XX INTRODUCTION. 



where the ocean or westerly winds prevail, they deposit their moisture ; 

 these do not extend farther north than the Rio Maule, in latitude 

 35, from which point the monsoons blow parallel with the coast; 

 during the southern summers they come from the south, while those 

 from the north prevail during the winter; with the former the 

 weather is clear and the sky generally cloudless, but the latter are 

 attended with rain, mist, and fogs. These monsoons are circum- 

 scribed within narrow limits. 



The south one rs sometimes confounded Avith the southeast trades, 

 from which it differs very materially in its direction, and, as I before 

 remarked, half the year it is intermitted. The southern monsoon is 

 a dry wind, and its daily duration is generally confined to five or 

 six hours, from 11 A. M. till 4 p. M.; a calm then succeeds, and 

 towards morning, in this season, the land wind is felt with almost the 

 same certainty. The winter monsoon blows moderately from the 

 north and northwest, has a high degree of moisture, and at times 

 violent storms take place. Although the winds are the great agents 

 in producing the changes in this climate, there are other causes 

 which also exert their influence. As far as the temperature along 

 the coast is concerned, its small variation may readily be ascribed 

 to the south polar or Chili stream, which sweeps throughout its 

 whole extent. At Valparaiso, in the latitude of 33 south, we found 

 its water at 56 Fahr., and, from many observations I have had 

 access to, it varies little from this temperature throughout the year. 

 The monsoons are found to prevail as well in the interior as on the 

 coast, and have the same characters; and to their influence in like 

 manner it owes its variation of climate. During the summer months, 

 the sky is almost cloudless throughout the day, and especially so at 

 night, when it is calm and brilliant; no rain falls, and little dew. In 

 the valley of the Maypo, they cultivate by irrigation; and, were it 

 not for this, Chili would be an arid and barren waste. What seems 

 remarkable, the dryness of the climate is observable in the highest 

 ridges of the Andes, as well as in the valleys or plains. The lofty 

 ridges in the interior, for the greater part of the year, have a distinct 

 and well-defined outline, resulting from an absence of moisture ; and, 

 from a like cause, the character of the vegetation is thorny. 



The rainy season throughout Chili, north of the Rio Maule, is in 

 June and July, when it rains in torrents. I have no account of the 

 quantity which falls ; it lasts at times for a fortnight, raining violently 

 and almost without cessation : the beds of rivers that were dry become 



