.METEOROLOGICAL OBSERVATIONS. 



189 



REMARKS. 



1803, June 30th, at 7\ P. M. The sun being just set, a beautiful rain-bow was painted in 

 the heavens forming a compleat semi-circle, excepting a small portion near the horizon which 

 was imperfect ; the external bow was very distinct : the inner bow, which was very vivid in the 

 upper parts, struck the view with an unusual appearance, and, when inspected minutely, two other 

 bows were distinctly seen, within the principal bow, concentric with it, and in contact with each 

 other ; (i.e.) where the purple of the first ended the red of the second commenced, and so of the 

 second and third; a dim ruddy appearance was seen within the third bow, which might have 

 been taken for the rudiments of a fourth. The second bow was only about half the breadth of 

 its principal, and the vividness of its colours was diminished in the same proportion. The third 

 was of the same breadth with the second, but its brightness was reduced to half that of the other. 

 These bows appeared to diminish in brightness, and to present appearances analogous to the 

 images of a candle reflected fr >m the double surfaces of a plate mirror. A s the rain-bow is a re- 

 flector by which we can find the place of the sun, we must conclude from this phenomenon-, that 

 the horizontal refraction of the atmosphere had produced two images of the sun, above and in 

 contact with the real sun, in the same order in which the bows were visible in the opposite side 

 of the hemisphere. 



1803, December 23d, at5ih. P. M. A very beautiful and %'ery bright halo was seen around 

 the moon ; the prismatic colours were very distinct — red within, yellowish in the middle, and 

 blue without. 



