he would like to know
whether our sun had any motion in space?"

"Yes," I replied; "as the result of a long series of observations and
calculations it has been determined that the sun is moving through space
and carrying with it all the planets in our system. Its rate of movement
is not known with certainty, but it is estimated at about 1,000,000
miles a day. Whether it is moving in a straight line or in a vast orbit
around some far distant sun is also an open question, and it may take
centuries to arrive at a definite result. This motion of our sun, rapid
though it is, is very slow compared with the motion of some of the
stars. One that appears only a small star to us, but which is probably
a sun enormously larger than ours, is moving through space at a rate
which cannot be less than 200 miles a second; and unless that movement
is direct across our line of sight its rate must be still more rapid.
Yet it is so enormously distant that, in 500 years, it would only appear
to have moved over a space of one degree on the sky! It is calculated
that Arcturus moves still more rapidly.

"The movements of several other stars have been calculated; but the
distance of the stars is so enormously great that the majority appear to
have no movement at all, though probably not one of the heavenly bodies
is at rest.

"It is estimated that the light of the nearest star we know of takes at
least four years to reach the earth, yet light travels at the rate of
186,000 miles a second. We know of others whose light takes centuries to
reach us, and, with regard to most of the stars, the light we see
probably left them thousands of years ago.

"It is only when a star is so near to us that the earth's revolution in
its orbit is sufficient to cause a change in the apparent position of
the star which can be measured with our instruments that any calculation
can be made to determine its distance from us. In nearly all cases where
the distance has been calculated, the change in position is so minute
and difficult to measure accurately, that the results obtained can only
be regarded as very rough approximations to the real distances.

"The universe is infinite in extent, and the human mind is quite unable
to conceive what is really implied in the distances of the planets
belonging to our own solar system; yet they are as nothing when
compared with the distances of the fixed stars, either from the earth or
from each other. We equally fail to reali