MECHANICS AND USEFUL ARTS. 83 



needle has entered the cloth, when they relinquish the duty to the 

 needle. 



WEAVING AND PRINTING CARPETS AND SHAWLS. 



JAMES MELVILLE, of Renfrewshire, Scotland, has enrolled a patent 

 for an invention, the peculiarity of wliich is, the weaving a duplex 

 fabric, or, in other words, two foundations or backs of fabrics, con- 

 nected together bv a Ions? pile of the material, forming the face of the 



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pieces the pile being afterwards severed transversely, to form distinct 

 pieces of pile fabrics without the use of intermediate slips or needles 

 lor raising and adjusting the pile. This important system of weaving 

 is as simple as it is ingenious. Instead of weaving both backs, so that 

 each shot of weft in the upper and lower backs is thrown at the same 

 time, in the same vertical line, the lower back is always kept several 

 shots ahead of the upper one ; that is to say, the woven portion of the 

 lower back always extends several shots further forward on the reed 

 side than the upper one. Then, during the process of weaving, the 

 angular distance between the two sheds of the upper and lower backs, 

 regulates the length of the intervening pile of wool. This system is 

 carried out by adding to the ordinary reed a species of secondary 

 reed, earned bv the slav in front of the usual reed. The latter acts 



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only on the lower shed, whilst the secondary reed, the dents of which 



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project down from the lower edge of their frame-bar, is similarly con- 

 fined to the upper shed, and each shot of weft in the upper shed is 

 held until secured by the succeeding one, by a row of hooks on a 

 holding-frame passing across the piece. 



Another portion of the improvements embodies a system of printing 

 shawls and other goods, by stretching the fabric on an impression 

 cylinder of large diameter, such cylinder being arranged to work in 

 concert with a printing roller, on which the " repeat " of the pattern 

 is engraved. In printing a border by this plan, the two opposite 

 parallel edges of the piece are stretched on the large cylinder in a 

 line with the cylinder ends, and the color apparatus being set on a 

 rail in front of the cylinder, the two borders are printed in succession ; 

 and the print-ing apparatus being then detached, is removed to another 

 cylinder, to make way for the succeeding color on the first. The 

 printing roller is so contrived as to be capable of the most accurate 

 adjustment to the impression cylinder on each change, so as to keep 

 perfect register ; and the attendants are thus enabled to print all the 

 colors in a series of pieces by continually running through a series of 

 impression cylinders, with the corresponding color rollers, one after 

 the other. By another modification, Mr. Melville also prints shawls 

 and other fabrics stretched upon a square table, hung vertically, the 

 printing roller revolving in fixed bearings, whilst the table traverses 

 in contact with it. But the most curious process is that in which the 

 pattern is engraved upon a conical printing roller, and the fabric is 

 stretched on a square table, revolving on a vertical plane. If a shawl 

 corner is to be printed, the pattern is so placed on the roller that the 

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