F. H. Bigelow—The Earth «a Magnetic Sheil. 87 
ADOPTED VECTOR VALUES. 
Adjusted Vectors. 
Station. Computeda. Meana. South North 
‘in 3 N. 8 oO a s o a 
1 53°1 51°6 52°4 45 28 54 38 23 54 
2 49°3 55°7 52°5 53 29 55 43 24 55 
3 62°0 58°2 60°1 60 30 58 52 24 58 
+ 63°2 62°6 62°9 59 30 59 52 23 59 
5 57°5 60°0 58°8 55 2" 60 49 22 60 
6 A4T'6 54°8 51:2 42 23 58 33 aly 58 
iu 55°8 63°9 59°9 34 18 55 26 13 55 
8 20°3 1-0 25°7 31 15 54 24 1l 54 
9 671 66°4 66°7 ~~ 20 12 48 14 8 48 
10 33°6 36°9 35°3 18 10 47 13 8 AT 
11 46°4 46°2 46°3 14 9 43 10 1 43 
12 41% 43°3 42°5 13 10 41 10 8 41 
13 a9 36°9 37°4 14 L1 40 13) 9 40 
14 45°6 49°7 47°8 16 lie 38 12 9 38 
15 57:0 64:2 60°6 17 12 37 13 10 37 
16 36°9 32°2 34°6 23 19 37 Li 16 Bt 
17 40°4 45°8 43°] 38 27 43 32 23 43 
- 18 56°3 61°0 58°7 ell 20 53 25 15 53 
19 32°2 33°6 32°9 19 14 36 15 Le 36 
20 38°2 33°6 35°9 15 Ly 39 Lt 8 39 
21 58-2 61:9 60°1 16 10 57 12 7 517 
22 60°0 — 55°8 579 22 12 58 15 8 58 
23 67°4: 71:4 69°4 36 Lg AT 31 16 47 
24 30°0 39°7 34°8 25 13 44 19 10 44 
25 54°6 46°6 50°6 20 12 43 15 9 43 
26 54°8 53:8 54°3 26 14 52 22 12 52 
The only stations which differ between the computed and 
adjusted values for the angle a to any important extent, are 
Sodankyla, Washington, Los Angeles and Stid Georgien. 
Sodankyla and Siid Georgien used soft iron bars in measuring 
the vertical force and therefore have less weight. Sodankyla 
shows a vertical force nearly eight times too large, and yet the 
reduced values being published in C. G. 8. units, there appears to 
be no room for doubting the method of interpreting the observa- 
tions. Los Angeles had trouble with the vertical force balance 
throughout the series at that station, only a couple of years 
being retained in their report. Washington has used an 
unsymmetrically shaped magnet, which was suspected of lack 
of sensitiveness. The four stations give values too large to 
agree with the rest of the series. These remarks apply 
only to the vertical force, as the horizontal elements are 
correct. In order to show the meaning of the vectors, they 
have been plotted on the accompanying diagram. 
The system is a magnetic meridian of the earth with the 
adjusted vectors at the surface. The notable features are the 
increased vector lengths in the polar regions and in latitudes 
10° to 35°, with diminished vectors at the poles in the middle 
latitude zones and at the equator. The angles show that an 
