152 Col. Francis Hall's Meteorological Observations 



o 



Thus, La Guayra, situated on a sandy beach backed by a 

 precipitous wall of rocks, has no counterpoise to the excess 

 of heat but the sea breeze, and the remote influence of the 

 ridge of the Silla, which nowhere reaches the limit of per- 

 petual snow. Humboldt considers it in consequence as the 

 hottest place on the shores of the New World, (Personal 

 Narrative, vol. iii. p. 386) the mean annual temperature bein«r 

 82^*6 ; yet the observations I made during some months' re- 

 sidence in Maracaybo, give an annual mean of 84'^*63 ; nor 

 is this surprising, when we consider the localities of both 

 places. 



In Maracaybo the sun's rays are reflected from a barren 

 sandy soil, scantily sprinkled with Mifnosas, and prickly plants; 

 the mountain chains are too remote to have any influence on 

 the atmosphere, so that several years frequently pass without 

 any regular fall of rain. The vicinity of the lake, no doubt, acts 

 slightly as a refrigerant, but the city is built on the border 

 of its outlet to the vsea, where it is both narrow and shallowest, 

 and is consequently heated nearly to the temperature of the 

 incumbent atmosphere. Add to this the small sandy eleva- 

 tions to the north, which intercept the partial effect of the 

 sea breezes, so that they are scarcely felt, except in the months 

 of December and January, when the thermometer sometimes 

 sinks to 73°*0 ; yet the medium even of these two months is 

 not less than 81°-0, while that of La Guayra from November 

 to December at noon is, according to Humboldt, 75°*8, and 

 at night 70°*9 (Pers. Nar., vol. ii. p. 387). Rio Hacha is 

 situated on a sandy beach ; the sea breeze blows with such 

 violence that boats can scarcely land between ten in the morn- 

 ing and four in the afternoon : these winds however, sweep- 

 ing over the hot plains of Coro and Maracaybo, have but a 

 partial effect in lowering the temperature, the annual mean of 

 which is l°-98 less than that of Maracaybo. I never saw the 

 thermometer lower than 75°-0, nor above 89°'0. In Santa 

 Marta the average of the coolest months is 82°*25. The 

 thermometer however never rose during my residence there 

 above 87°'0. The soil is sandy, and the city is surrounded 

 by bare rocky heights to the north and south, which counter- 

 poise the cooling influence of the Sierra nevada (snowy moun- 

 tains), from which it is but a few leagues distant. The tempe- 

 rature of Barranquilla, a village situated on the river Magda- 

 iena, about 18 miles from its mouth, is nearly the same with 

 that of Santa Marta ; for if on the one hand the air is re- 

 freshed by the evaporation from a damp soil covered with 

 luxuriant forests, and the vicinity of a large river ; on the 

 other it is beyond the reach of the sea breeze, and the in- 

 fluence of the mountains which operate in Santa Marta. The 



