716 ROPE-MAKING 



ropery, so that when the machinery of the carriage is set agoing by the endless rope, 

 k, k, and gives motion to the ground-rope shaft, as above described, the carriage will 

 necessarily move along the railway ; and the speed may be regulated either by the 

 diameter of the circle formed by the gubs on the wheel m, m, or by the number of 

 teeth in the pinion 3. At T, is a small roller, merely for preventing the ground-rope 

 from coming up among the machinery. At the head of tho railway, and under the 

 tackle-board, is a wheel and pinion z, with a crank for tightening the ground-rope. 

 The fixed machinery at the head, for hardening or tempering the strands, is similar to 

 that on the carriage, with the exception of the ground-rope gear, which is unnecessary. 

 The motion is communicated by another endless rope (or short band, as it is called, to 

 distinguish it from the other), which passes over gubs at the back of the wheel 1, 1. 



When tho strands are drawn out by the carriage to the requisite length, the spur- 

 wheels 3, R, are put out of gear. The strands are cut at the tackle-board, and fixed 

 to the hooks 1, 1, 1 ; after which they arc hardened or tempered, being twisted at both 

 ends. When this operation is finished, three strands are united on the large hook h, 

 the top put in, and the rope finished in the usual way. 



In preparing the hemp for spinning an ordinary thread- or rope-yarn, it is only 

 heckled over a large keg or clearer, until the fibres are straightened and separated, so 

 as to run freely in the spinning. In this case the hemp is not stripped of the tow, or 

 cropped, unless it is designed to spin beneath the iisual grist, which is about 20 yarns for 

 the strand of a 3-inch strap-laid rope. The spinning is still performed by hand, being 

 found not only to be more economical, but also to make a smoother thread than has 

 yet been effected by machinery. Various ways have been tried for preparing the 

 yarns for tarring. That which seems now to be most generally in use is, to warp the 

 yarns upon the stretch as they are spun. This is accomplished by having a wheel at 

 the foot, as well as the head of the walk, so that the men are able to spin both up and 

 down, and also to splice their threads at both ends. By this means they are formed 

 into a haul, resembling tho warp of a common web, and a little turn is hove into the 

 haul, to preserve it from getting foul in the tarring. The advantages of warping 

 from the spinners, as above, instead of winding on winches, as formerly, are, 1st, the 

 saving of this last operation altogether ; 2ndly, the complete check which the foreman 

 has of the quantity of yarn spun in the day ; 3rdly, that the quality of the work can 

 be subjected to the minutest inspection at any time. In tarring the yarn, it is found 

 favourable to the fairness of the strip, to allow it to pass around or under a reel or 

 roller in the bottom of the kettle while boiling, instead of coiling the yarn in by 

 hand. The tar is then pressed from the yarn, by means of a sliding nipper, with a 

 lever over the upper part, and to the end of which the necessary weight is suspended. 

 The usual proportion of tar in ordinary ropes is something less than a fifth. In large 

 strap-laid ropes, which are necessarily subjected to a greater press in the laying of 

 them, the quantity of tar can scarcely exceed a sixth, without injuring the appearance 

 of the rope when laid. 



For a long period the manner of laying the yarns into ropes was by stretching the 

 haul on the rope-ground, parting the number of yarns required for each strand, and 

 twisting the strands at both ends, by means of hand-hooks, or cranks. It will be 

 obvious that this method, especially in ropes of any considerable size, is attended with 

 serious disadvantages. The strand must always be very uneven ; but the principal 

 disadvantage, and that which gave rise to the many attempts at improvement, was, 

 that the yarns being all of the same length before being twisted, it followed, when the 

 rope was finished, that while those which occupied the circumference of the strand 

 were perfectly tight, the centre yarns, on the other hand, as they were now greatly 

 slackened by the operation of hardening or twisting the strands, actually would bear 

 little or no part of the strain when the rope was stretched, until the former gave way. 

 The method displayed in tho preceding figures and description is among the most im- 

 proved processes. Every yarn is given out from the bobbin-frame as it is required in 

 twisting the rope ; and the twist communicated in the out-going of the carriage can 

 be increased or diminished at pleasure. In order to obtain a smooth and well-filled 

 strand, it is necessary also, in passing the yarns through the upper board, to proportion 

 the number of centre to that of outside yarns. In ordinary-sized ropes, the strand 

 seems to have tho fairest appearance when the outside yarns form from two-thirds to 

 threo-ftmrths of tho whole quantity, in tho portion of twist given by the carriage in 

 drawing out and forming the strands. 



In laying cables, torsion must be given both behind and before the laying-top. 

 Figs. 1729 to 1732 represent the powerful patent apparatus employed for this purpose. 

 A, is a strong upright iron pillar, supported upon the great horizontal beam N, N, and 

 bearing at its upper end the three-grooved laying-top M. H, H, are two of the three 

 great bobbins or reels round which the three secondary strands or small hawsers are 

 wound. These arc drawn iip by the rotation of the thrco feeding rollers i, i, i, thence 





