72 CANARY ISLANDS. 



sunset, under the appearance of a serene whitish clearness, 

 resembling the galaxy. It has the form of a pyramid, with 

 its base turned towards the sun, and its axis in the zodiac. 

 As we approach the poles, it appears towards the end of 

 winter, and in the spring, after sunset ; and in autumn, or 

 the beginning of winter, we observe it before sunrise. 

 Many theories have been advanced with regard to its cause, 

 but none of them satisfactory ; it must be referred, how- 

 ever, either to the nature of the terrestrial atmosphere, or 

 to the position of the globe with its relation to the sun. 

 The delightful spectacle of the dawn and of twilight, is 

 almost entirely denied to those who live in the regions of 

 the equator, where the sun rises in a direction nearly 

 vertical ; the light or darkness comes on very near the 

 time that the sun approaches or recedes from the horizon. 

 It is towards the poles that these reflected splendors are the 

 longest visible. As we pass northward, or southward from 

 the equator, they become brigkter and brighter, until they 

 change the whole of the night into a magic day. 



Port Orotava, Friday, ) 

 October 4, 1833." \ 



