From Sagittarius the ecliptic runs in a northeasterly direction through
a region in which there are no very bright stars, nor any very distinct
outlines of figures. The two constellations through which it passes are
Capricornus and Aquarius. It then runs a few degrees into Pisces, and
there reaches the vernal equinox, where we began to trace its course.
Although one cannot trace the line of the ecliptic with the same
definiteness in this region as in one where there are bright stars
to mark the way, yet when a planet is in this part of its path it
is perhaps more conspicuous and more easily recognized than when it
appears in any other part of the sky, because of the very absence of
other bright bodies. These constellations comprise all that region
running from the Milky Way east to the vernal equinox. It is a part
of the heavens easily seen during the pleasant evenings of summer and
autumn, and if a planet is crossing it during those seasons it is
particularly well placed for observation.
The two brightest stars in Capricornus are of the third magnitude, and
lie about twenty degrees northeast of the “milk dipper.” The ecliptic
runs just under them. Through Aquarius it runs six or seven degrees
above a waving line of faint stars, which are supposed to represent the
water that Aquarius is pouring from his urn.
If one will take the trouble to trace the line of the ecliptic through
the sky, and remember that it lies exactly in the center of the zodiac,
and that the planets are, therefore, within a very few degrees of it,
one will have no trouble in keeping track of them. The mere knowing of
these constellations is in most cases sufficient, since the planets
will disclose their identity in other ways than by position merely.
The _signs_ of the zodiac are somewhat different from the
constellations. They are simply twelve equal divisions of thirty
degrees each, making in all three hundred and sixty degrees, which
is the whole number of degrees in any circle. They are so divided for
convenience in scientific observation and reckoning. About two thousand
years ago the signs and the constellations in the main coincided, and
they still bear the same names. The point of the vernal equinox was
then at the beginning of the sign and the constellation Aries. But,
owing to certain motions of the earth, this point shifts backward,
or toward the west, about one degree every seventy-two years. In two
thousand years it has shifted about twenty-eight degrees, until now
the sign Aries, with the vernal equinox at its western boundary, lies
almost wholly in the constellation Pisces, the sign Taurus corresponds
approximately to the constellation Aries, and so on around the circle.
It is important to know this in following the planets, because all
almanacs and scientific publications deal mainly with the _signs_ of
the zodiac, and not with the _constellations_. When a planet’s place
is said to be in Aries, Taurus, or Gemini, one will find it in Pisces,
Aries, or Taurus, respectively. And so it is with all the other signs;
they are each one constellation behind the one bearing the same name.
And this is why, beginning with the vernal equinox, Pisces is the first
constellation in the zodiac, while Aries is the first sign.
The following is a list of the signs of the zodiac, with the
corresponding constellations. The symbols given in parenthesis are the
ones used for these signs in all almanacs: