HISTORY29 - Maps

This article is about the history of map making or cartography.  Over the last 15 years, I’ve been writing about the history of my hometown Tucson, the state of Arizona, the United States, North America, and much of the rest of the world.  Maps have been key to my research and writing; I now really appreciate the relationship of maps to the history of the world.  I also have been personally passionate about maps for many years.  So, I concluded that it was time to talk about maps, and their history.

 

Maps have been used for thousands of years for many different purposes including helping ancient man grasp the idea of an unknown world, with himself at the center; plotting the location of towns and objects in one’s local area, then extending to much larger areas as knowledge of other places on earth expanded, sometimes augmented with the tales of travelers; early Christian maps that showed how the story of Christ penetrated the world; navigation for sea voyages, aiding exploration and commerce; settling boundary disputes; establishing tax and political regions; detailed city maps for travelers; tracking the weather, and so on.

Over the centuries, man’s view of his world changed from a narrow local area “flat-earth” view to an understanding that the world was round and contained other towns, countries, and even continents on the surface of a sphere.  The challenge was how to accurately represent areas on a curved surface on a flat map that would be useful for all the applications mentioned above. 

My online research for this article uncovered some fabulous examples of historic maps that I’m eager to share with you and relate the appropriate historical context.  I’ll also attempt to explain how mathematics were used to “project” spherical surface features onto flat maps.

I’m going to concentrate on historical mapping developments in Europe, the Mediterranean region, and the Near East, because these peoples were the most aggressive in exploring their world.  There were concurrent mapping developments in Arabia, Persia, China, and India, that I won’t be discussing.

I will talk about the earliest known maps, maps from the Ancient World, the Middle Ages, the Age of Exploration, the Industrial Age, the Information Age, and the future of mapping.

Earliest Known Maps

The earliest known maps are of the stars, not the Earth.  Dots dating to 14,500 BC found on the walls of the Lascaux caves in southwestern France map out part of the night sky, including well known individual stars and constellations. The Cuevas de El Castillo in Spain contain a dot map of the Corona Borealis constellation dating from 12,000 BC.

Cave painting and rock carvings used simple visual elements that may have aided in recognizing landscape features, such as hills or dwellings.  Archaeologists believe that these paintings were used both to navigate the areas they showed and to portray the areas that people visited.

Maps in the Ancient World

Between 1000 BC - AD 500, ancient civilizations in the Near East, Greece, and the Roman Empire made increasingly detailed maps to reflect their expanding knowledge of their surroundings, and began to incorporate innovations to make maps more useful and accurate.

Near East.  Maps were created in ancient Babylonia on clay tablets.  A surviving engraved tablet map, c. 1400 BC, shows walls and buildings in the holy city of Nippur.  The Babylonian World Map, the oldest surviving map of the world, c. 600 BC, is a symbolic representation of the Earth, showing a circular shape surrounded by water, which fits the religious image of the world in which the Babylonians believed.

Engraved clay tablet of the Babylonian holy city of Nippur, showing walls and buildings, c. 1400 BC.

Ancient Egyptian maps show an emphasis on geometry and well-developed surveying techniques, perhaps stimulated by the need to re-establish exact boundaries of properties after the annual Nile floods.  The Turing Papyrus Map, dated c. 1150 BC, shows the mountains east of the Nile, where gold and silver were mined, along with the location of miners’ shelters, wells, and the road network that linked the elements of the region.  The map contains informative inscriptions, has a precise orientation, and is in color.

Fragments of the Turing Papyrus Map, depicting an important mining area, c. 1150 BC.

Ancient Phoenician sailors made major advances in seafaring and exploration.  The first circumnavigation of Africa was accomplished by Phoenicians, c. 600 BC.  Unfortunately, nothing certain about their knowledge of geography and navigation has survived.  Some historians theorize that the Phoenician circumnavigation of Africa inspired the theory of a spherical Earth.

Greece.   Ancient Greeks created the earliest papyrus maps that were used for navigation and to depict certain areas of the Earth.  Early geography and early conceptions of the Earth lead back to the Greek epic poet Homer.  The depiction of the Earth conceived by Homer, which was accepted by the early Greeks, represents a circular flat disk surrounded by ocean.

