York, on the morning of 1892 March 7, the comet at the time having considerable southern declination. It was sufficiently bright at the date of discovery to be visible to the naked eye, and although there was no great increase in the theoretical brilliancy, it nevertheless became a very conspicuous object in the morning sky, the length of the tail being estimated by various observers at 10°, 11°, and even 20°, while the nucleus shone as a star of the third magnitude. Very successful photographs were taken at the Lick Observatory by Professor Barnard, which exhibited "creases, knots, and bends in the streams of luminous matter, apparently flowing out from the head and forming the tail." The diminution of brilliancy from the head to the extremity of the tail was not uniform. The course of the comet was through Aquarius, Pegasus, and Andromeda, and observations pursued through several months (it was seen at Bordeaux on November 20) showed that the path of the comet deviated sensibly from the parabola. Dr. Berberich found that the observations are best, represented by an ellipse of about 2000 years' period; and it is possible that the slight difference from parabolic velocity was produced by an approach to Saturn about 1887, but this point cannot be decided till the definitive elements have been computed. (b) On March 18, Mr. Denning, of Bristol, detected a faint comet near 8 Cephei, and, as the elements have shown, at a very considerable distance both from the Earth and Sun. Owing to these relations the comet remained small and inconspicuous, but observations have been possible through a considerable period, and in large telescopes the object is probably still visible. The observations, as at present discussed, do not exhibit any signs of ellipticity in the orbit. (c) Å return of the comet of Winnecke. Dr. Spitaler's long search for this comet, continued at favourable opportunities since 1891 February, was rewarded by success on March 18, the comet then being more than three months before perihelion passage. The position predicted by Dr. Haerdtl, whose admirable researches on the theory of this comet are well known, was in error only half a minute in the arc of a great circle, and this close agreement between theory and observation diminishes the probability that a faint cometary object, seen by Dr. Spitaler more than a year previously, was really Winnecke's comet, since this suspicious object was some twelve minutes from the path computed by Dr. Haerdtl. Observations were possible in the Northern Hemisphere till June, the brilliancy constantly increasing, but the position for observation less favourable as the comet approached the Sun. On emerging from the Sun after perihelion passage, the comet was more favourably situated for observations in the Southern Hemisphere, where it has been well observed. (d) On August 28 Mr. Brooks, of New York, detected a faint telescopic comet in Gemini, some four months before its Y perihelion passage. The comet was, therefore, increasing in brilliancy, and before the end of the year became a conspicuous object with a well-developed tail. The great southern declination, however, into which the comet has moved, has prevented the accumulation of observations in the Northern Hemisphere. A parabolic orbit represents the path of the comet with great accuracy. (e) The discovery of this comet is particularly interesting, owing to the fact that it was detected on a photographic plate, and is the first so discovered, if we except the somewhat doubtful record of a comet on plates exposed during a solar eclipse. The discovery is due to Professor Barnard, who on October 12 exposed a plate for a considerable time to the neighbourhood of a Aquila. On developing, a trail was observable, which was conjectured to have been impressed by a comet, and on the first favourable opportunity the comet was easily picked up, about two degrees from the place marked on the photographic plate. The elements also are interesting, since pronounced deviation from parabolic motion was at once evident. With elements computed from only five days' observations it was impossible to represent the middle longitude within half a degree; and, further, the elements showed great similarity to those of the periodic comet of Wolf. Dr. Schulhof called attention to the extreme probability of the two comets having formed part of one body, presenting a similar case to that of Biela and Brooks' comet, 1889, V. This conjecture is still further strengthened by the application of Tisserand's well-known criterion, where, following the usual notation, we have:- With a particular value of the period, not greatly different from that assigned by Dr. Schulhof, it would be possible that the comet should be near Jupiter in 1875, when Wolf's comet was also within the sphere of that planet's attraction; but the close agreement of these figures seems to indicate that the orbit is very exact, and that such alteration of the period is not permissible. This would indicate that the separation of the two bodies was probably earlier than 1875, but the decision of this point must be left till the orbit is definitely determined. It is unfortunate that the feebleness of the comet has prevented a very long series of observations. It was seen at Nice at the beginning of December, and may still be within the reach of the largest telescopes. (f) On November 6 Mr. Holmes, of London, discovered a bright comet in the constellation Andromeda, and the same comet appears to have been independently discovered in Queensland on November 9 by Mr. Davidson. The comet is described by the discoverer as 5' in diameter, and bright enough to be seen by the naked eye. The greatest theoretical brilliancy occurred in the latter portion of September, when the comet should have been rather brighter than on November 6, and well situated for observation in the Northern Hemisphere. It is therefore remarkable that so bright an object was not sooner detected, but this comet seems to have exhibited greater fluctuations in brilliancy than any other comet. Dr. Palisa has telegraphed that the present appearance of the comet (January 18) is that of a star of the eighth magnitude surrounded by a nebulosity extending not more than twenty seconds in diameter. Since this outburst has occurred, after the comet had become invisible in ordinary telescopes, it is not improbable that a similar outburst occurred shortly before November 6. Such variations of character would explain the non-appearance of the comet on the photographic plates that have been certainly exposed to the sky in the situations the comet was occupying, for though suspicions have been entertained of the photographic impression of the comet, yet, when submitted to exact calculation, the deduced position from the photographic plate has not given an entirely satisfactory result. Such variations of brilliancy would