the Tores of Saturn. 473 
Earth traverses the greatest ansal breadth of the rings at their 
densest. 
Instead, however, of being so found, the present thickenings 
occur in striking contrast to this, the maxima showing where 
the minima should and the minima where the maxima 
would be ; since their centres are situate at 1*27 and 1*83 
with a conspicuous gap at 1*60 and another falling-otf at 
1*92 outward. It is not, then, to line of sight massing from 
particles in one plane that the observed effect is due. 
But the moment we let our thought wander out of the 
plane we light upon an explanation which satisfies the 
phenomena. For suppose portions of the rings to be not 
flat rings but tores, that is, rings after the manner of anchor- 
rings, encircling the planet. Then, viewed edgewise, such a 
tore would make its presence perceptible by humps of light 
in two patches symmetrically placed on either side the planet; 
to wit, at its ansae where the sight-line would penetrate the 
greatest amount of it. The agglomerations, then, can re- 
present tores, but cannot represent flat rings *. 
Thus we are led by the phenomena presented by the rings 
to the same explanation to which those of the shadow con- 
ducted us. Furthermore, it is to be remarked that the line 
* Note. — It seems necessary to suppose that we see through the ring 
to its partially illuminated side ; for from observations made or published 
since this article was written, it appears that the agglomerations disappear 
when either the Sun or the Earth passes through the plane of the rings. 
Thus Mr. Lampland's observations of the rings gave : — 
Dec. 31. Agglomerations visible. 
Jan. ] . Ansae too faint to detect structure. 
„ 3 & 4. Ansae continuous. 
„ 7. No agglomerations. Rings easily seen.. 
Earlier observations by Aitken at the Lick, July 23 — Oct. 12, show that 
no agglomerations were seen between those dates. See Barnard to the 
same effect. 
Since this was written Barnard has published his observations with 
his explanations. His explanations, however, — for he gives two — one 
that the eye sees through the underside of the rings and that such light 
is greatest where the rings are densest, the other the exact opposite, that 
the light is most where the ring is least crowded, — are self-condemning on 
several counts ; one, for instance, that the inner condensation does not 
fall by his own showing on the ansal position of any part of ring A but 
wholly on the crape ring. Each explanation might possibly account for 
one agglomeration alone, but for that very reason fails for both together. 
The presence of the gaps is another fatal objection to them. 
As seen at Flagstaff, under the same seeing that disclosed the dark 
core to the rings' dusky shadow, the agglomerations were fairly con- 
tinuous, though uneven, for the whole length of them measured on 
November 9th. Their vertical width was about 0"'20, while that of the 
continuous ring was about 0"-02, giving for the width of the main plane 
of the rings some 80 miles or 130 kilometres. — P. L. 
