even measured their positions in the sky; but they only saw and recorded their observations. They could discern no plan or purpose in the bewildering galaxy of lights, other than their religious conceptions-as, for instance, that the mighty hunter Orion, after his death, was placed among the constellations. A geometrical plan was first assigned to the movements of the planets by Ptolemy of Egypt; but

universe than many of the famous astronomers who succeeded her.

But the study of the heavenly bodies was destined to a sudden change. Astronomers were no longer content to count the stars in the heavens and theorize on their mutual relations; they must know why the planets circled round the sun in peculiar orbits and yet the stars appeared immovable. And a couple of cen

our present theory of their motion, reversing the previously accepted theory that the earth was the center of the solar system, is credited to Copernicus, who lived in the Middle Ages. But long before this famous astronomer startled the world with the hypothesis that the earth circled round the sun, there lived at St. Hubert's monastery, near famed Bingenon-the-Rhine, in Germany, a holy abbess who upheld this then extraordinary and heretical theory. It was she who first perceived the heightening and failing light of some of the heavenly luminaries, and so directed attention to those wonders of the universe, the variable stars. Living close to nature's heart, she cast off the false notions of the times, and reasoned closer to the real status of the

MILLS SPECTROGRAPH ATTACHED TO 36INCH LICK TELESCOPE.

turies after the lonely abbess reasoned out the solar system, Newton discovered the law of gravitation; and, applying it to the whole universe, mathematically traced its action through all the intricate webb of its bearing on the planets. He gave the result of his work to the world by publishing his masterly "Principia ;" but for nearly fifty years after, mathematicians refused to give credence to his philosophy. It was left for two women to appreciate this, one of the greatest discoveries of all ages, and to bring it before the world in the light of its great importance. importance. These women were the Marquise du Châtelet and Marie Gastana Agnesi, who translated Newton's great work into French and Italian. The Pope showed his appreciation by giving the last-named scientist the chair of mathematics at Rome. Such a liberal recognition of woman's service to science was

PHOTO-HELIOGRAPH.

Used for photographing the sun.

phenomenal in that narrow-minded age, the early part of the eighteenth century, when any attempt on the part of women to devote themselves to other duties than those of the home was received with derision and contempt. In no other branch of activity where women have taken their places on a level with men, has so much help been extended them or have they been honored so surely and so quickly for their achievements, as in astronomy.

For a hundred years after Newton published his great work, the whole course of astronomical investigation was given up to testing and proving his theories. Astronomy, which had once meant only observing the stars, now became in addition a matter of abstruse mathematics, and the calculus played as important a part in its history as the telescope. But women, by their valuable work, had made a place for themselves in the astronomical world, and the time soon came when the work could not be carried on without their assistance. About the middle of the eighteenth century, Alexis Claude Clairaut, a noted mathematician and astronomer, was asked to predict when Halley's comet would. return to perihelion, i. e., come closest to the sun. This involved long, difficult calculations, and he freely admitted his inability to complete the task alone. "But," said he, "if Madame Lepaute will assist me, I will undertake the task." Mme. Nicole Reine Lepaute was the wife of the watchmaker to Louis XV., and she often helped her husband in his calculations for astronomical pendulums. She gladly consented to assist Clairaut, and for eighteen months they

worked day and night, figuring the orbit of this perturbed comet. At last they announced when it would reach perihelion, and the whole scientific world awaited with breathless interest the arrival of the comet. If it came when predicted, Newton's theories would be partly substantiated. The comet was sighted on Christmas day, 1758, and passed the point in its orbit nearest the sun on March 12th, 1759, just one day before the time predicted by these mathematicians. Newton's theories were partially proved, and Madame Lepaute was given the professorship of astronomy at Paris.

