82 
MR. HARRIS ON THE TRANSIENT MAGNETIC STATE 
Table VI. 
No. of the ring 
1st 
2nd 
3rd 
4th 
5 th 
6th 
7th 
8th 
Vibrations .... 
44 
76 
94 
124 
148 
166 
186 
210 
Ratio of force. 
8.54 
4.52 
3.45 
2.38 
1.83 
1.53 
1.25 
1.0 
In comparing the above numbers with those in the preceding Table, the 
energy of any number of rings, taken together, appears to be very nearly the 
sum of the same rings, taken separately, and is a curious deduction by the 
formula above given (16). Thus the energy of three rings combined is by 
the preceding Table 16.5, which is about the aggregate amount of the first, 
second, and third, as deduced above, and so on. It is true that some of the 
other numbers are not in such complete accordance as in this instance, but the 
approximation is nevertheless very remarkable. The intervening rings do not 
therefore intercept any very sensible portion of the inductive influence of the 
bar ; a result quite consistent with what is observed in the case of rotating 
discs, when covered with non-ferruginous screens ; and with this further con- 
dition, that whilst the inductive energy thus penetrates the intervening metal, 
it disturbs at the same time its magnetic distribution. 
23. The foregoing deductions were verified by combining a few rings not 
immediately successive, so as to leave an interval between them. The results 
are as follow. 
Table VII. 
Rings combined . 
lst + 4th 
4th + 8th 
lst+ 4 th + 8 th 
Vibrations 
-37 
100 
+ 33 
Force 
11.3 
3.2 
-11.7 
In these, as in the foregoing instances, it may be perceived, on comparing 
the actual observation, as given in this Table, with the values of the respective 
rings in the preceding one, that the numerical approximations are very close. 
The energy of any ring therefore may be estimated by subtracting from the 
aggregate effect, the sum of the others with which it is combined. 
24. It would not be difficult, from the above investigation, to arrive at some 
