that skilled observers see with an instrument of the same power are
only laying up for themselves stores of disappointment. Mr. Mee's
frank confession may be commended to the notice of those who hope to
see at the first glance all that old students have learned to see
by years of hard work. 'The first time I saw Saturn through a large
telescope, a fine 12-inch reflector, I confess I could not see
the division (Cassini's), though the view of the planet was one of
exquisite beauty and long to be remembered, and notwithstanding the
fact that the much fainter division of Encke was at the moment visible
to the owner of the instrument!' It is extremely unlikely that the
beginner will see the division with anything much less than 3 inches,
and even with that aperture he will not see it until the rings are
well opened. The writer's experience is that it is not by any means so
readily seen as is sometimes supposed. Three inches will show it under
good conditions; with 3-7/8 it can be steadily held, even when the
rings are only moderately open (steady holding is a very different
thing from 'glimpsing'), but even with larger apertures the division
becomes by no means a simple object as the rings close up (Fig. 26).
In fact, there is nothing better fitted to fill the modern observer's
mind with a most wholesome respect for the memory of a man like
Cassini, than the thought that with his most imperfect appliances this
great observer detected the division, a much more difficult feat than
the mere seeing it when its existence and position are already known,
and discovered also four of the Saturnian satellites. As for the minor
divisions in the ring, if they are divisions, they are out of the
question altogether for small apertures, and are often invisible even
to skilled observers using the finest telescopes. Barnard's drawing
(Plate XXIV.), as already noted, shows no trace of Encke's division;
but nine months later the same observer saw it faintly in both ansæ of
the ring. The conclusion from this and many similar observations seems
to be that the marking is variable, as may very well be, from the
constitution of the ring. The Crape Ring is beyond any instrument
of less than four inches, and even with such an aperture requires
favourable circumstances.
[Illustration: FIG. 26.
SATURN, 3-7/8-inch.]
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