236 MAGNETIC CURVES. 



polar condition. This is confirmed by the following 

 lines by Lucretius : v/.yat . 



Quod superest agere incipiam, quo foedere fiat 

 Natura lapis hie ut ferrum ducere possit, 

 Quem rnagneta vocant patrio de nomine Graii 

 Magnetum,-biflrsit patriis in fiuibus ortus. 



/*' 



Again we find Pliny employing the term magnetic, to 

 express this singular power. It was known to the 

 ancients that the magnetic power of iron, and the 

 electric property of amber, were not of the same 

 character, but they were both alike regarded as miracu- 

 lous. The Chinese and Arabians seem to have known 

 Magnetism ataperiod long before that atwhichEuropeans 

 became acquainted with either the natural loadstone or 

 the artificial magnet. Previously to A.D. 121, the 

 magnet is distinctly mentioned in a Chinese dictionary ; 

 and in A.D. 419 it is stated in another of their books 

 that ships were steered south by it.* 



The earliest popularly received account of its use in 

 Europe is, that Vasco d Gama employed a compass in 

 1427, when that really adventurous navigator first ex- 

 plored the Indian seas. It is highly probable, however, 

 that the knowledge of its important use was derived 

 from some of the Oriental nations at a much earlier 

 period. 



We have some curious descriptions of the leading 

 stone or loadstone, in the works of an Icelandic 

 historian, who wrote in 1068. The mariner's compass 

 is described in a French poem of the date of 1181 ; and 

 from Torfeeus's History of Norway, it appears to have 

 been known to the northern nations certainly in 1266. 



* Treatise on Magnetism, by Sir David Brewster. Cosmos : a 

 Sketch of a Physical description of the Universe ; by Alexander 

 Yon Huinboldt. Otte's Translation. 



