228 Mr Blackadder's Remarks on an Optical Phenomenon 



At the present day, when these phenomena have received the 

 most satisfactory explanation on well-known i physical prin. 

 ciples, the interest that is felt in them is no longer the same ; 

 but if it be less intense, it is more rational ; if less irresistible, 

 it is infinitely more pleasing. 



The following notice is extracted from Travels in Greece, 

 $c. by the Reverend Mr Hughes of Cambridge, 2 vols. 4to : — 

 " I must not forget to mention one extraordinary phenome- 

 non which we observed, and for which I have searched in 

 vain for a satisfactory solution. At the extremity of the vast 

 shadow which ./Etna projects across the island, appeared a 

 perfect and distinct image of the mountain itself, elevated 

 above the horizon, and diminished as if viewed in a concave 

 mirror. Where or what the reflector could be which exhibit- 

 ed this image, I cannot conceive ; we could not be mistaken in 

 its appearance, for all our party observed it, and we had been 

 prepared for it before-hand by our Catanian friends : it re- 

 mained visible about ten minutes, and disappeared as the 

 shadow decreased. Mr Jones observed the same phenome- 

 non, as well as some other friends with whom I conversed 

 upon the subject in England." 



The interesting phenomenon here described was observed 

 from the summit of Mount iEtna on the 28th June, at sun- 

 rise ; and the fidelity of the writer is not to be questioned. 

 But while Mr Hughes is persuaded that he and his friends 

 " could not be mistaken in its appearance," we all know that 

 " appearances are deceitful." There is indeed reason to sus- 

 pect that the alleged difficulty of solution has proceeded either 

 from inaccurate observation, or from the relation of the facts 

 having unintentionally received a deceptive colouring. We 

 are given to understand that a distinct and perfect image of 

 Mount ./Etna, diminished as if viewed in a concave mirror, 

 was seen elevated above the horizon, and by observers who 

 were at the time standing on the summit of the mountain, 

 whose image was thus seen reflected. On reading such a 

 statement, one who is at all familiar with phenomena of this 

 nature, is forced either to suspect inaccuracy, or to admit 

 something altogether new ; and, on such occasions, " le doute 

 lyhilosophiffuc" is certainly not out of place. It may be asked, 



