324 The Construction of the Heavens. [fuly, 
down, insomuch that, though he lived till 1824, he was 
incapable of great or prolonged mental exertion. 
Sir John Herschel’s labours among stars and nebulz were 
directed almost wholly to the completion of the survey of 
the heavens. I do not know that there is a single passage 
in his works in which he‘touches on the subject of the con- 
stitution of the heavens otherwise than as it were inci- 
dentally. He nowhere definitely enunciates a theory of the 
universe. 
Two circumstances, however, in Sir John Herschel’s work 
require to be attended to. 
The first relates to the distribution of the brighter orders of 
stars over the heavens. In his ‘‘ Outlines of Astronomy,” 
he says that the stars of these orders, including those down 
to and those somewhat below the range of the naked 
eye), increase largely in number as the Milky Way is 
approached. In his ‘‘ Observations at the South Cape,” 
he asserts the reverse. ‘‘Ona general view it appears,” he 
says, ‘“‘that the tendency to greater frequency, or the 
increase of density in respect of statistical distribution in 
approaching the Milky Way, is quite imperceptible among 
stars of a higher magnitude than the 8th, and except on the 
very verge of the Milky Way itself, stars of the 8th magni- 
tude can hardly be said to participate in the general law of 
increase. For the gth and iroth the increase, though 
unequivocally indicated over a zone extending at least 30° 
on either side of the Milky Way, is by no means striking. It 
is with the 11th magnitude that it first becomes conspicuous, 
though still of small amount when compared with that which 
prevails among the mass of stars of magnitudes inferior to 
the 11th, which constitute 16-17ths of the totality of stars 
within 30 on either side of the gala¢tic circle.” He then 
adds as a conclusion, ‘‘ following inevitably from this ” (and 
this conclusion is to be carefully noted, since, if just, it is of 
the utmost importance), ‘“‘that the larger stars are really 
nearer to us taken en masse, and without denying individual 
exceptions, than the smaller ones. Were this not the case, 
were there really among the infinite multitude of stars con- 
stituting the remoter portions of the galaxy numerous 
individuals of extravagant size and brightness, as compared 
with the generality of those around them, so as to overcome 
the effect of distance and appear to us as large stars, the 
probability of their occurrence in any given region would 
increase with the total apparent density of stars in that 
region, and would result in a preponderance of considerable 
stars in the Milky Way, beyond what the heavens really 
present, over its whole circumference.” 
