World View – what is the world like…

Ancient and Medieval Maps

Renaissance and the Age of Exploration: Early Modern Maps

Modern Views of the World

After St Augustine made the study of religion the major focus of human thought, the early church adopted the literal interpretation of the Bible as the source for geographical information.

This was summed up by a monk, Cosmas Indicopleus , who around 547 CE wrote a treatise called Topographia Christiana which suggests that the world is a flat surface with a sky above, and above the sky, heaven. Jerusalem was the center of the world, and the Garden of Eden off to the east. The sun revolved around a mountain to the north and was much smaller than the Earth. This rejected the knowledge of the Greeks who had agreed that the Earth was round (Aristotle had written that the shadow of the Earth on the Moon was rounded, so the Earth must be a sphere) and who had made quite accurate measurements of the circumference of the Earth as equivalent to 25,000 miles.

But Aristotle and the other Greeks were seriously wrong about some other ideas of geography. They divided the Earth into zones, and said that the Equatorial zone was too hot for human life, and the far north and south too cold. So only the northern regions from Egypt up to the northern forests were suitable for life. They also said that Asia must extend far to the east and that there would be no land between the eastern end of Asia and the western end of Europe.

Also, they clearly said that the Earth was immobile in space, and was the center of the universe, with the planets and stars revolving around it.

http://www.astro.utoronto.ca/~zhu/ast210/geocentric.htmlA neat animation that shows how the Ptolemaic astronomers explained the motions of the sun and planets… this would be a “geocentric” world system.

Not really a medieval picture, but from a book written in 1888 about what medieval people thought!

http://www.tertullian.org/fathers/cosmas_02_book2.htm

A link to a translation of Cosmas Indicopleus’ 547 CE account of the shape of the world… “The Deity, having thus in the order of nature, as the scripture declares, suspended the earth upon nothing, when it had reached the bottom of space laid its foundations upon its own stability so that it should not be moved for ever…”

A medieval European map of the world. The world is divided into three sections. North is at the left. The three sections are named for the three sons of Noah as recorded in the Bible (Genesis 9:18) who were Shem (father of the Semitic people) , Ham (father of the Hamitic or African people) and Japheth (father of the Europeans.)

The Orient is at the top and the Occident (West) is at the bottom. The meridien or southern part of the world is at the right.

The world is divided by the Mediterranean and the large sea (consisting of what we would call the Danube River, the Caspian Sea, the Euxine or Black sea, the Nile and Red Sea extending to the Ocean Sea which surrounds the entire world.

This style of map of the world was the routine way to show the world. Maps of this kind are called “T and O” maps. A Crusader starting off from, say, the Tower of London, on his way to Jerusalem would have probably had no more map than this.

Even after the early navigators had learned more about the world, the traditional maps were still produced. The ‘T and O’ map on the right was printed in 1493. It divides the world by the Mediterannean and the Danube separating Europe and Asia, while the Nile separates Asia and Africa.

The map at left, of about 1100 CE, now in the Library of the Vatican, shows Jerusalem at the center of the Earth, with the Garden of Adam and Eve marked where the Bible places it “eastward in Eden” (Genesis 2,3).

The Hereford Mappa Mundi------------------------------A ‘T and 0’ map of about 1300 CE on display in Hereford Cathedral in England. Drawn on a single sheet of vellum, It is well over 1 meter square. Jerusalem is at the centre of the circle, East is on top, showing the Garden of Eden in a circle at the edge of the world. Great Britain and Ireland are at the north-western border (bottom left).

Medieval scholars knew that the Earth was spherical, but they believed that the extreme northern and southern parts of the world were uninhabitable, so those did not need to be shown. The large river on the far right is the Nile, Which flows into the Mediterannean. The Don river flows into the Mediterannean from the left.

The Ebstorf map – a ‘T and O’ map of 1234 CE made by Gervase of Tilbury, an English scholar and diplomat who served various courts in Europe and was able to visit many scholars and centers of scholarship. He wrote a compendium of stories which he collected as he travelled, many of which are out and out folklore. This map was destroyed during WW II.

While many were still ignorant of the shape of the world, at the same time, the serious navigators were making maps that were closer and closer to the real shape of the world. The Spanish and Portuguese especially were exploring the trade routes to the East. This map shows a rather good depiction of Asia Minor (Turkey) with the Black Sea shown quite accurately , and the Caspian Sea correctly shown as landlocked. Also, Egypt with the Nile, the Red Sea, a somewhat distorted Arabia, India, and then a confused SE Asia with the mythical island of Tapobana.

