ARABIAN AND MEDIAEVAL SCIENCE. 73 



and many of its finest monuments date earlier than the fifteenth century. 

 But we must not suppose that the constructive skill displayed in the 

 grand Gothic edifices was a consequence of a knowledge of theoretic 

 mechanics, of which science, indeed, the most elementary propositions 

 were not enunciated until several centuries after some of the finest 

 Gothic cathedrals had been built. 



The fifteenth century may be almost characterized as showing the 

 dawn of modern science. It is marked by some events which greatly 

 accelerated the advance of science and learning. The art of printing 

 was invented in Germany about the middle of the century; and at the 

 end of it Columbus made his memorable voyage, upon which that of 

 Vasco da Gama round the Cape of Good Hope closely followed. 

 These voyages vastly increased men's knowledge of the earth ; and a 

 few years afterwards this knowledge received another extension by the 

 voyage of Magellan, who visited the South Pacific Ocean, circum- 

 navigated the earth, and brought back an account of the stars of the 

 southern heavens. If no great discoveries in physical science date 

 from this century, it may at least be said of some of the men who 

 belonged to it, that they placed themselves on the right road, and pre- 

 pared the way for the great revival of the succeeding century. Many 

 cultivators of the ancient Greek learning were, by the capture of Con- 

 stantinople by the Turks in 1482, driven to seek an asylum in Italy; 

 and these people carried with them copies of the masterpieces of 

 Hellenic literature we now possess. In this way the knowledge of the 

 ancient Greek language revived among the learned in Europe ; and 

 translations of the works of Euclid, Archimedes, and other Greek 

 mathematicians soon appeared, the newly-invented art of printing 

 giving unprecedented facilities for their dissemination. 



Germany for this century is the seat of the most remarkable scientific 

 labours, for we may almost date the true revival of astronomy from the 

 time of GEORGE PURBACH (1423 1461), who was professor of that 

 science at Venice about the year 1450. Purbach proclaimed the 

 importance of observation in astronomy as the only means by which 

 hypotheses could be confirmed or refuted. He measured with greater 

 accuracy than formerly the positions of the fixed stars, and he computed 

 some tables relating to the planetary motions. He introduced some 

 very important improvements into trigonometry, which greatly simplified 

 calculations. Purbach was desirous of giving the world a more accu- 

 rate translation of Ptolemy's great astronomical treatise, and his own 

 linguistic attainments not including Greek, he was setting about the 

 acquisition of that language when his death occurred. The design 

 entertained by Purbach was executed by his pupil and successor, JOHN 

 MULLER (1436 1476), of Konigsberg, whose name is better known 

 under the Latinized form of REGIOMONTANUS. To his translations he 

 added a Commentary, containing problems relating to astronomical 

 calculations. He made use of tangents in trigonometry, as the Arabs 



