l88 THE INTELLECTUAL RISE IN ELECTRICITY. 



at Pasitano near Amalfi at the beginning of the fourteenth 

 century. His fame rests on the line of Anthony of 

 Bologna, who lived later in the same century: 



Prima dedit nautis usum magnetis Amalphis. 

 (Amalfi first gave to seamen the use of the magnet.) 



Of GiojVs life nothing definite appears to be known, 

 and even the line quoted above does not ascribe to him 

 the invention of the compass, but only its introduction. 

 Flavius Blondus speaks merely of the "rumor" of the 

 Amalfitans being "entitled to the credit of the magnet 

 by the assistance of which navigators are directed to the 

 North Pole." 1 But, long before Gioja's day, the Italian 

 vessels from Venice, Genoa and other ports had been 

 transporting Crusaders by thousands to the Holy Land, 

 and making trips with a regularity which, since the com- 

 pass was fully known, leaves little doubt that they de- 

 pended upon that instrument to some extent; although the 

 pilots of that time, after the fashion of their ancestors, 

 kept close to shore. Peregrinus, as we have seen, had fully 

 pointed out that vessels could be steered from one place to 

 another by means of his pivoted needle when the latitude 

 and longitude of the objective point was known ; but that 

 description, it must be remembered, was buried in a private 

 letter. Gioja seems to have re-discovered this and hence 

 to have taught the adventurous sailors of the Mediterranean 

 that the compass could be used, not only to find the Pole 

 star, but directly to steer by. In so doing he earned a 

 title to fame but little inferior to that which he would 

 have merited had he been the original inventor of the 

 apparatus. It was probably Gioja also who first added to 

 the instrument the compass card or Rose of the Winds, 

 of which the Etruscans, ages before, had designed the pat- 

 tern one doubtless repeated over and over again in their 



litarum, Napoli, 1735, p. 935. Also McPherson : Annals of Commerce, 

 Lond., 1805, Vol. I., 365. 



'Italia Illustrata. Basle, 1559, 420, g. 



