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Made at the Observatory of EDWARD CROSSLEY, Esq., F.R.A.S., Park Road, Halifax.

Telescope, 9 inches aperture: focal length, 12 ft. 4 in.

During the last apparition of this noble planet, the disc was regularly and carefully scrutinised at this observatory from November 1869 to February 26, 1870, and some fifty drawings were made. Full descriptions of the various interesting and curious features were also entered in the note-books. A feeling, however, that most probably many experienced observers would shortly publish their observations, accompanied by good and wellchosen sketches, induced us to wait until April of this year before we sent any account to the journals of what had been done at this place.

In the Register for April a general account of the more striking phenomena was given, and further observations promised. Months passed, and still no systematic observations and plates appeared in the scientific journals. In June, however, a letter from Dr.

Mayer of the Lehigh University, Pennsylvania, accompanied by his interesting paper and lithograph of Jupiter, induced us to take our drawings to the lithographer. After much delay and difficulty the lithographs at the head of this paper were obtained; and although, as regards finish and softness, they are not all we could have wished, yet in other respects they faithfully convey the impressions received at the telescope.

They are intended to exhibit all the most prominent and some of the difficult details seen on the disc during one rotation of the planet. When these drawings were completed, the desire naturally arose of comparing them with those executed by distinguished astronomers in past times; and on looking over the books on our own shelves, we were struck by the extreme paucity of good delineations of this magnificent planet. And this was the more difficult to understand when we considered the noble disc it presents, the gigantic nature of the physical forces in operation, the comparatively small optical power required, and the great number of instruments of large aperture in the hands of amateur astronomers of the present day.

Few indeed were the sets of plates which gave a view of the opposite hemispheres. And although the physical forces at work on this huge sphere are of such a character as to cause the distribution of clouds to be pretty uniform in the same latitude, yet it cannot be doubted that many most interesting features have been lost by neglecting to secure complete representations of the sphere. Of the plates of Jupiter we found, the following is a list which may possess some interest :

1645. Hevelius (Selenographia) gives a figure in the Prolegomenæ. No parallel bands are shown: continuous cloudy patches, roughly parallel, run from north to south.

1713. Francisco Blanchini (Observationes Selecta) gives two figures, but it is very probable they were not meant to represent the whole of the markings seen on the disc. One shows two broad, dark bands, one on each side of, and parallel to, the equator; the others give only one broad, dark band, and it is to the south of the equator.

1785. Schröter (Beiträge zu den neusten astronomischen Entdeckungen) gives us ten woodcuts. They all have a broad band on each side of the equator and near it: some give a band near the north, and others are near the south pole. In one there is a narrow streak connecting the two central bands, and reminding one of that seen in Baxendell's beautiful drawing. These figures show many small dark spots, and to these Schroeter gave his special attention in his attempt to discover the rotation period of the planet. 1834. Mädler (Beiträge zur physischen Kenntniss, &c.) gives five plates. Three of them show a broad, dark band near to the equator, one on each side, and traces of a streak to the N. and S. of these. Large spots are also seen on the northern equatorial bands. In all the above representations the region near the equator is bright.

The drawings of Sir John Herschel are too well known to need description here.

1850. Lassell (Astronomical Notices, Vol. X.) gives a woodcut showing two very broad, dark bands in the southern hemisphere (the more northern having its north edge on the equator), and several narrow streaks in the northern. Six small bright spots are seen on the most southern belt.

1856. De la Rue (Chambers' Astronomy.) This is a magnificent picture: two enormous dark zones, full of character, stand one north and one south of the equator. In this year Professor Smyth executed three splendid drawings of Jupiter (Philosophical Transactions, 1858). They exhibit four principal belts corresponding pretty closely to Nos. 2, 3, 4, and 6. The most northern is very narrow in two of the figures, but broad in the third. The equatorial region is bright.

1857. Dawes (Astronomical Notices, Vol. XVIII.) made many drawings in this year, and in exquisite beauty of detail, richness of form and shade, the disc at this time has not been surpassed. He gives many bright spots in the southern broad band.

