( 165 ) 



Aerial Shadows seen froni the Cairngorm Mountains. By 

 John Macpheeson Grant, Esq. jun. of Ballindalloch. 

 In a Letter to the Editor. 



As you expressed a wish to have some account, in writing, of 

 the atmospheric appearance seen by Sir Thomas Dick Lauder» 

 and myself, in our late ramble among the Cairngorms, I have 

 transcribed the following passage from my note-book, and at- 

 tempted to give, by the accompanying diagram, some idea of 

 the beautiful phenomenon which we witnessed *. 



" On the 10th October 1830, at 3 p. m. we reached the sum- 

 mit of Ben-mac-dhuie. A thick mist enveloped the mountain, 

 like a curtain, conceahng from view the whole of the surround- 

 ing range of the Cairngorms, with the exception of the giant 

 hill on which we stood, and the scarce less elevated tops of 

 Cairentoul and Braeriach. The upper bounding line of the mist 

 was so perfectly horizontal, and the apparent undulations on 

 its surface resembled so closely the waves of the sea, that it 

 was extremely difficult to divest oneVself of the idea that we 

 stood on some desert rock in a vast ocean, with two others o? 

 similar character in sight. The day was fine ; and the sun, 

 though fast declining to the west, shone so bright and power- 

 fully on the huge masses of granite around us, that we sat down 

 for more than half an hour to rest from our fatigues, and to 

 prolong, as far as might be, the satisfaction of being on the 

 highest ground in Britain. 



" On descending from the top, at about half past three p. m., 



an interesting optical appearance presented itself to our view. 



We had turned towards the east, and the sun shone on our 



backs, when we saw a very bright rainbow described on the 



mist before us. The bow, of beautifully distinct prismatic 



colours, formed about two-thirds of a circle, the extremities of 



which appeared to rest on the lower portion of the mountain. 



In the centre of this incomplete circle, there was described a 



luminous disc, surrounded by the prismatic colours displayed in 



concentric rings. On the disc itself, each of the party (three in 



number), as they stood at about fifty yards apart, saw his own 



figure most distinctly delineated, although those of the other two 



• The diagram will be given in next Number of Journal, having been 

 received too late for the present. 



