en GENERAL RESULTS OF THE MAKERSTOUN OBSERVATIONS. 
TABLE 58.—Diurnal Variations of Magnetic Dip for different periods, deduced from Table 57. 
Six Months. 
March. | ‘ March Twelve 
April. ; : to || Months. 
Aug. 
~0-315 
~ 0-095 
+0-116 
+0-053 
+0-154 
40-248 | 
+0-404 | 
+0839 
+1502 | 
+1-912 | 
+1-971 
41-519 
+ 0-822 
40:055 
—0-475 
—0-874 
—1-151 
— 1-378 
— 1-365 
— 1-253 
— 0-963 
— 0-668 
— 0-596 
— 0-462 
KOCOONOUBRWNHH SO WD 
a 
129. The approximate epochs of maxima and minima in apparent time, from Table 58, are :— 
Dec. Jan. Feb. March, April. May, June, July, Aug. Sept. Oct. Nov. 
Maximum, +101 20™ a.m. +10" 15™ a.m. 95 50™ a.m. 9) 35™ a.m. +102 Om a.m. 
Minimum, 2" 50™ p.m. —5> O™ pM. 61 20™ p.m, 5» 30™ p.m. — 55 35™ p.m. 
Maximum, Qh 5™ a.m, Qh 10™ a.m. tee ete eee eee eee see ereeet ee se 12 55™ a.m. 
Minimum, — 65 5™ a.m. 5» 45™ aM. ste eee cee see eee tee eae eee cee ees 4b 55™ a.m. 
The principal maximum, near 10" 4.m., occurs earliest in July and August, and latest in December to Feb- 
ruary : the afternoon minimum occurs earliest in the three winter months, and latest in May and June: the 
other maximum and minimum occur earliest in the months September to November. (See the Continuous 
Curves, Plate IV., where it is to be remembered that the apparent minima of the curves are the maxima of dip.) 
The following Table contains the diurnal variations for the days selected as nearly free from intermittent dis- 
turbance. 
130. The approximate epochs of maxima and minima in apparent time for the undisturbed diurnal varia- 
tions, are as follow :— 
Dec. Jan. Feb. March, April. May, June. July, Aug. Sept Oct. Nov. 
Maximum, +105 45m™a mM. +105 20™ a.m. 9h 50™ aM. 9h 45™ a.m. +105 15™ a.m. 
Minimum, 5195m pm. — 7h 5m pm, 64 30™ p.m. 7h Om p.m. — 65 45™ pM. 
Maximum, 1h 35™ a.m. Sh, DOM aciiin aiy Setueeeteestukt well ovluesewhpeaete 1 55™ a.m. 
Minimum, — 6% 25m a.m, BE TOMO ARM ci Maree eee ee ey) VO wiatcacdoemm asics 5» 5™ aM. 
In the undisturbed, as in the disturbed variations, the principal maximum occurs earliest in July and 
August, and latest in December to February ; but, unlike the disturbed variations, the afternoon minimum 
occurs latest near the equinoxes ; it occurs rather earlier at the winter than at the summer solstice. (See the 
Dotted Curves, Plate IV.) 
