DAMASK. 



569 



Damask, tal figures, interwoven with tweeled cloth, is the com- 

 bination of two lines at right angles to each other. 

 That portion of yarn which is stretched in the loom, 

 and which weavers distinguish by the name of warp, 

 forms a superficies consisting of a very great number 

 of parallel straight lines, contiguous to, or in contact 

 with, each other, but until bound together by the in- 

 tersection of the weft or woof, without any cohesion 

 either chemical or mechanical. The intersection of the 

 •woof at right angles with the warp, forms the bond of 

 cohesion, and gives the tenacity required t6 form the 

 flat substance called cloth. In the common texture 

 the intersection is uniformly betwixt every individual 

 tliread, and the superficies of the cloth, when woven, 

 presents a complete uniformity of appearance, all the 

 intersections being uniform and equidistant betwixt 

 every alternate thread. 



The generic difference oftweeling, when compared 

 with common cloth, consists in the intersections, al- 

 though uniform and equidistant, being at determinate 

 intervals, and not between the alternate threads. 

 Hence we have specimens of tweeled cloth, where the 

 intersections take place at the third, fourth, fifth, sixth, 

 seventh, eighth, or sixteenth interval only. The threads 

 thus deflecting only from a straight line at intervals, 

 preserve more of their original direction, and a much 

 greater quantity of materials can be combined in an 

 equal space, than in the alternate intersection, where 

 the tortuous deflection at every interval keeps them 

 more asunder. On this principle tweeled cloths of 

 three and four leaves are woven for facility of combi- 

 nation alone. The coarser species of ornamented cloths, 

 known by the names of dornock and diaper, usually 

 intersect at the fifth, or half satin interval. The sixth 

 and seventh are rarely used, and the intersection at the 

 eighth is distinguished by the name of satin in com- 

 mon, and of damask in ornamental tweeling. It will 

 further be very obvious, that where the warp and 

 •woof cross only at every eighth interval, the two sides 

 of the cloth will present a diversity of appearance ; for 

 on one side the longitudinal, or warp threads, will run 

 parallel from one end of a web to the other, and on 

 the other the threads of woof will run also parallel, 

 but in a transverse direction across the cloth, or at right 

 angles to the former. The points of intersection being 

 only at every eighth interval, appear only like points ; 

 and in regular tweeling these form the appearance of 

 diagonal lines, inclined at an angle of 45° (or nearly 

 so) to each of the former. 



The appearance therefore of a piece of common 

 tweeled cloth is very similar to that of two thin boards 

 glued together, with the grain of the upper piece at 

 right angles to that of the under one. That of an or- 

 namented piece of damask may, in the same manner, 

 be very properly assimilated to a piece of veneering, 

 where all the wood is of the same substance and colour, 

 and where the figures assume a diversity of appear- 

 ance from the ground, merely by the grain of the one 

 being disposed perpendicularly to that of the other. 



From this statement of the principle, it results that 

 the most unlimited variety of figures will be produced, 

 by constructing a loom by which every individual 

 thread of warp may be placed either above or below the 

 woof at every intersection ; and to effect this in bound- 

 less variety, is the object of the draw loom. 



Besides what has been already stated under the ar- 

 ticle Cloth Manufacture, the reader will find some 

 details respecting the draw loom, as modified to pro- 



VOL. VII. PART II. 



duce ornamental figures upon double cloths, by refer- 

 ring to the article Carfet, where he will also find a 

 plan and description of a draw -loom capable of being 

 wrought by mechanical power, and adapted to those 

 peculiarities which distinguish carpet, or double-cloth 

 weaving, from damask or satin tweeling. In order to 

 complete the plans for applying power to ornamental tex- 

 ture, lie will now find in Plate CCXXVIf. a perspec- 

 tive representation of a draw-loom adapted for damask 

 tweeling, and which, although in some respects similar 

 in principle to the other, possesses many distinguishing 

 properties necessary to fit it for its immediate object. 

 By comparing the three, he will thus be able to form 

 a comprehensive estimate of their respective uses, and 

 the distinctions of their construction. 



Fig. 1. is an oblique perspective representation of 

 the loom, of which the following are the chief con- 

 stituent parts upon which the peculiarity of con- 

 struction depends. The posts and cross-sails which 

 constitute the framing are respectively at AAAA and 

 at aaaa. The yarn, or warp beam, is at B. The per- 

 forated board, or frame which regulates the harness, is 

 at C ; the frame of directing pidlies is above at D ; 

 the tail of the harness is at M, and the board, or table, 

 as weavers call it, to which its extremity is attached, is 

 at E ; the simples, or descending cords, are at L, their 

 extremities being fixed to the floor at O. In these 

 parts there is little difference from any ordinary draw- 

 loom, excepting in the obliquity of the simples at L, 

 which keeps them closely in contact with the cylinder 

 or barrel G, by Avhich they are moved. The heddles, 

 which consist of eight leaves, with the long eyes com- 

 mon in every species of harness-work, as there is no- 

 thing peculiar in their construction, and as they must 

 be almost entirely concealed by the harness, are entire*- 

 ly omitted, as are also the lay and cloth beam for the 

 same reasons. The eight treddles, or levers, which 

 give motion to the heddles, appear below at I, and 

 these are moved by the revolution of the shaft S, which 

 takes the motion from the power by a pulley and belt 

 in the common way, and which, as it communicates 

 the motion, either directly or indirectly, to every other 

 part, may be regarded as the primum mobile of the 

 whole engine. On the shaft S is a succession of eight 

 wipers, or traverse wheels, which successively move 

 all the treddles, so that woof is eight times inserted by 

 every revolution of the shaft, the motion of which must, 

 of course, be very slow, not exceeding at the utmost 

 eight revolutions per minute ; and if the loom be wide, 

 even this will be found too much. The wipers are 

 all similar, and are shaped to effect uniform reciproca- 

 ting motion. 



The barrel, or cylinder G, receives its motion from, 

 the shaft below, by means of the catch H, and the up- 

 right spindle L, which are moved by pins in the shaft 

 as often as the harness is to be shifted, instead of the 

 catch, which is drawn aside and returned by the ope- 

 ration of the cord K, acting by a weight at its opposite 

 extremity. Here it may be proper to remark, that 

 this motion may be very conveniently, simply, and 

 cheaply effected, merely by a straight lever moving 

 on or near its centre, one extremity of the lever being 

 jointed to the vertical rod L, and the other projecting 

 over a wiper fixed on the shaft S. The extremity over 

 the shaft, whenever elevated by a protuberance on the 

 wiper, would depress L, and move the barrel, after 

 which it woidd return by its own weight to its for- 

 mer position, until again set in motion. The latter 

 4 c 



Damask. 



Plate 

 ccxxvir. 



Fig. j; 