Anaximander was the first ancient Greek to draw a map of the known world, c. 550 BC, and is considered by many to be the first mapmaker. 

Hecataeus of Meletus produced another map fifty years later that he claimed was an improvement.  Hecatæus's map describes the earth as a circular plate with an encircling Ocean, and Greece in the center of the world.  This was a very popular contemporary Greek worldview, derived originally from the Homeric poems. Also, similar to many other early maps in antiquity, his map has no scale.  As units of measurements, this map used "days of sailing" on the sea and "days of marching" on dry land. The work follows the assumption of the author that the world was divided into two continents, Asia and Europe.

Recreated Hecataeus world map showing Greece at the center of the known world, c. 500 BC.

While various previous Greek philosophers presumed the Earth to be spherical, Aristotle (384-322 BC) is credited with “proving” it, with the following arguments:

·         The lunar eclipse is always circular.

·         Ships seem to sink as they move away from view and pass over the horizon.

·         Some stars can be seen only from certain parts of the Earth.

In 240 BC, Eratosthenes, an astronomer, mathematician, and geographer, was the first to come up with a scientific estimate of the size of the spherical Earth.  He noted the angles of shadows in two cities, Aswan and Alexandria, which he believed were on the same meridian, at mid-day of the Summer Solstice, and by performing calculations using his knowledge of geometry and distance between the cities, was able to make a remarkably accurate (within 0.5 percent) of the circumference of the Earth (24,860 miles).

Eratosthenes drew a world map, incorporating information from the campaigns of Alexander the Great and his successors.  Asia became wider, reflecting the new understanding of the actual size of the continent.  Eratosthenes was the first geographer to incorporate parallels and meridians on his maps, attesting to his understanding of the spherical nature of the Earth.  He was also the first person to use the word “geography.”

Recreation of Eratosthenes world map, incorporating information from the campaigns of Alexander the Great and his successors, 220 BC.  

Roman Empire.  The Roman Empire lasted over 500 years, from 27 BC to AD 476, and greatly expanded man’s knowledge of the world.  During Roman times, cartographers focused on practical uses: military and administrative needs. Their need to control the Empire in financial, economic, political, and military aspects, made evident the need to have maps of administrative boundaries, physical features, or road networks.

The first great attempt to make mapping more realistic came in the second century AD with Claudius Ptolemy, Roman citizen, an astrologer, astronomer, mathematician, and geographer, living in Alexandria, Egypt.  Driven by a desire to make accurate horoscopes, which required precisely placing someone’s birth town on a world map, Ptolemy gathered documents detailing the location of towns, and he augmented that information with the tales of travelers.  By the time he was done, he had devised a system of lines of latitude (parallels) and longitude (meridians), on which he precisely plotted some 10,000 locations - from Britain to Europe, Asia, and North Africa - encompassing the known world at that time.  Latitude was measured vertically from the equator, while longitude was measured from the westernmost landmass known to date, the Canary Islands off the coast of Spain.

Ptolemy revolutionized the depiction of the spherical Earth on a flat map by using the mathematics of perspective projection and Euclidean geometry, where meridians are drawn as straight lines converging at an imaginary point beyond the north pole, with the parallels drawn as curved arcs of different length, centered on the same point, and with fixed positions (latitude and longitude coordinates) of geographic features.  Because the meridian lines are converging, the map is distorted at the higher latitudes.  Ptolemy also informed mapmakers on the size of the Earth.

Ptolemy’s eight-volume atlas, Geographia, was a prototype of modern mapping and geographic information systems.  It included an index of place names, with the latitude and longitude of each place, and established the practice of orienting maps so that north is at the top and east to the right - an almost universal custom today.

Ptolemy world map, showing the known world at the peak of the Roman Empire.  Note the curved lines of latitude and the straight longitude lines, AD 150 (this copy made in 1482).

Middle Ages

The Middle Ages in Europe lasted from the late 5^th century to the late 15^th century, until merging into the Renaissance and Age of Exploration.  After the Roman Empire fell in 476, Ptolemy’s realistic geography was lost to the West for almost a thousand years. 

Medieval maps of the world in Europe were mainly symbolic. These maps were circular or symmetrical cosmological diagrams representing the Earth’s single land mass as disk-shaped and surrounded by ocean.

