Page:Popular Science Monthly Volume 67.djvu/241

Rh per 1,000 feet. This average is based upon the study of the climate of the cities of Puebla, Mexico, Guadalajare, San Luis Potosi, Pachuca, Zacatecas, Guanajuato, Oaxaca, Queretaro, Aguas Calientes, Leon, Pabellon, San Juan del Rio, Patzecuaro, Tacubaya, the list including all the cities situated on the tropical plateau and for which meteorological records are available. The highest figure (2.7°) is given by the city of Zacatecas, 8,187 feet high; the lowest (1.8°) by the city

of Oaxaca, which, although standing 1,319 feet above San José, has a warmer climate (69.0°) than the latter city.

There are in Central America but two seasons: the rainy season, extending from about the middle of May till the middle of November, and the dry season, covering the rest of the year. In the rainy season, rain falls only for a few hours every day, generally from 2 till 6  leaving both mornings and evenings cloudless. Patients suffering from lung troubles find both seasons about equally curative on the highland. Debilitated and neurasthenic invalids recuperate better in the dry than in the rainy term. During the rainy season, the cities situated on the Atlantic slope have a climate somewhat dryer than that of the cities which are located on the Pacific side. The contrary is true during the dry season.

The intensity of light, a result of altitude and latitude combined, is perhaps one of the most important therapeutic elements of the climate