T and O map
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A T and O map or O-T or T-O map (orbis terrae, orb or circle of the earth), is a type of medieval world map, sometimes also called a Beatine map or a Beatus map because one of the earliest known representations of this sort is attributed to Beatus of Liébana, an 8th century Spanish monk. The map appeared in the prologue to his twelve books of commentaries on the Apocalypse. It represents the physical world first described by the 7th century scholar Isidore of Seville in his Etymologiae (chapter 14, de terra et partibus):
- Orbis a rotunditate circuli dictus, quia sicut rota est [...] Undique enim Oceanus circumfluens eius in circulo ambit fines. Divisus est autem trifarie: e quibus una pars Asia, altera Europa, tertia Africa nuncupatur.
- "The [inhabitated] mass of solid land is called 'round' after the roundness of a circle, because it is like a wheel [...] Because of this, the Ocean flowing around it is contained in a circular limit, and it is divided in three parts, one part being called Asia, the second Europe, and the third Africa."
The theory of a spherical earth had always been the prevailing assumption, since at least Aristotle, who had divided the spherical earth in five zones: The poles were freezing and the equatorial zone was so hot, no one could pass through it. In between the poles and the middle hot zone lay two temperate zones. Thus for some Latin scholars the T and O map represents the top-half of the globe; it was thought that no one had ever been to the southern half, the antipodes, where people known as "antipodeans" lived. For other Latin scholars the T and O map represented a flat earth with all the climatic zones on the surface of the "wheel" as first described by Isidore.
The T is the Mediterranean, dividing the three continents, Asia, Europe and Africa, and the O is the encircling Ocean. Jerusalem was generally assumed to lie at the center of the circle.
The T-O map remained a common representation since at least the 7th century. It was presumably tacitly considered a convenient projection of the inhabited parts, the northern temperate half of the globe. Since the southern temperate clime, the antipodes were considered uninhabited, or unattainable (Saint Augustine had considered the proposition of reaching the southern hemisphere "absurd"), there was no need to depict them on a world map. Asia was typically the size of the other two continents combined. Because the sun rose in the east, Paradise (the Garden of Eden) was generally depicted as being in Asia, and Asia was situated at the top portion of the map.
This qualitative and conceptual type of medieval cartography could yield extremely detailed maps in addition to simple representations. The earliest maps had only a few cities and the most important bodies of water noted. The four sacred rivers of the holy land were always present. More useful tools for the traveller were the itinerary, which listed in order the names of towns between two points, and the periplus that did the same for harbours and landmarks along a seacoast.
Later maps of this same conceptual format featured many rivers and cities of Eastern as well as Western Europe, and other features encountered during the Crusades. Decorative illuminations were also added in addition to the new geographic features. The most important cities would be represented by distinct fortifications and towers in addition to their names, and the empty spaces would be filled with mythical creatures.
[edit] Gallery
 The world map from the Saint-Sever Beatus, dating to ca. AD 1050. |
 From a 12th c. copy of Etymologiae. |
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 Mappa Mundi in La Fleur des Histoires. 1459-1463. |
 Bünting clover leaf map. A 1581 woodcut, Magdeburg. Jerusalem is in the center, surrounded by Europe, Asia and Africa. |
 A "T-O" map made with modern cartography. |
[edit] See also
[edit] References
- Crosby, Alfred W. The Measure of Reality : Quantification in Western Europe, 1250-1600. Cambridge: Cambridge University Press, 1996.
