dynamo used as a motor. The charging of storage batteries would not be
difficult with such a machine, even from an alternating-current line,
though the losses might be considerable.

* * * * *




PHOTOGRAPHIC STUDY OF STELLAR SPECTRA, HARVARD COLLEGE OBSERVATORY.

HENRY DRAPER MEMORIAL.

_First Annual Report_.


Dr. Henry Draper, in 1872, was the first to photograph the lines of a
stellar spectrum. His investigation, pursued for many years with great
skill and ingenuity, was most unfortunately interrupted in 1882 by his
death.

The recent advances in dry-plate photography have vastly increased our
powers of dealing with this subject. Early in 1886, accordingly, Mrs.
Draper made a liberal provision for carrying on this investigation at
the Harvard College Observatory, as a memorial to her husband. The
results attained are described below, and show that an opportunity is
open for a very important and extensive investigation in this branch of
astronomical physics. Mrs. Draper has accordingly decided greatly to
extend the original plan of work, and to have it conducted on a scale
suited to its importance. The attempt will be made to include all