Page:Popular Science Monthly Volume 53.djvu/814

790 with a domestic summer resort. The interior of the building becomes absolutely untenable, the prejudices of the night-air-dread yield to the instinct of self-preservation, and before the noon of the next day the sweltering tenants begin to suspect the influence of a volcanic catastrophe or the possible correctness of Professor Falb's hypothesis of calorific meteor clouds.

But solar agencies are, after all, sufficient to account for the grievances of the atmospheric conditions. A brisk east wind will carry samples of African summer climate, sand haze and all, two thousand miles to seaward, and it might be questioned if the gehennapurgatory [sic] of the Great Desert could have aggravated the horrors of that afternoon of June 17, 1859, when the air waves from the Mexican alkali plains roasted the pears in the orchards of Santa Barbara, California, and blistered the arms of fishermen in San Pedro Bay.

The increasing frequency of droughts in the northwest provinces seems, however, to be mainly due to local causes. In the course of the last two hundred years the sugar and tobacco planters of western Cuba have cleared some five thousand square miles of once densely wooded coast plains, and a considerable portion of that area has shared the fate of the neglected grain fields on the east shores of the Mediterranean; uniform crops have at last exhausted the fertility of the soil, and winter rains have seamed the hill slopes with arid gullies. But in summer the moisture-freighted sea winds approach the thirsty coast lands in vain. Ascending air currents, caused by the refraction of sun rays from the treeless plain, sublimate the humidity of the atmosphere into a transparent haze, or waft the clouds across the low mountain ranges and the farther foothills of the island, which here measures hardly fifty miles from shore to shore.

From the terrace lands of San Cristobal (eighty miles southwest of Havana) heavy banks of clouds may often be seen rolling up from the Caribbean Sea, and twinkle with flashes of electric fire as they approach the chain of low islands which in a former geological period seems to have bridged the strait of Los Pinos. The afternoon heat increases with every minute, and all atmospheric auspices appear to herald a thunderstorm. Far in the south the horizon is streaked with evidences of a heavy shower, and thunder peals echo along the coast cliffs; but the sky overhead is still clear, and as the clouds approach the treeless vega their shadows pale, their masses dissolve and pass the island in the form of feathery cloudlets, high sailing and wholly revoking the promise of rain.

From the summits of the central sierra those same clouds may, perhaps, be seen lowering as they continue their northward course, and lavish torrents of rain on a reef of unappreciative rocks in the Strait of Florida. Billions of gallons for the felucca skippers who