92 L. H. Bigelow—The Earth a Magnetic Shell. 
The spherical harmonic potential system of a shell is given 
by Maxwell, Vol. I, p. 56, but in that case the shell is hollow; 
in our ease it is filled with an impenetrable obstacle. 
From the formule for the exflected and the inflected sys- 
tems and the constants above determined, the internal and the 
external systems of lines were computed. On comparison of 
the observed and computed systems the agreement is very 
close. 
The following table gives the codrdinate values of y for 
given w. N. and is the basis of the stream-lines shown in the 
diagram. The radius of equivalent flow is 1-25 times the radius 
of the earth, about 4950 miles. 
COMPUTED ORDINATES Y. 
Exflected. Inflected. 
N= 0:0 0°5 1 2 4 6 8 10” £59s20 24 Are 
e— 0’ “80. 1°81. FS2it Sarees, 692" eGo *80 
‘]'- 795 “80 y <8 82 "S60" :92— 2295 _ 88 
2 Se VASy SsSOR SaaS nollie wo 4: *82 “95 
63.) TA Mor nen ost) eta} = CRY ee? ‘48 °89 1:00 
"A s68"-. ON Bein it pe Ol eS weno *83 “94. 105 
‘5 61 ~ "64! eason Te er ss be 4290 64 87 99 1:09 
6 iy BT ‘H0re soa) pore eseile iesi 50 “70 (590 -15025 Siok 
“> fB8 44 e5O Pai BCS weSt 55 “SD 193) 1702 2 1eis 
°8 0. 22 424 “b0) “62 siow coe 60 °78 <9b. 1:06. eiers 
a) diysey | O33) CANS OI) rk KY ‘62. *81) "oO 0S as 
1:0 0. (BAe FS NARs 5851169. Fis ‘64 °83 :98 1:09 1°20 
Wo}, 0. 252 ho SO0e aor” a6. sone ean "66 + -85 ) 399) 1-tO eee 
Le 0) 20) BOR 394. 2545 oe. 74 ‘67 ‘86 1°00" TG eter 
pts) O} PHS fF 38> 60. > SGils ert -69 °89 1-03. 1-11 
20 OF pcS) 2b e340 49S 60 69 “T)] 91. 1504. toa ee 
It is evident that the system of forces described in the pre- 
ceding paragraphs is adapted to explain several important 
correlated phenomena, whose causes and relations have been 
the subject of the extensive research and discussion. As 
shown by Loomis (Encly]. Britann., Awrora), and others, the 
sunspot frequencies, the magnetic field, and the auroras, vary 
simultaneously in long periods, but especially in the 11-year 
period. My computations on the magnetic elements and the 
meteorological terms* indicate a synchronism of the same char- 
acter, even to minor details. The following group of curves 
exhibits a similar sympathetic action in the 26°68 day period 
of the sun’s equatorial rotation. Referring to the Amer. 
Meteorological Journal, Sept., 1893, it is found that a series of 
variations was obtained by grouping very diverse observations 
in this period, which were roughly similar to each other and 
to the European magnetic impulse. The lack of complete 
harmony is due to the fact that convectional movements, 
inversions, and all other disturbing terms were not considered, 
* This Journal, Dec., 1894. 
a a ee 
