y photographic
record of the solar prominences, and only lately he has secured results
that justified a special expedition to the Alps to photograph the sun's
corona, and he has now moved the Admiralty to grant a subsidy to Dr. Gill,
the government astronomer at the Cape, by aid of which Mr. Woods can carry
on the experiments that were so encouraging last summer in Switzerland.

We may, then, reasonably hope to obtain before long a daily picture of the
sun and a photographic record of its prominences, and even of a certain
portion of the solar corona; but the precious moments of each solar
eclipse will always be invaluable for picturing those wondrous details in
the corona that are now shown us by photography, and which can be obtained
by photography alone.

Again, how very much is to be learnt in solar physics from the marvelous
photographs of the sun's spectrum exhibited last summer by Professor
Rowland; photographs that show as many as one hundred and fifty lines
between H and K, and which he is still laboring to improve! The extension,
too, of the visible solar spectrum into the ultra-violet by Corun,
Mascart, and others, adds much to our knowledge of the sun; while the
photographs of Abney in the ultrared increase our information in a
direction less expected and certainly less easy of attainment. Both these
extensions we find most ably utilized in the recent discussion of the very
interesting photographs of the spectra of the prominences and of the
corona taken during the total eclipse of May 18, 1882; and the
photographic results of this eclipse afford ample proof that we can not
only obtain pictures of the corona by photography that it would be
impossible otherwise to procure, but also that in a few seconds
information concerning the nature of the solar atmosphere may be furnished
by photography that it would otherwise take centuries to accumulate, even
under the most favorable circumstances.

The advantages to be gained by accurate photographs of the moon and
planets, that will permit great enlargements, are too obvious to call for
lengthened notice in such a rapid sketch as the present; for it is
principally in the observation of details that the eye cannot grasp with
the required delicacy, or with sufficient rapidity, that photography is so
essential for rapid and sure progress.

Like the sketches of a solar eclipse, the drawings that are made of
comets, and still more of nebulae, even by the most accomplis