METEOROLOGY. 227 



December, 1856, at 7 a. id., north wind, 4.; on the 19th, at 7 a.m., clouds 

 from the north, 4. ; on the 20th, at 7 a. m,, clouds trom the north, 3. ; 

 at 9 p. m., clouds from the north, 4. Number 4, as an indication of 

 force attached to the winds or the clouds is extremely rare in the 

 register for Colonia Tovar, and therefore denotes something extraor- 

 dinary. The mean barometer height was remarkably low on the ] 9th, 

 20th, and 23d of December, vid : diagram of mean barometer height 

 for 1856. 



I could, no doubt, cite many more instances of this kind if I had 

 the means to know what is going on in other parts of the world. 



To make observations in this country about the higher strata of the 

 atmosphere and their motions, no place, I should think, would be 

 more adapted than the mountains of Merida, which are said to reach 

 the line of perpetual snow. There we have a gigantic range of snow- 

 capped mountains stretching from southwest to northeast. Its base is 

 washed on one side by the warm waters of the gulf of Maracaybo, that 

 great arm of the sea, which runs far inland, and expands in a vast 

 basin near the mountains. On the other side lie^ in near approach, 

 those immense, level, grassy plains, the Llanos of Venezuela, which 

 are but slightly elevated above the level of the sea, and entirely bare 

 I of forest. 



When in the dry season the sun, unobstructed by clouds, acts upon 



the extensive sheet of the already very warm water of the gulf, with 



all the power of its nearly vertical rays, the quantity of vapor carried 



into the air by evaporation must be immense, while at the same time^ 



: on the opposite side of the mountains, the rarified strata of the atmos- 



' phere vibrate over the dry and burning hot surface of the llanos as 



! over a heated furnace. 



I The phenomena which the different strata of air under such cir- 

 j cumstances must exhibit would, I think, form a worthy and highly 

 ; interesting subject of study for the meteorologist, and tend to advance 

 ' the cause of his science. Happy he who has the means and the mind 

 j to do so ! 



i In connection with the foregoing, I will mention only one phenom- 

 i enon, near the lake of Valencia, which may show some of the effects 

 : of evaporation with regard to its disturbance of the atmosphere. 



As otten as I have visited Valencia in the dry season I have ob- 

 served a violent northerly wind, amounting sometimes to a very stiff 

 breeze, blowing there late in the afternoon till 10 or 11 o'clock at 

 night. I found this same wind also in other parts of the valley of 

 Aragua near the lake of Valencia, as, for instance, in Cagua and San 

 Jose. 

 I By inquiry I learned that this is a regular wind, commencing and 

 i; ending with the dry season, returning every year as regularly as the 

 I season itself; that it rises every afternoon, continues till late at night, 

 : and is very annoying to the inhabitants by the dust it raises. 

 [ By reterring to Humboldt's Travels I find the following sentence^ 

 } where he speaks about the site of the town of Valencia: " liut there 

 1 is an opening on the meridian of Nueva Valencia, which leads towards 

 the coast, and by which a cooling sea breeze penetrates every evening 



