1 62 THE INTELLECTUAL RISE IN ELECTRICITY. 



toward the star. On the contrary, the rubbed portion of 

 the iron will follow the rubbing part of the magnet in any 

 direction, backwards or forwards, or to the right or left ; 

 and if the iron be floated in a vessel of water and the mag- 

 net placed beneath, the same part of the iron will sub- 

 merge itself to meet the magnet, while, if the magnet be 

 placed above, it will rise upward. On the other hand, if 

 the opposite portion of the magnet be presented, the iron 

 (rubbed part as before) will always fly from it, u as the 

 lamb from the wolf." Consequently he concludes that the 

 magnet is influenced by the four parts of the heavens, and 

 not by the one part in which the Pole star is located. 



If Bacon did not actually discover the law of magnetic 

 action (like poles mutually repel, unlike poles attract), it is 

 manifest, from the foregoing, that' he came very close to 

 doing so. At all events, he brought the condition of gen- 

 eral knowledge on the subject to a point where the very 

 next step resulted in discoveries of the highest importance. 



Bacon was pre-eminently a teacher, and seems to have 

 freely communicated his knowledge to others whenever he 

 was not restrained from doing so. To Brunette Latini, 

 the celebrated Florentine grammarian and preceptor of 

 Dante, he not only told what he knew about the magnet, 

 but repeated his experiments in his presence. Latini, at 

 that time, was in exile, and visited Oxford, where Bacon 

 resided, in about the year 1260. He died in 1294. He 

 describes the compass in his Li Livres dou Tresor, 1 and, in 

 certain letters written during his sojourn in England, he 

 tells how Bacon showed him the "ugly and black stone to 

 which the iron voluntarily joined itself," and the needle 

 which, when rubbed by the stone, turned to the star and 

 guided the mariners. 



In the Opiis tertium Bacon says that there are but two 

 perfect mathematicians, Master John of London and 

 "Master Petrus de Maharn, curia, a Picard." John of 



*Li Livres dou Tresor. Paris, 1863, p. 3. Mainly a collection of ex- 

 cerpts from earlier authors. 



