31 6 THE INTELLECTUAL RISE IN ELECTRICITY. 



ance of these practical achievements, induced Gilbert to 

 give the work to the world before it had reached comple- 

 tion and with its parts t disproportioned. That Gilbert 

 designed making additions to it is proved by the single 

 letter written by him now known to exist, which Dr. 

 William Barlowe, Archdeacon of Salisbury, appends as a 

 sort of testimonial to his own little essay on the magnet, 

 which appeared in 1613. In this letter, which was prob- 

 ably written early in 1602, Gilbert speaks of adjoining "an 

 appendix of six or eight sheets of paper to the book after 

 a while," which was to be descriptive of some new inven- 

 tions ; and probably of two instruments for finding latitude 

 at sea, which his friend, Thomas Blondeville, published 

 and ascribes to him in a curious astronomical treatise en- 

 titled "the theoriques of the Seven Planets," which he 

 produced in the last-named year. At all events, this ad- 

 dition to the De Magnete never was made; and Gilbert 

 appears to have devoted himself to the preparation of a more 

 elaborate exposition of his cosmical theories than that 

 which terminates the earlier work. This he left, however, 

 in a fragmentary state, only two books or divisions having 

 been written; or, more properly speaking, sketched, for they 

 show all the marks indicative of an intention to amplify at 

 some future time. They probably bear a similar relation 

 to the finished work as it would have been, as the two 

 books of the Advancement of Learning to the final De 

 Augmentis of Francis Bacon. This epitome, with the 

 title-page belonging to it, forms the first part of the post- 

 humous volume to which I have already alluded, and is 

 called "A new philosophy of our sublunary world;" its 

 contents being thus clearly distinguished in character from 

 those of the De Magnete, which bears the general title of 

 U A new physiology of the magnet, magnetic bodies and 

 of the great magnet, the earth." The later work was 

 manifestly intended to supplant existing cosmologies, and 

 to inculcate the philosophy of the world's place in the 

 universe which Gilbert believed that he had developed ; 