Other maps were concerned with storytelling, including Christian maps that related stories like Adam and Eve getting tossed out of the Garden of Eden, and a guide to get one to heaven.

In the early 8^th century, Islamic Moors from North Africa, invaded the Iberian Peninsula (today’s Spain and Portugal) until driven out by the Spaniards in the late 15^th century.  The Moors brought with them a renaissance in art, science and literature, in which for several centuries, while the rest of Europe was in a state of virtual intellectual stagnation, the Arabs led the western world.

During this time, Muslim scholars started to improve maps by using the knowledge, notes, and writings of the explorers and merchants during their travels across the Muslim world. There were advances in a more accurate definition of the measurement units, plus great efforts in trying to describe and define the calculations of the circumference of the earth. There were also numerous studies of methodologies to draw a system of meridians and parallels that helped greatly in the evolution of the science of Cartography.

In 1154, the Arab geographer, Muhammad al Idrisi, working on the island of Sicily, produced a milestone world map.  Tabula Rogeriana wasn’t just a map of the world - it was an extensively researched geographical text that covered natural features, ethnic and cultural groups, socioeconomic features, and other characteristics of every area he mapped.  The mapmaking and atlas effort took 18 years, including the commentaries and illustrations on the maps.

The atlas was created for King Roger II of Sicily.  Al Idrisi drew upon his own extensive travels, interviews with explorers, and draftsmen paid to travel and map their routes - in Africa, the Indian Ocean, and the Far East in order to create the maps in the Tabula Rogeriana. These maps describe the world as a sphere, with a circumference of 22,900 miles, but divided into seventy different rectangular sections, each of which was discussed in exacting detail.

The world map, written in Arabic, shows, the Eurasian continent in its entirety, but only shows the northern part of the African continent.  Notable features include the correct dual sources of the Nile, the coast of Ghana, and mentions of Norway.  The world map was produced with north at the bottom, so the map appears “upside down” compared to modern cartographic conventions.

There is nothing inevitable or intrinsically correct about the north being represented as up.  Some of the very earliest Egyptian maps show the south as up.  And there was a long stretch in the medieval era when most European maps were drawn with the east on the top.  Arab map makers often drew maps with the south facing up.  For reasons that have been lost to history, Ptolemy put the north up.  Most cartographers, who made the first big, beautiful maps of the entire world, were obsessed with Ptolemy and followed his lead.

Al-Idrisi’s Tabula Rogeriana map was the most accurate map of the world at the time, and remained the most accurate world map for the next three centuries. 

Al-Idrisi's world map, shown upside down here for easier comparison to other maps in this article, c. 1154.

From 1271 to 1275, Italian Marco Polo traveled to China and the court of Kublai Khan via central Asia. He eventually returned home between 1292 and 1295 via Sumatra, India, and Persia.  His account of his travels spurred a European desire for far eastern riches and contributed a lot to the knowledge of world geography.

In the same time frame, other Italians produced nautical charts, not simply maps, but documents showing accurate navigational directions.

In the early 1300s, the Majorcan Cartographic School, a predominantly Jewish cooperation of cartographers, cosmographers and navigational instrument-makers in the late 13^th to the 15^th century, operated on the island of Majorca, off the east coast of Spain.  With their multicultural heritage, the Majorcan Cartographic School developed unique cartographic techniques, most dealing with the Mediterranean.  The Majorcan school was (co-)responsible for the invention of superior, detailed nautical model charts, gridded by compass lines.

In 1407, a copy of Ptolemy’s Geographia was translated from Greek into Latin.  The book created a sensation, as it challenged the very basis of Medieval mapmaking - mapmakers before this had based the proportions of countries, not on mathematical calculations, but often on the importance of different places - the more important a country was, the bigger it appeared on the map.  Ptolemy’s introduction of mathematics, and the idea of accurate measurement, were to change the nature of mapmaking forever.

In 1490, German geographer and cartographer, Henricus Martellus Germanus, working in Florence, Italy at the time, produced a world map showing heavy influences from Ptolemy, and included the southern passage around Africa and an enormous new peninsula, southeast Asia.

