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THE POPULAR SCIENCE MONTHLY. 



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 pre- 

 vailing 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 thou- 

 sand 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 Jlorocco its length is about three hun- 

 dred 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 approach- 

 ing 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 in- 

 fluence 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 tlie otlier, 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 liroad 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 luxuri- 

 ance. 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 diversi- 

 fied with gardens and groves of orange, 

 lemon, palm, and myrtle, producing the most 

 charming harmony, combination, and contrast 

 of coloring as far as the hoi'izon, 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. Rebiere 

 in a recent communication, the first, Hypa- 

 tia, daughter of Theon, of Alexandria, lived 

 in the foui-th century, publicly taught mathe- 

 matics and philosophy to large classes, and 

 wrote treatises on mathematics. From her 

 the author comes down to Madame du Cha- 

 telet, in the eighteenth century, a mathema- 

 tician, 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. Rebiere are 

 Marie Agnesi, born at Milan in 1718 ; Sophie 

 Germain, who, at the end of the last century 

 corresponded with the mathematician Mon- 

 tucha ; Mary Somerville, the friend of La- 

 place and a student of astronomy and phys- 

 ics during her whole life ; and Sophie Ko- 

 waleski, born at Moscow in 1850, whose work 

 on the rings of Saturn has been complement- 

 ed by that of Mademoiselle Klumpke, of the 

 Paris Observatory. Besides these. La Na- 

 ture^ in its supplement, names a number of 

 less- known women who have attained a larger 

 or smaller degree of distinction by their la- 

 bors in this field. The Abbess Herrade, in 

 the twelfth century, was author of a cosmol- 

 ogy, 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 cen- 

 tury, Thiephaine Raguenel, wife of Dugues- 

 clin, was " learned in astronomy." Eimart- 

 Meller, wife of Regiomanes, assisted him in 

 his observations. Croris advocated the deci- 

 mal system ; Dum6e defended the Coperni- 

 can theory ; Cunitz calculated the astronom- 

 ical tables called Urania propitia ; Ardin- 

 gheli published works on mathematics and 

 natural science ; Bassi taught physics in the 

 , University of Bologna for thirty years ; Le- 



