British Association. 285 
indicate issues of lava on the southern and western sides? On the whole, 
the author is confirmed in the opinion he has elsewhere expressed, that 
on the moon’s face are features more strongly marked than on our own 
globe, which, rightly studied, may lead to a knowledge of voleanic action 
under grander and simpler conditions than have prevailed on the earth 
during the period of subaérial voleanoes. The author also exhibited a 
drawing of Aristarchus, showing some undescribed features in the aspect 
of that, the highest part of the moon’s surface. 
“On Sun Spots and their Connection with Planetary Configuration.” 
By Mr Batrovur Stewart.—The author of this note having recently found 
in the course of conversation with Prof. P. G. Tait of Edinburgh, that they 
had both, independently, and by different trains of reasoning, been led to 
suspect the existence of a new principle in Natural Philosophy, which, 
however, must of course stand or fall by appeal to experiment and ob- 
servation,—it fell to his lot to endeavour to ascertain if there be any 
connection between sun-spots and planetary configurations. In a pre- 
liminary inquiry with this object in view, he was led to observe the 
changes with regard to size which take place in sun-spots, from a remark 
by Mr Beckley of Kew Observatory, that, during a certain period, he did 
not observe any spots break out on the visible disc of our luminary. 
Besides about six months’ records of these phenomena, made by means of 
the Kew photoheliograph at the Kew Observatory, the author has had the 
opportunity of investigating a year’s records made by the same instru- 
ment at Mr De La Rue’s private Observatory at Cranford. All of these 
are collodion negatives, and besides embracing a few months in the end of 
1859, they give an almost continuous record of the state of the sun’s dise 
between February 1862 and the present date. There is little difficulty 
in finding from these, by means of a comparison of two or three conse- 
cutive pictures, approximately, at what portion of the sun’s disc any spot 
ceases to increase and begins to wane, or, on the other hand, breaks out 
into a visible appearance. Now it appears to be a law nearly universal, 
that if we divide the dise of the sun roughly into longitude by vertical 
diameters, and if there be a number of spots on the surface of the sun, 
these will all behave in the same manner as they cross the same longitude ; 
that is to say, if one spot decreases another will decrease also, and so on. 
This law can, of course, be only approximately ascertained by means of 
a preliminary examination of this nature; but the impression produced 
upon the author is very strong, that if one spot decreases before coming 
to the central line, another does the same; if, on the other hand, one 
spot breaks out on the right half and increases up to the border, another 
will do the same. The author thinks, moreover, that he has noticed a 
connection between this behaviour of sun-spots, and the configuration of 
the nearer planets, Mercury and Venus, and it would seem to be of this 
nature. Remembering that all motions are from left to right, let us sup- 
pose that Mercury and Venus are both in a line considerably to the left 
of the Harth ; then spots will decrease as they come round from the left- 
hand side, and before they reach the centre of the disc. On the other 
hand, if these two planets are considerably to the right of the Earth, 
there will be a tendency for spots to form on the right half of the dise, 
and to increase up to the border. The author would, however, guard 
himself against the supposition that he attributes all the phenomena of 
spots to the agency of these two planets. 
** On the Path of a Meteoric Fireball relatively to the Harth’s Centre.” 
By Prof. Corrin. 
‘‘Qn the changing Colours of the Star 95 Herculis.” By Prof. C. 
NEW SERIES.— VOL, XVIII. NO. I1,—OCTOBER 1868, 20 
