116 ANNUAL OF SCIENTIFIC DISCOVERT. 



tory slowly passes as the weaver works the machine with his feet, transmit- 

 ting the current to each color in the order in which they occur. 



Thus, of course, the current is sent through the comb to the electro-mag- 

 nets, which raise the thread of the warp below, where the weaver has his 

 color-slnittli-s arranged in the order in which they are to be used, and throws 

 them in accordingly. So the loom just as easily, and on the same principle, 

 transmits the pattern to a stuff of twelve colors as to that of only two. It 

 is in this that the weaving by electricity displays its superiority over the pre- 

 sent system, according to which, for example, if a material is to be worked 

 in six colors, it is necessary by the Jacquard loom to employ six times more 

 cards than for a similar design of one color. The advantages, therefore, 

 which ought to result from the introduction of the electro-magnetic loom in 

 the manufacture of all our patterned fabrics are sufficiently apparent. A 

 new method, which does away with all the operations necessary to the pre- 

 paration of the cards, must, of course, produce an all-important saving of 

 both time and money upon the present system of manufacture. But there 

 are other and not unimportant advantages, such, for instance, as permitting 

 all manufacturers to try the effect of new patterns without going through 

 the long and costly process of preparing cards. He can ascertain in a few 

 hours the effect of any design, and prepare a series of specimens for the 

 approbation of the trade before commencing upon a single yard of stuff. In 

 short, whatever can be done by printing, lithographing, or engraving, can be 

 thus stamped on tinfoil, and reproduced in colored silks, according to the 

 colors of the original, with all the fidelity of an electrotype. 



By this means, at a trifling cost, families can have special designs, such as 

 crests and initials, for carpeting, curtains, furniture covers, etc., at a week's 

 notice. In this loom also the workman is enabled, with the greatest facility, 

 to effect a reduction of the design, by means of varying the speed of the 

 cylinder on which the pattern is placed. Without alteration, or without 

 touching the design, it can with equal facility make stuffs more or less strong 

 or more or less light, by changing the number of the threads of the weft, and 

 by regulating, in accordance with that change, the speed of the cylinder on 

 which the pattern revolves. Of course, any required additional effect can be 

 made, or any part omitted from the design, without at all interfering with 

 the workman. As a matter of course, the electrical portions of the invention 

 are capable of application to any loom, and, in fact, occupy, at the top of the 

 machine, no more space than a small writing-desk. It is only the cards and 

 cumbrous accessories of the Jacquard loom which are done away with; its 

 mechanical properties are retained, and the electro-magnets can be applied to 

 any. It is expected that with this machine, in all very large or intricate pat- 

 terns, such as are now occasionally used in silks, a saving of eighty per cent 

 in money, and more than eighty per cent in time, will be gained upon the 

 production of similar designs by the present system. 



ON THE INFLUENCE OF MAGNETIC FORCE ON THE ELECTRIC 



DISCHARGE. 



The following is an abstract of a lecture recently delivered before the Royal 

 Institution, Great Britain, by Professor Tyndall, which was intended to illus- 

 trate the constitution of the electric discharge, and of the action of magnetism 

 upon it : 



1. The influence of the transport of particles was first shown by an experi- 



