Triangulorum), a fine object with a very low power. To the right is
[alpha] Triangulorum, certainly less brilliant than [beta]. Below
[alpha] are the three stars [alpha], [beta], and [gamma] Arietis, the
first an unequal and difficult double, the companion being purple, and
only just visible (under favourable circumstances) with a good 3-inch
telescope; the last an easy double, interesting as being the first ever
discovered (by Hook, in 1664), the colours of components white and grey.

Immediately below [alpha] Arietis is the star [alpha] Ceti, towards the
right of which (a little lower) is Mira, a wonderful variable. This star
has a period of 331-1/3 days; during a fortnight it appears as a star of
the 2nd magnitude,--on each side of this fortnight there is a period of
three months during one of which the star is increasing, while during
the other it is diminishing in brightness: during the remaining five
months of the period the star is invisible to the naked eye. There are
many peculiarities and changes in the variation of this star, into which
space will not permit me to enter.

Immediately above Mira is the star [alpha] Piscium at the knot of the
Fishes' connecting band. This is a fine double, the distance between the
components being about 3-1/2", their magnitudes 5 and 6, their colours
pale green and blue (see Plate 5).

Close to [gamma] Aquarii (see Frontispiece, Map 4), above and to the
left of it, is the interesting double [zeta] Aquarii; the distance
between the components is about 3-1/2", their magnitudes 4 and 4-1/2,
both whitish yellow. The period of this binary seems to be about 750
years.

Turning next towards the south-west we see the second-magnitude star