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on every side by lesser ones, adhering to it by 

 means of plates, bands or hinges, connecting them 

 mutually together, so as to be moved or fixed at 

 pleasure in any direction. Thus having adapted the 

 large or middle mirror to the rays of the sun, so as 

 to point them to the givfcn place, it will be easy ia 

 the same manner to dispose the rest, so that all the 

 rays together may meet in the same focus : and mul- 

 tiply compound mirrors of this kind, and giving thcn\ 

 all the same direction, there must thence infallibly 

 result to whatever degree of intenseneie, the conflagra- 

 tion required at the place given/ 1 



6. u The better to succeed in this enterprize, there 

 should be in readiness" he adds, u a considerable 

 number of those com pound mirrors to act ail at once 

 from four at least to seven.'* He concludes his dis- 

 sertation with observing, " that all the authors who 

 mention the burning machine of the divine Archi- 

 medes, never speak of it as of one compound mirror, 

 but as a combination of many." So large and accu- 

 rate a description is more than sufficient to demon- 

 strate the possibility of a fact, so well attested in his- 

 tory and by such a number of authors, that it wonld be 

 the highest arrogance, to refuse our suifrage to such, 

 invincible testimony. Vitellion, who lived about the 

 13th century, speaks of a work of Authemius of 

 Tralles, who had composed a burning glass consisting 

 of twenty-four mirrors, which conveying the rays 

 of the sun into a common focus, produced an ex- 

 traordinary degree of heat. Aud Lucian, speaking 

 of Archimedes says, that at the siege of Syracuse he 

 reduced by a singular contrivance, the Roman ships to 

 ashes. And Galen* that \vith burning glasses, he 

 fired the ships of the enemies of Syracuse. Zonaras 

 also speaks of Archimedes' glasses, in mentioning tfrose 

 of Proclus, who he says, burnt the tieet of VitelUus 

 at the siege of Constantinople, in imitation of Archi- 

 medes, who set tire to the Koman iluet at the siege- 

 of Syracuse, lie intimates that the mauner whereui 



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