The composition of the sizo used is of considerable importanee, when the best result is desired. An authoritative writer has recently given the following as a good practical recipe :-39 lb. wheat flour is mixed with eold water until a paste is formed ; 22 gal. of water is put to boil, and 2-3 lb. of eow-horn glue, Irish rnoss, or animal gelatine, 5 lb. of alum, and 6 lb. of tallow are added ; when boiling, the pasto is added, and the mixture is boiled until it thickens, when it is ready fur use in the machines. This is a good compound for medium and heavy twines ; for fine twines, the alum, and half of the tallow, is usually omitted.
The sizing-machines are made in two sizes ; in the smaller, the drying-cylinder is 72 in. across the face, and 30 in. dism., aud will size 1000-1800 lb. of twine in a week of 60 hours. This is the most suitable for light descriptions of twines, the drying of which is nut difficult. The larger one has a drying-cylinder 96 in. long, and 36 in.
diam., and will size, polish, and dry 1800 3000 lb. in 60 hours. This is employed for heavier twines ; but for the heaviest, it is necessary to have two eylinders, in order to dry them thoroughly.
Sizing is sometimes regarded as a need less and expensive process, but the weight imparted to the twine is ample compensation for the expense (yarn being generally sold by weight), bile the improvement in the quality is undoubted.
ts the last and finishing proeess in the manufacture of twine. Two bobbins of polished twine are placed upon the vertical spindles a a', in Fig. 1195. The twines are taken from these, passed through the necks of the fliers b b', and down one leg of each, whence it is wound upon the horizontal spindles c c', which, by other appliances, have imparted to them the peculiar automatic movements required to form the twine into balls. As tbe balls attain the required weight, they are doffed and finished by the attendant girl lapping the twine several times very firmly round the middle. In balling light twines, the double machine is usually employed ; for heavy descriptions, the single one, making only one ball at a time. They are fitted to be worked by manual or steam power, as may be most convenient.
ROPES.—The section now calling for attention is the manufacture of fibrous ropes ; these, as explained previously, are technically known as hawser-, shroud-, and cable-laid, besides flat ropes formed by placing several ropes parallel to each other, and uniting them by oblique stitches, thereby producing a flat band.
In manufacturing these articles, the raw material is treated as previously described in the preparatory stages, spun into yarn, a number of yarns twisted into strands, these into ropes, and the latter into cables. In these processes, it is invariably the method to twist the article in the direction opposite that of the preceding stage. Thus,
supposing the yarn is spun with a right-hand twist, the strands into which this enters will be twisted to the left, and the rope into which these are combined must be twisted to the right, or in the same direction as the yarn, and so on with succeeding combinations. This is requisite to prevent or overcome the tendency that would otherwise exist to run into loops or kinks whenever the ropes were brought into use, Necessarily the machinery for performing this heavy work differs considerably from that previously described, inasmuch as a machine seldom makes more than one article at a time. Again, to avoid excessive complexity of the machine, and the consequent liability to derangement, it is usually found preferable to employ machines for each operation, instead of combining all in one. Especially is this the ease in the heavier classes of ropes and cables. In the lighter articles, compound machines are frequently used. These are of two kinds, the vertical and horizontal, the former being employed in the manufacture of long ropes, and the latter generally of shorter lengths.
Laying.—A small horizontal compound rope-laying machine is shown in Fig. 1196. The largest rope of three strands that could be made on this machine would be one of 24 yarns-8 to each strand. It will serve to show the principle on which larger ones are constructed. By means of change-wheels, 3-strand ropes of smaller dimensions can be made upon it, containing 7, 6, 5, 4, 3, and 2 yarns to each strand, tbe ropes of course being a multiple of those figures by three. The machine has three fliers, each capable of containing 8 bobbins filled with yarn, which are placed in a creel inside the flier, and so arranged as to deliver their contents easily to the draught of the machine. The yarns are conducted through the trunnion of each flier, along the side, through tbe corresponding trunnion, and upon the three topping. motions. The revolutions of the fliers twist the yarns into strands, which are drawn forward by the topping-motions. The latter revolve with the fliers, and are furnished with grooved draw-rolls actuated by gearing. The strands pass upon and around these grooved draw-rolls, which, being coned, stretch and solidify them before they pass from the stranding part of the machine, and are combined into a rope in the front portion, as shown in the illustration, by their passage through rnachinery similar to that which formed the strand. The finished rope is wound upon a barrel driven by a differential gearing, in even layers, and when completed, is easily removed by doffing, the barrel being collapsible ; the machine is thus ready for work again in 2-3 minutes.