observe every part of the heavens visible in our northern hemisphere.
But with the planets the case is not quite so simple. They come into
view at no fixed season of the year: some of them can never be seen _by
night_ on the meridian; and they all shift their place among the stars,
so that we require some method of determining where to look for them on
any particular night, and of recognising them from neighbouring fixed
stars.

The regular observer will of course make use of the 'Nautical Almanac';
but 'Dietrichsen and Hannay's Almanac' will serve every purpose of the
amateur telescopist. I will briefly describe those parts of the almanac
which are useful to the observer.

It will be found that three pages are assigned to each month, each page
giving different information. If we call these pages I. II. III., then
in order that page I. for each month may fall to the left of the open
double page, and also that I. and II. may be open together, the pages
are arranged in the following order: I. II. III.; III. I. II.; I. II.
III.; and so on.

Now page III. for any month does not concern the amateur observer. It
gives information concerning the moon's motions, which is valuable to
the sailor, and interesting to the student of astronomy, but not
applicable to amateur observation.

[Illustration: PLATE VI.]

We have then only pages I. and II. to consider:--

Across the top of both pages the right ascension and declination of the