discovered many hundred double stars so difficult that they had
escaped the scrutiny of Maedler and the Struves, and gained for
himself one of the highest positions among the astronomers of the
day engaged in the observation of these objects. It was with this
little instrument that on Mount Hamilton, California--afterward
the site of the great Lick Observatory--he discovered forty-eight
new double stars, which had remained unnoticed by all previous
observers. First among the objects which show beautifully through
moderate instruments stands the moon. People who want to see the
moon at an observatory generally make the mistake of looking when
the moon is full, and asking to see it through the largest
telescope. Nothing can then be made out but a brilliant blaze of
light, mottled with dark spots, and crossed by irregular bright
lines. The best time to view the moon is near or before the first
quarter, or when she is from three to eight days old. The last
quarter is of course equally favorable, so far as seeing is
concerned, only one must be up after midnight to see her in that
position. Seen through a three or four inch telescope, a day or
two before the first quarter, about half an hour after sunset, and
with a magnifying power between fifty and one hundred, the moon is
one of the most beautiful objects in the heavens. Twilight softens
her radiance so that the eye is not dazzled as it will be when the
sky is entirely dark. The general aspect she then presents is that
of a hemisphere of beautiful chased silver carved out in curious
round patterns with a more than human skill. If, however, one
wishes to see the minute details of the lunar surface, in which
many of our astronomers are now so deeply interested, he must use
a higher magnifying power. The general beautiful effect is then
lessened, but more details are seen. Still, it is hardly necessary
to seek for a very large telescope for any investigation of the