ty of 27 miles a second would carry a
projectile right out of the solar system never to return.

LECTURE XIV

BESSEL--THE DISTANCES OF THE STARS, AND THE DISCOVERY OF STELLAR PLANETS

We will now leave the solar system for a time, and hastily sketch the
history of stellar astronomy from the time of Sir William Herschel.

You remember how greatly Herschel had changed the aspect of the heavens
for man,--how he had found that none of the stars were really fixed, but
were moving in all manner of ways: some of this motion only apparent,
much of it real. Nevertheless, so enormously distant are they, that if
we could be transported back to the days of the old Chaldaean
astronomers, or to the days of Noah, we should still see the heavens
with precisely the same aspect as they wear now. Only by refined
apparatus could any change be discoverable in all those centuries. For
all practical purposes, therefore, the stars may still be well called
fixed.

Another thing one may notice, as showing their enormous distances, is
that from every planet of the solar system the aspect of the heavens
will be precisely the same. Inhabitants of Mars, or Jupiter, or Saturn,
or Uranus, will see exactly the same constellations as we do. The whole
dimensions of the solar system shrink up into a speck when so
contemplated. And from the stars none of the planetary orbs of our
system are visible at all; nothing but the sun is visible, and that
merely as a twinkling star, brighter than some, but fainter than many
others.

The sun and the stars are one. Try to realize this distinctly, and keep
it in mind. I find it often difficult to drive this idea home. After
some talk on the subject a friendly auditor will report, "the lecturer
then described the stars, including that greatest and most magnificent
of all stars, the sun." It would be difficult more completely to
misapprehend the entire statement. When I say the sun is one of the
stars, I mean one among the others; we are a long way from them, they
are a long way from each other. They need be no more closely packed
among each other than we are closely packed among them; except that some
of them are double or multiple, and we are not double.

It is highly desirable to acquire an intimate knowledge of the
constellations and a nodding acquaintance with their principal
stars. A description of their peculiarities is dull and
uninteresting unless they are at least familiar b