Henricus Martellus Germanus world map, one of the last maps produced before the discovery of the New World, c. 1490.

Age of Exploration

The Age of Exploration, also known as the Age of Discovery, lasted from the beginning of the 15^th century to the mid-17^th century - a period of widespread European exploration of the world, marking the adoption of colonialism as a national policy in Europe.  Extensive lands, previously unknown to Europeans, were discovered during this period.

There is evidence that Norse Vikings discovered and attempted to settle North America as early as the late 10^th century.

European exploration outside the Mediterranean started with the Portuguese discoveries of the Atlantic archipelagos of Madeira and the Azores in 1419 and 1427 respectively, then the coast of West Africa after 1434, until the establishment of the sea route to India in 1498 by Vasco da Gama.  Portuguese explorers also discovered the coast of Brazil in 1500, and Australia and the Spice Islands in 1512.  Spain sponsored the transatlantic voyages of Christopher Columbus to the Americas between 1492 and 1504, the expedition of Hernan Cortez to Mexico in 1519, the expedition of Francisco Pizzaro to Peru in 1531, and the first circumnavigation of the globe between 1519 and 1522 by Ferdinand Magellan. France sponsored explorations of the east coast of America by Giovanni da Verrazano in 1524 and southeastern Canada by Jacques Cartier in 1534.  England sponsored discovery voyages to eastern Canada by John Cabot in 1497 and Henry Hudson in 1610.  

Contrary to popular opinion, the early European explorers knew that the world was spherical and not flat.  Indeed, on his first voyage to the Americas, Columbus carried a map influenced by Ptolemy’s ancient work that described a spherical earth.  But Ptolemy’s estimate of the circumference of the earth was off, and Columbus thought the world was thirty percent smaller than it actually was, and anticipated a much shorter voyage to Asia.

These explorations of discovery led to numerous naval expeditions across the Atlantic, Indian, and Pacific oceans, and land expeditions in the Americas, Asia, Africa, and Australia that continued into the late 19th century, followed by the exploration of the polar regions in the 20th century.

European overseas exploration led to the rise of global trade and European colonial empires, with the contact between the Old World (Europe, Asia and Africa) and the New World (the Americas), as well as Australia.    

European geographical discoveries allowed the mapping of the entire world, resulting in a new worldview.  As time went by, and more and more of the world became known, maps began to depict the new lands.  The seacoasts and major rivers were mapped first, followed by maps of the inland territories.

One of the first maps to depict the New World was published in 1507 by German cartographer Martin Waldseemuller.  The map, shown below, uses a modified Ptolemy map projection with curved meridians to depict the entire surface of the Earth.  Note that only the east coast of the Americas is shown.  This was the first time that the name “America” was used on a map.

World map by Martin Waldseemuller, one of the first to depict the New World, c. 1507.  Note that only the eastern coastal areas of the Americas are known at this time.

The single greatest innovation in mapping after Ptolemy was produced by Dutch geographer and cartographer Gerardus Mercator in 1569.  He invented an improved way to represent the surface of a globe on a flat map, retaining straight lines of latitude and longitude, by gradually widening landmasses and oceans the farther north and south they appear on the map, greatly distorting the size of objects closest to the poles.  The projection preserves the correct angles between directions within a small area, making it a great aid to navigation, because lines of constant bearing were straight. 

The earliest known terrestrial globe was constructed in the mid-2^nd century BC in Turkey.  The oldest surviving globe was made in 1492 by Martin Behaim, a German mapmaker, navigator, and merchant.  The globe was constructed of a laminated linen ball reinforced with wood and overlaid with a map painted by Georg Glockendon.  A grapefruit-sized globe, made from two halves of an ostrich egg, dated from 1504, may be the first globe to show the New World.  Of course, these early globes could only reflect the knowledge of world geography from that time.

In 1570, Abraham Ortelius, Dutch cartographer, geographer, and dealer in maps, books, and antiquities, published the first modern atlas, Theatrum Orbis Terrarum, a collection of 53 uniform map sheets and supporting text bound to form a book for which copper printing plates were specifically engraved.  The world map from this atlas, shown below, used Mercator’s projection approach.  Note how much more of the world is known at this date.  Note also the hypothetical continent, Terra Australis (Latin for South Land) that appears on the bottom of the map. The existence of Terra Australis was not based on any survey or direct observation, but rather on the idea that continental land in the Northern Hemisphere should be balanced by land in the Southern Hemisphere, a theory first expounded in the 5^th century.

