ROPE AND ROPE-MAKING, Ropes are usually made of vegetable fibers, and differ only from twine in their much greater thickness. The fiber most commonly used in Britain is hemp: but large quantities of plantain fiber, called manilla.bemp, made from the leaf-stalks of muss textilis, arc also employed, especially for the large ropes used for various purposes on board ships. Ropes consist of many thicknesses of yarn. which is spun by hand in places called rope-walks. The spinner has a large bundle of the fiber loosely gathered round his waist, from which he pulls out a few fibers, and attaches them to a hook in the turning-weel or whirl, which is stationary, and is worked by an assistant. Experience teaches him what number of filters to draw out, and bow to twist them so as to hold firmly on t3 the hook. He then walks 'slowly backward down the rope-ground, gradually drawing out or regulating the pulling out of the fibers so as to make an equal yarn, which receives the necessary twist from the whirl. When he has got to the end of the walk, another spinner takes the yarn from the hook of the whirl, and fixes it to a reel, which is then set in motion; and he attaches a second portion of hemp from his own supply to the hook, and proceeds down the walk ns the previous one had done. In the mean time, the first spinner gradually walks up the ground, carefully guiding his length of yarn as it is wound on the reel. When ho reaches the reel, it stops, and he waits until the second spinner's length is completed. Ile then in his turn takes it off the hook, and twists it on to his own; and the reel being again started, receives the additional length from the second man, and so on until the full length required is made up. The next operation is called moping, and consists in stretching out the number of yarns required for a rope. These arc all slightly twisted again separately, and stretched to an equal length. Then, if they are intended for tarred ropes, each yarn is drawn separately, either lengthwise or in a hank, through a kettle of hot tar. The superfluous tar is removed by drawing it through a hole lined with oakum. In the next process, called lacing, two or more yarns are attached to hooks on it whirl, so that when it is turned they will be twisted together the contrary way of the original twist they received in the first spinning. When this is done it is
called a strand. Then as many of these strands as are required for the rope are stretched at full length, and are attached at each end to whirls. One of the whirls has but one hook, to which all the strands are attached; the other has as many hooks as there are strands, one always being central, and a strand is attached to each. The whirls are then put in motion, hut in opposite directions, and this causes the outer strands to be laid with great regularity and firmness around the central one. Such is the ordinary process of rope-making; but machines have been invented which produce ropes with such mathematical precision that the strength of the rope may be calculated with great exactness. Captain Huddart has the merit of effecting these improvements; and very few applications of mechanism are more beautiful in their details than those which he has worked out. They, however, do not alter the principle of the manufacture. Within the last few years a great improvement has been patented by Mr. Edward Sang of Edin burgh, and is now in profitable use in the large establishment of the Edinburgh and Leith Ropery company. It consists of a machine which spins the yarn from material supplied as before by hand, but it does away with the long walk, and can be used in a small room.
Large ropes are either what is called cable-laid or hawser•laid. The former consist of three large strands, each made up of three smaller strands. A cable-laid rope of eight inches' circumference is made up in this way of nine strands, each containing 37 original yarns, or altogether 333 yarns. A hawser-laid rope consists of only three strands, each containing a sufficient number of yarns to make up the required thickness. The numerous lives and the vast property depending on the efficiency of ropes employed in shipping have caused a -great amount of ingenuity and care to be brought to bear on the manufacture. One very great improvement of mcdern times has been the introduction of wire ropes, which are now extensively used in rigging ships, and for other purposes. They are generally made of iron wire, sometimes but not always galvanized. The twisting is effected in the same way as that in which the strands of a hempen rope are laid together.