106 THE INTELLECTUAL RISK IN ELECTRICITY. 



tiized as magnetic by looking at it, and, unless the copy- 

 ing Arab possessed, not merely the knowledge of magnetic 

 attraction, which he might have had, but also that of 

 magnetic polarity, which he certainly did not have, it 

 would be impossible for him to reproduce the apparatus. 



Besides, the Chinese mariner was grossly ignorant, and 

 even if he could explain the mysterious little needle, it is 

 unlikely that the haughty Arab, of a totally different race 

 and religious belief, would view other than with contempt, 

 the signs and astrological hieroglyphics, which were part 

 of the Chinaman's religion, and to which he would be 

 sure to attribute much of the marvelous powers of the 

 compass. The Arabs had possessed charts and astrolabes 

 for a long time, and had proved them to be efficient guides 

 at sea, so that it is improbable that they would readily 

 supplant them by any such incomprehensible Chinese 

 contrivance. Nor indeed is it necessary, because the 

 Arabs made long voyages, or because early mariners of 

 the Indian Ocean undertook journeys on which the modern 

 navigator would never venture without the aid of a com- 

 pass, to assume that such an instrument existed among 

 them. A fairly good means of guidance at sea, known 

 since the days of the Phoenicians, was the flight of birds. 

 Those birds which accomplish the longest flights, and 

 cross the widest oceans, always select, by some marvelous 

 instinct, the shortest ocean routes; and birds which know 

 their way are an invaluable guide to the sailor who has 

 lost his. There is, for example, a kind of falcon which 

 breeds in Southern Siberia, Mongolia, and Northern 

 China, and winters in India and Eastern Africa. 1 It is 

 able to make this long migration by moving from station 

 to station in the Indian Ocean, so that it is plausibly 

 supposed that guided by these birds, the ancient ships 

 might have made voyages from the coast of Malabar even 

 to the far distant Archipelago of Madagascar. 



1 Dixon : Migration of Birds. London, 1892. Simcox : Prim. Civiliza- 

 tion, cit. sup. 



