वेदों की प्राचीनता एवं काल-निर्णय / ओरायन (लोकमान्य बाल गंगाधर तिलक - खगोलीय वैदिक शोध)

THE ARCTIC REGIONS. 47 continuous morning and evening in the year, and one day and one night of six months each, are thus the chief special features of the calendar at the North Pole. We have stated that to an observer at the North Pole, there will be a night of 6 months, and one is likely to infer therefrom that there will be total darkness at the Pole for one half the portion of the year. Indeed one is likely to contem- plate with horror, the perils and difficulties of a long night of six months, during which not only the light but the warmth of the sun has to be artificially supplied. As a matter of fact, such a supposition is found to be erroneous. First of all, there will be the electric discharges, known as Aurora Borealis, filling the polar night with their charming glories, and relieving its darkness to a great extent. Then we have the moon, which, in her monthly revolution, will be above the polar horizon for a continuous fortnight, displaying her changing phases, without intermission, to the polar observer. But the chief cause, which alleviates the darkness of the polar night, is the twilight before the rising and after the setting of the sun. With us in the tropical or the temperates zone, this twilight, whether of morning or evening, lasts only for an hour or two; but at the Pole this state of things is completely altered, and the twilight of the annual morning and evening is each visible for several days. The exact duration of this morning or evening twilight is, however, still a matter of uncertainty. Some authorities fix the period at 45 days, while others make it last for full two months. In the tropical zone, we see the first beams of the dawn, when the sun is about 16° below the horizon. But it is said that in higher latitudes the light of the sun is discernible when he is from 18° to 20° below the horizon. Probably this latter limit may prove to be the correct one for the North Pole, and in that case the dawn there will last