The Annual Report of the Astronomical Observatory.
Seventeen new variable stars have been discovered by examination of the spectra contained on photographic plates taken with the Draper telescope, and twelve more variables from photographic charts. The distribution of telegraphic announcements of discovery has been continued as in past years. Astronomers are requested to continue to send to their Observatory announcements of this discoveries for transmission to the observatories of Europe and American.
The principal work at the station at Arequipa, Peru, has been the obtaining of charts of clusters and of the brighter stars. The work has remained under the direction of Professor Bailey, and Professor Upton, of Brown University, has also spent a large part of the year there.
The library of the observatory has been increased during the year by the addition of 368 volumes and 1509 pamphlets.
The most interesting results of the year's work have been in the observations made with the meridian photometer, and in the experiments with kites at the Blue Hill Observatory. As a result of observations taken on 152 nights the total number of photometric settings is 100, 052, which is greater than that obtained in any previous year. The observations of all the stars north of 40 degrees, of the magnitude of 7.5 and brighter, are nearly completed. The exploration of the upper air with kites lifting automatic instruments which record atmospheric conditions has been continued. Last September records were brought down from a height of 9,255 feet, which is the greatest altitude ever reached by kites, and later another ascent was made which promised to be still higher but the wires holding the kite broke and the kite and instruments were lost. They have, however, been replaced.
These experiments have been greatly facilitated by a grant from the Hodgkins Fund of the Smithsonian Institute.