he sun? Before we
answer this we must try to get some idea of the size of this stupendous
body. It is not the least use attempting to understand it by plain
figures, for the figures would be too great to make any impression on
us--they would be practically meaningless; we must turn to some other
method. Suppose, for instance, that the sun were a hollow ball; then, if
the earth were set at the centre, the moon could revolve round her at
the same distance she is now, and there would be as great a distance
between the moon and the shell of the sun as there is between the moon
and the earth. This gives us a little idea of the size of the sun.
Again, if we go back to that solar system in which we represented the
planets by various objects from a pea to a football, and set a lamp in
the centre to do duty for the sun, what size do you suppose that lamp
would have to be really to represent the sun in proportion to the
planets? Well, if our greengage plum which did duty for the earth were
about three-quarters of an inch in diameter we should want a lamp with a
flame as tall as the tallest man you know, and even then it would not
give a correct idea unless you imagined that man extending his arms
widely, and you drew round him a circle and filled in all the circle
with flame! If this glorious flame burnt clear and fair and bright,
radiating beams of light all around, the little greengage plum would not
have to be too near, or it would be shrivelled up as in the blast of a
furnace. To place it at anything resembling the distance it is from the
sun in reality you would have to walk away from the flaming light for
about three hundred steps, and set it down there; then, after having
done all this, you would have some little idea of the relative sizes of
the sun and the earth, and of the distance between them.

Of course, all the other planets would have to be at corresponding
distances. On this same scale, Neptune, the furthest out, would be three
miles from our artificial sun! It seems preposterous to think that some
specks so small as to be quite invisible, specks that crawl about on
that plum, have dared to weigh and measure the gigantic sun; but yet
they have done it, and they have even decided what he is made of. The
result of the experiments is that we know the sun to be a ball of
glowing gas at a temperature so high that nothing we have on earth could
even compare with it. Of his radiating beams extending in all directions
few