oo ron PP w pp eH 
ee ee el ee 
SOMATA HO OR WHNrH OS 
——$ = - -- a ——. 
oppo bo DO DS hb DS | 
a oP WD 
F. H. Bigelow—The Earth a Magnetic Shell. 85 
so that we haves. a. a. 8. the total vector in magnitude, its 
horizontal component, the angle with the horizon, and the 
angle with the magnetic meridian, respectively. Only such 
stations could be used as have published reports of hourly 
observations for about a year, in all three of the magnetic ele- 
ments. This involves about 225,000 individual observations 
and reductions for each element, together with more than 9000 
transformations from rectangular to polar codrdinates. 
The results for each station were divided into two groups 
according to the azimuth §, all between 90° and 270° in one 
group, and all between 270°.and 90° in the other group. Thus 
all the vectors pointing south magnetically, and all those point- 
ing north, are given by themselves. The means are taken by 
26°68 day periods, in some cases by months before the year 
1875, and finally the mean of these periodic means, the result 
being contained in the following table. 
SUMMARY OF SOUTH AND NORTH VECTORS. 
South. North. 
Long. Lat. Mag. Lat. Year. B G4 Soe @ 8G 
h m ° ° é 
Kingua Fjord, 429W. +66°6 Ti >be 188e—3 WN6) +45 45.09% 337— 6 38T 23 
Fort Rae. T43W. +62°6 76.2 1882-3 190+ 8 46 30 5— 8. 39 22 
Point Barrow. 10 26W. +71°3 73 8 1882-3 180— 6 59 29 4+ 5 55 29 
Cap Thordsen. —1 3B. +85 71 4 1882-3 186—14 62 28 6+ 8 50 23 
Jan Mayen. 033 W. +71:0 68 49 1882-3 130+10 54 29 4— 9 44 22 
Bossekop. —136 EK. +170°0 6425 1882-3 188414 43 29 18-- 6 33 19 
Toronto. 517 W. +436 6214 1847. Vio-25- a2 18" So0+21 25 15 
Sodankyla.. --146E. +674 6124 1882-3 184+ 5 16 15 14— 2 14 12 
Washington. 5 8W. +389 Hood) aloou 179+19 18 tT oot 0 20 68 
Pawlowsk. —2 2K. +59°7 5568) O1882-3 196+10 12 10 li" 5 - 10-8 
Greenwich. 0 0 +51°5 50 24 1887 175— 6 13 SF Ss59- 13 9 
Pare St. Maur. —0 9K. +48°8 AT ANE T3884 Vite 2)" 12 9 3857— 4 11 8 
Vienna. —]1 5H. +4482 4447 1882-3 178+ 5 19 15 1— 1 20 16 
Pola. —055 HK. +449 4143 1892 183+14 23 16 I— 6 17 11 
Los Angeles. +753 W. +34°:0 40 20 1883 18L +10: 22 12 O— 8 23 10 
Tiflis. —259 BK. +41°7 36 7 1882-3 182+ 6 15 12 13— 7. 13.11 
Zi-ka-wei. —8 6K. +31°2 27 37 1882 18h 4 ADS 32 Sol rb 33) 28 
Bombay —451E. +18°9 9 53 71863 182+ 4 36 20 3— 5 33 16 
Madras. —521 KE. +13:1 350 1855 185+ 2 13 11 349— 1 12 10 
Singapore. —655H. + 13 — 625 1845 182— 2 14 11, 359— 8 12 10 
St. Helena. 023 W. —15'9 —1112 1843 178—10 17 9 349— 2 17-8 
Batavia. —j{ 1. . — 62. —15 8 1890 1824+13 16 8 1—12 16 9 
Sid Georgien. 224 W. —b4:9 —2948 1882-3 187+26 52 . 20 8—17 47 15 
Cape Horn. 441 W. —55°6 —3329 1882-3 176— 2 15 13 6+ 4 13 10 
Cape Good Hope. —116 BE. —33°9 —33 54 1842 185-16. 19. th gbs—cs 16. 1) 
Hobarton. —950 HK. —42:9 —5450 1842 1764+22 26 15 O—27 22 13 
