Chapter VII.
CLIMATE AND SEASONS.
Bolivia, in common with other mountainous regions of South America, has three general divisions: tierras calientes or calidas, tierras templadas, and tierras frias, a hot, temperate, and cold region. Situated within that part of the torrid zone lying between 8° south of the equator and the tropic of Capricorn, and traversed from northwest to southeast by the highest mountains of the Andean range, it necessarily posseses a great variety of climate. In a general sense, the eastern part is hot and humid, the central cordillera system cold, while the climate of the high plains (altiplanicie) of the western division assimilates that of the temperate zone.
As a whole, the climate is mild and salubrious. In the highlands or elevated regions of the Titicaca basin, where the principal centers of both urban and suburban population are located, the climate is remarkably healthful, though the extremes of temperature between day and night demand corresponding caution to avoid colds and consequent pneumonia. While smallpox is endemic to this region it is rarely epidemic, and, except in cases of black smallpox, which are of infrequent occurrence, is rarely fatal. As a rule, strangers on entering this part of the country suffer from dysentery, and, until heart and lungs have adapted themselves to the rarefied air, experience the discomforts of soroche, the chief characteristics of which are headache and great difficulty in breathing. Soroche is the Spanish translation of the Aymara word sorojche, the name by which this ailment is known among the Aymara Indians. In other parts of South America it is called puna.
