every one should know, because in them may be found some of the
brightest stars, those of the first magnitude. Magnitude means size, and
it is really absurd for us to say a star is of the first magnitude
simply because it appears to us to be large, for, as I have explained
already, a small star comparatively near to us might appear larger than
a greater one further away. But the word 'magnitude' was used when men
really thought stars were large or small according to their appearance,
and so it is used to this day. They called the biggest and brightest
first magnitude stars. Of these there are not many, only some twenty, in
all the sky. The next brightest--about the brightness of the Pole Star
and the stars in the Great Bear--are of the second magnitude, and so
on, each magnitude containing stars less and less bright. When we come
to stars of the sixth magnitude we have reached the limit of our sight,
for seventh magnitude stars can only be seen with a telescope. Now that
we understand what is meant by the magnitude, we can go back to the
constellations and try to find some more.

If you draw an imaginary line across the two stars forming the backbone
of the Bear, starting from the end nearest the tail, and continue it
onward for a good distance, you will come to a very bright star called
Capella, which you will know, because near it are three little ones in a
triangle. Now, Capella means a goat, so the small ones are called the
kids. In winter Capella gets high up into the sky, and then there is to
be seen below her a little cluster called the Pleiades. There is nothing
else like this in the whole sky. It is formed of six stars, as it
appears to persons of ordinary sight, and these stars are of the sixth
magnitude, the lowest that can be seen by the naked eye. But though
small, they are set so close together, and appear so brilliant,
twinkling like diamonds, that they are one of the most noticeable
objects in the heavens. A legend tells that there were once seven stars
in the Pleiades clearly visible, and that one has now disappeared. This
is sometimes spoken of as 'the lost Pleiad,' but there does not seem to
be any foundation for the story. In old days people attached particular
holiness or luck to the number seven, and possibly, when they found that
there were only six stars in this wonderful group, they invented the
story about the seventh.

As the Pleiades rise, a beautiful reddish star of the first magnitude
ri