WEAVING. 



require what is called drefling. Silk and woollen warps re- 

 qiuife little preparation after being put into the loom, ex- 

 cept to clear the yarn occafionally with a comb, to remove 

 knots or lumps which might catch in palling through the 

 reed ; the comb detefts fuch lumps, and they are removed 

 with the afiiftance of a pair of fciflbrs. Flax and cotton, 

 but particularly the latter, require the warp to be dreffed 

 with fome glutinous matter, to cement the fibres, and lay 

 themclofe. This is applied in a fluid itate, and as the weav- 

 ing does not proceed well after it is fuffered to dry, the 

 warp, is drelTed with a bru(h when in the loom, a fmall quan- 

 tity at a time, immediately before it is woven. 



Dreffmg The ufe of drefling is to give to yarn fuffi- 



cicnt itrength or tenacity, to enable it to bear the operation 

 of weaving into cloth. By laying fmooth all the ends of 

 the fibres of the raw materials, from which the yarn is fpun, 

 it tends both to diminilh the friftion during the procefs, and 

 to render the cloth fmooth and glofly when finifhed. The 

 drefling in common ufe is fimply a mucilage of vegetable 

 matter boiled to a confiftency in water. Wheat-flour, boiled 

 to a pafte like that ufed by book-binders, or fometimcs po- 

 tatoes, are commonly employed. Thefe anfwer fuflB- 

 ciently well in giving to the yarn both the fmoothnefs and 

 tenacity required ; but the great objeftion to them is, that 

 they are too eafily affedted by the aftion of the atmofphere. 

 When dreffed yarn is allowed to ftand expofed to the air 

 for any confiderable time, before being woven into cloth, it 

 becomes hard, brittle, and comparatively inflexible. It is 

 then tedious and troublefome to weave, and tlie cloth is 

 rough, wiry, and uneven. This is chiefly remarked in dry 

 weather, when the weavers of fine cloth find it neceffary to 

 work up their yarn as fpeedily as poflible, after it is dreffed. 

 To counteraft this inconveniency, herring or beef brine, and 

 other faline fubftances which attraft moifture, are fome- 

 times mixed in fmall quantities with the drefling : but this 

 has not been completely and generally fuccefsful ; probably, 

 becaufe the proportions have not been fufRciently attended 

 to ; for a fnperabundance of moifture is equally prejudicial 

 with a deficiency. The variations of the moifture of the 

 air are fo great and frequent, that it is impofllble to fix 

 any univerfal rule for the quantity of fait to be mixed. 

 Some weavers put butter-milk in the pafte. 



To apply the drefling, the weaver mull fufpend the 

 operation of weaving, whenever he has worked up that quan- 

 tity of warp which he has dreffed, or within two or three 

 inches ; he then quits his feat, and applies the comb to clear 

 away knots and burs ; next pulhes back the leafe-rods 

 towards the yarn-roll, one at a time, and if they Hide freely 

 between the yarns, it ftiews they are clear from knots ; he 

 then brufhes the yarn with the parte by two bruflies, holding 

 one in each hand. The fuperfluous humidity is afterwards 

 dried by fanning the yarns with a large fan, and then a fmall 

 quantity of greafe is brufhed over the yarn ; the leafe-rods 

 are returned to their proper pofition, and the weaving is 

 refumed. 



Drefling is of the firft importance in weaving warps fpun 

 from flax or cotton ; for it is impofllble to produce work 

 of a good quahty, unlefs care be ufed in dreffing the 

 warp. 



The fame praftice, when ufed upon filk, has a very de- 

 ftruftive tendency : it injures the colours of the filk when 

 ufed, as it is fometimes very improperly, by the weavers of 

 white fatin. The injury done to the work is irreparable. 

 In cotton, the operation of drefling is indifpenfable ; but in 

 nik, this is by no means the cafe. 



