ABSTRACT
The inequality of the length of day and night reaches its maximum at the poles, where there is a six-month day and a six-month night, while everywhere within the polar circles enjoys at least one day on which the sun does not set. This mathematical factor introduces a new conception in climates, for diurnal range has little meaning, since insolation is absent in midwinter and continuous at midsummer, however low the angle of the sun. The physical hardships and risks that man is called upon to undergo result in a high death-rate from accident and exposure; frostbite and snow-blindness are maladies directly attributable to climate, but otherwise the polar regions are healthy. Gold is a preservative and putrefactive organisms are inactive at low temperatures, germ-borne diseases are practically negligible risks.
