278 SPECIAL RESULTS IN THE URANOLOGICAL 



of the Earth, Batista Baliani, nearly two centuries and a half 

 before, in a letter to Galileo, described these spots as cooling 

 agencies ( 474 ). A similar inference has been drawn from 

 the essay made by the diligent astronomer Gautier at Ge- 

 neva ( 475 ), to compare four periods of frequency and paucity 

 of spots on the sun's disk (from 1827 to 1843) with the 

 mean temperatures shewn by 33 European and 29 American 

 stations ; but the residual quantity on the side of the sup- 

 posed cooling power of the solar spots, (scarcely 0*42 

 Centigrade, or less than 0'8 Fahrenheit), is so small, that 

 even for the particular localities it may be attributed to 

 errors of observation or to the influence of the direction of 

 the wind. We remark in this comparison indications of 

 the opposite affections of the two sides of the Atlantic, 

 in accordance with Dove's general inferences. 



It still remains to speak of the third and outermost of 

 the three solar envelopes which have been referred to ; it is 

 supposed to be above the photosphere, and to be cloudy and 

 of imperfect transparency. The remarkable phenomena of 

 red mountain- or flame-like forms, which, during the total 

 solar eclipse of the 8th of July, 1842, were seen, though 

 not for the first time yet much more clearly than before, 

 and observed simultaneously by several of the most prac- 

 tised observers, have led to the hypothesis or assumption of 

 such a third envelope or covering. Arago, with great acu- 

 men, and after a thorough examination of the observations, 

 has enumerated in a treatise on the subject ( 476 ), the grounds 

 which appear to necessitate this assumption. He has at 

 the same time shewn that similar rose-coloured marginal 

 protuberances have been already described on occasions of 

 total or annular eclipses of the sun since 1706 ( 477 ). On 

 the recent occasion, July 8, 1842, when the disk of the 



