Chap. 10.] Lunar and -Marine Bows. 483 



In the fame manner innumerable bows might be 

 formed by a greater number of reflections within the 

 drops ; but as the fecondary is fo much fainter than 

 the primary, that all the colours in it are feldom feen, 

 for the fame reafon a bow made with three reflec- 

 tions would be fainter frill, and in general altogether 

 imperceptible. Since the rays of light, by various re- 

 flections and refractions, are thus capable of forming, 

 by means of drops of rain, the bows which we io fre- 

 quently fee in the heavens, it is evident that there will 

 be not only folar and lunar bows, but that many 

 finking appearances will be produced by drops upon 

 the ground, or air on the agitated furface of the water. 

 Thus a lunar bow will be formed by rays from the 

 moon affected by drops of rain, but as its light is 

 very faint in comparifon with that of the fun, fuch a 

 bow will very feldom be feen, and the colours of it, 

 when feen, will be faint and dim. I was once a fpee- 

 tator of a lunar bow, in the courfe of a pedeflrian ex- 

 pedition by moonlight in the autumnal feafon. The i 

 night was uncommonly light, though fhowery, and 

 the colours much more vivid than I could have con- 

 ceived ; indeed I have feen rainbows by day not more 

 confpicuotis". There were not, however, fo many co- 

 lours diftinguiihable as' in the folar bow. 



The marine or fea bow is a phenomenon fome- 

 times obferved in a much agitated fea ; when the 

 wind, fweeping part of the tops of the waves, carries 

 them aloft, fo that the fun's rays, falling upon them, 

 are refracted, &c. as in a common fhower, and paint 

 the colours of the bow. 



Rohault mentions coloured "bows on the grafs, 

 formed by the refraction of the fun's rays in the 

 morning dew. 



Dr. 



