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A Phenomenon of the Rainbow, observed by R. Mant, D. D. 

 M. R. I. A., Lo)'d Bishop of Down and Connor, Nov. 14,it 

 1826. 



Read, April 2, 1827. .j-.ig lllj h 



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 X HIS phenomenon (vid. figure) was observed at the See House 

 near Belfast, between three and four o'clock on Tuesday, Nov. 14, 

 1826. It remained till the setting of the s«n. The colours of each 

 bow were brilliant, but the centre one was the least so. It is not 

 known how long it was visible, but it must have been at least ten 

 minutes. 



This phenomenon appears to afford an interesting illustration of 

 the theory of the rainbow.* It cannot be doubted that the extra- 

 ordinary, or centre bow, was occasioned by an image of the sun 

 reflected from the surface of water (probably the Lough of Bel- 

 fast). The description and figure answer exactly to this explana- 

 tion. The inner and centre bows have their colours in the same 

 order. They both appear to spring from the same points of the 

 horizon, as they ought ; because the sum, of the heights of the two 

 bows must be equal to twice the angle of the primary bow. The 

 centre bow appears to mix itself with the exterior or secondary bow. 



• A similar phenomenon was described in a periodical work published several years ago. Also 

 recently, Mr. Scoresby, in Jameson's Edinburgh New Philosophical Journal, Vol. II. p. 235, has 

 described some appearances of this kind observed in the North Seas, but these were much 

 more imperfect than that observed by the Bishop of Down. 

 VOL. XV. £ E 



