ECLIPSES. 41 



changes her apparent diameter, and may augment or diminish 

 the apparent distances of the centres of the sun and moon, so that 

 an eclipse of the sun may occur to the inhabitants of one country, 

 and not to those of another. In this respect the solar eclipses 

 differ from the lunar, which are the same for every part of the 

 earth where the moon is above the horizon. In solar eclipses, 

 the light reflected by the atmosphere diminishes the obscurity 

 they produce. Even in total eclipses the higher part of the 

 atmosphere is enlightened by a part of the sun's disc, and reflects 

 its rays to the earth. The whole disc of the new moon is fre- 

 quently visible from atmospheric reflection. During the eclipse 

 of the 19th of March, 1849, the spots on the lunar disc were dis- 

 tinctly visible, and during that of 1856 the moon was like a 

 beautiful rose-coloured ball floating in the ether: the colour is 

 owing to the refraction of the sun's light passing through the 

 earth's atmosphere. 



In total solar eclipses the slender luminous arc that is visible 

 for a few seconds before the sun vanishes and also before he re- 

 appears, resembles a string of pearls surrounding the dark edge of 

 the moon ; it is occasioned by the sun's rays passing between the 

 tops of the lunar mountains : it occurs likewise in annular eclipses. 

 A phenomenon altogether unprecedented was seen during the 

 total eclipse of the sun which happened on the 8th of July, 1842. 

 The moon was like a black patch on the sky surrounded by a faint 

 whitish light or corona about the eighth of the moon's diameter 

 in breadth, which is supposed to be the solar atmosphere ren- 

 dered visible by the intervention of the moon. In this whitish 

 corona there appeared three rose-coloured flames like the teeth of 

 a saw. Similar flames were also seen in the white corona of 

 the total eclipse which took place in 1851, and a long rose- 

 coloured chain of w^hat appeared to be jagged mountains or sierras 

 united at the base by a red band seemed to be raised into the 

 corona by mirage ; but there is no doubt that the corona and red 

 phenomena belong to the sun. This red chain was so bright 

 that Mr. Airy saw it illuminate the northern horizon through an 

 azimuth of 90 with red light. M. Faye attributes the rose- 

 coloured protuberances to the constitution of the sun, which, like 

 Sir William Herschel, he conceives to be an incandescent globe, 

 consisting of two concentric parts of very unequal density, the 

 internal part being a dark spherical mass, the external a very 



