SAILCLOTH AND SAILMAKING. Sailcloth, now more commonly called canvas (q.v.) or, in the United States, duck, is usually a double warp, single weft fabric of the same structure as bagging (q.v.) and tarpaulin, although it is sometimes made with single threads of warp. Hemp and ramie are occasionally used in the manufacture of this cloth, but flax and cotton are the chief fibres employed. Many of the sails of fishing smacks and similar vessels are made entirely of cotton—the fabric sometimes retain ing its natural colour, but more often dyed or stained tan. Since most of the larger vessels are now driven by steam or oil, the quantity of cloth used for sails is comparatively small. A large quantity of cloth, however, is used on steamships for covers, and for coal bags, sailcloth buckets, etc.
The very best kind of sailcloth is made from long flax, as this fibre possesses flexibility, lightness and strength combined. The number of threads per inch of warp varies from 14 double threads to 48 double threads, and from 12 to 36 shots per inch of weft, while the usual widths are 18, 24, 3o and 36 inches. Cotton canvas has for its limits about 26 to 54 threads of warp per inch, and Is to 46 shots per inch; the warp yarn for cottons may be 2, 3 or several ply.
Sailmaking.—This is a very ancient industry, but is natur ally much less important than it was before the introduction of steamships. The operations of the sailmaker may be stated as follows. The dimensions of mast and yards and sail plan being supplied, the master sailmaker is enabled to determine the dimen sions of each sail—after due allowance for stretching—in terms of cloths and depth in yards—if a square sail, the number of cloths in the head, number in the foot and the depth in yards ; if a fore and-aft sail (triangular), the number of cloths in the foot and the depth in yards of the luff or stay and of leech or after-leech; if a fore-and-aft sail (trapezium form), the number of cloths in the head, number in foot and the depth of mast or luff and of after leech. These particulars obtained, there is got out what is tech nically termed a "casting," which simply means the shape, length, etc., of each individual cloth in the sail. These figures are given to the cutter, who proceeds to cut out the sail cloth by cloth in consecutive order, numbering them 1, 3, 4, etc.; the series of cloths thus cut out are handed over to the workman, who joins them together by carefully made double flat seams, sewn with twine specially prepared for the purpose, with about 120 stitches in a yard. In the heavy sails the seam is about I lin. in width, and in the British navy stuck or stitched in the middle of the seam to give additional strength ; the seams in the lighter sails are about 'in. wide. The whole of the cloths are then brought to gether, and spread out, and the tabling (or hemming, so to say) is turned in and finished off with about 72 stitches to a yard. Strengthening pieces or "linings" are affixed where considered necessary, in courses and top-sails such pieces as reef-bands, middle-bands, foot-bands, leech-linings, bunt-line cloths; in top sails (only) a top-lining or brim; in other and lighter sails such pieces as mast-lining clew and head, tack and corner pieces ; holes, such as head, reef, stay (luff), mast, cringle, bunt-line, etc., are
also made where required, a grommet of line of suitable size being worked in them to prevent their being cut through. The next thing to be done is to secure the edges of the sail. Bolt-rope, a comparatively soft rope made from the finer hemp yarn (Italian) is used for this purpose ; in the British navy it ranges from 'in. (increasing in size by quarter inches) up to 8in. inclusive; it is then neatly sewn on with roping twine specially prepared, the needle and twine passing between and clear of every two strands of the rope in roping.
Where slack sail has to be taken in, it is the practice to leave it to the judgment of the sail-maker; but where possible it is bet ter to set up the rope by means of a tackle to a strain approxi mate to what it will have to bear when in use, and whilst on the stretch mark it off in yards, as also the edge of the sail in yards, so that by bringing the marks together in roping the sail will stand flat. In the British navy the largest size of rope sewn on to a sail is six inches ; sizes above this are used for foot and clew ropes of top-sails and courses, being first wormed, parcelled (that is, wound round with strips of worn canvas), tarred and served over with spun yarn; the foot of the sail is then secured to it by being marled in. Where two sizes of bolt-rope used in roping a sail have to be connected, it is effected by a tapered splice. Cringles (similar to the handle of a maund) formed by a strand of bolt-rope, mostly having a galvanized iron thimble in them as a protection, are then stuck where necessary, as at the corners, sides or leeches, mast or luff ; they are required either for making stationary or hauling "taut" by tackle or otherwise certain parts of the sail when in use. Fore-and-aft sails, such as spankers, gaff sails and storm try-sails, are reduced in size by reef-points made of stout line (four to 20 lb.), crow-footed in the middle, a hole being pierced through every seam ; one-half of the point is passed through and the crowfoot sewn firmly to the sail ; the number of reefs depends upon the size of the sail, and the reefs are placed Parallel to the foot. (T. W.) Sailcloth or canvas is better known by the American trade as numbered duck. England manufactures a great deal from flax, while the U.S. mostly uses cotton. It is a plain woven fabric of heavy construction which varies -with its use and is usually of plied warp and filling yarns (although in some cases the warp yarn may be single and drawn two ends per dent). Duck is used for many purposes including sails, tents, tarpaulin, bags, awnings, fire hose, wearing apparel such as overalls, hunting coats, belts, etc. The number of warp ends per inch vary from 26 to 48 and may be 2 to 5 ply and from 16 to 34 filling picks per inch 2 to 8 ply.