Ixii General Results of the Makeestoun Observations. 
Table 58. — Diurnal Variations of Magnetic Dip for different periods, deduced from Table 57. 
Mak. 
Mean 
Time. 
Dec. 
J an. 
Feb. 
March. 
April. 
May. 
June. 
July. 
Aug. 
Sept. 1 
uct. 
Nov. 1 
' i 
Six Months. 
Sept. 1 March 
to 1 to 
Feb. Anig. 
Twelve 
Months. 
li. 
m. 
' 
/ 1 
' 
12 
12 
+ 0-163 
-0-346 
-0-176 
-0-424 
-0-202 
-0-019 
-0-315 
-0-168 
13 
12 
+ 0-192 
-0031 
- 0-069 
-0-186 
-0-288 
-0-048 
-0-095 
-0-072 
14 
12 
+ 0-347 
+ 0-331 
+ 0-060 
-0-042 
-0-157 \ 
+ 0-095 
+ 0-116 
+ 0-105 
15 
12 
+ 0-075 
-0-042 
+ 0-168 
+ 0-032 
-0-382 
-0-153 
+ 0-053 
-0-051 
16 
12 
-0-140 
-0-048 
+ 0-331 
+ 0-179 
-0-443 
-0-291 
+ 0-154 
-0-069 
17 
12 
-0-370 
-0-158 
+ 0-447 
+ 0-454 
-0-448 
-0-409 
+ 0-248 
-0-081 
18 
12 
-0-423 
-0-184 
+ 0-731 
+ 0-664 
-0-270 
-0-346 
+ 0-404 
+ 0-029 
19 
12 
-0-360 
+ 0-180 
+ 1-148 
+ 1-190 
+ 0-181 
-0-089 
+ 0-839 
+ 0-375 
20 
12 
-0-146 
+ 0-928 
+ 1-721 
+ 1-856 
+ 0-768 
+ 0-311 
+ 1-502 
+ 0-906 
21 
12 
+ 0-163 
+ 1-463 
+ 2-012 
+ 2-261 
+ 1-374 
+ 0-768 
+ 1-912 
+ 1-340 
22 
12 
+ 0-399 
+ 1-679 
+ 2-023 
+ 2-210 
+ 1-511 
+ 0-955 
+ 1-971 
+ 1-463 
23 
12 
+ 0-374 
+ 1-485 
+ 1-483 
+ 1-589 
+ 1-191 
+ 0-782 
+ 1-519 
+ 1-151 
0 
12 
+ 0-241 
+ 0-916 
+ 0-718 
+ 0-833 
+ 0-655 
+ 0-448 
+ 0-822 
+ 0-635 
1 
12 
-0-036 
+ 0-183 
-0055 
+ 0-036 
+ 0-069 
+ 0-016 
+ 0-055 
+ 0-035 
2 
12 
-0-181 
-0-289 
-0-596 
-0-541 
-0-177 
-0-179 
-0-475 
-0-328 
3 
12 
— 0.1 79 
— yj' 1. 1 ci 
— 1-089 
— 0.^77 
yj'O t 1 
-0-274 
-0-874 
4 
12 
-0-159 
-0-799 
- 1-383 
- 1-270 
-0-379 
! -0-269 
-1-151 
: -0-710 
5 
12 
-0-092 
-0-913 
- 1-618 
- 1-603 
-0-502 
-0-297 
-1-378 
-0-838 
6 
12 
-0-125 
-0-837 
- 1-660 
- 1-597 
-0-497 
-0-311 
-1-365 
-0-838 
7 
12 
-0071 
-0-711 
- 1-640 
- 1-409 
-0-412 
-0-241 
- 1-253 
-0-748 
8 
12 
-0-033 
-0-611 
- 1-158 
- 1-120 
-0-336 
-0-184 
-0-963 
-0-574 
9 
12 
+ 0-043 
-0-469 
-0-739 
-0-797 
-0-308 
-0-132 
-0-668 
-0-401 
10 
12 
+ 0-198 
-0-552 
-0-565 
-0-671 
-0-291 
! -0-046 
-0-596 
-0-321 
11 
12 
+ 0-108 
-0-554 
-0-275 
-0-557 
-0-268 
-0-080 
-0-462 
-0-271 
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, + 10^ 20™ a.m. + 10'' 15"^ a.m. Q*" 50™ a.m. 9^^ 35™ a.m. + IQi^ a.m. 
Minimum, 2^' 50™ p.m. —5'^ 0™ p.m. 6^ 20™ p.m. 5'> 30™ p.m. — 5'' 35™ p.m. 
Maximum, 2'^ 5™ a.m. 2^ 10™ a.m. 1^ 55™ a.m. 
Minimvim, — 5™ a.m. 5^ 45™ a.m. 4^^ 55™ a.m. 
The principal maximum, near IC^ a.m., occurs earliest in Jiily and August, and latest in December to Feb- 
ruary : the afternoon minimum occurs eai'liest in the three winter montlis, imd latest in ^lay and Jxme : 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.) 
Tlie 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. Jlarcli, April. May, June. July, Aug. Sept Oct. Nov. 
Ma.ximum, + lO^^ 45™ a.m. + 10'^ 20™ a.m. 9'' 50™ a.m. 9^' 45™ a.m. + 10^ 15™ a.m. 
Miniminn, 5'> 25™ p.m. — 7'' 5™ p.m. 6'' 30™ p.m. 7'' 0™ p.m. — 6'' 45™ p.m. 
Maximum, I'l 35™ a.m. 3'' 20™ a.m 1'* 55™ a.m. 
Minimum, — (>'' 25"' a.m. 5'' 15™ a.m 5'' 5™ a.m. 
In the un(listurl)ed, as in the disturbed variations, the principal maximum occurs earliest in July and 
August, and latest in December to February ; but, unlike tlie disturbed variations, the afternoon minimum 
occurs latest near the eipiinoxes ; it occurs rather earlier at tlie winter than at the summer solstice. (See the 
Dotted Curves, Plate IV.) 
