tion, and this has always been a prominent feature of its work. The university furnishes a very full course in astronomy, an important feature of which is found in the practical work at the observatory.

Considerable use has been made of the equatorial in the observation of planets and comets, and the phenomena of Jupiter's satellites; but the most important contribution to astronomy made by this observatory is the long series of latitude determinations. This series came to an end in August, 1895, but it is much to be desired that it should be resumed in the near future.

TOTAL SOLAR ECLIPSE, JANUARY 22, 1898. ENGLISH PREPARATIONS.

BY EDWARD W. MAUNDER, F. R. A. S.

The importance of total solar eclipses has led in England to the appointment of a permanent body to organize their observations. This body bears the rather unwieldy title of the "Joint Permanent Eclipse Committee of the Royal Society and Royal Astronomical Society." The title is, however, descriptive of its constitution, and if we refer to it in future simply as the "Eclipse Committee," there need be no misunderstanding as to the body. indicated, and we may avoid repetition of this cumbrous name.

The expeditions sent out by the Eclipse Committee last August were to widely separated countries,-Japan and Norway —and included six principal observers. Three-the Astronomer Royal, Professor H. H. TURNER, and Captain HILLS- went to Japan; three- Professor NORMAN LOCKYER, Mr. FOWLER, and Dr. A. A. COMMON- went to the Varanger Fjord, in Lapland. The same observers, so far as can be at present foreseen, will go to India for the eclipse of January next, and will take with them the same instruments, and try to carry out the same programme as that to which the clouds were so hostile on August 9, 1896. For, one chief aim to be borne in mind in eclipse observation is the necessity of strict continuity. If we are to get the maximum result from the brief moments of totality afforded us at such long intervals, then the operations to be undertaken at any one eclipse must bear the strictest relation to the work done at the eclipses that have gone before, and to the work proposed for those that

will follow. It is hoped, however, that the party on the next occasion will be increased by two additional members; one will probably be Mr. NEWALL, the observer with the great NEWALL telescope at Cambridge; the other was to have been Mr. E. J. STONE, the Radcliffe observer, whose untimely death has recently left so serious a gap in the ranks of English astronomers. No arrangement has as yet been made for supplying his place on the expedition.

If we take the stations at present proposed to be occupied, beginning with the most westerly, the first party we come to is that of Professor LOCKYER and Mr. FoWLER, who will be stationed near Ratnagore, on the west coast. The equipment will be chiefly spectroscopic, and will include two telescopes of nine and six inches aperture, respectively, furnished with objective prisms, the great success which attended this method in 1893, and again in Mr. SHACKLETON's observations in Novaya Zemlaia in 1896 amply justifying great importance being attached to it. An integrating spectroscope, having two three-inch prisms of sixty degrees, will also be used. The method of observation with all three instruments will, of course, be photographic, a long series of photographs of varying exposures being used with the objective prisms, whilst an exposure of sixty seconds will be given with the integrating spectroscope.

The object of the prismatic cameras is, of course, to give the details of the bright line spectra of the chromosphere, prominence and corona, each several luminous point having its own distinct spectrum. The integrating spectroscope, on the other hand, is intended to sum up the spectrum of the whole composite phenomenon. It may be hoped, therefore, that the feeble intensity of the true coronal lines will be more than compensated by the breadth of the area over which they are diffused. If, then, on comparing the spectra obtained with these two widely differing instruments, we find that the integrating spectroscope brings into considerable evidence new lines beside those which the objective prism reveals to us as characterizing the prominences, there can be no hesitation in referring these new lines to the corona.

Crossing the Western Ghauts, the shadow-track intersects two main lines of railway (the Southern Mahratta Railway and the Great Indian Peninsular Railway), running southward from Bombay through Poona. The points where these two railway lines cross the line of totality will be very strongly occupied, but the

Most likely, the

precise spots are not as yet definitely fixed. expedition sent by the Eclipse Committee will occupy the one station, whilst a numerous band, organized in India itself by Professor K. D. NAEGAMVALA, of Poona, will occupy the other.

The official party in this region will consist of the Astronomer Royal, Professor H. H. TURNER, and Dr. A. A. COMMON. The Astronomer Royal will take the THOMPSON photoheliograph of nine inches aperture and eight feet six inches focal length, with secondary magnifier placed a short distance within the focus, giving an image of the Sun four inches in diameter. The camera will be furnished with eight plate-holders, taking 12 x 10inch plates, and the instrument will be fed by a coelostat with a sixteen-inch plane-mirror. Photographs will be taken of the partial phase, as well as of the total.

