62 



SCENERY OF THE HEAVENS. 



in the form of a corona, or luminous ring, encircling the moon and exhibiting a radiating 



.aspect. The most probable con 

 clusion, founded upon its round 

 shape, nebulous structure, and 

 gradually diminishing density out 

 wards, is, that the ring is due to 

 the presence of an extensive atmo 

 sphere which encompasses the solar 

 orb. Other striking features of total 

 eclipses are ruddy sj)ots, or pro 

 tuberances, varying in colour from 

 I light pink to deep crimson, which 

 appear upon the margin of the dark 

 lunar disk. They have been com 

 pared by different observers to 

 beautiful sheaves of flame, and to 

 the snowy peaks of the Alps, rose- 

 I coloured by the morning or evening 

 sun. These appearances are supposed to arise from clouds suspended in the atmosphere of 

 the sun, which absorb nearly all the rays of the spectrum, except the red, as in the case 

 of the terrestrial clouds when illuminated after sunset. It has been often remarked, that 

 when the margin of the moon comes into contact with that of the sun, the appearance pre 

 sented is that of a broken glimmer of light, which the late Mr Baily compared to a link of 

 bright beads. The curious spectacle of " Baily's beads," as they are called, seems to be 

 caused by the rough mountainous edges of the moon, which touch the margin of the sun, 

 while transiently the sunlight gleams through the chinks or valleys between them. 



A delicately luminous cone is sometimes seen accompanying the sun, extending from the 

 horizon obliquely upwards in the direction of the zodiac, and, therefore, called the Zodiacal 

 Light. It appears before sunrise and after sunset, but is never seen by us so well denned 

 as in the equatorial regions, though it may frequently be discerned after the evening 



twilight in March and April, 

 and before the morning twilight 

 in September and October. 

 The light resembles in appearance 

 the tail of a comet. The faintest 

 stars shine through it. Its colour 

 varies according to the state of 

 the atmosphere, but it is generally 

 of a pure rose tint. The bright 

 ness also varies, and some years 

 it has never been seen at alL 

 Keppler appears to have been the 

 first who noticed this phenome 

 non. Afterwards Cassini observed 

 it, and when Humboldt was tra 

 velling in South America, he had 

 several distinct views of it at Ca- 

 raccas. Its extent from the sun, 

 Zodiacal Ught. situated at its base to the vertex, 



varies from 45' to 50', and its breadth at the base from 20' to 30'. It has been conjectured that 