The preparation of pafte or Cze for warp, has been the 

 fubjeft of feveral patents. Mr. Foden, in 1799, recom- 



mends a quantity of calcined gypfum, or plafter of Paris, 

 to be reduced to a very fine powder, and then mixed with 

 alum, fugar, and the farina or ftarch of potatoes, or any 

 other vegetable farina. This powder, when mixed well 

 with cold water, forms a foft pafte, to which boiling water 

 is to be added, and the mixture thoroughly ftirred till it be- 

 comes fufEciently gelatinous for ufe. 



Another fize, for which Mr. M'^ilks had a patent in 1801, 

 is prepared as follows : — The ftarch or flour is to be ex- 

 tracted from any kind of potatoes which are mealy when 

 boiled, by grating them while raw (but waftied clean) into 

 a tub of water. The water, thus impregnated with the 

 grated potatoes, is run through a fieve or ftrainer, which 

 will retain the coarfer and fibrous parts of the potatoes, but 

 admit the finer particles, conftituting the ftarch or flour, to a 

 pafs with the water into a veffel beneath the fieve or ■ 

 ftrainer. This water muft remain in the veffel feveral hours ' 

 undifturbed, to permit the ftarch to fubfide to the bottom ; 

 then the water is poured off, and the ftarch io obtained is 

 put into frefli water, and paffed through a finer lieve into 

 another tub, where the ftarch is left to fubfide to the bottom 

 as before, and the water is again poured off. 



About two-thirds the quantity of potatoes, which fur- jl 

 nilhedthe ftarch, are alfo to be boiled without peeling, fo as J 

 to make them mealy when boiled ; they are then maftied, and 

 diluted with water, fo that they will pafs through a fieve 

 into a boiler. In this the maflied potatoes are heated till 

 they alnioft boil ; and the ftarch from the grated potatoes is 

 then to be added, and the whole boiled and ftirred for 20 

 minutes, when it will become pafte proper for ufe. It 

 ftiould be fpread in a flat open veffel to cool. 



Improved Syjlem of Weaving by Machinery, — In our article 

 Cotton we mentioned that weaving-looms, worked by me- 

 chanical power, were then coming into ufe : fince the time 

 that article was printed thefe have made great advances ; but 

 to ufe them with advantage, the preparatory proceffes of 

 warping and dreffing muft be conducted in a particular man- 

 ner. Many attempts have been made to diminifli the number 

 of operations through which the yarn muft pafs by combin- 

 ing feveral together. Mr. Stuart had a patent in 1800 for 

 fizing or ftarching cotton-yarn whilft in the cop, fo that it 

 would be ready to warp at once. Mr. Marfland had a patent 

 in 1805 for the fame objeft : his plan was to expofe the 

 cops of cotton to the aftion of the hot ftarch in an exhaufted 

 receiver; the preffure of the atmofphere being thus removed, . 

 the fize penetrated readily to the centre. It was found dif- 

 ficult to dry the cop perfeftly, and the threads were fome- 

 times fo glued together as to render the winding off dif- 

 ficult. 



Another plan has therefore been introduced both for flax 

 and cotton : this is to wind off the yarn from the cop or 

 bobbin in which it is fpun, and gather it upon the bob- 

 bins ready for the warping ; by this manner the reeling is 

 faved. A fmall quantity of ftarch is applied to the yarn 

 during the operation, by caufing it to pafs over a horizontal 

 wooden cylinder, which revolves on its axis in a trough 

 filled with fluid ftarch. The threads, in pafling from the 

 cop to the bobbin, are drawn over the upper furface of the 

 cylinder, and receive the ftarch with which it is covered. 

 The winding machine for this aftuated a great number of 

 bobbins at once ; the warping is then condufted, as we 

 have before defcribed, and the drefling is performed in the 

 loom whilft weaving, that is, if woven by hand ; but for 

 the power-loom it is dreffed previoufly to placing it in the 

 loom. 



Drejftng Machines. — Mr. Johnfon, of Stockport, had a pa- 

 tent, in 1804, for a method of drefling whole webs of warp at 



once. 



