72 Proofs from old English Books, that the 



instead of a watch-tower. The same is to be understood 

 of' the story mentioned by Porta*, That Ptolomy, by spe- 

 culums, could discern ships at the distance of 600 miles, 

 which could not possibly be done by our best telescopes. " 

 The doctor here reiers to the 357th page of the Opus Majus; 

 but, as he does not give us his author's express words, I 

 beg leave to cite a parallel passage from the 5th chapter of 

 Bacon's piece De Secretis, &c. i* Of the secret Works of 

 Nature and Art, and of the Nullity of Magic f." Possunt 

 ervim sic figurari perspicua, 8cc. " For transparent (bodies) 

 may be so figured, that things at the greatest distance may 

 appear to be the nearest, and the contrary; so that, from an 

 incredible distance, we may read the smallest letters, and 

 number things however minute : for thus it is thought that 

 Julius Caesar, on the coast of Gaul, discerned (per itigentia 

 specula) by, or through, very large glasses, the disposition 

 and situation of the camps and cities of Britannia Major." 

 Now, I can answer for it, that there is not in this chapter, or 

 in the whole of this very rational account of what is vulgarly 

 called magic, which I have perused with great pleasure and 

 admiration, a single syllabic about raising up speculums to a 

 great height. And I add, without any fear of contradiction, 

 that in this quotation there can be no mistake about the 

 word specula, which, happily for my argument, stands in 

 such a connection that it evidently is, and can only be, the 

 accusative plural of speculum (a mirror, or looking-glass) ; 

 but, as the author is talking of perspicua. (transparent things, 

 bodies, or substances), I am fully authorized to render itsim- 

 ply 6i glasses." It is not, indeed, very probable that Bacon 

 would have lefts it uncertain what specula he meant : for he 

 was an accurate grammarian; and, as Dr. Campbell ob- 

 serves J, his Latin style, though perhaps not always classi- 

 cal, is ^ neat, strong, and remarkablv expresssive; leaving 

 nothing perplexed or obscure, either from a want or from 

 a redundancy of words." 



26. Dr. S. next proceeds (Remark 118.) to show that 

 Bacon " was not qualified to invent a telescope by theory" 

 — u considering the false notions he had from the antients 

 about distinct and confused vision ; the false principle he 

 maintains, that the apparent magnitude of an object is as 

 the angle subtended at the eye, by its image, and recipro- 



*' In his Mogia Naturalis, lib. xvii. cap. n. as quoted by Dr. S. 



\ See torn. v. p. 851. of the Thtairum "Ciem.icum, Ar^entorati 

 (Strasburgh) 1660. in which this little work of liacon is invested entire, 

 and illustrated with notes. 



% Biog. Brit. art. Bacon (Rcga) note K. 



cally 



