xlviii GENERAL RESULTS OF THE MAKERSTOUN OBSERVATIONS. 
TABLE 42.—Means of the Positive and Negative Departures of the Daily Means from the Monthly 
Means of the Vertical Component of Magnetic Force, with their Differences. 
Mean Departures, without refer- 
| Mean Positive Departures. Mean Negative Departures. Caaetnylstan 
Diff. of oe 
Month. ] The ee Mean 
| Depart. 
1844. | 1845. | 1846. | Mean. || 1844. | 1845. | 1846. | Mean. 1844. | 1845. | 1846, | Mean. 
TABLE 43.—Mean Diurnal Range of the Vertical Component of Magnetic Force, as deduced from | 
the Ordinary Daily Observations. 
| 
Year. || Jan. Feb. | March, | April. | May. Jone: | July. | Aug. | Sept. Oct. Nov. Dec. Mean. 
| 
Prefix. || 0-00 0-00 0-00 | 0-00 0-00 0-00 0-00 0-00 0-00 | 0°00 | 0-00 0-00 
1843 |, 0330 | 0374 | 0480 | 0684 | 0562 | 0396 | 0490 | 0473 | 0502 | 0444 | 0305 | 0364 | 
1844 || 0481 | 0584 | 1202 | 1164 | 0830 | 0433 | 0522 | 0944 | 0936 | 1058 | 1034 | 0489 | 0806 
1845 | 0812 | 0630 | 0849 | 0859 | 0662 | 0461 | 0537 | 0797 | 0924 | 0601 | 0497 | 0504 | 
1846 | 0251 | 0310 | 0501 | 0811 | 0876 | 0681 | 1096 | 1204 | 1445 | 1098 | 0871 | 0332 | 0793 
i | | 
; || | | . 
‘eae 0290 | 0342 | 0490 | 0747 | 0719 | 0538 | 0793 | 0838 | 0973 | 071 | 0588 | 0348 | 0621 3 
| | | | | | 
‘eect 0646 | 0607 | 1025 1011 | 0746 | 0447 | 0529 | 0870 | 0930 | 0829 | 0765 | 0496 | 0742 
1| | | | 
| | | | 
i} | | 
seat 0468 | 0474 0758 0879 | 0732 0493 | 0661 | 0854 0952 | 0800 | 0677 | 0422 | 0682 
| | : | 
91. Annual Variation of the Diurnal Ranges of the Vertical Component of Magnetic Force — From the num- 
bers in Table 43, it appears, that the diurnal range of the vertical component is greatest at the equinoxes, and 
that it is least at the solstices. The values in Table 43 are deduced from the ordinary daily observations in 
the various years. When we consider the diurnal ranges from all the observations made in each of the years 
1844 and 1845 (in the manner already noted for the magnetic declination No. 12), we obtain the following 
means for the several months in each year, (prefix 0-00.) 
Jan. Feb. March. April. May. June. July. Aug. Sept. Oct. Nov. Dec. Mean. 
1844, 0496 0729 1373 1827 0964 0442 0545 1064 1050 1171 1182 0522 0905 
1845, 0943 0686 0934 0924 0697 0464 0546 0820 0961 0634 0540 0560 0726 
Mean, 0719 0707 1153 1125 0830 0453 0545 0942 1005 0902 0861 0541 0815 
These means give the same law as has already been deduced from Table 43; the values are greater than 
those for the same years deduced from the ordinary daily observations, but the increase is considerably less 
than in the cases of the magnetic declination and horizontal component. 
