A rope of large diameter, by which ships are held to their anchors or moorings. The materials of which cables are formed are very various, as bass, hemp, sunn, and coir, or the husk of the cocoa nut, and latterly iron chains, of a particular construction, have been extensively used, and are commonly called chain cables. Cables are composed of either three or four ropes twisted together, each rope consisting of either three or four strands, each strand containing an equal number of yarns, which number depends upon the diameter of the cable. Cables are denominated by their circumference in inches, as a 22-inch cable, meaning a cable 22 inches in circumference. The length of all cables is the same, viz. 120 fathoms. The larger class of ships in the navy and in the East India Company's service are usually provided with the following cables: viz. two spliced together, for the best bower anchor; two for the small bower anchor; two for the sheet; one spare cable; and one cable for the stream anchor. The chains employed for cables have a short stay bar in the middle of each link, to prevent the sides collapsing when the cable is exposed to a heavy strain.

The form of the links and stays, and the mode of applying the latter, have formed the subjects of numerous patents.

The annexed figures represent one of the links of Mr. Hawks's " Patent Chains for Cables and Hawser." and also illustrates the method of forming them. The novelty in the form of these links consists in their being thicker at the bends than at the sides; whereas in most other chain cables the links are either the same thickness throughout, or are smallest at the bends. The iron rod a a of which the link is formed, it will be seen has bulbous enlargements at regular distances asunder: these are produced either by cavities in the rollers between which the rod is drawn, or by swaging or forging. The rods being cut into exact lengths, they are turned round into links, and the ends welded together, when the bulbs should be situated exactly .it the ends, as represented by the annexed figure at a a, and the stay-bar b inserted. Chains for cables are commonly made in lengths of 10 fathoms, connected by a bolt and shackle, for the convenience of slipping on in an emergency, as cutting is of course out of the question; and at every 30 fathoms is a swivel, that the chain may not become twisted. A simple and effectual stopper for chain cables is much wanted, as considerable difficulty is frequently experienced in " bringing 2 ship up," as it is termed, when it blows hard.

The ordinary stopper consists of two concave plates of iron, between which the chain passes; the lower plate is firmly secured to the deck, and the upper plate turns upon a hinge A long iron bar is inserted into a socket cast upon the upper plate, and to the outer end of the bar is attached a tackle, hooked to a bolt in the deck; and a number of men being stationed at the tackle, by hauling upon it they compress the cable so tightly between the plates, as to prevent the cable running out, or, by slacking it, allow it to run freely. This apparatus frequently gives way, and occasions serious damage. The following substitute, invented by Lieut. kooystra, R N. h s been approved by the Society of Arts, who have presented the inventor with the silver Vulcan medal. The figure represents an under-view of the part of the deck where the stopper a a is fixed; this stopper is formed of an iron hook or clip, turning upon a bolt at b, and has a few links of chain at the other end; d and e are portions of two beams; f part of the chain cable, held fast by the stopper; g a square bar, sliding through the beam d, and through square holes in the metal facing plates h h; i the hook in the end of the bar g, which takes the link,; of the stopper; k a double-threaded screw, on the other end of the bar g; l the screwed end of a crank handle m, fitted on the screw k; the other end turns freely in the plate o o; p p the bolts which secure this plate to the beam e.

By turning the crank one way, it will be seen that the cable will be tightly pressed by the stopper against the iron knee q, and by turning it the other way the pressure is relaxed. The sliding bar g is shown separate above.

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Mr. William Shelton Burnett had a patent for a cable-stopper, of which the following is a description. This apparatus consists of a metallic box a, containing a spirally coiled spring, through the centre of which passes longitudinally a bar; one end of this is strongly rivetted to an iron plate, and the other terminates in a large eye, for the reception of a hook or a rope. Now, supposing the cylinder a to be made fast at b to some staple part of a ship, and the cable c, which passes over the side of a ship d, to have an anchor attached to the other extremity, when any strain comes upon it, the bar is drawn more or less out of the cylinder, compressing the spring, thus affording an elastic resistance, which, continually increasing with the force applied, will prevent those accidents of tearing away the fastenings, which might, without such apparatus, be the result. It is of course that this contrivance is equally applicable to any other tackle, which it will always keep in a proper state of tension after the cause of the adventitious strain has ceased to operate.

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