ay see in that direction.
In the direction of the axis of the cylinder, the distances of the
boundary are least, so that we see fewer stars. The farther we direct
our attention towards the equatorial regions of the system, the greater
the distance from us to the boundary, and hence the more stars we see.
The fact that the increase in the number of stars seen towards the
equatorial region of the system is greater, the smaller the stars, is
the natural consequence of the fact that distant stars come within our
view in greater numbers towards the equatorial than towards the polar
regions.

Objections have been raised to the Herschelian view on the ground that
it assumes an approximately uniform distribution of the stars in space.
It has been claimed that the fact of our seeing more stars in one
direction than in another may not arise merely from our looking through
a deeper stratum, as Herschel supposed, but may as well be due to the
stars being more thinly scattered in the direction of the axis of the
system than in that of its equatorial region. The great inequalities in
the richness of neighboring regions in the Milky Way show that the
hypothesis of uniform distribution does not apply to the equatorial
region. The claim has therefore been made that there is no proof of the
system extending out any farther in the equatorial than in the polar
direction.

The consideration of this objection requires a closer inquiry as to
what we are to understand by the form of our system. We have already
pointed out the impossibility of assigning any boundary beyond which we
can say that nothing exists. And even as regards a boundary of our
stellar system, it is impossible for us to assign any exact limit
beyond which no star is visible to us. The analogy of collections of
stars seen in various parts of the heavens leads us to suppose that
there may be no well-defined form to our system, but that, as we go out
farther and farther, we shall see occasional scattered stars to,
possibly, an indefinite distance. The truth probably is that, as in
ascending a mountain, we find the trees, which may be very dense at its
base, thin out gradually as we approach the summit, where there may be
few or none, so we might find the stars to thin out could we fly to the
distant regions of space. The practical question is whether, in such a
flight, we should find this sooner by going in the direction of the
axis of our system than by directing our course