_Divisions in the Outer Ring._—In the middle of the eighteenth century
Short, the optician, using one of his excellent reflectors, thought he
saw the outer ring divided by several dark lines; but no other observer
confirmed his suspicion. In the third decade of the present century
Quetelet and Capt. Kater appear to have observed Short’s divisions, but
Sir J. Herschel and Struve looked for them in vain. In 1837 Encke fully
satisfied himself, by several observations and measurements, as to the
objective existence of the divided outer ring. The division was not
central, cutting the ring into equal parts, but situated in the inner
part of the ring, so that the wider part was outermost. In subsequent
years this division has been sometimes seen and placed nearest the
outer edge of the ring. Certain observers, provided with ample means,
have seen nothing of it; others regard the division as variable. It is
sometimes described as a narrow black line; while others refer to it
as a faint pencil~like shading, and not a real division at all. One
observer occasionally sees it with considerable distinctness at the
very same time that another observer, with a more powerful telescope,
cannot glimpse it though looking specially for such an appearance! It
is difficult to reconcile such discordant experiences, and unsafe to
accept results of such a contradictory nature.
_The “Crape”-Ring._—A far more certain feature was discovered in the
autumn of 1850[38], and one in reference to which there is unanimity of
testimony. On Nov. 11 G. P. Bond, in America, and Dawes, in England, on
Nov. 25, saw a nebulosity or faint luminous appearance like twilight,
fringing the interior margin of the inner ring. Later observations
showed this to be occasioned by a transparent ring situated immediately
within the inner luminous ring. Dawes considered the new ring to
be divided into two parts; but Lassell, with his large reflector,
subsequently negatived this supposition. Both limbs of Saturn may be
readily perceived through the transparent ring where it crosses the
globe of the planet. Some irregularities have been suspected in it at
different times by various observers. In 1887 dark condensations were
reported to disturb its normal aspect; but these were not seen at many
observatories where such features, if real, could hardly have escaped
detection.
[Illustration: Fig. 40.
Saturn, as observed by F. Terby, February 1887.]
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