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Dr. Hartwig, in the place above cited, reports a decline of 0.25 magnitude between Oct. 3 and 14.

When these observations are platted it will be seen that there is no check in the rapidity of the decline, and therefore no signs of an approaching minimum. The curve resembles that of Anderson's former discovery in this constellation, 6100 RV Herculis (See POPULAR ÁSTRONOMY, V, 326), which was followed below the 15th magnitude with the 40-inch Yerkes telescope. (Astronomical Journal, No. 456). If this resemblance is confirmed the star may reappear after minimum in the spring of 1900, in position for morning observation.

THE SPECTRUM OF α ORIONIS DURING THE RECENT MINIMUM.— Mr. Henry Harrer, of the Allegheny Observatory, took six spectrograms of a Orionis during the interval 1898 December 24 and 1899 April 5, to seek for any spectral changes which might accompany the recent minimum. These plates were compared with three taken by Professor Keeler with the same instrument and the same adjustment in October and December 1894. The results of this comparison are thus stated by Mr. Harrer in a note in the Astrophysical Journal for November 1899. "The comparisons revealed no changes either in the number or relative intensities of the lines. The above six photographs therefore revealed no change in the spectrum of a Orionis within the limits which have been stated." About 130 lines were compared, between a 5130 and 5655.

ANOMALOUS MAXIMUM OF SS CYGNI.—If any apology were needed for the frequent reference to this variable, it would be furnished by Professor Bailey's

Mag.

9

10

12

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The maximum just passed was unique in character. Nothing like it has been seen before, or at least been published, in the light changes of this star. If the form of curve for this maximum depended on the comparisons of a single observer, the report would perhaps be doubted, but the observations of the four are in so satisfactory agreement that the anomalous form of the curve seems well established. The accompanying graphic representation will show at once the form of the curve and the agreement of the observations (Compare curves in V, 271 and 387, VI, 159 and VII, 145). The star had reached normal light after the October maximum on Nov. 6, so that the period of quiescence was only 14 days, the shortest on record. The curve shows a maximum Dec. 1.7, the time of passing 9.35 magnitude during the rise being Nov. 28.1.

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Definite Orbit of Comet 1894 IV, (E. Swift).—In Astronomische Nachrichten No. 3606-7 Mr. F. H. Seares gives detailed results of a definitive calculation of the orbit of E. Swift's comet, from all of the published observations. It will be remembered that a similarity was noted, soon after its discovery, between the elements of the orbit of this comet and those of the long lost De Vico comet 1844 I. The previous calculations, although pointing strongly to the identity of the two comets, yet left much uncertainty as to the conclusion to be derived from them. To clear up this uncertainty as much as possible has been the object of Mr. Seares' investigation, and the new determination of the elements of the comet 1894 IV has been a first step in the investigation.

The comet was so faint and the weather so bad that the total number of observations of the comet was only 64 for right ascension and 63 for declination. By comparing these observations with an ephemeris from Mr. Chandler's elements in Astronomical Journal No. 338 Mr. Seares formed seven normal places, and after correcting these for perturbations by Jupiter, Saturn, Mars, and Earth, calculated corrections to the elements by a least square solution of differential formulæ.

The definitive elements thus obtained are as follows:

Epoch 1594, Dec. 1.0. Osculation 1894, Dec. 10.0.

- 8° 22′ 58′′.2 ±

- 48 48

4".2

Мо

π

=345 23

11.1 土 44)

23.4 27.7 1900.0

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These elements place the perihelion passage on Oct. 12, 1894, and make the period 5.855 years. The next perihelion, neglecting perturbations, would be Aug. 20, 1900.

GENERAL NOTES.

It is scarcely necessary to say that the Leonids, though comparatively few in November anywhere, make something of a display in January from the pages of this magazine. Some of the charts present only a few true Leonids, and none a great many in view of what was expected, yet it has seemed best to give many reports from widely different localities in the hope that some useful data may be gained to help in solving some troublesome questions about the real location, dimensions and characteristics of the orbit of the Leonid stream of meteors.

Reports from Leonid Observers.-We have some more reports of Leonids observed in other localities not yet published. We have set aside other matter this month, and given large space to this, for reasons already given above. In presenting other reports later, we have still the same object in view, viz.: that of making as full a survey of the observational side as is possible under the circumstances.

The New Photographic Telescope of the Potsdam Astrophysical Observatory.-We have just received a beautiful photograph of the great telescope recently completed for the Astrophysical Observatory at Potsdam, Germany. No description accompanies the photograph and we have seen no reference to the telescope in recent publications except the barest mention that it was in the process of construction and that it was to be a photographic refractor consisting of two telescopes, the photographic objective having an aperture of 80cm (= 31.5 inches) and the visual objective having an aperture of 50cm (= 19.7 inches). The photograph (Plate I) shows the telescopes to be in position in the dome and that they have approximately the same focal length. The instrument will be of great value for photographing faint objects, like the smaller nebulae and star clusters, on a scale large enough to show their details of structure plainly. We presume also that a large part of its work will be in connection with the spectroscopic study of the fainter stars.

