94 Baron Von Buch's Observations 



ascending, in part very abruptly, at no great distance. Hence 

 there is, during the night, no perfect radiation of heat to the 

 open sky, and the diminution is inconsiderable. Around Lagu- 

 na, on the cbntrary, which is elevated 1588 Parisian feet above 

 the sea, there is a plain, about half a German square mile in ex- 

 tent, and there the nights are sensibly cold ; so much that, in 

 winter, it is no way rare for ice to be formed, though only of the 

 thickness of a knife. Yet it never snows in Laguna ; the fall of 

 temperature is peculiar only to the ground, since it is not in the 

 atmosphere, but arises from the radiation of heat, which is not 

 again reflected from the clear sky, and at places not far from 

 Laguna, though at the same level, would probably not occur. 



On these grounds, I do not think that any thing ought ei- 

 ther to be added to, or subtracted from, the observations of Dqn 

 Francisco ; and am of opinion, that they may be regarded as 

 giving a fair view of the climate of Santa Cruz. 



The mean temperature foi' each month is as follows : 



Fahr. 



Mean, 71.09 



These are, it must be allowed, very high temperatures. The 

 mean heat of January, the coldest month, is as great as that of 

 the whole year in the southern parts of Italy ; but from the 

 range of temperature in the several months, it is evident that 

 the sun here no longer passes through the zenith. There is no 

 twofold elevation and depression of the temperature, as in all 

 places under the tropics ; but as is almost universal in the tem- 

 perate regions, the greatest depression is in January, the great- 



