I860.] on the Electric Silk- Loom. 273. 



and secure mechanical arrangements, the following movements and 

 results take place in this part of the apparatus. As the pedal descends 

 under the weaver's foot at a certain time, the 400 teeth descend upon 

 the pattern ; then the circuit is completed at the interruptor in the 

 single wire ; the electric current passing through that wire is divided 

 into as many portions as there are teeth touching the metal in the line 

 of pattern under realization ; it makes all the electro-magnets sur- 

 rounded by these wires active, leaving the others non-magnetic ; and 

 then, as the foot is raised and the movements return in their course, the 

 interruptor is first separated, which, causing all current to cease, the 

 magnets lose their power, the teeth are raised from the pattern ; and 

 then the cylinder carrying it moves forward just so much as to give 

 the new line of pattern for the teeth to search out electrically (the 

 next time they descend) which corresponds to the next cast of the 

 weft thread. Because the pattern never moves, whilst it is in contact 

 with the teeth, it is not cut or worn by them : because the current is 

 made by the interruptor after the teeth are in contact, and before 

 they are separated, no fusion or burning of the metal occurs at the 

 teeth ; and because there is a tongue-like wiper or brush, which at 

 the right time passes under the teeth, sustains them, and from off 

 which they rub on to the pattern, there is never any want of cleanliness 

 or of contact there. 



Associated with these 400 magnets, and in the same line with 

 them, are 400 cylinders of soft iron, called pistons ; they are carried in 

 a frame which moves to and fro horizontally between the magnets and 

 the horizontal rods belonging to the suspensions of the warp threads; 

 and they move towards the magnets at a time so adjusted as to coincide 

 with the passage of the electricity round its circuit : they find therefore 

 some of the magnets excited, because their teeth touch the metal of the 

 pattern ; and, as the box of pistons begins to return before the current 

 is interrupted, such of the pistons as have touched excited magnets are 

 retained or held back, whilst the others have returned in their course ; 

 the pistons therefore are divided into two intermixed groups, of which 

 the one group is perhaps half an inch behind the other. Now comes 

 in the action of the perforated brass plate, which is to be converted for 

 the time into the equivalent of the particular Jacquard card required. 

 It is a vertical plate, associated with the extremities of the pistons 

 farthest from the electro-magnets : it can move up and down to a small 

 extent : it is pierced by 400 circular holes. The 400 pistons have 

 each a head or button, which can pass freely each through its corre- 

 spondent hole when the plate is up, but is stopped at the hole when the 

 plate is down, and then effectually closes it. Now the time is so ad- 

 justed, that when the box of pistons has moved so far forward as to 

 cause separation of the two groups, the plate descends, and by locking 

 such of the heads as belong to the unretained group, fills the corre- 

 spondent holes, whilst the heads of the retained group, being already 

 behind their holes, have left them open ; and so the Jacquard plate is 

 formed, and, moving a little further it acts on the horizontal rods 