Orbit of the Fifth Satellite of Jupiter.-The careful and thorough work done in 1898 and 1899 in observing the fifth satellite of Jupiter by Professor E E. Barnard, with the 40 inch equatorial of Yerkes Observatory, has already received full notice at home and abroad in various scientific publications. His micrometrical observations have made it possible for the mathematical astronomers to study the orbit of this new satellite with confidence that some uncertainties about it will be removed. Years ago, Tisserand called attentiɔn to the fact that early observations showed that the orbit of the satellite had eccentricity. This led Professor Barnard to plan a series of observations of the positions of the satellite that should be as nearly continuous as possible in order to settle this question. One result which he obtains from the work of the last two years is a period of revolution for the satellite which he regards as correct to one one hundredth of a second of time. The period given in his recent paper on this subject is

11h 57m 228.647.

Tisserand's results from early observations gave a daily motion to the apse line of 20.42, and an eccentricity of orbit equal to 0.0073. By Professor Barnard's later observations, it appears that Tisserand's daily motion of the apse line is too small, its true value being more nearly 2°.465, making a complete revolution of the orbit in 4.9 months.

It is suggested by a writer in a late number of Nature that "an interesting question may also be settled, by continued observation of this satellite; that is, the distribution of matter at the equator of Jupiter itself, as the motion of the perijove of the satellite does not agree with that deduced from the actual polar compression of the planet." This gives opportunity for more fine micrometrical work by the aid of a large telescope.

The Astronomical Director of the United States Naval Observatory. The expiration of the time limit for the office of Astronomical Director for Professor William Harkness at the United States Naval Observatory, Washington, D. C., occurred Dec. 17, 1899. His retirement completes the list of those men who have been long in service together in the professorships of mathematics at the Observatory, viz: Professors Hall, Frisby,Eastman and Harkness. The time of service of these eminent men at the Observatory has been during a transition period of the character and history of our national astronomical Observatory. When these men came it was little more than a depot of charts with some astronomical instruments needed for the rating of chronometers and the observations for the Nautical Almanac and the American Ephemeris. The ability of these men in their chosen profession, and in a long and skillful service, faithfully rendered at their respective posts, has, more than anything else, brought the Naval Observatory to a rank worthy of a national name which it noes not yet bear. This transition period has been one of conflict, trouble, jealousy and illmanagment that have defeated much of the best work that might have added largely to the usefulness of the Observatory to astronomy and the country at large. Notwithstanding this these men have lived through it it all, and each and all of them have come to honorable retirement when they were at their best in scientific ability and experience for the performance of professional work to which they have ambitiously devoted their whole lives.

From a recent number of the Washington Star, we copy the following statement about Professor William Harkness, who is the last in retirement of the four persons referred to:

"Professor Harkness was born in Scotland, Dec. 17, 1837, and came with his father, who was a Presbyterian minister, to the United States when a mere child. He entered the University at Rochester, N. Y., and graduated in 1858. He studied medicine in New York, became an M. D. in 1862, and enlisted as a surgeon in the Federal army. He resigned that position, was appointed an aid in the United States Naval Observatory in 1863, and became a professor of mathematics the same year.

"His first scientific work was with the the United States monitor Monadnock, in 1864-5 in investigating compasses and iron-clad vessels. On his return he was attached to the Hydrographic Office. While observing a total eclipse of the Sun at Des Moines, Iowa, in 1869, he discovered the 1874 line of the SolarCorona. In 1871 Professor Harkness was attached to the Transit of Venus Commission,' and designed the instruments of the expedition. In 1878 he was placed in charge of the government party which observed the total eclipse of that year at Creston, Wyo. In 1882 he was made executive officer of the 'Transit of Venus Commission,' and reduced the photographic work of the numerous observations taken.

"Among his inventions are the sphereometer caliper, for measuring inequalities of the pivots of astronomical instruments. In 1890 Professor Harkness was made astronomical director of the United States Naval Observatory. In 1897, on the retirement of Professor Newcomb, he was made head of the Nautical Almanac. As a member of various scientific societies, he has contributed numerous reports on mathematical astronomy and the application of mechanics to astronomy. His 'Solar Parallax and its Related Constants" is one of the most important. Professor Harkness has been honored with the degree of A. M., Lafayette College, and with the degree of LL. D. from Rochester University. He will continue his scientific work in Washington in his retirement.

SIRIUS

The Andromede Meteors.-The nights of Nov. 22 and 23 were cloudy at Northfield. The 24th was perfectly clear up to 10h P. M. and a considerablenumber of meteors were seen by several persons. On account of another engagement systematic watch was not kept until after 10h.

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Nov. 24, 1899, by H. C. Wilson and students at Goodsell Observatory.

In the first five minutes, one observer counted 10 meteors, all from Andromeda, while the others were getting the apparatus for charting into position. After this the meteors came more slowly and soon clouds covered the sky, lasting until about 11h, when the sky cleared again and remained clear until the Moon rose. The shower was evidently nearly over at 11 o'clock, for after that, though the sky was perfectly clear, the meteors were very few. The few that were

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