CALICO-PRINTING 



591 



in the clamming-machine the die revolving in contact with the mill repeats its surface 

 so many times on the surface of the mill. By this means as little skilled labour as 

 possible is used. When a pattern having more than one colour is to be engraved, 

 the drawing is reduced to scale as before, each roller being made of the same diameter; 

 then a tracing is made of each colour, which is engraved on a separate die and mill 

 a mill being required for each colour which engraves its separate copper roller ; 

 when these rollers come to be worked in the printing-machine, each roller fits its part 

 of the pattern into place, and the original pattern is reproduced. The annexed 

 drawings of engraving machinery are from those made by Messrs. Gadd and Hill, of 

 Manchester, to whose courtesy are due also the drawings of the printing-machines and 

 their drying apparatus hereafter described. Fig. 332 is a front view of the clamming- 

 machine, and fig. 333 is a side view 



of the same. A A cast-iron frame- 332 



work; B a headstock screwed on 

 the frame work A ; c a sliding piece, 

 capable of movement from back to 

 front on the headstock B ; the 

 position being determined, it is 

 secured by the screw shown under 

 c ; the roller D revolves in bearing 

 attached to the sliding piece c ; the 

 supporting piece E has a motion 

 backwards and forwards on the sup- 

 porting piece o, which moves up or 

 down ; e is a small sted roller, which ._ 

 again supports the die roller seen * 

 in the centre of the drawing. The 

 roller F is of softened steel called 

 the mill, which revolves in bearings 

 attached to the headstock, -which 

 has a sliding movement on the slide 

 block H, which is moved from right 

 to left by the screw i, worked by 



the lever K. t is a pinion gearing 



into the toothed wheel K, and turned 



by the winch-handle M ; the shaft p has a sliding movement through the wheel N, and 

 carries the boss o, which has a square aperture to receive the centre of the mill, which 

 is squared to fit into it. q is a screw used to tighten and keep in the desired position 

 the saddle pieces E o, which together are pushed up or down to meet the varying size 

 of the die. 



The die d having been hardened, 333 



is inserted in the machine resting 

 on the auxiliary hard steel roller 

 e, which again rests on the sup- 

 porting piece E; the die being in 

 contact with the hard steel roller 

 D, the soft steel roller or mill E 

 is next forcibly screwed up in con- 

 tact with the die, rotatory motion 

 being given to the roller D by the 

 toothed wheels, those portions which 

 are in intaglio in the die become in 

 relievo on the mill. It is then ready 

 for the machine engraver to transfer 

 its pattern to the copper roller. 

 Fig. 334 is an elevation of the 

 engraving machine. A A is a man- 

 drel which carries the copper roller 

 B; the mandrel is fitted in the 

 universal joint c, which is secured 

 on the shaft of the wheels D D, 

 which are a double pair of wheels 

 for the purpose of altering the 

 speed from fast to slow, and are 

 moved by the winch-handle or ~~~~ 

 pulley. The lever B is fitted, works loosely on the shaft, on which is keyed the 

 wheel F. By means of the screw o, the levor B can be secured to the wheel F, 



