magnetic phenomena produced by electricity. 15 
fixed in the centre of this circle, so that the circle was parallel 
to the horizon, and an electric shock was passed through the 
wire, its upper part being connected with the positive side of 
a battery, and its lower part with the negative. After the 
shock all the wires were found magnetic, and each had two 
poles ; the south pole being opposite to the north pole of the 
wire next to it, and vice versa ; and when the north pole of 
a needle was touched with a wire, and that wire moved round 
the circle to the south pole of the same needle, its motion was 
opposite to that of the apparent motion of the sun. 
A similar experiment was tried with six needles arranged 
in the same manner ; with only this difference, that the wire 
positively electrified was below. In this case the results were 
precisely the same, except that the poles were reversed ; and 
any body, moved in the circle from the north to the south 
pole of the same needle, had its direction from east to west. 
A number of needles were arranged as polygons in dif- 
ferent circles round the same piece of paste-board, and made 
magnetic by electricity ; and it was found that in all of them, 
whatever was the direction of the paste-board, whether ho- 
rizontal or perpendicular, or inclined to the horizon, and 
whatever was the direction of the wire with respect to the 
magnetic meridian, the same law prevailed; for instance, 
when the positive wire was east, and a body was moved round 
the circle from the north to the south poles of the same wire ; 
its motion (beginning with the lower part of the circle ) was 
from north to south, or with the upper part from south 
to north ; and when the needles were arranged round a cy- 
linder of paste-board so as to cross the wire, and a pencil 
mark drawn in the direction of the poles, it formed a spiral. 
