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Zone, in astronomical geography, is applied to a division of the earth's surface by certain parallels of latitude.
The Zones are 5 in number, viz.
1. The torrid zone, lying between the two tropics. It comprehends the West India Islands, the greater parts of South America and of Africa, the southern parts of Asia, and the East India Islands.
2. The north frigid zone, lying round the north pole, and bounded by the north polar circle. It comprehends part of Greenland, of the northern regions of North America, and a little of the northern parts of Europe and Asia.
3. The south frigid zone, lying round the south pole, and bounded by the south polar circle. It contains no dry land, so far as yet discovered.
4. The north temperate zone, lying between the torrid and north frigid. It comprehends almost the whole of North America, Europe, and Asia, with the northern part of Africa.
5. The south temperate zone, lying between the torrid and south frigid. It comprehends the southern part of South America, of Africa, and of the great island of NewHolland.
In the torrid zone, the sun is vertical twice a year to every part of it, and there is very little diversity in the length of the day throughout the year, the longest day varying only from 12 to about 131 hours.
In the tempe rate zones the sun is never vertical, and the length of the longest day varies from about 131 to 24 hours. In the frigid zones, the length of the longest day (or time between the sun's rising and setting) varies from 24 hours to 6 months.
1 2 3 4 5 6 7
REMARKS. 1. There is a small variation in the inclination of planets' orbits, the longitude of
2. The diameter of the earth being 1. that of the sun will be 111.45 and that of the moon .2731.
3. The inclination of the sun's axis is about 8°, and the time of his rotation about 25 days 6h.
4. The inclination of the moon's orbit to the ecliptic is about 5° 8', that of her axis about 2o. 18',
5. The periodical revolutions in the tables are those termed sidereal, and the distances of the
6. The orbits of the 1st, 2d, and Sd, satellites of Jupiter are very nearly circular, and coincident
7. The elements of the above Tables are taken chiefly from Laplace and Lalande, the places