790 POPULAR SCIENCE MONTHLY. 



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 gehenna 

 of the Great Desert could have aggravated the horrors of that after- 

 noon 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 fer- 

 tility 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 



