TERRESTRIAL MAGNETISM. 53 



Two centuries earlier, in the reign of Marcus Aurelius 

 Antoninus (called An-tun by the Chinese writers of the 

 dynasty of Han), Roman legates had come by water by Tunkin 

 to China ; but it was not through so transitory a communi- 

 cation that the use of the compass reached Europe ; where 

 it was not introduced until the 12th century, after its use 

 had become general throughout the Indian seas and the coasts 

 of Persia and Arabia. The introduction was effected either 

 directly by the influence of the Arabians, or through the me- 

 dium of the Crusaders, who since 1096 had been in contact 

 with Egypt and the Levant. In historical inquiries of this 

 class, the only epoch which can be assigned with certainty is 

 that which must be regarded as the latest or limiting date. 

 In a political satirical poern of Guyot of Provins, in 1199, the 

 mariner's compass is spoken of as an instrument long known 

 among the nations of Christendom ; and this is also the 

 case in a description of Palestine which we owe to Jaques 

 de Yitry, Bishop of Ptolemais, and which was finished 

 between 1204 and 1215. Guided by the compass, the 

 Catalans sailed to the northern isles of Scotland, and to 

 the west coast of tropical Africa ; the Basques to the whale 

 fishery ; and the Normans to the Azores (the Bracix Islands 

 of Picigario). In the first half of the 13th century, 

 the Spanish " Leyes de las Partidas," the work " del sabio 

 Hey Don Alonso el Nono," extols the compass-needle as the 

 faithful mediatrix (medianera) between the "magnetic 

 stone" "la piedra" and the "north star." Gilbert, in 

 his celebrated work "de Magnete Physiologia nova/' 

 speaks of the compass as a Chinese invention, but adds, 

 which is clearly incorrect, that it was first brought to Italy by 

 Marco Polo, "qui apud Chinas artem pyxidis didicit." As 