This map was drawn about 1470 – 1490 based on the descriptions of the world given by Claudius Ptolemaeus (Roman lived about 90 CE to 170 CE), called Ptolemy. Columbus would have used this map, or others very similar to it to plan his trip.

According to historian Matt Rosenberg, “not much is known about the life of the Roman scholar Claudius Ptolemaeus who is more commonly known as Ptolemy. However, he was estimated to have lived from approximately 90 to 170 CE and he worked in the library at Alexandria from 127 to 150. He is known for his three scholarly works: the Almagest - which focused on astronomy and geometry, the Tetrabiblos - which focused on astrology, and, most importantly, Geography - which advanced geographic knowledge. Geography consisted of eight volumes. The first discussed the problems of representing a spherical earth on a flat sheet of paper (remember, ancient Greek and Roman scholars knew the earth was round) and provided information about map projections. The second through seventh volumes of the work were a gazetteer of sorts, as a collection of eight thousand places around the world. This gazetteer was remarkable for Ptolemy invented latitude and longitude - he was the first to place a grid system on a map and use the same grid system for the entire planet. His collection of place names and their coordinates reveals the geographic knowledge of the Roman empire in the second century.”

“The final volume of Geography was Ptolemy's atlas - featuring maps that utilized his grid system and maps that placed north at the top of the map, a cartographic convention that Ptolemy created. Unfortunately, his gazetteer and maps contained a great number of errors due to the simple fact that Ptolemy was forced to rely upon the best estimates of merchant travelers (who were incapable of accurately measuring longitude at the time).”

“Like much knowledge of the ancient era, the awesome work of Ptolemy was lost for over a thousand years after it was first published. Finally, in the early fifteenth century his work was rediscovered and translated into Latin, the language of the educated populace. Geography gained rapid popularity and there were more than forty editions printed from the fifteenth through sixteenth centuries. For hundreds of years, unscrupulous cartographers of the middle ages printed a variety of atlases with the name Ptolemy on them, to provide credentials for their books.” (Matt Rosenberg)

Eratosthenes Measures the World in Ancient Egypt -- 200 BCEratosthenes was born in the Greek city of Cyrene in Libya in 276 BC, educated in Athens, and died in the Greek City of Alexandria in Egypt in 194 BC. Remember that Alexander the Great, a Macedonian Greek, conquered Egypt and around 330.B.C he founded a new city there which he modestly named after himself, Alexandria. One of his generals took over Egypt when Alexander died. Then for 300 years the general's descendants were rulers of Egypt and were called "Hellenic" (Greek for "Greeks"). There was a long series of Greek rulers who were mainly called Ptolemy if they were male or Cleopatra (Greek for "Father's Glory") if they were female. This line continued right down to the famous Cleopatra who fooled around with Julius Caesar - she was actually Cleopatra Theo Philopater (the VII) and her father was Ptolemy XII Auletes. But that was a lot later, she became queen in 51 B.C. About 245 B.C. Eratosthenes was brought from Athens to Alexandria by the Hellenic (Greek) Pharoah Ptolemy II Euergetes to be the tutor for the Pharoah's son. A few years later he became the 3rd Head Librarian of the Great Library, the Mouseian (Library of the Muses), which had been built by the previous Greek Pharoahs Ptolemy I and Ptolemy II Philadelphus to house copies of the works of the Greek writer Aristotle and other scrolls. He probably got the Alexandria job because the 2nd head librarian, Callimachus, had been one of his teachers in Athens. Nothing like a good "networking" connection!

Historical accounts from the ancient historian Strabo and several later authors tell us that Eratosthenes made a very good estimate of the actual size of the earth by the following method: one day as he was researching in the library he found a book that said, on the longest day of the year the reflection of the sun could be seen at the bottom of a deep well in the city of Syene, in southern Egypt.This is an important observation. It means that in Syene the sun had to be directly overhead on that day of the year. But, he knew that on Midsummer Day the sun at Alexandria did cast a small shadow. That is, the sun was nearly, but not quite, directly overhead -- about a 7 degree angle. If the earth was flat, this would not be possible. The earth had to be curved and the distance from Alexandria to Syene had to represent 7/360ths of the total. OK, if it is about 500 miles between the two cities, then 500/7 x 360 = about 25,700 miles around the earth -- that is, by simple geometry he could calculate the angles and the whole distance around the earth. He didn't have an accurate clock, astronomical instruments or measuring devices, but still, since the actual distance is now measured as a little less than 25, 000 miles he did pretty well for 200 B.C.!

