MUSEUM OF COMPARATIVE ZOOLOGY. 175 



wire from paying out faster than its own weight can take it off the reel. 

 The action of the now macliinc has the efl'ect of a governor on the mo- 

 tions of the reel, which can be explained as follows : If the ship plunge 

 or roll downward, the strain is relieved from the wire, and the conse- 

 quent effort of the cross-head to rise is transferred to the friction line. 

 Thus more resistance is automatically placed upon the reel, checking its 

 speed or stopping it altogether, — rarely the latter, — until the rising 

 of the vessel or tlic slowing down of the reel causes an increased strain 

 on the wire. As the strain increases the ci'oss-head is borne down, which 

 again eases the friction line, allowing the reel to revolve more rapidly. 

 In general terms, then, if the tension of the wire increases the tension 

 of the friction rope diminishes, and vice versa. When the vessel is quiet 

 the accumulator has no inherent effect in changing the amount of re- 

 sistance on the reel. This alternating movement of the cross-head when, 

 paying out is scarcely perceptible to the eye, and the motions of the 

 reel were found to be not fitful, but remarkably smooth. 



With the original machine, when the sinker strikes bottom the weight 

 of the sinker ceases to act as a moving force for the reel, and if a resist- 

 ance slightly in excess of the weight of the wire payed out has been 

 placed upon the reel, the latter will stop. In the same case with the 

 new machine, the weight of the sinker not only ceases to act as a mov- 

 ing force for the reel, but the force, due to the weight of the sinker, 

 is automatically transfeiTcd to. the friction line thus : the cross-head, 

 being freed from the bearing-down effort of the weight of the sinker, 

 rises and communicates that effort to the friction line. This pecu- 

 liarity of the new machine may not appear to give any great advan- 

 tage over the original machine ; but, since it is a safeguard, and results, 

 without extra costs, from the action of such parts of the machinery as 

 are devised for other and more necessary purposes, it may be considered 

 a good point in the working of the apparatus. 



As soon as the sinker strikes bottom, which is made apparent by the 

 stopping of the reel, read the register and the odometer, and at the 

 same time ship the crank on the axles of the reel. Throw the bight of 

 the friction line out of the friction score, and, to insure the detachment 

 of the sinker, pay out, if necessary, a few turns of the wire by hand 

 until the wire feels slack. Then reel in a few turns cautiously, and the 

 distance that the cross-head travels down its guides will indicate whether 

 the sinker has been detached. Generally, with a good form of detacher, 

 it drops off on striking bottom. Avoid slacking the wire more than is 

 necessary. It is well to keep a record of the time occupied by the reel 



