XXXIV 
Geneeal Results of the Makeestoun Obseevations. 
Table 25. — Means of the Positive and Negative Departures of the Daily Means from the Monthly 
Means of the Horizontal Component of Magnetic Force, with their Differences. 
Month. 
Prefix. 
Jan. 
Feb. 
Mar. 
April 
May 
June 
July 
Aug. 
Sept. 
Oct. 
Nov. 
Dec. 
Mean Positive Departures. 
1844. 
0-00 
0172 
0317 
0445 
0404 
0355 
0193 
0217 
0353 
0248 
0459 
0280 
0258 
1845. 
0-00 
0316 
0303 
0214 
0285 
0228 
0177 
0204 
0386 
0315 
0285 
0330 
0358 
1846. 
0-00 
0159 
0284 
0299 
0314 
0346 
0441 
0314 
0393 
0463 
0345 
0496 
0311 
Mean. 
0-00 
0216 
0301 
0319 
0334 
0310 
0270 
0245 
0377 
0342 
0363 
0369 
0309 
Mean Negative Departures. 
1844. 
0-00 
0215 
0404 
0712 
0472 
0330 
0178 
0271 
0380 
0316 
0494 
0382 
0413 
1845. 
0-00 
0538 
0303 
0250 
0641 
0387 
0225 
0297 
0241 
0315 
0307 
0357 
0608 
1846. 
000 
0171 
0171 
0299 
0428 
0403 
0514 
0393 
0288 
0540 
0586 
0390 
0335 
Mean. 
0-00 
0308 
0293 
0420 
0514 
0373 
0306 
0320 
0303 
0390 
0462 
0376 
0452 
Diff. of 
Mean 
Depart. 
0-00 
-0092 
+ 0008 
-0101 
-0180 
-0063 
-0036 
-0075 
+ 0074 
-0048 
-0099 
-0007 
-0143 
Mean Departures, without refer- 
ence to Sign. 
1844. 
Mean. 
0-00 
0-00 
0-00 ; 

0-00 
0191 
r\ o no 
0165 
0251 
0356 
0303 
0213 
0291 
0548 
0231 
0299 
0359 
0436 
0394 
0362 
0397 
0342 
0287 
0372 
0334 
0185 
0198 
0475 
0286 
0241 
0242 
0349 
0277 
0366 
0297 
0332 
0332 
0278 
0315 
0499 
0364 
0476 
0296 
0434 
0402 
0323 
0343 
0437 
0368 
0318 
0451 
0323 
0364 
59. The following are the conclusions from Table 25. 
1st, The daily mean value of the horizontal component is both most in excess and most in defect of its 
monthly mean value in April, and in the months from August to November ; while the smallest departm.-es 
from the monthly means occur about the solstices. 
2d, The average negative departure is greater than the average positive departure, in every mouth of the , 
year with two exceptions, February and August, and the excess of the former over the latter is gi'eatest in April 
and December. ■ 
Sd, As both the positive and negative departures obey nearly the same law, we in consequence find, as in | 
the last column of Table 25, that the greatest departures of the daily means from the monthly means occur j 
immediately after the equinoxes, and the least departures immediately after the solstices. We may generalize ' 
this result (as in the case of the magnetic declination, No. 11, 4th) thus : — The differences of the daily means of | 
the horizontal component of magnetic force from the monthly means were a maximum when the horizontal j 
component was least, and a minimum when it was greatest. * , 
Table 26. — Mean Diurnal Range of the Horizontal Component of Magnetic Force, as deduced from 
the Ordinary Daily Observations. 
Year. 
Jan. 
Peh. 
March. 
April. 
May. 
June. 
July. 
Aug. 
Sept. 
Oct. 
Nov. 
Dec. 
Mean. 
Prefix. 
1843 
1844 
1845 
1846 
0-00 
1396 
1920 
4095 
1988 
0-00 
1567 
2750 
2672 
2051 
0-00 
2333 
4980 
3276 
3520 
O'OO 
4102 
4990 
5695 
5663 
0-00 
4119 
4510 
4512 
6711 
0-00 
3815 
3710 
4010 
5886 
O'OI) 
4846 
4290 
4151 
6807 
0-00 
4128 
4600 
4597 
6750 
O'OO 
3268 
4020 
4441 
5986 
0-00 
2932 
3690 
3164 
3947 
0-00 
1682 
3140 
2480 
3597 
O-lX) 
1609 
2510 
3565 
2048 
0-00 
2983 
3760 
3SSS 
4579 
1843) 
1846j 
1692 
1809 
2926 
4882 
5415 
4850 
5826 
5439 
4627 
3439 
2639 
1828 
3781 
1844) 
1845/ 
3007 
2711 
4128 
5342 
4511 
3860 
4220 
4598 
4230 
3427 
2810 
3037 
3824 
Mean}^ 
of all / 
2350 
2260 
3527 
5112 
4963 
4355 
5023 
5019 
4429 
3433 
2725 
2433 
3S02 
1 
