flattened, and everywhere detached stratum, whose major axis is
estimated at seven or eight hundred, and its minor axis at a hundred and
fifty times the distance of Sirius from the Earth."[11] And since it is
concluded that the Solar System is near the centre of this aggregation,
it follows that our distance from the remotest parts of it is some four
hundred distances of Sirius. But the stars forming these remotest parts
are not individually visible, even through telescopes of the highest
power. How, then, can such telescopes make individually visible the
stars of a nebula which is half a million times the distance of Sirius?
The implication is, that a star rendered invisible by distance becomes
visible if taken twelve hundred times further off! Shall we accept this
implication? or shall we not rather conclude that the nebulae are _not_
remote galaxies? Shall we not infer that, be their nature what it may,
they must be at least as near to us as the extremities of our own
sidereal system?

Throughout the above argument, it is tacitly assumed that differences of
apparent magnitude among the stars, result mainly from differences of
distance. On this assumption the current doctrines respecting the nebulae
are founded; and this assumption is, for the nonce, admitted in each of
the foregoing criticisms. From the time, however, when it was first made
by Sir W. Herschel, this assumption has been purely gratuitous; and it
now proves to be inadmissible. But, awkwardly enough, its truth and its
untruth are alike fatal to the conclusions of those who argue after the
manner of Humboldt. Note the alternatives.

On the one hand, what follows from the untruth of the assumption? If
apparent largeness of stars is not due to comparative nearness, and
their successively smaller sizes to their greater and greater degrees of
remoteness, what becomes of the inferences respecting the dimensions of
our sidereal system and the distances of nebulae? If, as has lately been
shown, the almost invisible star 61 Cygni has a greater parallax than
[Greek: a] Cygni, though, according to an estimate based on Sir W.
Herschel's assumption, it should be about twelve times more distant--if,
as it turns out, there exist telescopic stars which are nearer to us
than Sirius; of what worth is the conclusion that the nebulae are very
remote, because their component luminous masses are made visible only by
high telescopic powers? Clearly, if the most brilliant star