PORTION OF THE COSMOS. THE SUIT. 279 



Moon covered the entire solar disk, (its apparent diameter 

 being at that time greater than that of the Sun,) there was 

 seen not only a ( 478 ) white shining appearance forming acorona 

 or bright circle surrounding the Moon, but also, as if attached 

 in the limb or margin of the Moon, two or three rose-tinted 

 elevations, which some observers compared to mountains, 

 others to reddened masses of ice, and others to motionless 

 jagged or pointed flames. Arago, Laugier, and Mauvais at 

 Perpignan, Petit at Montpellier, Airy on the Superga near 

 Turin, Schumacher at Vienna, and many other astronomers, 

 agreed perfectly with each other in respect to the main 

 features of the general phenomenon, notwithstanding the 

 great diversity of the telescopes employed. The elevations 

 were not seen in all cases at the same moment of absolute 

 time, and at some places they were even observed with the 

 naked eye. Their heights were also differently estimated by 

 the different observers : the surest estimation is probably 

 that of Petit; the director of the Observatory at Toulouse : 

 it was r 45", which, if the protuberances were really solar 

 mountains, would correspond to elevations of 40,000 geo- 

 graphical miles : this is almost seven times the diameter of 

 our globe, while the solar diameter is only 112 times that 

 diameter. The consideration of the whole of these phe- 

 nomena has led to the very probable hypothesis of these 

 roseate forms being undulations or protuberances of the third 

 envelope, or masses of cloud illuminated and coloured by 

 the photosphere ( 479 ). Arago, in putting forward this hy- 

 pothesis, expresses at the same time the conjecture, that the 

 darkness of the deep blue sky at great terrestrial altitudes, 

 the intensity of which I had myself measured on the highest 

 Cordilleras, (instrumental means for such measurements 



