In the Philosophical Magazine for September Prof. Trowbridge describes his experiments on the spectra of hydrogen. The four line spectrum he found very readily produced in the presence of water vapor. The presence of the four line spectrum of hydrogen in the sun he regards as substantial evidence in favor of the presence in the sun of water vapor, and consequently of oxygen.

The Astrophysical Journal for July devotes fifty pages to American eclipse reports from the various parties along the path of totality. Spectroscopic work constitutes a considerable part of the total work of the larger parties.

The Naval Observatory was represented by three parties, two near the central line, at Pinehurst, N. C., and at Barnesville, Ga., and one just inside the northern limit of totality, at Griffin, Ga. The equipment included a prismatic camera, a slitless spectrograph, two grating objectives, and three concave gratings. The observations with the concaye gratings for various reasons all failed. Dr. Huff with a grating objective (plane grating with quartz lens) at Pinehurst obtained three successful plates, one giving four corona lines in the ultra-violet. With the prismatic camera, using erythro plates, a good photograph of the spectrum of the flash was obtained, showinga large number of bright lines, including six or eight in the red and orange between C and D3. Prof. Lord's observations with objective prism train seem to indicate a very short duration of flash. Mr. Jewell at the station near the limit of totality was able to observe the gradual appearance of the reversal of the metallic lines; and infers that the chromosphere is dense at its base, probably merging into the upper photosphere.

With the Smithsonian party at Wadesboro, N. C., the objective prisim with the 135 ft. lens, which was responsible for the striking bifurcated appearance of that apparatus, for some unknown reason failed to give any results.

In the Princeton party at Wadesboro, N. C., Prof. Miller observed in the flash fewer lines than had been expected, and at mid totality saw eight bright rings. Prof. Young, contrary to his experience at three previous eclipses, was entirely unable to see the green corona line, and Mr. Russell was equally unsuccessful. The plate exposed in the large spectrograph especially with a view of determining the position of the corona line in the spectrum failed to show any trace of the line.

In the Yerkes Observatory, also at Wadesboro, Prof. Frost, assisted by Dr. Isham, obtained photographs of the flash spectrum at second and third contacts and of the spectrum of the cusps some seconds after totality. One plate of the violet part of the corona spectrum was secured, showing several chromosphere lines and one or possibly two corona lines. No results were secured from the attempt to obtain a photograph of the red end of the spectrum with a plane grating.

In the party from Brown University, stationed at Centerville, Va., Mr. Slocum used successfully a prismatic camera, securing plates which show a considerable number of bright lines, including prominently the chief chromosphere lines.

PLANET NOTES FOR OCTOBER.

H. C. WILSON.

Mercury will be evening star during this month, coming to greatest eastern elongation, 23°44′ from the Sun, on Oct. 29. The planet may then be seen near southwestern horizon soon after sunset, but only for a short time.

Venus is the bright star in the east, rising a little before three o'clock and reaching the meridian about nine o'clock in the morning. Her course is south

eastward through Leo. On the morning of Oct. 7 Venus will be in conjunction with the first magnitude star Regulus, the former being about one degree north of the latter. The waning moon will be in conjunction with Venus on the 19th. Mars rises toward the northeast about midnight, and moves eastward through Cancer during this month. The planet is conspicuous for its ruddy color to the naked eve, being a little redder and brighter than the star Aldebaran. The Moon will be in conjunction with Mars on the night of October 16. The distance of Mars from the Earth is about 158,000,000 miles and the apparent diameter of the disk of the planet is only six seconds, so that observations of its surface-markings are yet very difficult.

Jupiter, Saturn and Uranus are evening stars but too low in the southwest for observation except during the twilight.

Neptune rises between nine and ten o'clock in the evening and may be observed under favorable conditions during the latter half of the night. The position of the planet October 1 is R.A. 5h 56m 385, Dec. 22° 13′ 16′′, North.

Eros-The Astronomische Nachrichten No. 3662 contains an extension of the ephemeris of Eros, by Millosevich, from Jan. 1 to April 1, 1901.

VARIABLE STARS.

J. A. PARKHURST.

Minima of the Variable Stars of the Algol Type.

(Given to the nearest hour in Greenwich Time.)

The dates are taken as before from Dr. Hartwig's paper in the Vierteljahrsschrift, except for Y Cygni for which I have used Duner's data given in No. 3633

of the Nachrichten. These times are two and three hours later than those in Hartwig's ephemeris.

W Persei is called V Persei in Chandler's Third Catalogue.

SS CYGNI.-The maxima are now about a month behind the ephemeris, which is founded on the changes observed previous to the reversal of the order of maxima which occurred in the early part of 1900. The rise which was set for Aug. 8 by this ephemeris, did not take place till Sept. 7.

OBSERVATIONS OF VARIABLE STARS AT THE GERMAN
OBSERVATORIES.

The following items of news are extracted from Part 2 of Vol. 35 of the Vierteljahrsschrift, which has just appeared.

BAMBERG -For the year ending May 1, 1900, Dr. Hartwig reports 733 observations of variables by Argelander's method. Of this number 77 referred to SS Cygni. Of this star the intervals between the times of rise since Oct. 25, 1899, were 32, 35, 69 and 48 days. U Geminorum was found bright from April 1 to 3. Mininra of Algol and λ Tauri were observed on three nights, and light estimates were made of ẞ Lyrae, 7 Aquilae and § Cephei on 18 nights. The variability of one of the Pleiades stars, B.D. + 24°531, was discovered by photography. Its magnitude in the B.D. is 9.5, but it was fainter than 12th magnitude in November 1899 and certainly fainter than 11th magnitude in April 1900.

Heidelberg.-Dr. Valentiner announces the early publication of Schönfield's original observations of variable stars. Most of them were made at Mannheim from 1865 to 1875. There are 35963 complete observatons of 117 variables, comprising over 80000 single estimates, besides 4000 or 5000 comparisons of the comparison stars among themselves. It is needless to say that the quality of these observations is fully equal to the quantity, and the publication will be simply invaluable.

MUNICH.-Observations of Nova Aurigae were continued and a decline of 0.2 magnitude was recorded in 1899. On the 22d of December it was estimated as 12.7 or 12.8 magnitude.

VIENNA.-(The Von Kuffner Observatory.) Dr. Wirtz has continued the investigation begun by Dr. Schwartzchild of the determination of the photographic light curves of variables. Preliminary reductions lead to the conclusion that the curve for & Cephei resembles that for 7 Aquilae, that is the photographic amplitude is nearly double the optical, thus showing a decided increase of redness at minimum.

OBSERVATIONS OF FAINT VARIABLES AT THE YERKES OBSERVATORY.

The greater part of the work hitherto done on variable stars consists in determinations of their maxima and periods, comparatively few of them being tollowed through the complete cycle of their change. As a result our knowledge of the variation of most stars is fragmentary. For this reason the opportunity to observe faint minima with the Yerkes 12 and 40-inch telescopes was welcomed by the writer, and the following items from the work done between January and August, 1900, may be of interest. They are extracted from Bulletin No. 13 of the Yerkes Observatory:

This preliminary report will be followed by more definite results when the magnitudes of the comparison stars have been determined with the stellar photo