ribed as a "vast gorge,"
because, under very oblique light, it is filled with black shadow; or an
insignificant hillock is magnified into a mountain when similarly viewed.
Hence the importance, just insisted on, of studying lunar features under
as many conditions as possible before finally attempting to describe
them.

However indifferent a draughtsman an observer may be, if he endeavours to
portray what he sees to the best of his ability, he will ultimately
attain sufficient skill to make his work useful for future reference: in
any case, it will be of more value than a mere verbal description without
a sketch. Doubt and uncertainty invariably attend to a greater or less
extent written notes unaccompanied by drawings, as some recent
controversies, respecting changes in Linne and elsewhere, testify. Now
that photographs are generally available to form the basis of a more
complete sketch, much of the difficulty formerly attending the correct
representation of the outline and grosser features of a formation has
been removed, and the observer can devote his time and attention to the
insertion and description of less obvious objects.

PROGRESS OF SELENOGRAPHY.--Till within recent years, the systematic study
of the lunar surface may be said to have been confined, in this country
at any rate, to a very limited number of observers, and, except in rare
instances, those who possessed astronomical telescopes only directed them
to the moon as a show object to excite the wonder of casual visitors. The
publication of Webb's "Celestial Objects" in 1859, the supposed physical
change in the crater Linne, announced in 1866, and the appearance of an
unrecorded black spot near Hyginus some ten years later, had the effect
of awakening a more lively interest in selenography, and undoubtedly
combined to bring about a change in this respect, which ultimately
resulted in the number of amateurs devoting much of their time to this
branch of observational astronomy being notably increased. Still, large
telescopes, as a rule, held aloof for some unexplained reason, or were
only employed in a desultory and spasmodic fashion, without any very
definite object. When the Council of the British Association for the
Advancement of Science, stimulated by the Linne controversy, deemed the
moon to be worthy of passing attention, observations, directed to objects
suspected of change (the phenomena on the floor of Plato) were left to
three or four observers,