354 THE POPULAR SCIENCE MONTHLY 



light, heat, magnetism, double refraction and the polarization of light 

 were partially solved. Some traces of a knowledge of the results of the 

 interference of light are seen in the works of Grimaldi, Hooke, William 

 Gilbert and Halley. But it was the discovery of the calculus by Newton 

 and Leibnitz, and its use by scientific men, that the new impulse was 

 given to the study of astronomy and physics. Some of the marked 

 periods in history may be mentioned. One of these periods was that of 

 the Argonautic Expedition under Jason in search of the Golden Fleece 

 which took place about 1200 B.C. Another was the passage of Europeans 

 into the regions of the Euxine and the settlements made there by the 

 Greeks; another the expeditions of Alexander the Great, whose cam- 

 paigns have been called scientific as well as military. Another period of 

 great importance is marked by the growth of scientific interest, espe- 

 cially in Egypt, under the Ptolemies, and still another by the dominion 

 of Eome and the influence of the Caesars. In the Middle Ages, Arabs 

 who had absorbed and added to the learning of the Greeks, brought it 

 back from Bactria, a kingdom which lasted 116 years, to western 

 Europe and thus in the fifteenth century became the pioneers in the 

 new world of awakened thought. Phoenicians led in the early voyages 

 of explorations. The Greeks followed and established colonies on the 

 coasts of Asia Minor and on the southern shores of the Black Sea. 

 Wherever Bomans went they remained as conquerors. From the Phoe- 

 nicians we have few descriptions of nature. From Eoman writers like 

 Cicero, Ovid, Livy, Csesar, there are more. There are some also in the 

 writings of the Greeks from Homer and Hesiod down, but for the most 

 part the interest centers in man, not in the beauty or striking features 

 of the region in which he lives. The Hebrews are not insensible to the 

 importance of natural scenery upon the character of men, nor are they 

 unable to give vivid utterance to the impression which sublime scenery, 

 as witness Ps. 104, makes upon them. From the christian fathers, as 

 in the writings of Basil the Great, whom Humboldt especially admired, 

 we have many descriptions, though even here the human element is 

 always of prime importance. The Aryan races, natives of India and 

 Persia, recognize the charms of nature, but still men are the objects 

 upon which interest in their writing rests. In the early Italian 

 writers, and in the poets to the time of Petrarch and Dante, there is evi- 

 dence of a growing fondness for scenes of natural beauty. Calderon is 

 a representative of many a Spanish poet who does not think it beneath 

 his dignity to convey to others some of the impressions which the 

 vision of a lovely landscape has made upon the mind. Camoens in his 

 Lusiad proves that this is true for Portugal also. In the fourteenth 

 and fifteenth centuries travelers were careful to describe the strange- 

 ness and at the same time the attractions of the regions they visited. 

 Thus the way was prepared for Columbus, who had the ability to give 

 a description in a single luminous sentence which lingers in the mera- 



