i22 ESSAYS AND OBSERVATIONS 



the fun near fetting, and your fliadow 

 projeifled a good way on the other fide. 



When one has travelled for fome time 

 in the mift, his cloths become, as it were, 

 crufted over with particles of dew or hoar 

 froft, and the rays of the fun are refrad- 

 cd in paffing through them. The rays 

 which proceed from parts near each verge 

 of the fun form the exterior and interior 

 bow, if I may call them fo, and the rays 

 that proceed from parts near the centre 

 form a bow in the middle. 



This agrees with the account of that 

 phaenomenon by Don Antonio D'Ulloa ; 

 but when there are only two bows, it 

 would feem that they are formed only by 

 the rays proceeding from each verge, 

 which occalioned the darkilh interval a- 

 bove mentioned, and the great bending 

 of the rays by refradlion occafioned the 

 fhadow to be contradled. 



It would feem that this phasnomenon 

 was feen on the mountains of Peru always 

 accompanied with the white bow above 

 defcribed ; but the above obfervation 

 Ihews they were not necelTarily connedled. 



Art. 



