stars in the constellation Ursa Major, the ``Greater Bear.'' The
handle of the ``Dipper'' corresponds to the tail of the imaginary
``Bear,'' and the bowl lies upon his flank. In fact, the figure of a
dipper is so evident and that of a bear so unevident, that to most
persons the ``Great Dipper'' is the only part of the constellation
that is recognizable. Of the seven stars mentioned, six are of nearly
equal brightness, ranking as of the second magnitude, while the
seventh is of only the third magnitude. The difference is very
striking, since every increase of one magnitude involves an increase
of two-and-a-half times in brightness. There appears to be little
doubt that the faint star, which is situated at the junction of the
bowl and the handle, is a variable of long period, since three hundred
years ago it was as bright as its companions. But however that may be,
its relative faintness at the present time interferes but little with
the perfection of the ``Dipper's'' figure. In order the more readily
to understand the changes which are taking place, it will be well to
mention both the names and the Greek letters which are attached to the
seven stars. Beginning at the star in the upper outer edge of the rim
of the bowl and running in regular order round the bottom and then out
to the end of the handle, the names and letters are as follows: Dubhe
({\alpha}), Merak ({\beta}), Phaed ({\gamma}), Megrez ({\delta}),
Alioth ({\epsilon}), Mizar ({\zeta}), and Benetnasch ({\eta}). Megrez
is the faint star already mentioned at the junction of the bowl and
handle, and Mizar, in the middle of the handle, has a close, naked-eye
companion which is named Alcor. The Arabs called this singular pair of
stars ``The Horse and Rider.'' Merak and Duhbe are called ``The
Pointers,'' because an imaginary line drawn northward through them
indicates the Pole Star.

Now it has been found that five of these stars -- viz., Merak, Phaed,