The AEON magazine website has a long essay by Kurt Hollander simply titled Middle Earth that takes as its subject not the fantasy realm of J. R. R. Tolkien but the equator, the imaginary line marking the middle of the Earth’s sphere. Unfortunately this essay is severely marred by a series of errors, myths and falsities about the history of cartography and geodesy. I have selected some of the worst here for critical analysis and correction.
Our author gets off to a flying start with the biggest geodesic myth of them all:
Medieval Christian mapmakers, familiar only with a small corner of the planet, worked within strict horizons that were fixed by the Church’s interpretation of the Bible. Their Earth was flat.
My friend Darrin Hayton (@dhayton) has written several posts on the excellent PACHS blog over the years criticising the people who still insists on propagating the myth that the Europeans in the Middle Ages believed that the world was flat. Just once more for those that haven’t been listening, they didn’t. That the world was a sphere was probably first recognised by the Pythagoreans in the sixth century BCE and almost all educated people accepted this fact from at the latest the fourth century BCE up to the present.
First created in the 7th century, the Christian orbis terrarum (circle of the Earth) maps, known for visual reasons as ‘T-and-O’ maps, included only the northern hemisphere.
T and O maps actually have their roots in Greek geography and cartography and only display part of the northern hemisphere because that was all that their creators knew about.
The T represented the Mediterranean ocean, which divided the Earth’s three continents — Asia, Africa, and Europe — each of which was populated by the descendants of one of Noah’s three sons. Jerusalem usually appeared at the centre, on the Earth’s navel (ombilicum mundi), while Paradise (the Garden of Eden) was drawn to the east in Asia and situated at the top portion of the map. The O was the Ocean surrounding the three continents; beyond that was another ring of fire.
Given that the Greeks, the originators of the geography on which the T and O maps are based, lived in the Mediterranean Sea (not ocean!) they were of course well aware of the fact that it is not T shaped. The T on T and O maps actually represents in schematic form the Mediterranean and the Don and Nile rivers, as the dividing lines between the three known continents.
For the Catholic Church, the Equator marked the border of civilisation, beyond which no humans (at least, no followers of Christ) could exist. In The Divine Institutes (written between 303 and 311CE), the theologian Lactantius ridiculed the notion that there could be inhabitants in the antipodes ‘whose footsteps are higher than their heads’. Other authors scoffed at the idea of a place where the rain must fall up. In 748, Pope Zachary declared the idea that people could exist in the antipodes, on the ‘other side’ of the Christian world, heretical..
As has been pointed out by numerous people writing about the flat earth myth, Lactantius had almost no supporters of his theories.
This medieval argument was still rumbling on when Columbus first sailed southwest from Spain to the ‘Indies’ in 1492. Columbus, who had seen sub-Saharans in Portuguese ports in west Africa, disagreed with the Church: he claimed that the Torrid Zone was ‘not uninhabitable’.
Our author appears to be prejudiced against the Portuguese. Throughout the fifteenth century in a series of expeditions, started by Henry the Navigator (1394 – 1460), a succession of Portuguese explorers had been venturing further and further down the West African coast reaching the Gulf of Guinea, which lies on the equator, in 1460. These expeditions reached a climax in 1488, four years before Columbus set sail to the Indies, when Bartolomeu Dias rounded the tip of South Africa proving that one could reach the Indian Ocean by sea and pathing the way for Vasco de Gama’s 1497 voyage to India.
Although he never actually crossed the Equator, he did go beyond the borders of European maps when he inadvertently sailed to the Americas. To navigate, Columbus used, among others, the Imago Mundi (1410), a work of cosmography written by the 15th-century French theologian Pierre d’Ailly, which included one of the few T-and-O maps with north situated at the top.
The importance of Pierre d’Ailley’s Imago Mundi for Columbus lay not in the orientation of its T and O map but in the fact that d’Ailley severely underestimated the circumference of the globe thus making Columbus’ attempt to sail westward to the Indies seem more plausible than it in reality was.
Columbus’s eventual ‘discovery’ of America stretched the horizons of the European mind. The Equator was gradually reimagined: no longer the extreme limit of humanity, a geographical hell on Earth, it became simply the middle of the Earth.
In particular, Cobo has problems with the direction that mapmaking has taken. In 150AD, Ptolemy drew the first world map with north placed firmly at the top.
Earlier Greek geographers such as Eratosthenes, who also drew world maps, almost certainly also drew their maps with north at the top. Ptolemaeus is not the beginning but the culmination of Greek cartography.
This orientation has become the standard one for maps everywhere. The preeminence of north derives from the use of Polaris, also known as the North Star, as the guiding light for sailors.
This is a piece of pure fantasy on the part of out author. To quote Jerry Brotton from his excellent A History of the World in Twelve Maps, “Why north ultimately triumphed as the prime direction in the Western geographical tradition, especially considering its initial negative connotations for Christianity […], has never been fully explained. Later Greek maps and early medieval sailing charts, or portolans, were drawn using magnetic compasses, which probably established the navigational superiority of the north-south axis over an east-west one; but even so there is little reason why south could not have been adopted as the simplest point of cardinal orientation instead, and indeed Muslim mapmakers continued to draw maps with south at the top long after the adoption of the compass.” I would add to this the fact that many European Renaissance maps also had south at the top.
Yet Polaris, or any other star for that matter, is not a fixed point. Because of the Sun and Moon’s gravitational attraction, the Earth actually moves like a wobbling top. This wobble, known to astronomers as the precession of the Equator, represents a cyclical shift in the Earth’s axis of rotation. It makes the stars seem to migrate across the sky at the rate of about one degree every 72 years. This gradual shift means that Polaris will eventually cease to be viewed as the North Star, and sailors will have to orient themselves by other means.
In 1569, the Flemish cartographer Gerardus Mercator, the first to mass-produce Earth and star globes,
devised a system for projecting the round Earth onto a flat sheet of paper.
Our author, probably unintentionally or at least I hope so, creates the impression that Mercator was the first to devise a map projection from the sphere onto a flat sheet of paper; he, of course, wasn’t. This achievement is usually credited to Eratosthenes in the third century BCE. Ptolemaeus’ Geographia (about 150 CE) outlines three different map projections.
His ‘new and augmented description of Earth corrected for the use of sailors’ made the Earth the same width at the Equator and the poles, thus distorting the size of the continents. Although Mercator created his projection (still used today in almost all world maps) for navigation purposes, his scheme led to a bloated sense of self for the northern countries, located at the top of the map, while diminishing the southern hemisphere’s sense of size and importance.
Our author is rather vague about how or why this distortion occurs. Because the distance between the parallels of longitude in the Mercator projection increases the further one moves from the equator, landmasses become distorted in area (larger than they are in reality) the further they are away from the equator. Because the major landmasses in the northern hemisphere are further removed from the equator than those in the southern hemisphere they take on an illusionary physical dominance.
Might I, not so politely, suggest to Mr Hollander that if he wishes to write about the history of cartography in the future that he indulges in some proper research of the subject before he puts finger to keyboard.
 Jerry Brotton, A History of the World in Twelve Maps, Allen Lane, London, 2012, p. 11