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
[epsilon] Pegasi, some 40 deg. above the horizon. This star is a wide but
not easy double, the secondary being only of the ninth magnitude; its
colour is lilac, that of the primary being yellow.

Towards the right of [epsilon] Pegasi and lower down are seen the three
fourth-magnitude stars which mark the constellation Equuleus. Of these
the lowest is [alpha], to the right of which lies [epsilon] Equulei, a
fifth-magnitude star, really triple, but seen as a double star with
ordinary telescopes (Plate 5). The distance between the components is
nearly 11", their colours white and blue, their magnitudes 5-1/2 and
7-1/2. The primary is a very close double, which appears, however, to be
opening out rather rapidly.

Immediately below Equuleus are the stars [alpha]^{1} and [alpha]^2
Capricorni, seen as a naked-eye double to the right of and above [beta].
Both [alpha]^1 and [alpha]^2 are yellow; [alpha]^2 is of the 3rd,
[alpha]^1 of the 4th magnitude; in a good telescope five stars are seen,
the other three being blue, ash-coloured, and lilac. The star [beta]
Capricorni is also a wide double, the components yellow and blue, with
many telescopic companions.

To the right of Equuleus, towards the west-south-west is the
constellation Delphinus. The upper left-hand star of the rhombus of
stars forming the head of the Delphinus is the star [gamma] Delphini, a
rather easy double (see Plate 5), the components being nearly 12" apart,
their magnitudes 4 and 7, their colours golden yellow and flushed grey.

Turn we next to the charming double Albireo, on the beak of Cygnus,
about 36 deg. above the horizon towards the west. The components are 34-1/2"
apart, their magnitudes 3 and 6, their colours orange-yellow, and blue.
It has been supposed (perhaps on insufficient evidence) that this star
is merely an optical double. It must always be remembered that a certain
proportion of stars (amongst those separated by so considerable a
distance) _must_ be optically combined only.

The star [chi] Cygni is a wide double (variable) star. The components
are separated by nearly 26", their magnitudes 5 and 9, their colours
yellow and light blue