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THE AMERICAN MUSEUM OF NATURAL HISTORY

MEMBERSHIP

For the enrichment of its collections, for scientific research and exploration, and for publications, the American Museum of Natural History is dependent wholly upon membership fees and the generosity of friends. More than 4000 friends are now enrolled who are thus supporting the work of the Museum. The various classes of membership are:

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Full information regarding membership may be obtained from the Secretary of the Museum, 77th Street and Central Park West.

NATURAL HISTORY: JOURNAL OF THE AMERICAN MUSEUM NATURAL HISTORY, recording popularly the latest activities in natural science and exploration, is published monthly from October to May, inclusive, by the American Museum of Natural History. The subscription price is Two Dollars a year. NATURAL HISTORY is sent to all classes of members as one of the privileges of membership. Subscriptions should be addressed to the Secretary of the Museum.

POPULAR PUBLICATIONS

A large number of popular publications on natural history, based on the exploration and research of the Museum, are available in the form of handbooks, guide leaflets, and reprints. A detailed list of these publications will be found in the Appendix to NATURAL HISTORY. Price lists and full information may be obtained by addressing the Librarian of the Museum.

SCIENTIFIC PUBLICATIONS

The field and laboratory researches of the American Museum of Natural History and other technical scientific matters of considerable popular interest are represented by a series of scientific publications comprising the Memoirs, Bulletin, and Anthropological Papers. A condensed list of these publications will be found on the inside back cover of NATURAL HISTORY. Price lists and complete data may be obtained from the Librarian.

244

GIGANTIC

PROMINENCES ON
THE SUN'S LIMB

During the eclipse,
flames of hydrogen gas
were seen to shoot out
from the sun's surface
at velocities sometimes
as great as a hundred
miles a second, reach-
ing such colossal dis-
tances as 480,000 miles.
The upper prominence
in the picture, which
resembles some great
monster, is at least
47,000 miles high.
Fiery streamers trail
from each of the out-
bursts as though blown
by an equatorial gale.

This photograph was
made at Green River,
Wyoming, by Professor
E. E. Barnard of the
Yerkes Observatory,
with a camera of 612
feet focus. With

shorter exposure the
lower prominence is
shown in delicate detail
as made up of thin fiery
filaments

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The corona and prominences as observed through thin clouds at the United States Naval Observatory Station, Baker, Oregon. (Original size of painting 49 x 331⁄2 inches)

NATURAL HISTORY

VOLUME XIX

W

MARCH, 1919

The Total Solar Eclipse of 1918

By S. A. MITCHELL

Director of the Leander McCormick Observatory, University of Virginia

HO is not interested in a total eclipse of the sun? He who has once seen such an eclipse can never forget it; the slow but gradual obscuration of the sun, the darkness covering the face of the earth even at noontime, and the glorious sight that meets the eye during the few short minutes of totality! It is no wonder, therefore, that in the early days of the world's history these wonderful phenomena should have been looked upon with great fascination and dread, and that the astronomer-and more often the astrologer-should have been regarded as almost a demigod because of his ability to predict the coming of eclipses. But with the increase of knowledge and the progress of science, the astronomer has gradually been dragged from his lofty pinnacle of fame, until now in the twentieth century the popular fancy pictures him as a foolish old man who would rather stay up at night and do his work than act as an ordinary civilized human being.

Not only do eclipses appeal to the popular imagination by their spectacular beauty, but there is also a great fascination to the lay mind in the almost uncanny power with which the astronomer is able to predict, years in advance, the exact time at which an eclipse will take place, where this eclipse may be seen, and how long this eclipse will last. As a matter of fact, Oppolzer's "Canon der Finsternisse" gives

NUMBER 3

the elements of no fewer than 13,000 eclipses, both of sun and moon, partial and total-all the eclipses, in fact, which have taken place since the year 1207 B.C. or which will be seen before the end of the year 2152 A.D. Maps are given in this great work which, almost at a glance, tell when and where an eclipse was seen three thousand years ago, or where an eclipse may be observed two hundred and fifty years in the future.

The earliest recorded eclipse is that which was seen in China in the year 2136 B.C., or more than four thousand years ago! An account of this eclipse is given in one of the ancient Chinese classics. This eclipse, which was not a total eclipse, had rather direful consequences for the two royal astronomers Hi and Ho, who instead of staying in the sober paths of science for this important occasion, went and got drunk. In order that a terrible warning might be given to all future generations of astronomers, who might be tempted to follow in their footsteps, the emperor ordered that both have their heads chopped off.

The progress of science during the last fifty years is nowhere better illustrated than in the attitude of astronomers toward observations at the time of a total eclipse of the sun. Up to the middle of the last century, the only observations that were made at the time of a total eclipse were for the purpose of perfecting the tables of motion of

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