274 THE INTELLECTUAL RISE IN ELECTRICITY. 



men who had sunk the Danish harriers, and who longed 

 to voyage to Virginia and the strange lands of the New 

 World, and perchance to find fortune in some gold-logged 

 galleon on the Spanish Main. 



Errors likely to wreck ships, made when the eyes of all 

 Englishmen were turned to the sea, were likely to prove 

 doubly harmful, especially as there was nowhere the cor- 

 rect knowledge necessary to recognize their fallacy, or 

 even to prevent people presumably expert in such matters 

 from endorsing them as truths. Edward Wright, in his 

 prefatory address to Gilbert's treatise, although looking 

 askance at the magnetic theory of the earth's rotation, 

 (nevertheless he does u not see why it should not meet 

 with indulgence ") grows eloquent over Gilbert's mistaken 

 idea that the dip of the magnetized needle "differs in the 

 ratio of the latitude of each region," and that hence, the 

 dip being once determined and the latitude observed, 

 "the same place and the same latitude may thereafter be 

 readily found by means of the dipping needle even in the 

 darkness and fog." Equally erroneous was his opinion 

 that compass variation is nothing but the deviation of the 

 needle to more massive or elevated parts of the globe, and 

 that it is constant at the same place. When these beliefs 

 were proved to be wrong, it must have seemed to many 

 that not only was Gilbert's general theory vague and 

 indefinite, but that even his especial practical applications 

 of it to the purposes of the navigator were misleading, and 

 more likely to invite the perils of the sea than to prevent 

 them. 



Before the extent of his errors and uncertainties was 

 generally perceived, his work was generally praised ; but 

 later it seems to have fallen into oblivion. Small wonder, 

 when to the many who believed it heretical were added 

 more who thought it open to the charge of teaching 

 delusions. But in time the world separated the delu- 

 sions from the truths ; it rehabilitated Gilbert, not for his 

 speculations, not even because he rescued the study of 



