Clime
The
seven climes (
klima, plural
klimata, meaning "inclination", referring to the angle between the axis of the
celestial sphere and the horizon) was a notion of dividing the Earth into zones in
Classical Antiquity. The lists of
klimata found in early geographers vary in their extension, but by convention, they numbered seven, counted from south to north. This number was taken up by
Ptolemy who in his
Geography divided the northern temperate zone into seven zones (
klimata).
Aristotle, on the other hand, divided the Earth into five zones, assuming two
frigid climes (the
arctic and
antarctic) around the poles, an uninhabitable
torrid clime near the
equator, and two
temperate climes between the frigid and the torrid ones (
Meteorology 2.5,362a32).
Ptolemy gives a list ofparallels, starting with the equator, and proceeding north at intervals, chosen so that the longest day (
summer solstice) increases in steps of a quarter of an hour from 12 hours at the equator to 18 hours at 58° N, and then, in larger steps, to 24 hours at the
arctic circle.
But for the purposes of his geographical tables, Ptolemy reduces this list to eleven parallels, dividing the area between the equator and 54°1' N into ten segments, at half-hour intervals reaching from 12 hours to 17 hours. Even later in his work, he reduces this to seven parallels, reaching from 16°27' N (13 hours) to 48°32' N (16 hours).
In reducing his original system, informed by the spherical shape of the earth, into seven climes, Ptolemy was thus trying to reconcile his work with the geographical tradition of seven
klimata. This division in seven zones may go back to notions of geography predating the idea of a
spherical Earth introduced by
Pythagoras in the
6th century BC. Persian tradition knows seven
karshvar (
Modern Persian keshvar) or zones, organizing the world map into a seven-storied
ziggurat.
Maybe for this reason, Ptolemy's system of seven climes was primarily adopted by
Arab and
Persian authors such as
al-Burini,
al-Idrisi and
Amin Razi, the author of the
16th century haft iqlīm (seven climes), while in Europe, Aristotle's system of five climatic zones was more successful. This view dominated in medieval Europe, and existence and inhabitability of the Southern temperate zone, the
antipodes, was a matter of dispute.
To identify the parallels delineating his climes, Ptolemy gives a geographical location through which they pass. The following is a list of the 33 parallels of the full system of climes, the reduced system of seven climes is indicated by additional numbers in brackets (note that the latitudes are the ones given by Ptolemy, not the exact or modern values):
# 12:00 (
equator) # 12:15, 4°4' N:
Taprobana (
Sri Lanka)# 12:30, 8°25' N:
Avalite bay (
Saylac,
Somalia)# 12:45 12°00' N: bay of
Adulis (
Eritrea)# (1.) 13:00, 16°27' N:
Meroe island# 13:15, 20°14' N:
Napaton (
Sudan)# (2.) 13:30, 23°51' N: Soene (
Aswan)# 13:45, 27°12' N:
Thebes# (3.) 14:00, 30°22' N:
Lower Egypt# 14:15, 33°18' N:
Phoenicia # (4.) 14:30, 36°00' N:
Rhodes# 14:45, 38°35' N:
Smyrna# (5.) 15:00, 40°50' N:
Hellespont# 15:15, 43°04' N: Massalia (
Marseilles)# (6.) 15:30, 45°01' N: the middle of the
Black Sea# 15:45, 46°51' N:
Istros river# (7.) 16:00, 48°32' N: the mouths of Borysthenes (
Dnepr)# 16:15, 50°04' N:
Maiotian lake# 16:30, 51°06' N: the southern shore of
Britannia# 16:45, 52°50' N: mouths of the
Rhine# 17:00, 54°30' N: mouths of the
Tanais river (
Don)# 17:15, 55° N:
Brigantion in Britannia# 17:30, 56° N: the middle of
Great Britain# 17:45, 57° N: Katouraktonion in Britannia# 18:00, 58° N: the southern part of Britannia Minor# 18:30, 59° N: the middle part of Britannia Minor# 19:00, 61° N: the North of Britannia Minor# 19:30, 62° N:
Ebudes island# 20:00, 63° N:
Thule (
Iceland)# 21:00, 64° N: unknown "
Scythian people"[?]# 22:00, 65° N # 23:00, 66° N # 24:00, 66°08'40
'' N: the
polar circle*
Climate*
Seven Seas*J. Lennart Berggren and Alexander Jones,
Ptolemy's Geography: An Annotated Translation of the Theoretical Chapters, Princeton University Press (2000).
The Itinerary of Alexander through the Seven Climes of Antiquity according to the Aljamiado-Morisco Rrekontamiento del rrey Alisandre. Santa Barbara, CA. Fifth Annual Middle East Studies Regional Conference. March 22, 2003.