1858. Lassell saw bright spots in the central bright zone. The belts had altered much since Dawes sketched the disc. The streaks are numerous, but narrow.

In 1860 and 1863 exquisite sketches were made by Jacob, Baxendell, and Gorton, and are given by Chambers in his valuable treatise on Astronomy. These, compared with the drawings in 1869 and 1870, indicate changes of the most stupendous nature. It deserves special remark that in 1869 and 1870 the equatorial region was dark.

The following are the detailed observations:

1869.

Oct. 21st, 12h.-Band No. 4 was observed to be broken near the W. extremity. The E. half was dark and sharp, while the W. half was faint. Oct. 26th, 9b.-A short dark streak connected bands 4 and 5: it was near middle of that part of the disc. It is extremely probable that this object was the E. end of the ellipse.

Nov. 4th, 13h.-Upon the upper and lower edges (but still within the band) of 6, are now seen several small, bright, circular spots. Some 8 or 10 were counted, but the motion was too great to allow of fixing their exact position.

Band 2 was broken near its W. extremity.

Nov. 6th, 11h. 45m.-The break or gap in band 6 was seen to have a loop or bridge thrown across the opening towards the N.

Nov. 9th, 7h.-Band 2 was apparently rough and irregular in outline. At 11h. a large bright spot, the diameter of which was one-third that of the band, lay in the middle of 6, and in the centre of that portion of the disc.

Nov. 10th, 13h.-The narrow northern band, No. 1, was now seen to be much darker in the middle than near its extremities.

Nov. 14th, 10h. 50m.-Several small, bright, circular spots were seen on 6. At this time No. 4 seemed considerably bent towards the N. at its E. extremity. It was very dark at this place.

No. 5 has come on the disc and slopes down to 4, but the space between the two bands is dusky, and not, as is usually the case, bright.

No. I was now seen to be broken in the middle, where it was also darkest.

Nov. 15th, 12h.-Bright spots were seen on 6; motion on disc very great. At 13h. 15m. a faint circular spot was seen in middle of 6.

Nov. 16th, 12h.-A thin dark streak seemed to lie from the NE. corner of the ellipse to band 5.

Several small bright spots were seen on 6; one lay just over the W. end of the ellipse: another was midway between this and the W. edge of disc. Again the space between 4 and 5 was dusky.

Nov. 19th, 6h. 30m.-Under 4 was seen a large dark square space; a smaller one lay a little to the W. At 7h. a minute spot was seen just in advance of the gap in 6.

At 7h. 45m. the gap in 6 was again seen with a connecting bridge on the N. Flecks of light were at this time seen in the dusky southern polar region, especially near 6.

At 9h. 45m. several spots were seen on 6.

At 11h. 30m. band 4 was again seen bent to N. at the E. end.

Nov. 25th, 9h.-Three small bright spots were seen to the E. of the gap in 6, and within the band; others were suspected on the W. of the gap.

At 10h. 30m. a small bright circular spot was seen just to W. of the ellipse on 6. The break or gap in 2 was now again seen. The whole band was apparently broken up into many nearly detached portions. No. 6 was irregular at its upper edge as if indented by light flecks.

At 11h. 15m. two large ellipses lay in the centre under 4, and looked like great staring eyes; one also lay under the eastern ellipse, having its north edge resting upon band 3.

Nov. 28th, 8h. 30m.-Band I was dark along the eastern half.

At 10h. 45m. a large bright spot was seen in the middle of 6.

At 11h. 5m. a bright spot lay on lower edge of 6 but within it, and near

W. end of ellipse; a second was seen upon the upper edge of 6, a little

to the W.; and a third still more to the W. but on the lower edge.

Nov. 30th, 9h.-The spots to the W. of the ellipse were again seen on 6. At 11h. the western portion of No. I was dark.

The bridge under the gap in 6 was again seen.

At 12h. 15m. a large spot was seen in the middle of 6, another half way towards the E. edge of disc, and a third a little to the E. of the first, but upon the band. In diameter the central spot exceeds the others, and its diameter is fully one-third that of the band.

