the air will have some ill effect on their hearts. I know a woman who was determined to die of heart failure if she made a flight. She isn't logical, for she rolls lazily through life encased in 100 lbs. of extra avoirdupois, which surely adds a greater strain on her heart—besides not giving it any fun, at all.
Seriously, of course a person with a chronically weak heart, who is affected by altitude, should not invite trouble by flying. A lame man should exercise special care in crossing a street with crowded traffic, and one with weak lungs should not attempt swimming a long distance unaccompanied.
Consciousness of speed in the air is surprisingly absent. Thirty miles an hour in an automobile, or fifty in a railroad train, gives one greater sensation of speed than moving one hundred miles an hour in a large plane. On the highway every pebble passed is a speedometer for one's eye, while the ties and track whirling
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