The Ortelius world map, c. 1570, used Mercator's projection approach.

 

Towards the end of the Age of Exploration, in 1658, Dutch engraver, cartographer, and publisher, Nicolaes Visscher, produced an engraved double-hemisphere map that included knowledge of the world to date.  Note that California is depicted as an island, a mistake first made in 1622 that that persisted well into the 18^th century.   The northwestern coastline of North America would not be determined until late in the 18^th century.  Note also that the continent of Antarctica is not shown; the existence of Antarctica would not be proven until 1820.

Visscher double-hemisphere world map, c. 1658.

In the 16^th and 17^th centuries, the nature of maps began to change from purely information repositories and navigation aids.   Everyday people realized that a map was an act of persuasion.  For example, maps of towns were used to distinguish land ownership and political boundaries.  Maps were used to settle arguments.  The persuasive power of a map was its glanceability - data made visual.

Maps conferred power.  With a good map, a military had an advantage in battle.  A king knew how much land could be taxed.  Unmapped inland territories cried out for discovery and colonialism.

Maps were so valuable that seafarers plundered them.  Seventeenth century buccaneers exulted in capturing maps from Spanish ships that showed all the harbors, bays, sand and rocks, and rising of the land.

Industrial Age

The Industrial Age lasted from the mid-17^th century to the late 20^th century - a period characterized in general by inventions to make manufacturing more efficient.  The parallel with mapmaking, the beginning of modern cartography, was the invention of tools like the compass, telescope, binocular lenses, the sextant, quadrant, theodolites, and the printing press - permitting maps to be made more easily and accurately, and printed in large numbers.  New technologies also led to the development of different map projections that more precisely showed the world or focused on special applications.

There is no limit to the number of possible map projections.  Wikipedia lists over 70 different projections, including applications for topographic, geological, and thematic mapping; presentations; navigation; and the United States Geological Survey.

In the 17^th and 18^th centuries, the United States Geological Survey and the National Geodetic Survey developed tools to map trails and survey government lands.  In the 20^th century, airplanes and satellite aerial photographs changed the types of data that could be used to create maps.

During this time period there were additional explorations that added to the knowledge of world geography.  In 1773, Britain’s Captain James Cook discovered islands near Antarctica, and in 1778 discovered the Hawaiian Islands and explored the coastline of the Pacific Northwest.  The continent of Antarctica was discovered in 1820.

In 1794, British mathematician and amateur astronomer Samuel Dunn produced a map of the entire world in a double hemisphere projection.  The map followed shortly after the explorations of Captain Cook in the Arctic and Pacific Northwest.  However, when this map was made, few inland expeditions in America had extended westward beyond the Mississippi River.  Antarctica is noticeably absent, 26 years before its discovery.

World map by Samuel Dunn, 1794.

In 1851, England’s Sir George Airy established a geographical meridian reference line that passed through the Royal Observatory at Greenwich in London, England.  According to Airy, the meridian would represent zero degrees longitude on world maps, and east and west longitudes would be measured from there around the Earth.  By 1884, over two-thirds of all ships used it as a reference meridian.  In October of that year, the International Meridian Conference adopted Airy’s reference line as the prime meridian.

The prime meridian was established in 1884.

 

Geographical knowledge of the world continued to progress, particularly in the polar regions and the inland regions of the world’s continents.  Mapmaking kept pace with increasingly detailed and accurate maps.

In parallel, as the Industrial Age progressed, trading and commerce increased enormously throughout the world.  The era brought the rise of a middle class who started to be able to afford luxuries such as books and travel.  Travel was often necessary for business; now travel for pleasure expanded rapidly.  Geographers and cartographers responded to the increasing demand for useful maps.  Large, decorated, almost artistic folio maps, so popular during previous centuries, gave way to smaller, more practical, and portable maps with smaller features that gave more importance to the accuracy of the elements represented than to the decorative meaning of the map.

