Page:Popular Science Monthly Volume 47.djvu/327

Rh him away from home and friends himself does not know? Besides, there are many constituent elements which enter in to make up what we call "climate." The first of these to be mentioned is usually the thermometrical readings, and the "mean" temperature is generally quoted as proof positive of superiority when it varies a few degrees one way or the other from that of another locality with which it is compared. Now, the truth is, that to know the mean temperature of a place, and to know only that, is to know very little about its climate. The physiological effects of a climate must necessarily include the degree of humidity, the force and direction of the prevailing winds, the sunshine and cloudiness; the fogs and their characteristics—whether thin or dense, high or low, whether coming down from the mountains or rolling in from the sea; besides other unmeasurable influences not seen though felt: all these and more must be appreciated in order to give the single factor of relative temperature any positive quality whatever. For instance, the mean temperature of the seven hundred and seventy miles along and near the coast of California varies but a few degrees, though the extremes vary much. But the physiological effects of the climates of different areas vary greatly. There are stiff northwest winds from off the Pacific, carrying a thin, swift-moving fog that chills an invalid to the bone, during July and August in San Francisco. To correspond to the sensations, the thermometer there lies like a cheap watch, and should be twenty degrees lower. A few miles back from the coast, with less wind and little fog, one's bodily comfort is perfect, and life is worth living, though the unlucky thermometer persists in recording nearly the same average as when you had been shivering on the coast. I conclude that the physiological influence of a given temperature below a certain degree, say below sixty, with the wind ten or fifteen miles an hour, is equal to at least ten or fifteen degrees lower in scale. On the other hand, a thermometrical showing of 90º and over is not uncomfortable if there is a gentle breeze and little humidity, but with a strong wind becomes a sirocco, when prostrations are numerous, and, if long continued, many aged and feeble die under its influence. In one of the interior valleys of California I have seen the thermometer indicate 100º to 110º F. for days and weeks together, and no one complained of the heat as excessive, while all labor of man and beast went on as usual, and prostrations are unknown. I refer to the temperature in the shade. In the sun, where men work, it must be ten or fifteen degrees higher. In New York, when summer heat approaches 90º we expect many prostrations and some deaths. I am not trying to show that 110º of heat in California with no prostrations is a better climate than New York at 90º and many prostrations, but to illustrate the