Ch. IX. SOUTH AMERICA. 443 



regard to himfelf, and not that relating to others. 

 The diameter of the arches gradually altered with the 

 afcent of the fun above the horizon ; and the phasno- 

 menon itfelf, after continuing a long time, infenfibly 

 vaniflied. In the beginning the diameter of the in* 

 ward iris, taken from its laft colour, was about five 

 degrees and a half ; and that of the white arch, which 

 circumfcribed the others, not lefs than fixty-feven de- 

 grees. At the beginning of the phenomenon, the 

 arches feemed of an oval or elliptical figure, like 

 the difk of the fun; and afterwards became per- 

 fectly circular. Each of the leaft was of a red co- 

 lour, bordered with an orange and the laft followed 

 by a bright yellow, which degenerated into a ftraw 

 colour ; and this turned to a green. But in all, the 

 external colour remained red. 



On the mountains we alfo had frequently the plea- 

 fure of feeing arches formed by the light of the moon ; 

 particularly one on the 4th of April 1738, about eight 

 at night, on the plain of Turubamba. But the moft 

 fingular was one feen by Don George Juan, on the 

 mountain of Quinoa-loma, on the 22d of May 1739, 

 at eight at night. Thefe arches were entirely white, 

 without the mixture of any other colour ; and formed 

 along the flope or fide of a mountain. That which 

 Pon George Juan faw, confifted of three arches, touch- 

 ing in the fame point : the diameter of the inner arch 

 was fixty degrees ; and the breadth of the white 

 mark, or delineation, took up a fpace of five degrees ; 

 the two others were in every refped: of the fame di- 

 menfions. 



The atmofphere, and the exhalations from the foil, 

 feem more adapted than in any other place for kind- 

 ling the vapours meteors being here more frequent, 

 and often very large ; laft longer, and are nearer the 

 earth, than the like phgenomena feen in other parts. 

 One of thefe inflammations, of a very extraordinary 

 laigeriefs, was feen at QL]ito whilft we were there. 



1 can- 



♦ 