A great wave of popular enthusiasm and interest in astronomy now swept over the world. Women in all countries were turning their attention to this enchanting study. In historic Rome, Catherine Scarpellini conducted a meteorological station, published the first catalogue of the meteors of Italy, discovered a comet, and printed a monthly scientific bulletin. Co-worker with Sir William Herschel, that beacon-light of astronomy in England, his sister, Caroline Lucretia, attained great prominence in sidereal science. Nor was it altogether a reflect

SUN SPOT. Photographed at Yerkes Observatory, October 10, 1903, with Rumford Spectro-heliograph.

kept at her work, however, fortified in the belief that some time she would be understood and her work esteemed. After the death of her first husband, she married Dr. Wm. Somerville of the Royal Navy, who recognized his wife's ability and found interest and pleasure in the work she loved. Mrs. Somerville's greatest gift to astronomy was her book "The Mechanism of the Heavens."

But England and Italy were not alone in their encouragement of women astronomers. In care-free Paris, Eva J. Leland accomplished the arduous task of measuring 40,000 stars for the standards of stellar magnitude. In scholastic Germany, Madame Rumker computed comet orbits and discovered the great comet of 1847. In the shadow of the grim old walls of the University of Stockholm, Sophie Konyalewski was accorded official recognition by being given the chair of astronomy.

Previous to this time, the United States had enlisted no recruits to swell the ranks of women astronomers; but in the life-work of a single woman, America pushes to the forefront of astronomical progress. The visitor at Nantucket, a little island off the coast of Massachusetts, is proudly shown an old frame. house called the Pacific Bank Building, where a woman discovered a new comet on the night of October 1, 1843. Maria Mitchell, a Quakeress, here made the discovery which brought her reputation in scientific circles. Her father was then

cashier of the bank, and they had arranged a little observatory on the roof of the building. Miss Mitchell never let pass a clear night without going up to her telescope and watching the skies. Quietly excusing herself from visitors. one evening, she donned her working garb, antl, with lantern in hand, hastened to the roof. She soon returned, however, and hurriedly told her father that she had found a comet. Following his excited daughter, he mounted to the observatory, watched the queer star intently, and was convinced that she had made a great discovery. He wrote that evening. to the astronomer at Cambridge, who announced the new comet to the scientific world. Miss Mitchell was awarded a gold medal by the King of Denmark for her brilliant discovery.

Maria Mitchell was the daughter of a noted astronomer, and was brought up in the atmosphere of exact science. She gave considerable attention to the mathematics of astronomy, for her position as Librarian at Nantucket left considerable time for study. She worked steadily and faithfully-often she said of herself that she had not genius but persistency. In 1850 she was elected a member of the American Association for the Advancement of Science, and she was the first woman made a member of the American Academy of Sciences. In 1852 she was

given the degree of LL. D. from Hanover, but it was not until her first trip to Europe that she began to realize that she had gained a reputation across the water. This journey may well be called a triumphal entry into astronomy's home field, for there had been considerable illfeeling between the American and European scientists. But in the long list of celebrities that she visited during her stay abroad we can perceive how great was her popularity there. John Herschel, Sir George Airy, Verrier, Alexander von Humboldt, the Hawthornes, who were in Italy, and Mary Somerville, were among her hosts.

The

She returned in two years to find herself doubly popular in her own country. The women of America had given her an observatory and a large telescope, with which to continue her labors. republic of San Marino presented her with a bronze medal as an appreciation of her work in science. In 1887 she was given the degree of LL. D. by Columbia College.

She kept assiduously at work in independent investigations for six years more, when she was given the professorship of astronomy in Vassar College. There she spent twenty years in active service, teaching and promoting the cause.

of women's work throughout the United. States. Her time was largely occupied with these duties, so that her original research in science was somewhat curtailed. The higher education of women became one of her hobbies; and her classes at Vassar were popular, although hard application was required from all her students. But the progress of the science which she loved was watched with keenest interest, and she was personally connected with an eclipse expedition to Burlington, Iowa, in 1869. She observed another eclipse at Denver in 1878, just five years after a second trip to Europe. At the end of her seventieth year, she felt that declining strength compelled her to retire from active life, and she resigned from the faculty of Vassar. She arranged to continue her observations of the heavens, however; but her strength failed, and she passed away June 28, 1889.

Miss Mitchell's career covered the transition period between the old and the new astronomy. The old mathematical astronomy was fast giving way to a new régime, ushered in by the perfection of the telescope and the application of the spectroscope and camera to astronomical work. Miss Miss Mitchell gained fame largely through her mathematical