Professor TURNER'S apparatus is the double camera used in the West African expedition in 1893 by Sergeant KEARNEY. The body of the instrument is six feet long, and consists of two square tubes of 7x7-inch section. In one is placed the "ABNEY" photographic lens, of four inches aperture and five feet two inches focal length, used in so many eclipses, and which gives an image of the Sun 0.57 inch in diameter; in the other, the photoheliograph objective No. 2, belonging to the Royal Observatory, Greenwich, and used in the Transit of Venus Expedition of 1874, and which is also of four-inch aperture and five feet focal length, but which is to be used with a DALLMEYER secondary magnifier of seven and one half inches focus, placed five inches within the focus, so as to give an image of the Sun one and one half inches in diameter. The double camera is furnished with six plateholders, each taking two plates of 160 mm, square, both plates being exposed by a quarter turn of one shutter. The double camera, like the Astronomer Royal's instrument, will be fed by a sixteen-inch plane mirror, on a coelostat mounting. A similar instrument was to have been placed under the charge of the late Mr. STONE at the third station. This instrument was taken by Dr. COMMON, in 1896, to Lapland.

Apart from this, it is probable that Dr. COMMON's equipment will be the same as that which he had in Norway last year; i. e. a six-inch doublet lens, by GRUBB, lent by Mr. F. MACLEAN, F. R. S., and giving an image of the Sun three and one half inches in diameter; a slit spectroscope, with 31⁄2-inch lenses, and two light flint prisms of sixty degrees, and a grating

spectroscope, to be used without a slit. The plates for Mr. CHRISTIE'S coronal photographs, Dr. CомMON's photographs with the six-inch GRUBB, and those with the grating spectroscope, are all to be 12 x 10 plates.

The third station, at Wardha, on the Great Indian Peninsular Railway line from Bombay to Nagpur, will be occupied by Mr. NEWALL, who proposes to use a large slit spectroscope, with two prisms of sixty-two degrees, in the attempt to determine the speed of rotation of the corona by the relative displacements of its lines as observed east and west of the Sun. In the same neighborhood, Captain HILLS will probably fix his apparatus, which will consist of two slit spectroscopes, having the slit tangential to the Sun's limb at the point of second contact, and diametral respectively. The slits are 11⁄2 x 0.004 inches, and 2 x 0.004 inches respectively; and the prisms are, for the first spectroscope, of two flint prisms of sixty degrees, 41⁄2-inch base, 21⁄2-inch height at minimum deviation for Hy; and for the second spectroscope, of four quartz prisms of sixty degrees, 34-inch base, 234-inch height at minimum deviation for He. The collimator and camera lenses are single quartz lenses, of 21⁄2-inch aperture, 30-inch focus and 3-inch aperture, 36-inch focus respectively. The objectives are all achromatic COOKE lenses, of 41⁄2inch aperture, 5 feet 10 inches focus, and a single quartz lens of 5-inch aperture, 4 feet 9 inches focus.

Professor TURNER'S equipment in Japan also included a polariscopic apparatus, consisting of an ordinary slit spectroscope, with an Iceland spar double image prism substituted for the ordinary prisms. This will probably again be included in his armory.

Some thirty or forty amateur astronomers belonging to the British Astronomical Association will also proceed to India, and divide into four companies, stationed near the four above-mentioned sites respectively, but the precise programmes to be adopted cannot be ascertained at present.

EARTHQUAKE OF JUNE 20, 1897 (OAKLAND).

BY ALLEN H. BABCOCK.

A prolonged shock of earthquake was observed here to-day, commencing at 12" 13" 9" P. M., P. S. T., and continuing for at least twenty-five seconds. It was noticed first as a sharp settling of the floor; then came a rumbling sound, followed by a slow, swaying motion, which gradually increased in strength and frequency for about ten seconds, when the maximum was reached. At this time the vibrations were decidedly marked: the house creaked, the windows rattled, and the pictures bumped against the walls. The swing of the chandeliers was in an approximately north and south line. The vibration gradually diminished, until 12 13 34, when they could no longer be observed. In a jeweler's shop, about two blocks away, a pendulum clock, which was fastened on a wall running in an east and west direction, had stopped at 12" 13" 27. This clock is usually kept very close to

standard time.

The intensity of the shock at its maximum may be estimated at IV, or possibly V, on the ROSSI-FOREL Scale. Two persons report a very faint shock about fifteen minutes later, but it was not observed by me.

OAKLAND, Cal., June 20, 1897.

2826 California Street, }

SAN FRANCISCO, June 23, 1897.

On Sunday, June 20th, at 12:13 P. M., I felt a slight

shock of earthquake, location N.W. 4 Section 32, Township 17 S., Range 14 E., M. D. B. & M., on Cantua Creek, Fresno County. Duration about fifteen seconds; 9 shock; undulation and whirling motion. Yours respectfully,

S. C. LILLIS.