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October 8. 9h om. The ring could only be seen by occultation of the planet. It was very faint and narrow. The south belt across the planet was far more conspicuous than the north one, which was rather difficult.

Position of the shadow on the ball. 9h 10m :—

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Very uncertain-the planet very faint in haze.

11h om. I could not see anything of the ring with Saturn uncovered in the field, but with occulter I could see it at both sides of the planet very easily, though it was faint. It was straight and very narrow, with no irregularities. A faint satellite at the following side interfered. The ring was easier than at the previous observatious since its disappearance. The south belt was very diffused to the south, while the north belt was diffused to the north. The equatorial space between these two belts was the brightest region of the planet.

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11h 25m Thickness of shadow on ball was o"69(2). Distance of south belt from shadow 2" 20(2). A satellite following half way to end of ring was very much brighter than the ring. October 13. 8h 25m. The ring could be seen with Saturn uncovered in the field. It was thin and rather faint. A satellite following and another preceding.

Micrometer positions on the ball :

:

South belt from south limb 677(2)

South belt from north limb 10*94(2)

Shadow from south limb 8.81(2)
North belt from south limb 10'64(2)

Shadow from north limb 8.25(2)

North belt from north limb 7.30(2)

There was a faint broad shading parallel to the equator in the northern hemisphere. The southern edge of this was 13"9(2) from the S. limb, aud 3"-8(2) from the N. limb. The seeing was very bad. This last marking was a very faint and diffused belt. Though the ring was faint, it could be distinctly seen with 460 diameters, with Saturn uncovered in the field, while with the occulter it was seen quite easily on both sides.

IIh om. The ring was easily visible without occultation of the planet. it was very thin, but by occultation it was quite conspicuous. There were two regions of greater brightness on both the preceding and following ansa [the condensations]. The seeing was good.

Thickness of the shadow o" 28(2). The equatorial region was brighter than any other part of the planet. The north belt was fainter than the south one.

October 28. 6h 30m. The ring was distinctly visible. The two luminous spots were quite conspicuous on each ansa. November 3. 6h 30m. The ring and condensations were easily seen. The outer condensations were the brighter. These were so distinct that they looked almost as definite as an ill

defined satellite would be if projected on the ring. Measures were made at 7h 10m.

From the following limb:

The distant one.

7" 88(7) [7" 34]

From the preceding limb:

The distant one.

8"*14(5) [7"*59]

The near one.

3" 04(6) [2"-84]

The near one.

2" 68(5) [2"'50]

Distance between the centres of the two following condensations:

4"*40(4) [4′′*10]

Thickness of the trace of ring on the ball :

o" '71(4) [0"'66]

The position of the centre of the trace was measured, but the seeing was so poor that the result was uncertain.

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7h 50m. The inner condensation was a little the brighter in each case. It looked as if it might be double, but the seeing was not good enough to decide. Between the two condensations the ring was almost discontinuous. From the inner condensation to the ball the ring was easily seen to join up to the ball, and was but little less bright than the adjacent condensation. The outer ones seemed to be more brightly condensed, or like very small blurred stars. The inner condensations were about as bright as the faint satellite (Tethys) preceding, and somewhat brighter than the distant ones (condensations).

Assuming that these luminous places were symmetrical with respect to the ball, and taking the means of the measures, we find the distance of the nearest condensatious from the limb was

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November 5. Very bad sky--thick, with misty clouds.

Ioh 17m. In moments of steadiness and clearness the distant condensation in the preceding ansa looked like a small, ill-defined satellite. There was a faint satellite (Enceladus) close to it, and it was not possible from their appearance to tell which was the satellite. They were the same size, same form, and same brightness-small hazy spots. The nearer condensation was the brighter, and at times it seemed to be double. The space between it and the ball was nearly as bright as the condensation. The ring between the distant and near condensations was faint and almost discontinuous. The full extent of the ring was seen with difficulty because of the poor sky.

At 10h 22m the following measures were made between the preceding limb and the condensations:

Distant condensation.

8" 17(3) [7" 63]

:

Near condensation.

2" 82(2) [263]

At 10h 31m the distant condensation and the faint satellite appeared as one. On the following side the nearer condensation was decidedly brighter than the distant one, say by half a magnitude The inner condensation was certainly double. Perhaps a faint satellite was close to it. The trace of the ring on the ball did not appear black, but the seeing was too poor to be sure.

or more.

November 12. 5h 45m. The condensations were readily visible. There were two considerable satellites of equal brightness, one near the preceding and the other near the following end of the ring.

5h 50. The condensations were bright and nearly equal. The inner ones were bright up to the ball. The space between them was almost discontinuous.

