must excite wonder and admiration. The general conclusion is that,
besides the shining stars which exist in space, there may be any number
of dark ones, forever invisible in our telescopes. May it not be that
these bodies are so numerous as to cut off the light which we would
otherwise receive from the more distant bodies of the universe? It is,
of course, impossible to answer this question in a positive way, but
the probable conclusion is a negative one. We may say with certainty
that dark stars are not so numerous as to cut off any important part of
the light from the stars of the Milky Way, because, if they did, the
latter would not be so clearly seen as it is. Since we have reason to
believe that the Milky Way comprises the more distant stars of our
system, we may feel fairly confident that not much light can be cut off
by dark bodies from the most distant region to which our telescopes can
penetrate. Up to this distance we see the stars just as they are. Even
within the limit of the universe as we understand it, it is likely that
more than one-half the stars which actually exist are too faint to be
seen by human vision, even when armed with the most powerful
telescopes. But their invisibility is due only to their distance and
the faintness of their intrinsic light, and not to any obstructing
agency.

The possibility of dark stars, therefore, does not invalidate the
general conclusions at which our survey of the subject points. The
universe, so far as we can see it, is a bounded whole. It is surrounded
by an immense girdle of stars, which, to our vision, appears as the
Milky Way. While we cannot set exact limits to its distance, we may yet
confidently say that it is bounded. It has uniformities running through
its vast extent. Could we fly out to distances equal to that of the
Milky Way, we should find comparatively few stars beyond the limits of
that girdle. It is true that we cannot set any definite limit and say
that beyond this nothing exists. What we can say is that the region
containing the visible stars has some approximation to a boundary. We
may fairly anticipate that each successive generation of astronomers,
through coming centuries, will obtain a little more light on the
subject--will be enabled to make more definite the boundaries of our
system of stars, and to draw more and more probable conclusions as to
the existence or non-existence of any object outside of it. The wise
investigator of to-day will l