Magnet on Electric Currents. 205 
current at the moment of making or breaking the magnet 
circuit. 
It has been stated above that in the experiments thus far 
tried the current apparently tends to move, without actually 
moving, toward the side of the conductor. I have in mind a 
form of apparatus which will, I think, allow the current to fol- 
low this tendency and move across the lines of magnetic force. 
If this experiment succeeds, one or two others immediately 
suggest themselves. 
make a more complete and accurate study of the phe- 
nomenon described in the preceding pages, availing myself o 
the advice and assistance of Prof. Rowland, will probably 
occupy me for some months to come. 
Baltimore, Noy. 19th, 1879. 
It is perhaps allowable to speak of the action of the magnet 
as setting up in the gold leaf strip a new electromotive force at 
right angles to the primary electromotive force. 
_ this new electromotive force cannot, under ordinary condi- 
tions, manifest itself, the circuit in which it might work being 
Incomplete. When the circuit is completed by means of the 
homson galyanometer, a current flows. 
The actual current through this galvanometer depends of 
course upon the resistance of the galvanometer and its connec- 
tions, as well as upon the distance between the two points of 
the gold leaf at which the ends of the wires from the galvano- 
meter are applied. We cannot therefore take the ratio of OC 
and ¢ above as the ratio of the primary and transverse electro- 
Motive forces just mentioned. 
If we represent by EH’ the difference of potential of two 
points a centimeter apart on the transverse diameter of the 
Strip of gold leaf, and by E the difference of potential of two 
polnts a centimeter apart on the longitudinal diameter of the 
Same, a rough and hasty calculation for the experiments already 
pression 5 Where C is the primary current through a strip of 
the gold leaf 1 cm. wide, and sis the area of section of the 
Same, we have H’ « ee 
November 22d, 1879, 
Am. Jour. Sct.—Tuirp Serres, Vor, XIX, No. 111.—Marcu, 1880. 
15 
