150 



" Carrick Blacker, Portadown, Co. Armagh, 

 ''March 7, 1848. 

 " My dear President, — I have just observed a curious 

 rainbow, which presented the following appearance, and think 

 a note of the occurrence may be interesting to you. 



" In the rough diagram I have sketched, a represents the 

 primary rainbow; b the secondary: cc two spurs, or portions 

 of another bow, shooting off from the two ground ends of the 

 primary bow, and joining the secondary ; dd two minor bows, 

 composed of the violet colour only. 



" In the two spurs the order of colours was the same 

 as in the primary bow, and not reversed, as in the secondary. 

 The whole was relieved against a dark, eastern sky, and very 

 vivid and intensely bright in colour, and perfect in form. 

 The hour, about a quarter to 5 o'clock, and the sun nearly 

 setting, with a smart, passing shower. Of all the rainbows 

 I have ever seen, none appeared so close to me. 

 " Very truly your's, 



" Stewart Blacker." 



In a subsequent letter Mr. Blacker writes : 

 •' Between the bow and the sun (which, as I observed be- 

 fore, was very bright, and near setting) was the River Ban, 

 swelled by the winter rains into a large lake. 



" Do you think the triple rainbow could possibly be ac- 

 counted for by supposing the sun's rays reflected from the 



