394 
MESSES. DE LA RUE, STEWART, AND LOEWT’S RESEARCHES 
high as tliat of either of the other two — in fact the curve has the appearance as if it 
were pressed down from above, and pressed out laterally so as to lose in elevation 
what it gains in time. 
Lastly, after undergoing the process of equalization which has been described, there is 
still the appearance in all the three curves of a secondary maximum in the second 
branch ; and this peculiarity has induced us to compare the solar curves with the curves 
of brightness of two variable stars, the peculiarities of which have been well determined. 
We annex with this purpose the light-curve of L. Sagittse (Plate XXXI. fig. 1) deter- 
mined by Baxendell, showing like the sun’s spot-curve a secondary maximum in the 
second branch of the curve ; and we also exhibit the light-curve of (3 Lyrae (fig. 2) deter- 
mined by Pogson from the observations of Argelander, exhibiting two maxima, which 
are, however, both of the same value as well as can be estimated. 
29. We were induced to imagine from our preliminary researches that the amount of 
spotted area may possibly be influenced by the positions of the planets in such a way as 
to exhibit excessive solar action when two influential planets are together at the same 
ecliptical longitude ; we therefore resolved to test this hypothesis by the series of results 
which we have just described. As the two most influential combinations, we have 
selected that of Venus and Jupiter, and that of Venus and Mercury. With regard to 
the former combination, or that of Venus and Jupiter, as the period is about eight 
months, the influence, if any, would not be materially equalized by the three-monthly 
means, and it might therefore be expected to appear in the black curve which represents 
these means, separated to a great extent from any influence of shorter period, such as 
that due to conjunctions of Mercury and Venus. 
Any influence due to the relative positions of Jupiter and Venus might therefore be 
supposed to show itself in the curve of three-monthly means, and any due to the rela- 
tive positions of Venus and Mercury in the fortnightly curves. 
Viewing, therefore, the dotted curve as the normal line which equalizes all the ine- 
qualities of short period, including that which may be due to the relative positions of 
Jupiter and Venus, we have laid down the departures of the black curve from the dotted 
one for every fortnight of the whole series of observations; and joining all these into a 
curve, we have found from it the united values of the departures corresponding to those 
times when Venus and Jupiter were between 0° and 30° of one another, or between 30° 
and 60°, between 60° and 90°, and so on. 
There are in all fifty-four periods. 
30. In like manner, if we take the three-monthly curves as equalizing any influence 
due to the relative positions of Venus and Mercury, and lay down the departures of the 
fortnightly means from the corresponding three-monthly means, we are thus furnished 
with another set of departures which we may suppose likely to exhibit any influence 
due to the relative positions of Venus and Mercury. But these departures of very 
short period will no doubt embody, as well as inequalities due to physical causes, others 
