540 PHYSICAL GEOGRAPHY. 



fluid in this country of volcanoes, is probably produced in a much greater quantity than 

 in any other. The air, strongly impregnated with this matter, and confined betwixt two 

 ridges of mountains -at the same time exceedingly agitated from below by the violence 

 of the current, and the impetuous whirling of the waters may it not be supposed to 

 produce a variety of appearances ? And may not the lively Sicilian imaginations, ani- 

 mated by a belief in demons, and all the wild offspring of superstition, give these appear- 

 ances as great a variety of forms ? Remember, I do not say it is so ; and hope yet to 

 have it in my power to give you a better account of this matter." 



Ingenious as Brydone was, he here indulges a most unfortunate speculation, which, had 

 he enjoyed the good fortune of personally observing the phenomenon, most likely, he 

 would not have proposed. It is to be accounted for upon optical principles, which 

 M. Biot, in his Astronomic Physique, thus applies, from Minasi's dissertation upon the 

 subject: " When the rising sun shines from that point whence' its incident ray forms an 

 angle of forty -five degrees, on the sea of Reggio, and the bright surface of the water in 

 the bay is not disturbed either by wind or current when the tide is at its height, and 

 the waters are pressed up by the currents to a great elevation in the middle of the 

 channel ; the spectator being placed on an eminence, with his back to the sun and his 

 face to the sea. the mountains of Messina rising like a wall behind it, and forming the 

 background of the picture on a sudden there appear in the water, as in a catoptric 

 theatre, various multiplied objects numberless series of pilasters, arches, castles, well- 

 delineated regular columns, lofty towers, superb palaces, with balconies and windows, 

 extended alleys of trees, delightful plains, with herds and flocks, armies of men on foot, 

 on horseback, and many other things, in their natural colours and proper actions, passing 

 rapidly in succession along the surface of the sea, during the whole of the short period of 

 time while the above-mentioned causes remain. The objects are proved, by accurate 

 observations of the coast of Reggio, to be derived from objects on shore. If, in addition 

 to the circumstances already described, the atmosphere be highly impregnated with 

 vapour and dense exhalations, not previously dispersed by the action of the wind and 

 waves, or rarefied by the sun, it then happens that, in this vapour, as in a curtain 

 extended along the channel to the height of above forty palms, and nearly down to the 

 sea, the observer will behold the scene of the same objects not only reflected on the surface 

 of the sea, but likewise in the air, though not so distinctly or well defined. Lastly, if 

 the air be slightly hazy and opaque, and at the same time dewy, and adapted to form the 

 iris, then the above-mentioned objects will appear only at the surface of the sea, as in the 

 first case, but all vividly coloured or fringed with red, green, blue, or other prismatic 

 colours." 



Aerial images of terrestrial objects are frequently produced as the simple effect of 

 reflection. Dr. Buchan mentions the following occurrence : " Walking on the cliff 

 about a mile to the east of Brighton, on the morning of the 18th of November 1804, while 

 watching the rising of the sun, I turned my eyes directly to the sea, just as the solar disc 

 emerged from the surface of the water, and saw the face of the cliff on which I was 

 standing represented precisely opposite to me, at some distance from the ocean. Calling 

 the attention of my companion to this appearance, we soon also discovered our own figures 

 standing on the summit of the opposite apparent cliff, as well as the representation of a 

 windmill near at hand. The reflected images were most distinct precisely opposite to 

 where we stood ; and the false cliff seemed to fade away, and to draw near to the real 

 one, in proportion as it receded towards the west. This phenomenon lasted about ten 

 minutes, till the sun had risen nearly his own diameter above the sea. The whole then 

 seemed to be elevated into the air, and successively disappeared. The surface of the sea 

 was covered with a dense fog of many yards in height, and which gradually receded 



