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tory and Mt. Wilson Observatory, will be located at the Van Vleck Observatory, Middletown, Connecticut. Astronomers from the Allegheny, Sproul, Wellesley and Yale Observatories will be at New Haven, Connecticut. A small party from Harvard, and possibly one from Wellesley, will be located at the Maria Mitchell Observatory on Nantucket Island.

A new feature of eclipse observing will be the use of the United States navy dirigible Los Angeles, for carrying observers from the United States Naval Observatory, with cameras for photographing the corona, out into the path of the eclipse over the Atlantic Ocean.

What can the amateur do? Perhaps some suggestions may be obtained from the following list of things which are to be done by the professional astronomers.


Observe the times of contact of the moon with the edge of the sun's disk.

2. Photograph the corona with ordinary plates and with plates sensitive to different colors of light. For the latter the camera must be provided with an appropriate color filter.

3. Photograph the spectrum of the corona with ordinary plates and with those sensitive to different colors.

4. Photograph the flash spectrum just as the sun's light vanishes and reappears.


Determine the motion of the corona with etalon interferometers. 6. Study the polarization of the corona.

7. Make photometric observations determining the brightness of

the corona.

8. Measure the coronal radiation with vacuum thermocouple. 9. Observe the flash spectrum and coronal and chromospheric rings with field-glasses fitted with replica gratings.

10. Make observations determining the effect of the eclipse on magnetic and wireless instruments.

11. Observe the shadow bands visually.

12. Photograph the shadow bands.

13. Take moving pictures of the eclipse and corona.

14. Take moving pictures of the flash spectrum.

Some of these observations can be best made at the physical laboratories, of which many lie along the path of the total eclipse, where the light of the sun can be thrown into fixed spectroscopes in the laboratory. Observers who are situated at the edge of the path of the moon's shadow will have much better opportunity for studying the flash spectrum than those nearer the central line, for the phenomenon will last only two or three seconds near the central line but may be prolonged to even a minute or more at the edge of the path. The shadow bands, too, are likely to last longer near the edge than along the central line of the path of totality.

The amateur should not be discouraged by the lack of a telescope.

from taking photographs of the corona, for it is possible to make a comparatively long focus camera with very simple lenses. By taking out one of the two lenses of an ordinary large size camera and inserting the tube carrying the other lens in a light-tight wooden box, one can make a camera of twice the ordinary length. Suggestions for such cameras are given by Mr. J. H. Worthington and by Mr. E. A. Fath in articles in the May, 1924, number of POPULAR ASTRONOMY.

For photographing the shadow bands the camera should be of very short focus with a very rapid lens. In order to see the shadow bands, which are rather vague and hazy, a large sheet of white cloth should be stretched upon the ground, or, possibly better, inclined at an angle of from 30° to 45°, so that the camera may be better focused upon it. The exposure should be very short.

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FIG. 1. DIAGRAM OF THE TOTAL SOLAR ECLIPSE OF JANUARY 24, 1925. The hours of beginning and end are expressed in Greenwich Civil Time.

The accompanying diagrams will show to the reader the area over which the eclipse will be partial, covering the greater part of North America, the Atlantic Ocean, the eastern part of Europe and Africa. The path of totality crosses the northeastern part of the United States, curves upward across the Atlantic Ocean and ends just north of Scotland. The larger diagram shows the portion of the path of totality which crosses the United States, beginning about 150 miles northwest of Duluth, Minnesota, running east-southeastward across northern Wis

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consin and Michigan, the southern part of Canada, the southern part of New York, and almost the whole of Connecticut and Rhode Island. Places close to the central line which are not gvien on that chart are: Two Harbors, Minnesota; Florence, Wisconsin; Crystal Falls, Iron Mountain, Northport, Bellaire, Grayling and Tawas, Michigan; Stratford, Ontario; Warsaw, Geneseo, Danville, Watkins, Elmira, Lanesboro, Newberg and Carmel, New York; and Danbury, Connecticut. Places close to the edge of the path of the moon's shadow very favorable for study of the flash spectrum are Superior, Rhinelander, Crandon and Marinette, Wisconsin; Marquette, Manistique, Menominee, Frankfort, Cadillac, Gladwin and Sandusky, Michigan; Weedsport, Morrisville, Cooperstown and many of the suburbs of New York City, New York; Wellsboro, Laporte, Wilkes-Barre, Newton and Boonville, Pennsylvania; Paterson, New Jersey; Springfield and New Bedford, Massachusetts; and Providence, Rhode Island.

