The Carnegie Institution has recently organized an enterprise for
carrying on the study of the sun under a combination of better
conditions than were ever before enjoyed. The first requirement in
such a case is the ablest and most enthusiastic worker in the
field, ready to devote all his energies to its cultivation. This
requirement is found in the person of Professor Hale himself. The
next requirement is an atmosphere of the greatest transparency,
and a situation at a high elevation above sea-level, so that the
passage of light from the sun to the observer shall be obstructed
as little as possible by the mists and vapors near the earth's
surface. This requirement is reached by placing the observatory on
Mount Wilson, near Pasadena, California, where the climate is
found to be the best of any in the United States, and probably not
exceeded by that of any other attainable point in the world. The
third requirement is the best of instruments, specially devised to
meet the requirements. In this respect we may be sure that nothing
attainable by human ingenuity will be found wanting.

Thus provided, Professor Hale has entered upon the task of
studying the sun, and recording from day to day all the changes
going on in it, using specially devised instruments for each
purpose in view. Photography is made use of through almost the
entire investigation. A full description of the work would require
an enumeration of technical details, into which we need not enter
at present. Let it, therefore, suffice to say in a general way
that the study of the sun is being carried on on a scale, and with
an energy worthy of the most important subject that presents
itself to the astronomer. Closely associated with this work is
that of Professor Langley and Dr. Abbot, at the Astro-Physical