Thanks to our wonderful modern instruments and the ingenious methods
used by astronomers, we have to-day a remarkable knowledge of the sun.
Look at the figure of the sun in the frontispiece. The picture
represents an eclipse of the sun; the dark body of the moon has screened
the sun's shining disc and taken the glare out of our eyes; we see a
silvery halo surrounding the great orb on every side. It is the sun's
atmosphere, or "crown" (corona), stretching for millions of miles into
space in the form of a soft silvery-looking light; probably much of its
light is sunlight reflected from particles of dust, although the
spectroscope shows an element in the corona that has not so far been
detected anywhere else in the universe and which in consequence has been
named Coronium.
We next notice in the illustration that at the base of the halo there
are red flames peeping out from the edges of the hidden disc. When one
remembers that the sun is 866,000 miles in diameter, one hardly needs to
be told that these flames are really gigantic. We shall see what they
are presently.