During the 19^th century, railroads expanded rapidly throughout the world, making travel faster, cheaper and more accessible to more and more people. Cartographers put more of their energy and effort into producing up-to-date maps, showing the latest extensions to railroad networks.  During this time, maps eliminated the remaining decorative features and became almost entirely factual.

With the introduction of automobiles for general use early in the 20^th century, and the gradual creation of networks of roads and highways, mapmaking responded again with roadmaps for travelers.

 

My personal roadmap of Arizona with the roads I've traveled highlighted in yellow.

Local mapping became deeply granular, especially for cities.  Tourists could confidently tour new places, their annually updated travel guides in hand, able to located individual sites and buildings.  Being prominent on local maps was valuable to merchants, so mapmakers sold “advertising” rights.

Maps could even help win wars.  In the Second World War, Winston Churchill fought with guidance from his “map room,” an underground chamber where up to 40 military staffers shoved colored pins into the map-bedecked walls, helping Churchill plan how to defend the British coast and launch offensive strikes into Germany.

Information Age

The Information Age, also known as the Computer Age or Digital Age, began in the mid-20^th century, characterized by a rapid transition from traditional industry to information technology associated with the development of computers and transistors, the fundamental building blocks of digital electronics. 

Modern cartography found an essential tool in the use of computers, and peripheral instruments like plotters, printers, and scanners, along with image processing, spatial analysis, and database software.  Beginning in 1968, a computerized geographic information system (GIS) evolved for capturing, storing, checking, manipulating, and displaying data related to positions on the Earth’s surface.  GIS can show many different kinds of data on one map, such as streets, buildings, and vegetation, enabling people to more easily see, analyze, and understand patterns and relationships.  Globalization of data, with the use of the internet, web mapping services, and new software applications, plus the transfer of these tools to mobile devices, has made powerful cartography available to everyone.

With the exponential increases in technology, the knowledge of terrestrial Earth has increased.  The use of surveillance aircraft and satellite imagery have documented many areas that were previously inaccessible.  Services such as Google Earth, and other free online digital maps, have made accurate maps of the world more accessible than ever before.

 

Google Earth map of a portion of London, England.

The convenience of the satellite Global Positioning System and online mapping means we live in an increasingly cartographic age.  Many online searches produce a map as part of the search results - for a local store, a vacation spot, live traffic updates, and so on.  People today see and interact with maps every day.

These days, our maps seem alive:  they speak, in robotic voices, telling us precisely where to go - guided by satellites and mapping of companies like Google, Bing, and Mapquest, providing turn by turn directions and time to destination.  There’s no need to even orient yourself to north:  the voice tells you turn right, turn left, with you always at the center.  And these capabilities are now available in our automobiles, on our smart phones, and even on our watches.

Map and directions from Mapquest for the San Francisco area.

All this technology comes together in apps like Rome2Rio that searches any city, town, landmark attraction, or address across the globe to find and display multi-modal routes (trains, buses, ferries, airplanes, cars) to easily get you from point A to B.

Future of Mapping

The future of mapping is tied to the expanding use of video, lasers, and radar (all together VLR) as a primary mapping data source and machine learning with artificial intelligence.  This means that the mapping pipeline to ingest data from VLR sensors and mapping software tools we use for mapping geospatial analytics must change.

Future maps won’t rely on humans to input fast-paced changes to mapping elements.   Instead, they must grow on their own from an array of VLR sensors deployed across cars, drones, and airplanes.  By automatically georegistering (setting accurate coordinates) all data coming from VLR sensors, a smart map will confidently update itself to reflect changes such as a terrain shift, status of construction, location of traffic signs or obstacles, and so on.  

A smart map will be aware of its history and understand important changes taking place in the physical world.  Machine learning software will generate actionable information.  Users will watch changes play out before their eyes, helping them gain valuable insights into, for example, how a city, park, building, or road is changing.

Potential applications for future mapping are mind boggling, and include self-driving cars, urban planning, transportation planning, defense battle awareness and logistics, first responder directions, oil and gas physical infrastructure, post disaster damage assessment, fighting forest fires, electric grid infrastructure status and recovery, weather prediction and storm warning, crime analysis, pandemic mapping, accident analysis, environment impact analysis, land use mapping, navigation, natural resources management, water management, traffic control, pest control, community development …