4 96 
Mr. Babbage on electrical 
which the motion is directed, be exterior to that which denotes 
the same force when the plate is at rest. But in the case of 
the plate being in motion, the force which is measured by the 
area of the curve is greater on one side than on the other ; 
there will therefore be a small tendency in the plate to draw 
the point N towards that side to which it is moving. The 
points which have not passed vertically under the pole N, 
will in reality be a little less magnetised than they would be 
if they were at rest, because when they reach any particular 
place, they may not be exposed to the magnetic influence for 
a time sufficient for them to acquire the full degree of mag- 
netism which they would obtain, if they remained longer in 
that place. If the moving plate be circular, and if the mag- 
net be suspended in a balance of torsion, this extremely 
small tendency of each part to drag the pole N in the direc- 
tion of its motion being repeatedly applied by each succeeding 
particle, and during many revolutions, may at last produce 
motion in the magnets above, even though the attractive 
force of the revolving substance be so exceedingly feeble as 
to be insensible to other methods. 
In this analysis of the action of a magnet on a moving 
body susceptible of magnetism, it is to be observed, that no 
part of the effect is attributed to the velocity with which the 
agent* immediately producing the attraction traverses from 
the former to the latter: the nature of the action is not 
* It is difficult to write on any physical subject without employing words which 
are more or less connected with the various hypotheses prevailing at the time. In 
the present Paper I have no intention of giving any opinion on the theories at 
present received, but merely propose stating facts that I have noticed, and the 
reasonings to which they appear to me to lead. 
