80 



JProclus effected this, was by launching upon the cne. 

 my's vessels, from the surface of reflecting mirrors, 

 such a quantify of flame as reduced them to ashes. 



7. Eustathius in his commentary upon the Iliad, 

 says that Archimedes by a catoptic machine, burnt 

 the Roman fleet at a bow-shot's distance. Insomuch', 

 that there is scarcely any fact in history warranted 

 by more authentic testimony; so that it would be 

 difficult not to surrender to such evidence even al- 

 though we could not comprehend how it were possi- 

 ble for Archimedes to have constructed such glasses; 

 but now that the experiment of Father Kircher, and 

 M. de Buffo n hath made it apparent, that nothing is 

 more easy in the execution, than what some gen- 

 tlemen have denied the possibility of; what ought 

 they to think of the genius ef that man, whose in- 

 Tendons even by their o\vn accounts, surpass the 

 conception of the most celebrated mathematicians of 

 our days, who think they have done something very 

 extraordinary, when they have shewed themselves 

 capable o( imitating in some degree the sketches of 

 those great masters, of whom, however, they are very 

 unwilling to be thought the disciples. 



8. Again, it appears that the ancients were ac- 

 quainted with refracting burning glasses, for we find 

 inAristophaues's comedy of the Clouds,a passage which 

 clearly treats o! ihe eiieciS of those glasses. The 

 author introduces Socrates as examining Strepsiades, 

 about the method he had discovered for getting clear 

 *'or ever of his debts. Ho replies that he thought of 

 leaking use of a burning gh-.ss, which he had hitherto 

 used in kindling his fire; for, says he, should they 

 bring a writ against me, I'll immediately place my 

 glass in the sun, at some little distance from the writ 

 and set it on fire. Where we see he speaks of a glass 

 which burned at adistance,and which could be no other 

 than a convex glass. Pliny and Lactantius have 

 also spoken of glasses that burnt by refraction. The 



