OCEANIC DISCOVERIES. 253 



Accounts of the Indian and Arabian trading places on the 

 eastern shores of Africa, and of the configuration of the south- 

 ern extremity of the continent, may, indeed, early in the Mid- 

 Ale Ages, have been transmitted to Venice through Egypt, 

 Abyssinia, and Arabia. The triangular form of Africa is in- 

 deed distinctly delineated as early as 1306, on the plamsphe- 

 rium of Sanuto, in the Genoese Portulano della Mediceo-Jyiu- 

 renziana of 1351, discovered bv Count Baldelli, and ou the 

 map of the world by Fra Mauro. I have briefly alluded to 

 these facts, since the history of the contemplation of the uni- 

 verse should indicate the epochs at which the principal details 

 of the configuration of great continental masses were first 

 recognized. 



While the gradually developed kiiowledge of relations r\ 

 space incited men to think of shorter sea routes, the means for 

 perfecting practical navigation were likewise gradually in- 

 creased by the application of mathematics and astronomy, the 

 invention of new instruments of measurement, and by a more 

 skillful employment of magnetic forces. It i-s extremely prob- 

 able that Europe owes the knowledge of the northern and 

 southern directing powers of the magnetic needle — the use of 

 the mariner's compass — to the Arabs, and that these people 

 were in turn indebted for it to the Chinese. In a Chinese work 

 (the historical Szuki of Szumathsian, a writer who lived in 

 the earlier half of the second century before our era) we meet 

 with an allusion to the "magnetic cars," which the Emperor 

 Tsing-wang, of the ancient dynasty of the Tscheu, had given 

 more than nine hundred years earlier to the embassadors from 

 Tunkin and Cochin China, that they might not miss their way 

 on their return home. In the third century of our era, under 

 the dynasty of Han, there is a description given in Hiutschin's 

 dictionary Schuewen of the manner in which the property of 

 pointing with one end toward the south may be imparted to 

 an iron rod by a series of methodical blows. Owing to the 

 ordinary southern direction of navigation at that period, the 

 south pointing of the magnet is always the one especially men- 

 tioned. A century later, under the dynasty of Tsin, Chinese 

 ships employed the magnet to guide their course safely across 

 the open sea ; and it was by means of these vessels that the 

 knowledge of the compass was carried to India, and from 

 thence to the eastern coasts of Africa. The Arabic designa- 

 tions Zohron and Ayhron (south and north),* which Vincen- 



■* Avron. or avr (au?-), is a more rarely employed term for north, used 

 uislead of the ordinarv " sckemdl ;'^ the Arabic Zokrori,, oi Z-hi , from 



