6 VOYAGE TO THE 



chap, more charged with humidity, and the sky thicken- 

 w^ ed with dark clouds, which, latterly, moved heavily 

 June, m a u directions, pouring down torrents of rain. 



On the 16th, the sun was eclipsed ; and we made 

 many observations to determine the moment of con- 

 junction. In doing this, my attention was arrested 

 by a very unusual appearance. It consisted of a 

 luminous haze about the moon, as if the light 

 had been transmitted through an intervening atmo- 

 sphere. I made a sketch of it very soon afterwards,* 

 of which I was very glad, as a similar phenomenon, 

 I found, had been observed by M. Dolland in an- 

 other eclipse ; and as the subject has since received 

 much interest from the circumstance of Aldebaran, 

 and Jupiter and his satellites, having been seen pro- 

 jected upon the disc of the moon. About the time 

 of the greatest obscuration, Leslie's photometer 

 stood at 27°, exactly half what it afterwards showed. 

 Between the intervals of observation, we amused 

 ourselves with making experiments with a burning 

 glass upon differently coloured cloths, in imitation 

 of those recorded in the Memoirs of the Astrono- 

 mical Society, and which will convey to the general 

 reader a more intelligible idea of the decrease of in- 

 tensity in the sun's rays at the time of the greatest 

 obscuration, than the observations with the photo- 

 meter, as well as of the readiness with which some 

 colours ignite in comparison with others : for in- 

 stance, 



Black Blue Scarlet, Pea-Green 



burned instantly ; required 3%7, 15 s , 7: would not ignite. 



* See t!ie plate. 



