XXXVlll 
General Results of the Makerstoun Observations. 
diately before and after those stated, a secondary minimum occurring at conjunction, and a secondai'y maximum 
at opposition ; but these secondary points are probably accidental. 
2d, The departure of the horizontal component from its monthly mean position for the coi'responding hour 
is least when the moon is farthest south and also when farthest north ; maxima occurring at the intermediate 
periods (see No. 16). 
Diurnal Variations for the Horizontal Component of Magnetic Force. 
Diurnal Variation of the Horizontal Component. — The discussions for 1843 and 1844 will be found in 
the volumes for these years, the Tables for 1845 and 1846 are given in this volume, pages 13 and 34. Table 
31 has been foi'med from all the ordinary daily observations made in the 4 years, in the manner already de- 
scribed for the declination (Nos. 26, 27.) 
Table 31. — Diurnal Variations of the Horizontal Component of Magnetic Force for each Month, as 
deduced from the Regular Daily Observations made during the Four Years 1843 to 1846. 
Mak. 
Mean 
Time. 
Jan. 
Feb. 
March. 
April. 
May. 

June. 
July. 
Aug. 
Sept. 
Oct. 
Nov. 
Dec 
li. 
■m. 
0-Ofl 
0-00 
0-00 
0-00 
0-00 
0-00 
0-00 
0-00 
0-00 
0-00 
0-00 
0-00 
12 
12 
0456 
0358 
1576 
1746 
1816 
2191 
2346 
2476 
1751 
1672 
0843 
0098 
13 
12 
0404 
0202 
0995 
1758 
1743 
1991 
2158 
2182 
1875 
1694 
0884 
0221 
14 
12 
0000 
0077 
0893 
1158 
1630 
1856 
2012 
2023 
1592 
1648 
0855 
0227 
15 
12 
0630 
0129 
1285 
1572 
1557 
1770 
1918 
2031 
1770 
1918 
1039 
0327 
16 
12 
0855 
0252 
1271 
1651 
1476 
1655 
1745 
2029 
1816 
1945 
1162 
0607 
17 
12 
1062 
0521 
1329 
1890 
1521 
1480 
1574 
1745 
1978 
1842 
1227 
0791 
18 
12 
1054 
0614 
1575 
1805 
1421 
1151 
1435 
1584 
1708 
1654 
1330 
0897 
19 
12 
1022 
0641 
1275 
1521 
1008 
0831 
1080 
1027 
1047 
1419 
1125 
0764 
20 
12 
0769 
0519 
0709 
0757 
0420 
0329 
0560 
0316 
0550 
0752 
0740 
0573 
21 
12 
0616 
0105 
0308 
0145 
0119 
0004 
0094 
0000 
0023 
0180 
0183 
0278 
22 
12 
0348 
0000 
0000 
0000 
0000 
0000 
0000 
0140 
0000 
0000 
0000 
0001 
23 
12 
0444 
0042 
0208 
0132 
0414 
0518 
0502 
0718 
0531 
0284 
0104 
0000 
0 
12 
0556 
0268 
0632 
0782 
1102 
1284 
1249 
1417 
1268 
0753 
0566 
0097 
1 
12 
0932 
0535 
1324 
1557 
1978 
1949 
1915 
2380 
2082 
1484 
0835 
0332 
2 
12 
1027 
0784 
1756 
2201 
2530 
2549 
2764 
2781 
2524 
1744 
1028 
0521 
3 
12 
1007 
0840 
2071 
2691 
2947 
2891 
3444 
3349 
2860 
2122 
1131 
0604 
4 
12 
1057 
0726 
2185 
3003 
3722 
3185 
3753 
3558 
3100 
2078 
1027 
0668 
5 
12 
0995 
0658 
2132 
3456 
3969 
3487 
4049 
3997 
2982 
2109 
1431 
0648 
6 
12 
0868 
0658 
1958 
3482 
3875 
3685 
4148 
3888 
2827 
2169 
1428 
OSSS 
7 
12 
0819 
0729 
2049 
3026 
3825 
3667 
3847 
3740 
2780 
2059 
1139 
0670 
8 
12 
0933 
0714 
1966 
2706 
3177 
3297 
3459 
3402 
2352 
2034 
1111 
0366 
9 
12 
0830 
0586 
1769 
2386 
2574 
2933 
2957 
3010 
2314 
1961 
0866 
0249 
10 
12 
0623 
0212 
1575 
2484 
2308 
2711 
2654 
2939 
2123 
1875 
0878 
0200 
11 
12 
0598 
0264 
1808 
2197 
2004 
2344 
2543 
2625 
2123 
1715 
0776 
0241 
69. The following are the approximate epochs of maxima and minima in apparent time, as deduced from the 
numbers in Table 31 ; the principal maximum is distinguished by +, the principal minimum by — , 
Jan. 
Feb. 
March. 
April. 
li. in. 
li. m. 
h. m. 
h. in. 
Mill. 
22 10 
-22 15 
-22 15 
-22 15 
Max. 
+ 40 
+ 2 45 
+ 4 15 
+ 5 45 
Mill. 
-14 0 
-14 0 
14 0 
14 0 
Max. 
+ 18 0 
18 45 
18 0 
17 30 
Jlay. 
li. m. 
22 0 
5 15 
June, 
li. m. 
21 50 
6 45 
July. 
Aug. 
Sept. 
Oct. 
Nov. 
Dec 
li. m. 
h. m. 
li. m. 
h. 111. 
h. ni. 
h. m. 
21 40 
21 25 
-21 50 
-22 10 
-22 40 
-22 40 
5 50 
5 10 
+ 4 20 
+ 5 
+ li 0 
+ 6 15 
14 0 
13 0 
11 0 
-12 0 
17 15 
16 0 
+ 1S 30 
+ 1S 0 
The diurnal variation of the horizontal component, at Makerstoun, consists of one niaxiiinim and one 
mininimn in tlic four months jNIay till August, and of two maxima and two minima in the eight mouths 
September till April ; in each of tl\c four montlis November till February, the two maxima liave nearly equal 
values, and in each of the last three of tlicsc, tlie two miniina are also nearly equal ; from March till April, 
