under the able direction of Mr. Birt, the
largest instruments available being an 8 1/4 inch reflector and the
Crossley refractor of 9 inches aperture! During the last decade, however,
all this has been changed, and we not only have societies, such as the
British Astronomical Association, setting apart a distinct section for
the systematic investigation of lunar detail, but some of the largest and
most perfect instruments in the world, among them the noble refractor on
Mount Hamilton, employed in photographing the moon or in scrutinising her
manifold features by direct observation. Hence, it may be said that
selenography has taken a new and more promising departure, which, among
other results, must lead to a more accurate knowledge of lunar
topography, and settle possibly, ere long, the vexed question of change,
without any residuum of doubt.

Lunar photography as exemplified by the marvellous and beautiful pictures
produced at the Lick Observatory under the auspices of Dr. Holden, and
the exquisite enlargements of them by Dr. Weinek of Prague; at Paris by
the brothers Henry; and at Brussels by M. Prinz; point to the not far
distant time when we shall possess complete photographic maps on a large
scale of the whole visible disc under various phases of illumination,
which will be of inestimable value as topographical charts. When this is
accomplished, the observer will have at his command faithful
representations of any formation, or of any given region he may require,
to utilise for the study of the smaller details by direct observation.

Desultory and objectless drawings and notes have hitherto been more or
less characteristic of the work done, even by those who have given more
than ordinary attention to the moon. Though these, if duly recorded, are
valuable as illustrating the physical structure, the estimated brightness
under various phases, and other peculiarities of lunar features, they do
not materially forward investigations relating to the discovery of
present lunar activity or to the detection of actual change. It is
reiterated _ad nauseam_ in many popular books that the moon is a
changeless world, and it is implied that, having attained a state when no
further manifestations of internal or external forces are possible, it
revolves round the earth in the condition, for the most part, of a
globular mass of vesicular lava or slag, possessing no interest except as
a notable example of a "burnt-out planet." In answe