The learned have divided the <Greek> into seven parts, to each of which they have given the name of <Greek>.* Some reckon from the equator as Ptolemy shows in his Almagest.* Another school omitting 12° 45' north of the equator, divide the remainder and terminate as is known at the 50° 31° parallel of latitude.* In the former case, therefore, the parallels from the equator will be seven circles and in the latter, eight. The seven belts which these lines form are called climates. A climate therefore is a belt on the surface of the earth between two semi-circles parallel with each other and with the equator. A climate increases in length as it approaches the equator; moreover its first parallel will be longer than its second. It is demonstrable from (experiment with) spheres that every parallel circle increases as it nears the equatorial line. The length of the first parallel of the first climate is said to be 11,856 miles approximately, and the length of its second parallel 11,230, while the length of the last parallel of the seventh climate is 1,627 farsakh. But every climate, like the longitudinal extension of the earth from west to east, is divided into an equal number of degrees of longitude, and not more or less in proportion to its length. The latitude of each belt varies.
There are two reasons given for the selection of seven as this number. The first is that ancient sages have verified by experience that each tract of superficial area was specially connected with one of the planets, as for instance, the first climate with Saturn. For this reason the inhabitants of that zone generally are dark-skinned, curly-haired, long-lived and indolent in action. The second climate, according to the Persians, had an affinity with Jupiter, but according to the Romans, with the Sun. The third climate, in the opinion of the former, with Mars, in that of the latter, with Mercury. The fourth, with the Sun, as the first mentioned suppose, but with Jupiter according to the second opinion. Both concur in ascribing the fifth to Venus. The sixth is allotted by the first to Mercury, by the second to the Moon. The seventh, the former connect with the Moon, the latter with Mars. The second opinion is that in former ages a single monarch ruled the whole habitable earth. With far-seeing and prudent policy he divided it severally among his seven sons.
The word climate may be taken in two senses,* viz., the ordinary sense in which men commonly speak of a tract of country as a climate, such as Rome, Turán, Irán and Hindustán; and the true signification already explained. In the latter meaning India is an aggregate of the first, second, third and fourth climates.
The beginning of the first climate is defined by general opinion to be north of the equator. Its latitude according to accurate information is 12° 42' 2" 39'". Its longest day is 12 hours and 45 minutes. Its centre has a location according to concurrent testimony, where its longest day is 13 hours. Its latitude is 16° 37' 30". Twenty large mountains and thirty considerable rivers are comprised in it, and its population are generally black in colour.
The beginning of the second climate has a latitude of 20° 31' 17" 58'". Its longest day consists of 13 hours, fifteen minutes. The longest day at its centre is 13 hours, 30 minutes. Its latitude is 24° 40'. It includes 27 mountains and 27 rivers. The colour of the inhabitants of this zone is between black and wheat colour.
The beginning of the third climate has a latitude of 27° 34' 3" 33'". Its longest day is 13 hours, 45 minutes. Its day at the centre is of 14 hours and the latitude 30° 40'. It comprises 33 mountains and 22 rivers, and its inhabitants are generally of a wheat colour.
The beginning of the fourth climate has a latitude of 33° 43' 17" 36'". Its longest day, 14 hours, 15 minutes. At the centre the longest day is of 14 hours, 30 minutes. Lat. 36° 22'. It includes 25 mountains and 22 rivers; the colour of its inhabitants is between wheat colour and a fair skin.
The beginning of the fifth climate is in Lat. 39° 0' 19" 5'". Longest day, 14 hours, 45 minutes. Longest day at centre, 15 hours. Lat. 41° 15'. Colour of inhabitants fair. Has 30 mountains and 15 rivers.
The beginning of the sixth climate is in Lat. 43° 29' 58" 8'". Longest day, 15 hours, 15 minutes. Longest day at centre, 15 hours, 30 minutes. Lat. 45° 21'. Has 11 mountains 40 rivers. Colour of inhabitants fair inclining to tawny and with tawny hair.
The beginning of the seventh climate is in Lat. 47° 58' 59" 17'". Longest day, 15 hours, 45 minutes. Longest day at centre, 16 hours. Lat. 48° 52'. Its mountains and rivers as in the sixth climate. Colour of inhabitants ruddy and white. Its extreme parallel according to general opinion is in Lat. 50° 31' 31" 54'". The longest day 16 hours, 15 minutes.
The differences in latitude of these climates are determined by the increase of half an hour in the length of the longest day. From the last parallel to the furthest inhabited point is not included in a climate on account of the paucity of its inhabitants. Some suppose the northernmost parallel of the seventh climate to be the extreme of the habitable world. According to others, the parallel of 50° 20' is inhabited, but they do not include it in this climate; and there is an island called Thule in Lat. 63°. From the severity of the cold the inhabitants pass their days in heated chambers. In Lat. 63° 30' is habitable land the dwellers wherein are Scythians as recorded by Ptolemy. In Lat. 66° a tract has been discovered the inhabitants of which resemble wild animals, as mentioned by him in the Geographia. The remaining portion of the quarter of the globe is according to some, a tenantless waste, while others regard it as simply unknown country. In Lat. 54° and a fraction, the longest day is 17 hours; in Lat. 58°, 18 hours; in Lat. 61°, 19 hours; in Lat. 63°, 20 hours; in Lat. 64° 30', 21 hours; in Lat. 65° and a fraction, 22 hours; and in 66° 23 hours, and in the latitude, equal to the complement of the sun's greatest declination from the ??uator, 24 hours. In Lat. 67° the day increases by one month, in Lat. 70°, 1¾ months; in Lat. 73° 30', three months; in Lat. 78° 30', four months; in Lat. 84°, five months, and in the Lat. 90° which is the extremity of the earth, the day is said to be of six months, and the other six months is night. But it is more correct to say that a year is one nycthemeron. If the day be reckoned from sunrise to sunset, the day there would be seven nycthemera longer than the nights, but if it be calculated from the dawn of light and the disappearance of the fixed stars, to the occultation of light and the reappearance of the stars, the day there would be seven months and seven days and the remainder (of the year) night. Again if the day be counted from the dawn of morning to the evanescence of twilight, this day would be of nine months and seventeen days and the complement of the year would be the night.*
To lend an interest to this work a table of the various climates with other details is here introduced.
Tables for the ascertainment of the Longitudes and Latitudes of places of the inhabited quarter of the globe from the Latitude of the Equator, according to the learned, especially of places beyond the limits of the seven climates to the 60th degree of Latitude.