Man against Desert
MAN was never cut out for an arid existence. Strand a healthy human adult in the middle of a desert, without water, on the morning of a hot summer day, and he will experience no instant discomfort. After an hour he will have lost up to a quart of salty water by perspiring, and will be very thirsty. By mid-afternoon, with his body's water-cooling mechanism working hard to throw off heat, his weight will be down 12 to 18 pounds and he will be weak. By nightfall, if it has been a 120-degree day, he may well be dead, but if the temperature has gone only to 110 in the shade he has a life expectancy of one more such day. Even if he is given a daily ration of a gallon of water instead of none at all, the sun will kill him within a week.
Nevertheless, as far back as human prehistory can be traced, men have found ways to live in desert lands. No race of men has ever adapted in any significant physiological way to the environment, yet every division of humanity is well represented among the world's persistent desert dwellers. Negroid people have survived many centuries in all the deserts of Africa, the Caucasoid or European type in Africa and the Middle East as well, the