348 POPULAR LECTURES AND ADDRESSES. 



over a quarter circumference of a "castor- 

 pulley," mounted on the ship's taffrail, and three- 

 quarters, or once and three-quarters, round an 

 " auxiliary pulley " inboard. This pulley over- 

 hangs the bearings of its own axle, so as to 

 allow the loop or the two loops of the wire to 

 be laid on it. Two handles attached to the shaft 

 )f the auxiliary pulley, worked by one man on 

 ^ach or two men on each, take from two-thirds 

 to nine-tenths of the strain off the wire before 

 it reaches the main sounding wheel, on which 

 it is coiled by one man or two men working on 

 handles attached to its shaft. 



If the ship is hove to when the wire is 

 being hauled in over the castor-pulley on the 

 taffrail, the wire will generally stream to one side. 

 By having the bearing of the stern pulley, an 

 oblique fork turning round a horizontal axis (like 

 the castor of a piece of furniture laid on its 

 side), the wire is hauled in with ease though 

 streaming to either side, at any angle. 1 This 



1 An improvement was made on the first arrangement of 

 framing for bearing the castor axle of the forked piece in which 



