987 
but with the restriction, that up to the time ¢= tj; the first k terms 
only of the series are to be taken. Hence, with each discontinuity 
the number of terms of the series expression for @ is increased by one. 
2 de 
For the velocity Fane get 
C 
dé 1 ; (> 
— SS >» An N B a tn) ot uv, é 
en es fy 
dt (7,—#,) n 
| RN 
Immediately after the moment f, the velocity zi therefore in- 
creased by the amount 
1 
—_——~ A;, N' (ae) = A; N' 
(7,—#,) 
Therefore, the effect of the 4’ discontinuity is, that the velocity 
existing just before it occurred, is increased by the amount 
K 
Ay N= — A; N 
rm 
Hence every discontinuity in the magnetic induction causes a 
proportional increase of the velocity of the galvanometer system. 
Finally let us consider what becomes of the deflection 4 if, as 
was the case with the moving coil galvanometer, the galvanometer 
is greatly damped and therefore 
DE a". 
In this case a deflection, once obtained, decreases only very 
slowly (as with the Grassot-fluxmeter). 
Now the roots v, and w, are approximately 
Tied 1 w? 
oe. mn ee | ree 
a aa 
hence 
i} zen ) 
. | ’ \ n 
OS AN! te? « — e~2e(t+t,) 
If the experiment does not last too long, we have for all values 
to be considered 
aa : 
nn (hy) 
7, 
