nd it at various distances, deriving their light and
heat from the sun--the planets and their moons, certain comets and a
multitude of meteors: in other words, all bodies whose movements in
space are determined by the gravitational pull of the sun.

The Sun

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.

Regions of the Sun

The astronomer has divided the sun into definite concentric regions or
layers. These layers envelop the nucleus or central body of the sun
somewhat as the atmosphere envelops our earth. It is through these
vapour layers that the bright white body of the sun is seen. Of the
innermost region, the heart or nucleus of the sun, we know almost
nothing. The central body or nucleus is surrounded by a brilliantly
luminous envelope or layer of vaporous matter which is what we see when
we look at the sun and which the astronomer calls the photosphere.

Above--that is, overlying--the photosphere there is a second layer of
glowing gases, which is known as the reversing layer. This layer is
cooler than the underlying photosphere; it forms a veil of smoke-like
haze and is of from 500 to 1,000 miles in thickness.

A third layer or envelope immediately lying over the last one is the
region known as the chromosphere. The chromosphere extends from 5,000
to 10,000 miles in thickness--a "sea" of red tumultuous surging fire.
Chief among the glowing gases is the vapour of hydrogen. The intense