explain the fact that the comet had not been seen at some earlier return, for the orbit has proved itself to be one of short period, and it is probable that the comet has made more than one return to the Sun in practically the same orbit. Subsequent inquiry has shown that it is not impossible that Holmes' comet belongs to the same family as that of De Vico, 1844, I. (g) The last cometary discovery of the year was effected by Mr. Brooks, who perceived a bright comet in the constellation of Boötes on the morning of November 19. Its steady increase in brilliancy, coupled with its northerly motion, made it a tolerably easy object for observation. Since the perihelion passage falls in 1893, this comet will appear in the catalogues of that year. The Fifth Satellite of Jupiter. W. E. P. The astronomical event of the year is undoubtedly the discovery of a fifth satellite to Jupiter, made at the Lick Observatory, California, on Sept. 9, at midnight, by Professor E. E. Barnard, who, while carefully examining the neighbourhood of Jupiter with the 36-inch, detected "an exceedingly smail star" close to the planet and near the third satellite, which he at once suspected to be a new satellite, a suspicion soon verified. The discovery was the result of a systematic search for new objects instituted by Professor Barnard. The satellite has since been frequently observed and measured at the Lick Observatory. Professor Barnard has occasionally been able to follow it to within 8" of the planet's limb, but remarks that, examining it under the best conditions with a high power, he has never seen it other than as a star, nor has he been able to catch the slightest glimpse of its shadow when in transit. In all his later observations a piece of smoked mica has been used in front of the eye-lens to dull the light of Jupiter, the planet and satellite then being readily seen at the same time. Nearly all his observations were made at east elongation. The following elongations were observed among others :-- October 21, 17h 2.8, east elongation. October 23, 16h 49m o, east elongation. From the first two a period of 11h 57m 20s 5 results. From an elongation on October 28 the period was computed as 11h 57m 179. The mean of ten measured east elongations, reduced to the mean distance of Jupiter, between September 10 and October 28 is 48"100"011, while the mean of four (including a discordant one) west of the planet gives 47" 42+0"042, the probable error of a single observation being o∙II and ±o"17. These two values represent a distance from Jupiter's centre of 112,520 miles and 110,930 miles respectively. The west elongations are about 1" less than the eastern, so that the orbit is apparently elliptic. The measures for latitude seem to show that the satellite's orbit lies sensibly in the plane of Jupiter's equator, which would signify that it is not a recent addition to the Jovian family. The fifth satellite has also been observed at a few other observatories possessing instruments of sufficient calibre. Professor Stone has seen and measured it with the 26-inch at the University of Virginia. At Princeton it was observed on several occasions between October 10 and 29 by Mr. Reed, Professor Young's assistant, who, however, was unable to obtain any complete set of measures embracing both sides of an elongation. His observations point to a period of 11h 57m 238, with an error probably less than 10 secs. Mr. Reed stated that he found it an easier object than Ariel, the inner satellite of Uranus, which reverses the experience of Professor Hough, who saw it with the 18-inch at Evanston, Illinois, and reported it much more difficult than Ariel and Umbriel. The satellite was also observed with Dr. Common's 5-foot reflector at Ealing, on five occasions between October 18 and December 26, but no measures are reported. On December 13, at 6h 55m, Mr. Taylor observed it in conjunction with the first satellite, which was below the fifth. On December 25 and 26 it was seen when at W. elongation between 5 and 6h G.M.T. A full account of the discovery was given by Mr. Barnard in the Astronomical Journal, No. 275, 1892 October 4, together with all his micrometer measures obtained from September 9 to 16. Later details were given in a paper communicated to the R.A.S. meeting 1892 November 11. Mr. Marth, in his second provisional ephemeris (1892 December 1 to 1893 January 28), has adopted 11h 57m 37s as the period. Nova Auriga. A. E. On February 2 the following circular was issued from the Royal Observatory, Edinburgh : 66 Yesterday an anonymous postcard was received here, bearing the following communication :-Nova in Auriga. In Milky Way, about two degrees south of x Auriga, preceding 26 Auriga, fifth magnitude, slightly brighter than x Auriga. "At 6h 8m G.M.T. the star was easily found with an operaglass. It was of a yellow tint and of the sixth magnitude, being equal to 26 Auriga. Examined with a prism between the eye and the eye-piece of the 24-inch reflector, it was immediately seen to possess a spectrum very like that of the Nova seen in 1866. The C line was intensely bright; a yellow line about D fairly visible; four bright lines or bands were conspicuous in the green; and, lastly, a bright line in the violet (probably Hy) was easily seen. A telegraphic notice was sent to Greenwich in the afternoon, and, later on, when the true nature of the object was recognised, to Kiel, for general distribution. The star was photographed last night at Greenwich. Its place for 1892 is 5h 25m 38+30° 21'. It does not occur in the Bonn maps.' Dr. Thomas D. Anderson, the author of the postcard to Professor Copeland, is an amateur astronomer living in Edinburgh, and he discovered the new star by means of a star-atlas and a small pocket-telescope. In a letter to Nature, 1892 February 18 (p. 365), he announced that the star was visible as of the 5th magnitude for some days before the postcard was despatched to Professor Copeland. The previous history of the star was, by singularly good fortune, partly recovered from photographs taken at Harvard College. Professor E. C. Pickering, the Director, recently conceived the idea of "patrolling the heavens," every fine night, by means of a small photographic transit instrument, which automatically sweeps the meridian in a series of steps of sufficient exposure to photograph 6th-magnitude stars, at intervals corresponding to the equatorial breadth of the field. The scheme is perfectly adapted for the detection of strange objects brighter than the 6th magnitude, and its merits were thus clearly demonstrated within a few months of its inception. The Nova was found on thirteen photographs taken on December 10, 11, 13, 17, 18, 18, 28, 30, January 5, 8, 9, 16, 20. It does not appear on a photograph taken at Heidelberg on December 8, showing stars to the 9th magnitude. After remaining of the 4th or 5th magnitude till the end of |