the far north, where a very slight deflection east or west might alter their whole course, and in that case they would naturally strike either Iceland or the west coast of Norway, and in either case would reach the east coast of Britain. But, if by storms and the prevailing winds of the North Atlantic coming from the west, they had been driven out of their usual course, they would strike the coast of Norway, and so find their way to Britain in the company of their congeners. It is maintained that the height of flight is some fifteen hundred feet to fifteen thousand feet.
The Atlas Mountains.—The great chain of the Atlas forms a mountain system which is described by Charles Rolleston as, for the grandeur and beauty of its romantic scenery, not to be surpassed, perhaps, by any in the African continent. The range extends into the adjacent French possessions in Algeria, but in Morocco its length is about three hundred miles, of which thirty miles, stretching from the sources of the river known as the Ouad Tissout, attain a general elevation of about twelve thousand feet. On approaching this imposing mountain line the aspect is truly sublime. At the time of early dawn of certain seasons the heights are imbedded in masses of white mist, which, under the influence of the rising sun, dissolve with the appearance of a thin, gauzy veil, disclosing a magnificent panorama of mountains rising behind mountains. Toward the Atlantic on the outer side, and in the direction of Algeria on the other, a broad line of snow edges the mountain tops; and at intervals loftier snow-clad peaks tower up, piercing the background of dark blue sky. Just below the region of snow the mountain sides are intersected by broad valleys bounded by wild, craggy heights; but lower still, where vegetation begins, the slopes are furnished with forests, stretching at places into long expanses of parklike woodland of pine, oak, walnut, and larch trees, growing with wonderful luxuriance. The view of the landscape, looking down five thousand or six thousand feet, is variegated and beautiful, for, watered by thousands of rivulets pouring from the base of the Atlas, there stretch away miles of fertile country strewn with Berber hamlets, plantations, and fruit orchards, the deep-green grass land and cultivated fields diversified with gardens and groves of orange, lemon, palm, and myrtle, producing the most charming harmony, combination, and contrast of coloring as far as the horizon, and the whole together presenting a landscape of the most enchanting beauty.
Women Astronomers.—Of six famous women mathematicians and astronomers whose work is mentioned by M. A. Rebière in a recent communication, the first, Hypatia, daughter of Theon, of Alexandria, lived in the fourth century, publicly taught mathematics and philosophy to large classes, and wrote treatises on mathematics. From her the author comes down to Madame du Châtelet, in the eighteenth century, a mathematician, astronomer, and physician, who in a memoir on fire, in the French Academy of Sciences, maintained that heat and light were produced by the same cause. Other women mathematicians mentioned by M. Rebière are Marie Agnesi, born at Milan in 1718; Sophie Germain, who, at the end of the last century corresponded with the mathematician Montucha; Mary Somerville, the friend of Laplace and a student of astronomy and physics during her whole life; and Sophie Kowaleski, born at Moscow in 1850, whose work on the rings of Saturn has been complemented by that of Mademoiselle Klumpke, of the Paris Observatory. Besides these. La Nature, in its supplement, names a number of less-known women who have attained a larger or smaller degree of distinction by their labors in this field. The Abbess Herrade, in the twelfth century, was author of a cosmology, the Hortus deliciarum; in the same century, Sainte Hildegarde gave, in her De Physica, a summary of the sciences of her time. In the thirteenth century, Nontis Sabucco described the function of the white matter of the brain. In the fourteenth century, Thiephaine Raguenel, wife of Dugueselin, was "learned in astronomy." Eimart-Meller, wife of Regiomanes, assisted him in his observations. Croris advocated the decimal system; Dumée defended the Copernican theory; Cunitz calculated the astronomical tables called Urania propitia; Ardingheli published works on mathematics and natural science; Bassi taught physics in the University of Bologna for thirty years; Le-
