs 
without much risk. 
The paying-out machine consists essentially of a large dram, 
Fia. 104. 
round which the cable takes four turns, and which is provided 
with two of Appold’s friction brakes applied to its axle. 
Above the place at which the cable comes in contact with 
the drum, a guide rapidly directs each turn of the cable, so 
that it may not overlie the preceding turn (fig. 104 ). 
The weight of the cable paid out would be sufficient to make 
the drum revolve when the vessel is in motion, but sometimes 
it is necessary to make it revolve when the ship is stationary. 
The paying-out machinery is therefore provided with cylinders 
and pistons, and the direction of rotation can also be reversed, 
