332 HOW LATITUDE IS RECKONED 



the year 1204; he returned afterward to Europe, and subsequently back to the 

 holy land, where he wrote his work entitled "Historia Orientalis," as nearly 

 as can be determined, between the years 12 15 and 1220. In chapter 91 of 

 that work he has this singular passage : "The iron needle, after contact with 

 the lodestone, constantly turns to the north star, which, as the axis of the firma- 

 ment, remains immovable while the others revolve, and hence it is essentially 

 necessary to those navigating on the ocean." 



These words are as explicit as they are extraordinary, they state a fact 

 and announce a use. The thing, therefore, which essentially constitutes the 

 compass must have been known long before the birth of Giola. In addition 

 to this fact, there is another equally fatal to his claim as the original discov- 

 erer. It is now settled beyond a doubt that the Chinese were acquainted with 

 the compass long before the Europeans. It is certain that there are allusions to 

 the magnetic needle in the traditionary period of Chinese history, about 2,600 

 years before Christ, and a still more credible account of it is found in the reign 

 of Chingwang of the Chbw dynasty, before Christ, 11 14. All this 

 however, may be granted without in the least impairing the just claims of Giola 

 to the gratitude of mankind. The truth appears to be that the position of 

 Giola in relation to the compass was precisely that of Watt in relation to the 

 steam engine — the element existed ; he augmented its utility. The compass 

 used by marines in the Mediterranean during the twelfth and thirteenth cen- 

 turies was a very uncertain and unsatisfactory apparatus. It consisted only of 

 a magnetic needle floating in a vase or basin by means of two straws on a bit 

 of cork supporting it on the surface of the water. 



. The compass used by the Arabians in the thirteenth century was an instru- 

 ment of exactly the same description. Now the inconvenience and inefficiency 

 of such an apparatus are obvious — the agitation of the ocean and the tossing 

 of the vessel might render it useless in a moment. But Giola placed the mag- 

 netized needle on a pivot, which permits it to turn to all sides with facility, 

 afterward it was attached to a card, divided into 32 points, called rose de vents, 

 and then the box containing it was suspended in such a manner that, how- 

 ever the vessel might be tossed, it would always remain horizontal. 



