124 ANNUAL OF SCIENTIFIC DISCOVERY. 



to remain uninjured by the pressure of the heaviest artillery passing 

 over it. By this means orders are to be instantaneously conveyed 

 from the Emperor's station, and that of the chief commander to 

 troops at almost any distance on the field of the manoeuvres. 



WEAVING BY ELECTRICITY. 



The Commerce Sericole, a French commercial paper, gives an ac- 

 count of the remarkable invention by which it is proposed to utilize 

 the electric current in the process of weaving. In the Jacquard loom, 

 as is well known, the regulation of that particular order of the threads 

 which determines the distinctive character of the fabric, and which 

 was formerly effected by children crouched under the loom pulling 

 cords, is at the present produced by the movement which the weaver 

 gives himself to a treadle. This invention, however admirable, is not 

 without difficulties and certain defects, which it would be satisfactory 

 to overcome by still simpler means. At each passage of the shuttle, 

 there must be a piece of card-board of a certain breadth, pierced with 

 holes arranged so as to correspond with the design ; and when we 

 bear in mind that, for certain designs, as many as 40,000 of these 

 pieces of card-board have to be used, and that 1,500 are required in 

 ordinary cases for a design of the simplest coloring, and calculating 

 that they cost about 15 francs (12s. 6d.) per hundred, it will be easily 

 seen that these cards must be the cause of great expense, as well as 

 inconvenience. There are other objections, of more or less impor- 

 tance ; such as the noise which the loom makes in working, the space 

 which it occupies, and its constant liability to derangements. All 

 these inconveniences are about to disappear, by the introduction of 

 electricity, the action of which is so powerful, so easy to be directed, 

 and so prompt in its various operations. The treadle of the weaver 

 lifts the threads and connects the extremity of each by means of cop- 

 per wire, with a current of electricity either positive or negative at 

 will, and the result is, that without any noise some of the threads re- 

 main suspended, and others descend, according as the current is di- 

 rected. By this means as great a simplicity is effected in the weaving 

 of fabrics of the most complicated nature, as in that of common 

 cloth. To direct the electricity, there is no longer need of mechan- 

 ism for transferring or tracing the design. A series of points are ar- 

 ranged in a line like the teeth of a comb, each point communicating 

 with an electro-magnet. The weaver will only have to pass under- 

 neath these points the design, traced in varnish on a cylinder or on a 

 metallic leaf, in communication with the battery. The current will 

 pass only where the varnish is wanting, and it will be the correspond- 

 ing threads only which will remain suspended, and which, by that 

 means, will reproduce the design as it came from the hands of the 

 artist, with a surprising exactitude. Instead of the expense of a de- 

 sign, through the means of complicated cards, you have only that of 

 a simple design, and of the tending of the battery. Telegraphic expe- 

 rience proves how slight will be this last. There will be a saving in 



