Electro- Masrnetic and Mascneto-Electric Formula. 357 



In those experiments Mr. Schweigger employed an electro-mag- 

 netic multiplier, formed of only six brass-wires, one twelfth of 

 an inch in thickness, which we shall designate by AE, A'E^, 

 A'''E'', &c., and of which each was folded, as shows in the fig. 1, 

 the line ABCDE. By means of small grooves filled with mer- 

 cury, the extremities of these wires can be placed in commu- 

 nication in two modes, and thus send the current at will either 

 from the first wire AE into the second A'E'; from this into 

 the third A'^E^', &c. ; or in causing to communicate on one part 

 all the extremities A, A^, A.", and on the other, the extremities 

 E, E', E'^, through the six wires at once. In this last disposition, 

 when the multiplier forms but one circuit, the current produced 

 by the rotation of a magnet, and conducted to the multiplier by 

 conductors of a pretty large mass, (thick bands of copper,) causes 

 the needle to deviate instantaneously 80° to 90°, and if the needle 

 continues to be turned, stops finally between 50° to 60°. If, the 

 multiplier remaining the same, two disks of zinc and copper, 

 wetted with a saline solution, are used, the constant deviation of 

 the needle is but 10° to 15°. 



Fig. 1. 



Fig. 2. 



Fig. 3.« 



E A 



An ordinary multiplier, of which Mr. Faraday made use, 

 composed of numerous turns, and formed with a wire, thin, and 

 very long, folded as shown by fig. 2, (that which, according to 

 the Journal of Chemistry and Physics, by Mr. Schweigger, 1825, 

 Vol. Ill, is the best form which can be given to it,) produces a 

 deviation of only 10° to 15°, by the current of the same magnet 

 turning round its axis. By a proper combination of several mag- 

 nets turning around their axes, this same multiplier (fig. 2,) 

 shows an increase of the electric force, whilst the multiplier, 

 which we described in the beginning of this note, and is destined 



* See J. S. C. Schweigger ilber Mythologie. Tab. I. Fig. 1. 



