576 UNIVERSAL ERUDITION. 



not to give themtclves up to thefe, and there- 

 by lofe that precious time of which every man 

 of letters ought to be ib thrifty and even avari- 

 cious. 



XXIV. In the lad place, the art of draw- 

 ing and raifing fortifications on the ground ; 

 that of turning wood, ivory, mother of peari 

 and even metals , that of polifhing glades, and 

 fetting them for optical inftruments, &c. all 

 thefe and many other like matters, belong ra- 

 ther to ufeful arts than exercifcs. It is true, 

 a man of fedentaiy life may apply himfelf to 

 them by way of relaxing his mind and exer- 

 cifmg his body, but thefe arts are to be learn- 

 ed of thofe who make them their profefiion ; 

 it is fufficient for us jufl to mention their 

 names and thereby rccal them to the re, 

 memory. 



CHAP. 