6h 30m. Seeing very poor. At this time there was a faint satellite (Mimas) between the bright satellite on the following side and the end of the ring. The outer condensations seemed to be perhaps a little brighter than the inner ones, and possibly a little larger. They were all very conspicuous. The outer one, following, was at least two times as bright as Mimas. The small satellite itself (Mimas) was about the same brightness as the ring between the two condensations. There was a faint satellite (Enceladus) close to the preceding end of the ring, which was nearly as bright as the outer condensation on that side. It was a little north, following the condensation. Occasionally the full extent of the ring was seen up to near Mimas.

ho. The faint satellite (Enceladus) preceding and the outer condensations were together at this time, and made quite a large spot. Distance between the two condensations on the

following ansa:—

=5"04(4) [476]

Roughly, the length of the outer condensation was

2" 10(4) [198]

It was perhaps 2 times as long as broad, and diffused rather abruptly on each side. I should say that the outer condensation wasas bright as the bright satellite following.

7h 20m. The faint satellite (Mimas) following was going back at this time, and was making a double bright spot with the outer condensation. The faint satellite (Enceladus) preceding was then between the two preceding condensations and very slightly north of the line between them. Could not make out anything on the ball except the trace which was seen only once in a while, though it was conspicuous enough when seen. The inner condensation seemed to go up to the ball without much if any loss of light.

The seeing did not permit any accurate measures from the limbs, but the following results were obtained.

Distance of preceding condensation from preceding limb

7" 66(6) [7"*23]

The limb was only a blur, from bad seeing. With the planet unobscured in the field, the condensations were quite conspicuous.

7h 40m. At this time the faint satellite (Mimas) was between the two condensations following, but nearer the distant one. Distance from following limb to outer condensation—

7" 72(8) [729]

At the time of these measures the faint satellite (Mimas) following was close preceding the outer condensation.

The outer and the inner condensations seemed to be of the same brightness. It looked as if the preceding condensation on the preceding ansa was not quite as bright as the one on the following ansa, but the presence of the faint satellite (Mimas) near the following one may have been the cause of this. A half moon, with bad seeing, made the sky very bright.

The Condensations.

The following table contains the measures of the distances of these condensations from the preceding and following limbs of Saturn. They are reduced to the mean distance (9.5389) of Saturn from the Sun, and are therefore comparable.

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It is evident that the condensations are symmetrical with respect to the centre of Saturn. The individual differences are not large when we take account of the indefinite character of the phenomenon.

I have at various times compared the brightness of these condensations with that of Mimas, Enceladus, and Tethys. The following approximate values of the magnitudes of these satellites reduced to the mean distance of Saturn have been supplied me

by Mr. Parkhurst from his unreduced measures of the magnitudes of the satellites of Saturn :—

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Taking the positions of the condensations from the measures, and comparing them with the dimensions of the ring system (from my own measures in M.N., lvi. p. 171), it is seen at once (Plate 10, fig. 2) that the outer condensations are located on the outer part of the inner bright ring, in a region that is the brightest of the entire Saturnian system. The inner ones apparently fall on the crape ring. These condensations, therefore, would seem to be on the brightest and the faintest parts of the system. As this light is unquestionably transmitted through the material of the rings, it is evident that the above facts are opposed to each other if we assume that the condensations are caused by the crape ring and the outer part of the inner bright ring, or the thinnest and densest portions of the ring system. It is improbable that the two similar phenomena are produced by exactly opposite conditions. In the crape ring there are so few particles that the sunlight would readily pass through with little or no scattering effect or augmentation by additional reflection. It is known that a narrow portion of the inner bright ring is very much brighter than any other part of the rings or ball. The explanation of this is doubtless due to a denser collection in this zone of the small bodies that form the rings-just as the scarcity of them produces the duskiness of the crape ring for the want of material to reflect light. It is probable, therefore, if they are not too densely crowded to let the sunlight shine through among them, that when seen from the under side they will appear brighter than the other portions of the ring by repeatedly reflecting aud scattering the transmitted light. Looking at the diagram, it would seem that the outer condensations are due to the inner bright ring alone. It would appear most probable that the outer bright part of the inner bright ring is responsible for both condensations. On this supposition, the inner condensations are due to the two brighter portions of the inner bright ring seen in perspective. Just why there should be a loss of illumination between the condensations is not quite clear at present, unless it is that the greater depth of the rings in perspective in some way militates against either the transmission or reflection-or bothof the solar rays in that direction.

In the description, I have used the word 'condensation' for these luminous appearances, although I believe it to be misleading. Though these bright places look decidedly broader than the thin trace of the ring on the sky, and appear to be condensations on the ring, I think it is simply a matter of contrast or irradiation, and that they are not any broader in reality than the trace of the ring where they occur. I have come to this conclusion from the drawings that I have made, and which are communicated with this

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