382 
ME. C. CHAMBEES ON THE SOLAE YAEIATIONS OF 
I am aware, this is the first time that any diurnal variation of magnetical phenomena has 
been pointed out in which the sun’s position relatively to the meridian of the place 
appears so directly related to the expressed phenomena. To exhibit the general cha- 
racter of this variation more distinctly the curves Nos. 44 and 45, Plate XXX., are drawn 
on a larger scale to represent the average variation for the north- and south-latitude 
stations respectively. For all the stations, except St. Helena and Greenwich, the above 
are the results derived from the observations after the separation of the larger disturb- 
ances by the method above described ; for St. Helena the effect of disturbances on the 
diurnal variation is very slight, and all observations are included ; for Greenwich com- 
plete days of large disturbance are thrown aside, and the remainder used for the calcu- 
lation of the diurnal variation. 
15. Solar-diurnal Inequality . — The following Table shows the mean diurnal inequa- 
lity when all observations, disturbed and undistubed, are included in the calculations as 
compared with the mean diurnal variation after the exclusion of disturbances exceeding 
F‘4 in amount ; and it is seen that at Bombay the disturbances have a very slight effect 
on the diurnal variation, the largest difference at any hour not exceeding 0'-061. 
Table XVII. 
Bombay Astronomical Hours. 
h m 
h m 
h m 
h m 
h m 
h m 
h m 
h m 
h m 
h m 
h m 
h m 
0 12 
1 12 
2 12 
3 12 
4 12 
5 12 
6 12 
7 12 
8 12 
9 12 
10 12 
11 12 
Mean I 
diurnal 
\ 
-1-590 
-1-424 
-0-936 
-0-342 
+0-064 
+0-023 
-0088 
-0-108 
-0084 
-0 032 
+0025 
+0-144 
inequality. J 
l 
Mean 1 
diurnal ] 
[ 
— 1 -585 
-1-388 
-0-896 
-0-337 
+0072 
+0-015 
-0-098 
-0125 
-0123 
-0 059 
+0-012 
+0-118 
variation. J 
Excess of 
inequality 
over 
variation. 
-0-005 
-0036 
-0-040 
-0005 
-0-008 
+0008 
+0-010 
+0-017 
+0039 
+0-027 
+0013 
+0-026 
Bombay Astronomical Hours. 
h m 
h m 
h m 
h m 
h m 
h m 
h m 
h m 
h m 
h m 
h m 
h m 
12 12 
13 12 
14 12 
15 12 
16 12 
17 12 
18 12 
19 12 
20 12 
21 12 
22 12 
23 12 
Mean 1 
diurnal 
+0-212 
+0-258 
+0-238 
+0-174 
+0-084 
+0159 
+0-719 
+ 1-216 
+ 1-388 
+0-951 
+0006 
-1-052 
inequality. J 
I 
Mean 1 
diurnal 
f 
+0-185 
+0-237 
+0-215 
+0155 
+0068 
+0157 
+0-721 
+ 1-192 
+ 1-424 
+ 1-006 
+0-067 
-1-037 
variation. J 
I 
Excess of 1 
inequality 
over 
variation. 
! 
+0-027 
+0-021 
+0-023 
+0019 
+0-016 
+0002 
-0-002 
+0-024 
-1-036 
-0-055 
-0-061 
-0015 
