458  H. A. Rowland—Studies on Magnetic Distribution. 
feet long and 25 inch diameter. At the center a single layer 
of fine wire was wound for a distance of 1 foot, and the current 
for magnetizing the bar was sent through this. The zero-point 
was at the center of this helix and at the center of the bar, so 
that the observations on the first 6 inches include the part of 
the bar covered by the helix. 
The values of Q’e are the sum of four observations on each end 
of the bar and with the current reversed. The three tables are 
comparable with each other, the same arbitrary unit being used 
TaBLE VII. Magnetizing current 1°12. 
tA , " 
€ € Q’. 1 € 
L. Ob- Cor- Cor- 7? ee Calcu- 
served. | recte rected is lated. 
0 3.5 762-4 0 
1 wf ee. We oy ae 
2 we ils et ete eee ee 
3 ea eee eg Ce, Cee 
4 ye ae yoet || oc) ae 
5 66°6 ss Me oe oe ae 
6 m2 | wa | 5967] _.. oe 5 
1 595 | 59-7 | 5245 | -o239 | 41°83 
8 510 | 512 | 4648 | -0200 | 50-0 
9 452 | 45:2 | 413°6| 0162 | 61°7 
10 403 | 403 | 3684 | -0141 70-9 “ 
11 363 | 368 | 3281 -0120 | 83-3 sf 
12 333 | 33:5 | 291-3 -0107 | 93:5 & 
13 30°6 | 305 | 2578! -0110 | 909 3 
14 28-1 | 28-0 | 22731] -o116 | 86-2 = 
15 256 | 26-4 | 1993} 0118 | 84-7 J 
16 93-4 | 99% | 173-9 40 | 14 
17 200 | 203 | 151-2 | -0147 68-0 = 
18 181 | 130°2| -0161 | 6271 ” 
19 ' 340 | 160 | 1128] -0180 | 556 eo 
20 6-8 
End | 96:8 
Here we see an excellent confirmation of the results deduced 
from Table IV. In Table V, where the magnetizing-force is 
very small, and where, consequently, no part of the iron has y et 
R’ 
reached its minimum resistance, the value of Pr ase * =R’ap de- 
creases continually as the value of Q’ decreases, as it should do. 
In Table VI, with a higher magnetizing-power, which was suffi- 
cient to bring a portion of the bar to about the minimum resist- 
ance, we see that — remains nearly stationary for a short dis- 
tance from the helix and then decreasesin value. In Table VII, 
where the bar is highly magnetized and the portion — the 
_ zero-point approaches the maximum of magnetization, ;3¥ 
