58 BULLETIN OF THE 



taiued by keeping hold of the wire rope on doclc, where the movements 

 of the dredge are repeated by the vibrations of the steel rope so promptly 

 that the moment it fouls or passes over rough bottom the speed of the 

 vessel can at once be checked, or its direction altered, before the 

 tension is great enough to affect the accumulators. It is only while 

 hoisting the dredge that the accumulator is \iseful, and long before it 

 works to its full power, the changes of form of the catenary of the wire 

 rope, from an easy winding in of the dredge to the fouling of the same, 

 will produce a greater or less strain, entii'ely unnoticed, on the accumu- 

 lator, while winding up, if (as in our case) the strain is less than 2,000 

 pounds. The steel rope was hoisted by a small double-cj'linder winding 

 engine, with a surging drum of two feet in diameter, round which from 

 six to ten turns were taken, according to the depth, and the rope then 

 passed to the reel, where it was coiled as closely as practicable, the reel 

 being turned by four men at the crank. A gi'eat improvement could 

 be made in driving the reel from the winding engine at a greater speed 

 than the drima of the engine. 



In dredging, the dredge or trawl was invariably lowered indepen- 

 dently of the winding engine from a reel built especially for our work. 

 This reel, built of iron, consisted of a hollow axle two feet in diameter, 

 four feet long, flanked by flanges extending eighteen inches above it, 

 capable of winding 3,000 fathoms of 1^" steel-wire rope. The axle upon 

 which the reel ran was supported upon bearings carried upon a strong 

 iron frame securely bolted to the deck ; the reel was checked by a band 

 friction break, by which one man could readily control the velocity of the 

 steel rope as it was unwound and accurately regulate the speed. The 

 break was of sufficient strength to stop the dredge even at a depth of 

 nearly 2,000 fathoms, and while dredging or trawling the break was se- 

 curely held in place and the dredging carried on from it. To wind up, 

 the wire rope was stopped and sufficient slack taken from the reel to 

 make the necessary turns round the surging drum of the hoisting-engine. 

 AVhen this was done the reel was made taught, the stops imfastened, 

 and the wire rope wound up by the winding engine until the dredge 

 came in sight. 



During the whole time the dredge or trawl was lowered or hoisted an 

 accurate record was taken of the time spent in paying out or reeling in 

 the rope, so that at any moment we knew the precise position of the 

 dredge and the quantity of rope still out. The recorders were either 

 Dr. Nourse or the (Captain's clerk, Mr. Sigsbee. 



The uniform success which attended all our hauls was undoubtedly 



