ON DEEP-SEA SOUNDING. 349 



castor arrangement is a very important addition 

 to the hauling-in gear. By means of it it is 

 easy to keep the wire on the stern pulley when 

 the ship is rolling very heavily. Even on the 

 steam launch of the Hooper, rolling sharply 

 through great angles off Funchal Bay, a small 

 castor pulley which I used accommodated itself 

 perfectly to the motion, and allowed the wire 

 to be coiled safely on the sounding wheel, 

 which would have been scarcely possible without 

 the aid of some such appliance. The quick- 

 ness with which the wire allows the sinker to 

 descend, and the ease of getting it on board 

 again by aid of the castor pulley, notwithstand- 

 ing a considerable degree of lateral drifting of 

 the ship, render it easy to take deep-sea 

 soundings of 2,000 or 3 ; ooo fathoms, from a 

 sailing vessel hove to in moderate weather. 



But it is not necessary to keep the ship 

 hove to during the whole time of hauling in 



the castor wheel or pulley runs, which consisted merely in 

 lengthening the castor axle, and providing for it two bearings, 

 instead of its having only one, as was the case in the machine 

 shown at the meeting. 



