CUM ATE. 



151 



tant from the equator, makes them of the greatest 

 importance in the study of meteorology. This science 

 can advance only by the determination of certain 

 numerical elements, which are the indispensable 

 basis of the laws we wish to discover. As the 

 appearance of vegetation on the confines of the 

 torrid zone and under the equator is the same, we 

 are accustomed vaguely to confound the climates of 

 the zones comprised between the 0° and 10°, and 15° 

 and 23° of latitude. The region of the palm, the 

 banana, and the arborescent grasses, extends far 

 beyond the tropics, but we should err in applying 

 the result of our observations on the limit of the 

 torrid zone, to the phenomena we may observe 

 in the plains under the equator. 



It is important to establish first, in order to correct 

 these errors, the means of temperature for the year 

 and the months, as also the oscillations of the 

 thermometer at different stations under the parallel 

 of Havana ; and by an exact comparison with other 

 places equally distant from the equator, Eio Janeiro 

 and Macao, for example, to demonstrate that the 

 great decline of temperature which has been observed 

 in Cuba, is owing to the descent and irruption of the 

 masses of cold air which flow from the temperate 

 zones toward the tropics of Cancer and Capricorn. 



The mean temperature of Havana, as shown by 



