JS6 On the Catoptrkal and Dioptrical 



kind, if historians have truly related the facts, was that spe- 

 culum, which king Ptolemy Euergetes is said to have con- 

 structed on the Pharos tower, in which were represented 

 hostile fleets, and whatever else was to be seen by sea or 

 land throughout Egypt ; to all which things, since they 

 exceed the limits of nature, no credit is to be given." 



8. " Taught by experience that many facts reckoned 

 chimerical by a number of learned men, having been better 

 examined by other learned men, have been found not only 

 possible but in actual existence, I have suspected that the 

 same might be the case with this mirror of Ptolemy. I 

 therefore at once concluded that the decision of this fact 

 ought not to depend on the sole authority of some learned 

 men ; but that, in the laws of optics, dioptrics, and catop- 

 trics, we ought to look for just marks to condemn it as 

 fabulous, or good reasons to demonstrate its possibility. 



9. " We frequently observe, that in historical details re- 

 lating to the sciences, which are commonly but little known 

 to such authors, their ignorance makes them intersperse 

 circumstances which render their accounts obscure and un- 

 distinguishable, and even sometimes unintelligible or im- 

 possible, although, in truth, they may be perfectly real. 

 Optics catoptrics, and dioptrics, are among the sciences 

 of which most historians are ignorant, or of which they 

 possess but a very superficial knowledge. To banish, then, 

 to the regions of fable or impossibility this famous mirror 

 of Ptolemy, it is not enough that we find in its historians 

 impossible circumstances which stamp it as chimerical ; 

 we must moreover have proofs, which, independently of 

 the accessory circumstances with which ignorance has 



cm knowing it, the example of holy mother church, when they ascriha 

 the wonders performed by Michael Sco?, to his being a ivarlock, or a per- 

 son in compact iui the dtil. They will tell you. that if you put a wand 

 through the key-hole of his door at Melrose, it will come out peeled; 

 that the deil carried him through the air to Rome, and back again, in 

 one day, iScc. Sec. It seems that Scot really was sent to Rome to represent 

 to the pope the absurdny of some claim of superiority over the clergy of 

 Scotland, which had been set up by the archbishop of York. About 17 

 or L$yptr*4£3» a writer in one of the periodical publications alleged 

 (seriously to all appearance) that an air-balloon had been the vehicle in 

 this wonderful journey. The believers in Scot's supernatural powers al- 

 ways add, that he got ail his lair, and was taught all his uncanny' tricks \ 

 at Oxford. The truth is, that Wlubael Scot, of Balwirie, the cotemporary 

 of Rop-cr Ba on t (for he wns born about the end of the izth or the be- 

 gfopjng of the \y\\ century, and died in 1290,) " was one of the greatest 

 philo, ophers. mathematicians, and linguists, of his age.'' See Macken- 

 zie's Lives of Scottish Writers, vol. i. p. 214., as quoted in Henry s Hist. # 

 of G. Bii:. id ed, vol. viii. p. zzz. — Translator. 



clothed 



