TABLE XV.—Continued. 
VERTICAL COMPONENT OF Macnetic Force. 
239 
| October, |November.| December. 
0-01 0-01 O-OL 
5417 5254 5169 
5415 5258 5173 
[5356] 5188 5169 
5300 5279 5147 
5344 5292 [5163] 
5460 5337 5087 
5649 [5287] 5159 
5596 5243 5247 
5469 5301 5314 
[5557] 5269 5184 
5626 5282 5207 
5532 [5206] 
5373 5332 5207 
Table XV. was formed in the following manner ; the means of the balance micrometer readings, corrected 
for temperature, were first obtained for each civil day, and these means were reduced to parts of the vertical 
component by the following formule :— 
January 1—August 22. f= m x 0:000009 
August 25—August 31. = (m — 160) 0-000009 
September 6—November 11. f = (m — 222) 0:000009 
November 14—December 31. f = (a — 260) 0:000009 
Where f is the quantity in the previous Table and n the mean micrometer reading corrected for tempera- 
ture. 
The balance needle was removed three times in 1848 for the purpose of determining its temperature correc- 
tion, namely, on August 23 and 24, on September 1, 2, 3,4, and 5, and on November 13. These removals neces- 
sarily broke the series of observations, but it is conceived that the different portions after August have been 
reduced to nearly the values which they would have had, had there been no removal, by the following methods :— 
1st, To connect the observations after November 13, with those immediately before it,— 
Mean of the micrometer readings, week, Oct. 16— 21. = 830-3 
ono COS EO TER DUSGEDE PER Eede ¢ Bee Mee ee ase Ear Oct, 23— 28. = 829°8 
“ot oocosigob oasbOhoSEEBpnACE odge:cAcaRpoRCAREEEMEnS Oct. 830—Nov. 4. = 829-7 A _f— 06 
a ee, Nowe a ui = nat Ce sic { =a 
-oedongoobitHanboacanoeebecessoncketed period, Oct. 16—Nov. 11. = 826-1, before adjustment, ‘ 
The mean corresponding to October 30 is, therefore, 826-1, and the mean change for 14 days being — 7-8, 
the mean corresponding to November 13 will be 818°3. 
Mean of micrometer readings, week, Nov. 14— 18. = 858:3 
aogbAncegooaonseaeady pace eceeceBeoeneodaeae JeKays C= 25, = 8456°3 
iit oo ok aE ipa oe ea Nov.27—Dec. 2. = 8488 ae (ueata 
i ; Thee ADS Toni ves 3873} EOIN CUS { — 8:0 
setteeecesceseereeseesene period, Nov. 14d—Dec, 9. = 847-4, after adjustment. 
The mean corresponding to November 27 is, therefore, 847:4, and the mean change for 14 days being 
— 8°7, the mean corresponding to November 13 will be 85671, This gives nearly 38-0 micrometer divisions 
more than the previous result ; 38-0 was therefore subtracted from all the daily means in micrometer divisions 
after November 13, 1843. 
