
OF THE EARTH'S MAGNETISM. 515 
TABLE IV.—YEARLY MEAN Horizontat FoRCcE (minus A CONSTANT) AT 
x 
HOSA OO Se. 
St Hevena, 1842 0 10000 
1842, 1843, 1844, 1845 
MonrTuH. e20e 
Mean. | Change.| Mean. | Change.} Mean. | Change.| Mean. | Change. 
peauary, BO? bode ene ti.00} 280214 bp 
February 64:74 : 40°55 . 24°50 
) 0°71 1:96 1°62 
March 64:03 ; 88°59 22°88 
eee 0:87 iesyg) 1:12 
April wa 63:16 : 36°60 ‘ 21-76 i 
P Poe 2:02 1:88 
May, ve | +, | 62°05] 7.59] 84.58) 76>] 19°88) 5 24 
June 66-03| .,| 60°55| 5°. | 3291) 7 24] 18-34 
’ +0°69 2-14 1:28 
July 66-72|" 4. 0; | 68-41} 3.--| 81:63) >. 
u ~,|+0°02 2°55 0-81 
August, . 66°74 é 59°86 ‘ 30°82 ; 
—0:-16 3:00 0:36 
September, 66-58| 2. | 52°86| 5... | 30-46] | 
—0°21 3:14 0:58 
October, . 66°37 : 49-72 29°88 
—0°38 22 1:04 
November 65:99 47-00 94 | 28°84 ps 
fe Cau Naess | ore) lee 
BecemDer, 790 20:30 2-11 1-49 

















TABLE V.—YEARLY MEAN HorizonvTaL FORCE (minus A CONSTANT) AT THE 









Cape or Goop Hors, 1842-45. 1.00= eH 
1842. 1843. ra a Seay 
Monta. PIAS AARS B08 FAR Teh A be 
Mean. | Change.| Mean. | Change.| Mean. | Change.| Mean. | Change. 
January, 46°28 ; 30°78 : 64:10 : 
Febuary, 47-07) * 079 | 33-33 1 5ae 6a-74|t O04 
March, AN oe ana Ga ar 30°57|— 5.4) | 73-28 | > 
TE OMG So a leoBi04 + 3-48 
April, Geet Misty | 48 We ey ee eel igas MOO ey 
May, 3643 | "5.36 | 48°68 17 9.45 | 28°20] 7.39 78°27 |_ o.70 
June, 38°79 | | 1.97 | 48°83 |" o.7¢| 80°00] 1 3.56 | 77°50) 9.43 
July, 40°66 ae 48:07 |" 1.36| 38°56] 4¢7| 75°09] 9.55 
August, . 42°17 Les ACHE) Ty egy SO iat eo e8 | — o. 
September, 43:22 |" 9 79| 44°87|_ 9.94 | 43:65 tees G7:20,| 1 figs 
October, . FAW gl 68 Boag 49 25) teeing 6220 aa 
November, 44:69 40°70 40:33 _ 9.99 54°51 44-93 56°74] 5.99 
December, 45°39 |" 5.59 | 28°04] 5.5| 5944/7 4 gg | 50°84 







7. The yearly mean horizontal intensity increases throughout the period 1842-45 
at Singapore. At Trevandrum it diminishes from the mean epoch August 1842 
to August 1843, after which it increases. At St Helena the yearly mean hori- 
zontal force diminishes from the mean epoch July 1842 till the end of the period July 
1845. Atthe Cape of Good Hope it increases from the mean epoch July 1842 to 
June 1848, diminishes from June 1843 to May 1844, thence increases to June 
1845, diminishing thereafter. At Toronto there was a rapid increase; but as 
VOL. XXII. PART III. 6k 
