372 NOTES TO BOOK IV, 



of Roger Bacon's mode of treating Arts and Sciences ; 

 and have also compared more fully his philosophy with 

 that of Francis Bacon ; and I have given a view of the 

 bearing of this latter upon the progress of Science in 

 modern times. See Phil. Ind. Sc. B. xn. chaps. 7 and 1 1 . 



(o.) p. 362. Since the publication of my first edition, 

 Mr. Willis has shown that much of the " mason-craft " 

 of the middle ages consisted in the geometrical methods 

 by which the artists wrought out of the blocks the complex 

 forms of their decorative system. 



To the general indistinctness of speculative no- 

 tions on mechanical subjects prevalent in the middle 

 ages, there may have been some exceptions, and espe- 

 cially so long as there were readers of Archimedes. 

 Boetius had translated the niechanical works of Archi- 

 medes into Latin, as we learn from the enumeration of 

 his works by his friend Cassiodorus (Variar. lib. i. 

 cap. 45), " Mechanicum etiam Archimedem latialem 

 siculis reddidisti." But Mechanicus was used in those 

 times rather for one skilled in the art of constructing 

 wonderful machines than in the speculative theory of 

 them. The letter from which the quotation is taken 

 is sent by King Theodoric to Boetius, to urge him to send 

 the king a water-clock. 



