W. R. Dawes on the Telescopic Appearances of Saturn. 189 
_ junctions with the planet. When exterior to a tangent to the ex- 
_tremity of the ring, this satellite has frequently been perceived 
as soon as my eye was applied to the telescope. Last spring it 
_ Was seen several times in strong twilight ; for instance, on March 
16th, 17th, and 20th, at about 7" G. M. T. In separating power, 
the glass is competent to divide a sixth-magnitnde star composed 
of two equal stars, whose central distance is °/”-6. 
Ihave thought it proper to premise thus much respecting the 
performance of the telescope, that a correct idea may be formed 
as to the degree of dependence to be placed upon the views it 
has afforded me of Saturn ; the special subject of my present 
communication, to which I will now proceed. 
l. The outer Ring A.—The interior edge of this ring is de- 
cidedly its brightest part: its light rapidly fades away towards 
the middle, where there is a very dark, narrow, well-defined line 
concentric with the ring, and about one-fifth of its breadth by 
careful estimation. This line has been always seen when the 
air was in a tolerably good state, and much more readily than last 
year. On the 26th of November, 1854, it was traced more than 
half Way round towards the ball, and was equally well seen at 
both anse, I have recorded on 10th January, 1855, “I am sur- 
prised at the positiveness of the dark line near the middle of this 
Ting. It was well seen with every power from 355 to 1000.” 
This is now the fourth apparition of Saturn in which I have no- 
ticed this dark line, and it does not appear to me to have varied 
10 its position on the ring, or in its breadth and depth of shade. 
- The interior bright Ring, B.—The concentric shaded bands 
on this ring have been on two or three of the most favorable oc- 
fasions very well brought out. On this appearance I find the 
following notes in my journal :— : 
“1854, Nov. 26. “The ring B is decidedly in stripes, and they 
are not regulurly darker from the exterior one inwards. About 
Very bright ; then a narrow stripe is lightly shaded ; immed 
i ae stiis ns ia. 8 
and then a much darker one extending nearly to the interior edge, 
Where there is a very narrow bright line, far less decided than it 
Was in 1851 and 1852,” i oa 
"Dec. 7, By brief views the step-like character of the shad- 
“ 1855, ious 10. The bands of shading towards the interior 
ra of this ring are occasionally well brought out ; and I think 
Me : 
least in some parts of it, for 1 doubt if itbe quite uniform. The 
interior edge is visible, but is not, I think, 
*° bright as it was in the two previous apparitions.” 
one-fifth of the breadth of the ring, from its exterior etn 
( = exterior fifth; next to that is a considerably darker stripe, 
