BURNING MIRRORS. 461 



ing of twenty.four mirrors, which conveying the rays of the sun 

 into a common focus, produced an extraordinary degree of heat. 

 And Lucinn speaking of Archimedes, says, that at the siege of Sy. 

 racuse he reduced, by a singular contrivance, the Roman ships to 

 ashes. And Galen ; that with burning glasses he fired the ships of 

 the enemies of Syracuse. Zonaras also speaks of Archimedes' 

 glasses, in mentioning those of Proclus, who, he says, burnt the 

 fleet of Vitellius at the siege of Constantinople, in imitation of 

 Archimedes, who set fire to the Roman fl< j et at the siege of Syra. 

 cuse. He intimates, that the manner wherein Proclus eflVcted this, 

 was by launching upon the enemies vessels, from the surface of re- 

 flecting mirrors, such a quantity of flame as reduced them to 

 ashes. 



Eustathius, in his Commentary upon the Iliad, says that 

 Archimedes, by a catoptric 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 although we 

 could not comprehend how it were possible for Archimedes to 

 have constructed such glasses : but now that the experiments of 

 father Kircher and Mr. de Buffon have made it apparent, that 

 nothing is more easy in the execution, than what some gentlemen 

 have denied the possibility of ; what ought they to think of the 

 genius of that man, whose inventions, even by their own 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 of imitating in some 

 degree, the sketches of those great masters, of whom, however, 

 they are very unwilling to be thought the disciples? 



Again, it appears that the ancients wore acquainted with re. 

 frarting burning glasses ; for we find in Aristophanes's Comedy 

 of the Clouds, a passage which clearly treats of the effects of those 

 glasses. The author introduces Socrates as examining Strepsiades 

 about the method he had discovered for getting clear for ever of 

 his debts. Me replies, that he thought of making use of a burn, 

 ing-glass, \v:ii< h h* hail hitherto us--J in kindling his fire ; for, 

 says he, should they bring a writ against me. 111 immediately place 

 my class in the sun, at sjme litile distance from the writ, and set 

 it a fire. Where we see he speaks of a glass which burned at a 

 distance, and which could be no other than a convex glass. Pliny 



