XXXIV GENERAL RESULTS OF THE MAKERSTOUN OBSERVATIONS. 
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. 
| Mean Positive Departures. | Mean Negative Departures. eet Mean ee Re notes 
Month. een lbact if, 41a? lhc ae i | Mean 
| | Depart. 
1844. | 1845. | 1846. Mean. || 1844. | 1845. | 1846. | Mean. || 1844, | 1845, | 1846. || Mean. 
) | | | \! 
Prefix. | 0-00 0-00 0-00 0:00 0-00 0-00 10:00 0-00 | 0-00 | 0-00 | 0-00 | 0°00 0°00 
Jan. | 0172 | 0316 | 0159 | 0216 || 0215 | 0538 | 0171 | 0308 |—0092 | 0191 | 0398 | 0165 || 0251 
Feb. || 0317 | 0303 | 0284 | 0301 || 0404 | 0303 | 0171 | 0293 |4+0008 0356 | 0303 | 0213 || 0291 
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Mar. || 0445 | 0214 | 0299 | 0319 |} 0712 | 0250 | 0299 /-0101 | 0548 | 0231 | 0299 || 0359 
April 0404 | 0285 | 0314 | 0334 || 0472 | 0641 | 0428 | 0514 ||—0180 | 0436 | 0394 | 0362 | 
May 0355 | 0228 | 0346 | 0310 || 0330 | 0387 | 0403 | 0373 | —0063 || 0342 | 0287 | 0372 | 0334 
June 0193 | 0177 | 0441 | 0270 || 0178 | 0225 | 0514 | 0306 | —0036 | 
July 0217 | 0204 | 0314 | 0245 || 0271 | 0297 | 0393 | 0320 | —0075 
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Aug. | 0353 | 0386 | 0393 | 0377 || 0380 | 0241 | 0288 | 0303 | +0074 | : 
Sept. | 0248 | 0315 | 0463 | 0342 | 0316 | 0315 | 0540 | 0390 |-0048 | 0278 | 0315 | 0499 | 0364 
Oct. | 0459 | 0285 | 0345 | 0363 | 0194 | 0307 | 0586 | 0462 —0099 | 0476 | 0296 | 0434 | 0402 
Nov. | 0280 | 0330 | 0496 | 0369 || 0382 | 0357 | 0390 | 0376 | —0007 | 0323 | 0343 | 0437 | 0368 
Dec. | 0258 | 0358 0311 | 0309 | 0413 | 0608 | 0335 | 0452 | —0143 | 0318 | 0451 | 0325 | 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 departures 
from the monthly means occur about the solstices. 
2d, The average negative departure is greater than the average positive departure, in every month of the 
year with two exceptions, February and August, and the excess of the former over the latter is greatest in April 
and December. : 
3d, 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 
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 
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. 
March, May. | June. | July. | Aug. | Sept. 
0-00 0-00 0-00 0-00 | 0:00 0°00 
2333 4119 | 3815 | 4846 | 4128 | 3268 
4980 4510 | 3710 | 4290 | 4600 | 4020 
3276 | 4512 | 4010 | 4151 | 4597 | 4441 
3520 6711 | 5886 | 6807 | 6750 | 5986 | 
| | | 
2926 5415 | 4850 | 5826 | 5439 | 4627 
4220 | 4598 | 4230 
| 
5023 | 5019 | 4429 
