ach page, and opposite the number of each successive day
of the month the position of the planet is given in hours, minutes, and
seconds of right ascension, and degrees, minutes, and seconds of north
and south declination, the sign + meaning north, and the sign - south.
Do not trouble yourself with the seconds in either column, and take the
minutes only when the number is large. The hours of right ascension and
the degrees of declination are the main things to be noticed.

Right ascension, by the way, expresses the distance of a celestial body,
such as a star or a planet, east of the vernal equinox, or the first
point of Aries, which is an arbitrary point on the equator of the
heavens, which serves, like the meridian of Greenwich on the earth, as
a starting-place for reckoning longitude. The entire circuit of the
heavens along the equator is divided into twenty-four hours of right
ascension, each hour covering 15 deg. of space. If a planet then is in
right ascension (usually printed for short R.A.) 0 h. 0 m. 0 s., it is on
the meridian of the vernal equinox, or the celestial Greenwich; if it is
in R.A. 1 h., it will be found 15 deg. east of the vernal equinox, and
so on.

[Illustration: CHART NO. 3.--FROM RIGHT ASCENSION 8 HOURS TO 12 HOURS;
DECLINATION 30 deg. NORTH TO 10 deg. SOUTH.]

Declination (printed D. or Dec.) expresses the distance of a celestial
body north or south of the equator of the heavens.

With these explanations we may proceed to find a planet by the aid of
the Nautical Almanac and our charts. I take, for example, the ephemeris
for the year 1901, and I look under the heading "Jupiter" on page 239,
for the month of July. Opposite the 15th day of the month I find the
right ascension to be 18 h. 27 m., neglecting the seconds. Now 27
minutes are so near to half an hour that, for our purposes, we may say
Jupiter is in R.A. 18 h. 30 m. I set this down on a slip of paper, and
then examine the declination column, where I find that on July 15
Jupiter is in south declination (the sign - meaning south, as before
explained) 23 deg. 17 min. 52 sec., which is almost 23 deg. 18 min.,
and, for our purposes, we may call this 23 deg. 20 min., which is what
I set down on my slip.

[Illustration: CHART NO. 4.--FROM RIGHT ASCENSION 12 HOURS TO 16 HOURS;
DECLINATION 10 deg. NORTH TO 30 deg. SOUTH.]

Next, I turn to Chart No. 5, in this chapter, where I find the meridian
line of R.A. 18 h. running through the center o