76 Proofs from old English Books, that the 



MS. of the Opus Tertium in the Cottonian library, T must 

 observe that the passage can by no means be said to ic stand 

 alone," while it so admirably corresponds with the chapter 

 which Dr. S. himself has translated, and which we have 

 above transcribed (§ 23), unless Roger Bacon be the only 

 old author who is to have his meaning elucidated, or, where 

 necessary (as in this instance it scarcely is), ascertained 

 and supported by collating different parts of his writings. 



28. Dr. S.'s next remark (the 120th) is, that " this au- 

 thor speaks only hypothetically, saying that glasses may be 

 figured, and objects may be magnified, so and so ; ' but 

 never asserts one single trial or observation upon the sun or 

 moon (or any thing else), though he mentions them both." 

 And, where is the mystery in this ? Bacon, who was re- 

 presented as a magician, and bitterly persecuted* by his 

 ignorant brethren of the church, was now writing to the 

 pope, and might naturally wish that his holiness would 

 send for him to explain his meaning more fully, which 

 might have led to a settlement under the protection of that 

 excellent pontiff. Besides, the inventor, who rashly imparts 

 his discoveries to any ...man, will generally have cause to 

 regret his communicative disposition. But would it be fair 

 to say, that because lord Napier, or the marquis of Wor^ 

 cesterf, or any other inventor, (and Bacon certainly was at 

 least in part the inventor of the optical knowledge he pos- 

 sessed,) did not at once explain the whole of their discove- 

 ries, that therefore they made u no experiments, trials, or 

 observations % on the subjects which they professedly 

 treated? It is true, that I cannot back this question with 

 any original document ; but I read in respectable modern 

 works, founded on such documents, that Bacon himself 

 states, that (C in experiments, instruments and scarce books, 

 he spent in 20 years no less than 2000 1., an amazing sum 

 in those days ;" also that i{ he had great numbers of burn- 

 ing-glasses § ;" that 6i the first burning-glass he made cost 

 him 20l. sterling || ;" and that, in his inquiries into che- 

 mistry 



V: Hutton's Diet. art. Bacon {Roger).' 



t See my first letter, in vol. xviii. p. 53, &c. of this Magazine. 



% See Dr. S.'s 88th and 120th remarks. 



$ Dr. Hutton's Dictionary, art. Bacon {Roger). 



I Equal to 60I. Paris money ; so that, at-that time (about the year 

 1150) the French Iwe was worth 6s. 8d. sterling (See B/og. Briiann. 

 art. Bacon (Rogei), note B.) For the pound in money of France, Eng- 

 land, and Scotland, was, originally, a Troy {Troisf) pound in weight of 

 hnc silver, and hence the name. But the pound in England has since 

 dwindled to 6s. 8d. j in Scotland, at the time of the Union, to about 



is. 8d. 



