PORTION OF THE COSMOS. THE PLANETS. 329 



to the always equable, but by no means desirable or agreea- 

 ble, " vernal climate" which prevails under the equator on 

 the chain of the Andes near the limits of perpetual snow, 

 and from which I suffered much on the desert mountain 

 plains the Paramos ( 529 ) at elevations between ten and 

 twelve thousand French, or about eleven and thirteen thou- 

 sand English feet, above the sea. The temperature of the 

 air in these regions always oscillates in the day-time between 

 4 and 9 Reaumur, or 42 and 52 Fahrenheit. ' 



The ancient Greeks were much occupied with rough mea- 

 surements of the obliquity of the ecliptic, and with conjec- 

 tures respecting its variability, and respecting the influence 

 of the inclination of the terrestrial axis on climate, and on 

 the luxuriance of organic development. These speculations 

 were more especially pursued by Anaxagoras, by the Pytha- 

 gorean school, and by (Enopides of Chios. The passages 

 which illustrate them, so far as they have come down to us, 

 are indeed scanty and vague ; but they enable us to perceive 

 that the development of organic life, and the first appearance 

 of animals, were imagined to have been cotemporaneous with 

 the epoch at which the terrestrial axis began to incline, which 

 inclination also altered the habitability of the planet in par- 

 ticular zones. According to Plutarch (de Plac. Philos., ii. 

 8), Anaxagoras believed te that the World, after it had 

 began and had brought forth living beings from its bosom, 

 spontaneously inclined itself towards the noon or southern 

 side." To the same effect, Diogenes Laertius (ii. 9) says, 

 when speaking of the opinions of the Clazomeriian philoso- 

 pher " The stars had first begun to revolve, as it were, 

 round a dome, so that what appeared the pole was vertically 

 above the Earth ; but subsequently they assumed an oblique 