Dec. 4th, 7h. 15m.-The spots were seen to the W. of the ellipse.

At 7h. 30m. two dark swellings were seen on No. 1, near the W. extremity. The western half of this band was dark, well seen, and stood well off from the dusky shading of the N. polar region.

Dec. 10th, 9h.-The dark elliptic forms under 4 were not now seen, but dark flocculent lines inclined to E. across the dark zone; this was often seen, but only on bad nights.

Dec. 13th, 9h.-A large bright space was seen about the W. end of the ellipse in band 6. A smaller round spot was also seen in 6, above the middle of the ellipse.

At 10h. 30m. band 4 was seen, bent slightly upwards, as if the ellipse which lies under it had been pushed southwards.

Dec. 21st, 11h. 10m.-Under 4 in centre of disc was a large flat ellipse above its western end, and on 5 was seen a dark protuberance. The whole of band 5 was much broken up.

Dec. 27th, 6h.-The dusky patch close to W. of gap in 6, and upon that band, was well seen now.

At 9h. 10m. a fine large spot was seen in the middle of 6; another was seen midway between it and E. edge of disc.

1870.

Jan. 25th-(Tuesday). The sky cleared at 5h. and the night was superb. Power 240 was used with the full aperture. There was no motion on the disc.

The British Association-Meeting at Liverpool, 1870. 213

At 5h. 35m. a very fine, large, bright circular spot was seen within No. 6, near its upper edge, a little to W. of its middle point. The diameter of this spot appeared fully one-third that of the band. Not far from the E. edge of the disc was seen what appeared to be a large, bright spot with a dark square patch above it. After watching this object to the middle of its path, I could not be sure that the spot was round. Sometimes I thought the band was quite cut through on the N., and at first took the whole object for the well-known "break" in No. 6. It was never easy and good to see. On reflection and comparison of times of transit, it occurred to me that I had been thus baffled on a previous occasion; and a reference to the notes made in 1869 gives 11h. 30m., Nov. 30, as the time when a loop was seen lying under No. 6, and being rather a difficult object, was taken for the "break" by a friend who was examining the planet. But the "break" had passed the centre at about 7h. 40m. So also on the present occasion I had but to wait for about an hour to decide the question; and at 7h. 15m. the expected loop appeared again. Just to the E. of it, and within No. 6, was a fine, large, bright spot. A second spot was also seen nearer the E. edge of the disc, also in No. 6.

At 8h. 10m. the two light streaks seen on the 23rd appeared again on No. 6. After long and patient scrutiny while these faint objects were far from the edge of the disc, I could regard them only as two small oval bright spaces, very much like those under No. 4. They lay in the bright zone between No. 6 and the dusky shade of the southern pole.

At 9h. 50m. the southern ellipse was on the disc; No. 5 was again seen to pass on to the NE. corner of the ellipse and not to slope down to No. 4.

JOSEPH GLEDHILL, F.G.S. &c.

THE BRITISH ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE.-MEETING AT LIVERPOOL, 1870.

MATHEMATICAL AND PHYSICAL SCIENCE.-The proceedings of this section opened on September 16th, under the presidency of Mr. J. Clerke Maxwell, F.R.S. Professor Huxley, president of the British Association, was present.

Mr. James Glaisher, F.R.S., superintendent of the Meteorological Department of the Royal Observatory at Greenwich, read the annual report, "On Luminous Meteors." The first part of the report spoke of the loss experienced by the Committee in the death of Professor E. Brayley, a philosopher who had given the Committee much information on the astronomy of aerolites, from observations extending over many years. From investigations on the microscopic structure of meteorites and other data, he had also written a valuable paper on the origin of these bodies. He likewise had given much attention to the theory that the paths of shooting stars are connected with the orbits of comets, and in an address which he drew up about the sun, he pointed out that a part of the light of the corona surrounding the sun might be due to the reflection of the solar light from meteoric bodies near the atmosphere of the sun. The Committee recommended that Mr. C. Brooke, F.R.S., should be appointed as his

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