ON SOLAR PHYSICS. 
395 
due to the fact that large groups come abruptly into view, and depart abruptly from the 
disk of the sun, so that a high positive departure for one fortnight is sometimes followed 
by a negative one for the next. 
We have endeavoured to eliminate the effect of this source of inequality by the fol- 
lowing means. Suppose, for instance, that the departures for the beginning of 1850 are 
as follows : — 
(1) 
January 
7 . 
. . +194 
(2) 
21 . 
. . - 66 
( 3 ) 
Februar} 
7 . 
. . - 68 
( 4 ) 
21 . 
. . + 36 
( 5 ) 
March 
7 . 
. . +228 
(6) 
21 . 
. . - 13 
we should, by taking the mean of (1) and (2) of (2) and (3), and so on. form a second 
series as follows : — • 
January 
14 . . . 
. + 64 
28 . . . 
. - 67 
February 
14 . . . 
. - 16 
28 . . . 
. +132 
March 
14 . . . 
• +107 
If this operation be repeated once more, we obtain results which, without any further 
attempt at equalization, may be formed into a series of short-period curves, which may 
be taken to be due to some physical cause, and from which we may hope to discover 
traces of the action of Mercury if such exist. 
We have, as in the previous case, taking this curve as our basis, found the united de- 
partures for those times when Mercury and Venus are between 0°and 30° of one another, 
between 30° and 60°, and so on. There are in all ninety periods of this nature. 
31. The results of our investigation regarding planetary influence are exhibited in the 
following Table : — 
Table VI a. 
Angular separation 
between 
Excess or 
deficiency. 
Jupiter and Venus. 
Venus and Mercury. 
O 
0 and 
O 
30 
+ 881 
+ 1675 
30 
55 
60 
- 60 
- 139 
60 
5 5 
90 
— 452 
— 1665 
90 
55 
120 
- 579 
— 2355 
120 
55 
150 
- 705 
-2318 
150 
55 
180 
- 759 
-1604 
180 
55 
210 
- 893 
— 481 
210 
55 
240 
— 752 
+ 547 
240 
55 
270 
- 263 
+ 431 
270 
55 
300 
+ 70 
+ 228 
300 
55 
330 
+ 480 
+ 1318 
330 
55 
360 
+ 1134 
+ 2283 
