172 Transactions.— Miscellaneous. 
intensely heated than it is now. All the elements of which it is composed 
were there uncombined. Hydrogen, the gas of the smallest density, 
ordinarily extended furthest from the centre of the globe, and this hydrogen, 
its outer envelope, was nearly always near the confines of the normally cold 
regions of space. Thus it would have a somewhat lower temperature than 
the rest of the sphere, and hence well-marked hydrogen lines would appear 
in its spectrum at this period. Comparatively small quantities of other 
elements, however, would frequently be erupted from the interior portions 
of the sphere, and would reach what may be called the surface. The 
presence of these would cause the appearance of numerous fine lines in the . 
spectrum. As eternity went on, if I may use the expression, the star 
radiated a large portion of its heat into space, the elements began to combine 
chemically to a certain extent, large volumes of hydrogen ceased to exist as 
such, through combining with oxygen and forming water-vapour, of which 
the outer star envelope would now consist. In place of the hydrogen lines 
of the white star therefore, we now find the aqueous vapour spectrum—* the 
atmospheric lines" as they are called. The result of the combination of 
the oxygen and the hydrogen would, of course, be a great decrease in the 
volume of the outer envelope. This would probably bring the lines of 
sodium, magnesium, iron, and calcium into greater prominence, and we 
should have the spectrum which y Crucis now presents. Between the two 
conditions described there would be an intermediate one. Through such a 
stage our Sun may possibly be passing now. It may be, in short, that 
our Sun was once a Sirius, is now a Procyon, and will by-and-by be a y 
Crucis. This is a mere hypothesis, of course, though it appears to account 
pretty fairly for some of the phenomena of the stars. In fact, I give it 
merely as a suggestion, feeling that it is as little entitled to carry weight 
with it as an hypothesis, founded on observed phenomena and not at vari- 
ance with known facts, can be. 
y Centauri.—R. A. 12hrs. 94min. 21:46secs. Decl. 58° 14' 48-94". — This 
is a very fine close pair of stars, each component being of the fourth magni- 
tude, and purely white. In his “ Results of Observations at the Cape 
of Good Hope," Sir John Herschel gives the position-angle as 854-8°,. the 
epoch being 1835-89, while the distance is stated to be 3". To this estimate 
of distance Herschel attaches no value. For the year 1878-98 the angle of 
position is 6:6?, or 186:6?, and the distance 2-9". 
B Crucis.—' This fine white star has a distinct deep blood-red companion, 
the position angle being 2604? and the distance (1879)-208'. It seems to 
me that the small star varies in size from about the eleventh to nearly the 
eighth magnitude. It would be well if the small star could be watched, so 
that its period and the amount of its variation in brightness might be 
accurately ascertained, 
