running through the center of the chart.

I know that Jupiter is to be looked for about 30 m.

east, or to the left, of that line.

At the bottom and top of the chart, every twenty minutes of R.A.
is indicated, so that it is easy, with the eye, or with the aid of a ruler, to place the vertical line at some point of which Jupiter is to be found.
[Illustration: CHART NO.

5 .-- FROM RIGHT ASCENSION 16 HOURS TO 20 HOURS; DECLINATION 10 deg.