The Inhabitants Of Caracas Complain Of Having Several Seasons In One And The Same Day; And Of The Rapid Change From One Season To Another.

In the month of January, for instance, a night, of which the mean temperature is 16 degrees, is sometimes followed by a day when the thermometer during eight successive hours keeps above 22 degrees in the shade.

In the same day, we may find the temperature of 24 and 18 degrees. These variations are extremely common in our temperate climates of Europe, but in the torrid zone, Europeans themselves are so accustomed to the uniform action of exterior stimulus, that they suffer from a change of temperature of 6 degrees. At Cumana, and everywhere in the plains, the temperature from eleven in the morning to eleven at night changes only 2 or 3 degrees. Moreover, these variations act on the human frame at Caracas more violently than might be supposed from the mere indications of the thermometer. In this narrow valley the atmosphere is in some sort balanced between two winds, one blowing from the west, or the seaside, the other from the east, or the inland country. The first is known by the name of the wind of Catia, because it blows from Catia westward of Cabo Blanco through the ravine of Tipe. It is, however, only a westerly wind in appearance, and it is oftener the breeze of the east and north-east, which, rushing with extreme impetuosity, engulfs itself in the Quebrada de Tipe. Rebounding from the high mountains of Aguas Negras, this wind finds its way back to Caracas, in the direction of the hospital of the Capuchins and the Rio Caraguata. It is loaded with vapours, which it deposits as its temperature decreases, and consequently the summit of the Silla is enveloped in clouds, when the catia blows in the valley. This wind is dreaded by the inhabitants of Caracas; it causes headache in persons whose nervous system is irritable. In order to shun its effects, people sometimes shut themselves up in their houses, as they do in Italy when the sirocco is blowing. I thought I perceived, during my stay at Caracas, that the wind of Catia was purer (a little richer in oxygen) than the wind of Petare. I even imagined that its purity might explain its exciting property. The wind of Petare coming from the east and south-east, by the eastern extremity of the valley of the Guayra, brings from the mountains and the interior of the country, a drier air, which dissipates the clouds, and the summit of the Silla rises in all its beauty.

We know that the modifications produced by winds in the composition of the air in various places, entirely escape our eudiometrical experiments, the most precise of which can estimate only as far as .0003 degrees of oxygen. Chemistry does not yet possess any means of distinguishing two jars of air, the one filled during the prevalence of the sirocco or the catia, and the other before these winds have commenced.

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