ON THE DIRECTIVE POWER OF MAGNETS. 
489 
12, 46, and all to the right of it must be directed almost exactly to the centre of the 
right-hand end of the magnet, and a similar direction must be made at 65, 27, 20, 54 
in respect of the left end, with corresponding changes for intermediate stations. 
The angles of position were never measured, but they are fully taken into account in 
the subsequent resolution of forces into longitudinal and transversal components. 
The following Table exhibits the total force at each station, as ascertained by the 
operations described above. It will be remembered that the numbers for the “ Galvanic 
coil with iron core” are not necessarily on the same scale as those for the “Large 
magnet,” and that the numbers for the “ Galvanic coil without core” must be divided 
by 120 to make them comparable with those for the “ Galvanic coil with iron core.” 
Total force acting on the small magnet at each station. 
No. of Station. 
Large magnet 
presenting its 
edge. 
Large magnet 
presenting its 
flat side. 
Galvanic 
coil with 
iron core. 
Galvanic 
coil without 
core. 
1 
16 
274 
250 
310 
216 
2 
15 
17 
30 
326 
293 
330 
240 
3 
14 
18 
29 
408 
363 
413 
333 
4 
13 
19 
28 
566 
480 
515 
550 
5 
12 
20 
27 
678 
542 
634 
1000 
6 
11 
21 
26 
622 
480 
585 
1470 
7 
10 
22 
25 
513 
454 
565 
1925 
8 
9 
23 
24 
600 
584 
840 
2700 
31 
50 
160 
160 
164 
184 
32 
49 
51 
68 
16.3 
165 
180 
192 
33 
48 
52 
67 
191 
183 
195 
225 
34 
47 
53 
66 
224 
200 
221 
305 
35 
46 
54 
65 
235 
217 
227 
400 
36 
45 
55 
64 
211 
197 
215 
427 
37 
44 
56 
63 
193 
180 
200 
444 
38 
43 
57 
62 
175 
173 
195 
485 
39 
42 
58 
61 
181 
177 
208 
583 
40 
41 
59 
60 
201 
193 
227 
690 
Perhaps the following points are worthy of present notice : — 
1. Remarking that, in the experiment in which the edge of the large magnet is pre- 
sented to the small magnet, the distance of the small magnet is in each circuit the same 
at every station, it will be seen that the greatest directive force is not longitudinal at the 
end of the magnet, but transversal, at about part (or probably less) of the length 
from the end of the magnet. There is, however, a diminution and then an increase in 
proceeding from either of these positions to the other, and the directive force opposite 
the middle of the magnet’s length is less than either of them ; so that, in making the 
entire circuit of the magnet, there are six maxima and six minima. 
2. When the flat side is presented to the small magnets, the same statement holds 
for the outer circuit, but not for the inner circuit. 
3. With increase of distance, the diminution of force is much more rapid at the end 
than at the side of the large magnet. 