In the early part of December the writer addressed a letter to each of the directors of the observatories in the United States and Canada, asking for information which might be published concerning their plans for observing the eclipse. Nearly all have answered and the replies are given in very nearly their own words in the pages which follow. The account by Professor Edwin B. Frost, Director of the Yerkes Observatory, is so extended and contains so many useful suggestions for both the amateur and professional astronomer, that we have found it best to give it as a separate article immediately following this report.

ALLEGHENY OBSERVATORY. Dr. Heber D. Curtis will be associated with the Swarthmore party, located on the campus at New Haven. He is taking along a polar axis, on which he will mount two instruments. The first of these is an infra-red flash spectrograph, utilising a grating 5.2 x 3.1 inches, and of only 34 inches focal length. The second is a prism interferometer, using an etalon of 1 mm separation, for an attempted attack on the green coronal line.

"The eclipse is rather a forlorn hope, at best. Still, no one can tell; we might 'draw' a crystal clear winter morning."

CINCINNATI OBSERVATORY will send out no expedition but will make such observations as can be made there. If clear the times of contact will be observed and Dr. Smith will take some photographs.

DOMINION ASTROPHYSICAL OBSERVATORY has made no preparations for observing the eclipse on account of the uncertain weather conditions, "Though it may probably be fine there and shame the famed California weather which behaved so scandalously."

DOMINION OBSERVATORY. Director R. Meldrum Stewart writes that the Dominion Observatory will send a small party to a location a few miles south of Hamilton, the same point as that chosen by Professor Chant. Owing to the probability of poor observing conditions the party

will devote itself mainly to magnetic and wireless observations. Magnetic observations will be made for declination and inclination for several hours before and after totality, as well as on preceding and succeeding days, according to the usual eclipse program. The wireless observations will consist of a comparison, for both long and short waves, of the eclipse effects on receiving conditions with those depending on the ordinary daylight-darkness effects. If the weather is favorable, times of contacts will also be observed.

DRAKE UNIVERSITY OBSERVATORY will send no one to observe this eclipse. "As the time draws near that old feeling and desire is certainly strong, and if it were at all possible I would be on the ground. with the faithful old telescope, but must forego the pleasure this time.”

DUDLEY OBSERVATORY is making no preparations to observe the eclipse. Some of the observers will undoubtedly run down to Poughkeepsie to see the eclipse but will take along no equipment.

DETROIT OBSERVATORY, Ann Arbor, Michigan, will not make any special observations of the eclipse. Some of the observers may go just to witness it.

FUERTES OBSERVATORY, Cornell University, Ithaca, New York. Director Samuel L. Boothroyd writes, "We are preparing to make the following observations at the time of the total eclipse of January 24:

"To get the times of contact. We shall get our own observations for clock correction before and after the eclipse. We may also compare our clocks with the wireless signals from Arlington on the day of the eclipse and on the preceding day.

"To photograph the inner corona with the 12-inch equatorial of this observatory.

"To photograph the outer corona with a lens to be loaned by the Lowell Observatory.

"To photograph the coronal spectrum with a slitless spectrograph to be loaned by the Lowell Observatory.

"We should like also to get the flash spectrum with a concave grating but are not quite sure yet whether we can arrange for this.

"Several persons have volunteered to observe the shadow bands and I hope we shall have several more observers who will do this."

GOODSELL OBSERVATORY will send no formal expedition, but Professor E. A. Fath and a number of students will probably go to Bayfield, Wisconsin, to witness the eclipse and to make such observations as can be made with light portable apparatus. They will attempt to photograph the corona with cameras, to photograph the flash spectrum with the two-prism apparatus used at the eclipse of 1918, to make visual observations of the shadow bands and photograph them if possible.

HARVARD OBSERVATORY will set up four small stations along the eclipse path. One will be in western New York State, one in the vicinity of Poughkeepsie, one at New London, and one at the Maria

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