Columbus?But what about Columbus? Didn't he "prove the world was round?‘

Ha! As you know, the idea that in 1492 educated people thought the earth was flat is silly. The story of Columbus arguing with people about whether the Earth was round or flat was probably made up around the year 1800 by the American author Washington Irving for a book he was writing about Columbus. The real argument with Columbus was not whether the earth was round, but whether it was possible to sail far enough to get around it -- to sail to China. The Spaniards wanted to get to China and the Orient in order to trade for spices, silk and other valuable goods as Europeans had been doing for centuries. But, in the late 1400s they could not sail through the Mediteranean. At that time the Turks and other Muslim rulers had blocked the trade routes. In 1454 the Turks captured the major Christian city of Constantinople (Istanbul) and cut off trade almost completely. Europeans were desperate for the Asian spices, and there was a fortune to be made by anyone who could get them. Portuguese sailors were trying to get to China and India by working their way eastward around Africa, but Columbus wanted to sail directly westward to reach China.

What was the argument?

Columbus said he could sail west to China. The Spanish court geographers said it was impossible. The disagreement was not about whether the Earth was flat -- only ignorant peasants believed that! The argument was about how far it was to China. Every trader knew that it was approximately 9,000 to 10,000 miles eastward from Europe to China by the ancient trade routes -- those roads had been travelled for centuries. And, the geographers knew that the Earth was about 25,000 miles around, so that meant that sailing westward to China could be a 15,000 mile trip or more. No one, including Columbus, believed that their ships could sail that far without stopping for repairs and supplies. And, that's why the King of Spain was so reluctant to give Columbus any ships or sailors. Once Columbus set sail, no one expected to see him alive again! In the end the King just gave Columbus some old ships that weren't worth much, and prisoners from the local jail for sailors -- no one would miss them.

What was Columbus' big idea?

Columbus claimed that the distance around the world was only about 18,000 miles at most -- he was depending on the estimate made by the ancient scholar Ptolemy whose calculations translate to about 18,600 miles in modern terms. That meant that in Columbus' calculations, the distance to China by sea was only 7,000 to 8,000 miles rather than 15,000. That was still a very long sail, further than any European ship had ever sailed out of sight of land. But, it was a lot shorter than going all the way around Africa to China. He thought that with luck he might make it, and he was courageous enough to take a chance. Unfortunately for Columbus, the King's court geographers were almost exactly right and he was dead wrong. It is over 13,000 miles westward from Spain to China. His leaky ships would never have made it all the way! But fortunately for Columbus, when he had sailed less than 4000 miles and his ships were starting to have problems, America got in the way and saved him from being drowned. He was foolish and wrong, but he was also brave and determined. Without his persistence, the Americas might not have been discovered for hundreds of years more.... the United States would probably never have existed. World history would have been totally different! So, was he a hero or not?p.s. Like many famous historical figures, our image of Columbus is quite distorted. The accounts of his appearance written by people who actually knew him all agree that he had red hair and a fair, ruddy complexion. He was Italian, but from the North of Italy, not Sicily. (see the classic biography, Admiral of the Ocean Sea by S.E. Morison

This map was draw just about 50 years after the Ptolemy map shown in the previous slides was printed.

This map of the Americas was drawn by the brilliant Dutch mapmaker Ortelius who was active mainly between about 1587 to 1612.

Longitude

The failure to be able to accurately calculate longitude was a major problem for navigators up to the end of the 1700s. Without calculations of longitude the sailors mostly had to creep along the shoreline, never venturing far out to sea, for fear of losing their bearings. Those who wanted to trade over long distances were seriously constrained by the lack of proper methods for finding their way on the ocean.

Among the earliest scholars to try to address the issue of navigation was an Englishman who became a kind of math tutor to Phillipa, the granddaughter of King Edward III of England. Later when she was married to the King of Portugal she remembered her lessons and taught them to her son Henry. Henry caught the navigation bug from his mother and started a school for navigation in Portugal. Though he never went on long voyages himself, his support for the courageous Portuguese explorers earned him the title of “Prince Henry the Navigator.” His mother’s old tutor – Geoffrey Chaucer!

The Portuguese explorers kept detailed records of their voyages. How long they sailed, how strong the wind was, everything that they could easily observe. These records, called ‘rutters’ were considered trade secrets and pilots of the ships would go to great lengths to protect them from falling into the hands of rivals and enemies. Still, they could not keep exactly correct records as long as they could not calculate the longitude.

We will consider this problem further later on.

An English map printed in 1800 after the introduction of Harrison’s clocks.