New blog

The Islamic empire began to expand beyond the Arabian Peninsula after the death of the prophet and founder of Islam, Mohammed, in 632 AD. Islamic leaders conquered Iran in 641 and in 642 Egypt was under Islamic control. In the eighth century, all of northern Africa, the Iberian Peninsula (Spain and Portugal), India and Indonesia became Islamic lands. The Muslims were stopped at France by their defeat at the Battle of Tours in 732. Nonetheless, Islamic rule continued on the Iberian Peninsula for nearly nine centuries.

Around 762, Baghdad became the intellectual capital of the empire and issued a request for books from throughout the world. Traders were given the weight of the book in gold. Over time, Baghdad accumulated a wealth of knowledge and many key geographical works from the Greeks and Romans. Ptolemy's Almagest, which was a reference to the location and movement of heavenly bodies along with his Geography, a description of the world and a gazetteer of places, were two of the first books translated, thus keeping their information in existence. With their extensive libraries, the Islamic view of the world between 800 and 1400 was much more accurate than the Christian view of the world.

The Muslims were natural explorers since the Koran (the first book written in Arabic) mandated a pilgrimage (hajj) to Mecca for every able-bodied male at least once in their life. With thousands traveling from the farthest reaches of the Islamic Empire to Mecca, dozens of travel guides were written to assist in the trip. Pilgrimage during the seventh to tenth month of the Islamic calendar each year led to further exploration beyond the Arabian Peninsula. By the eleventh century, Islamic traders had explored the eastern coast of Africa to 20 degrees south of the Equator (near contemporary Mozambique).

Islamic geography was primarily a continuation of the Greek and Roman scholarship which had been lost in Christian Europe. There were some additions to the collective knowledge by their geographers, especially Al-Idrisi, Ibn-Batuta, and Ibn-Khaldun.

Al-Idrisi (also transliterated as Edrisi, 1099-1166 or 1180) served King Roger II of Sicily. He worked for the king in Palermo and wrote a geography of the world called Amusement for Him Who Desires to Travel Around the World which wasn't translated into Latin until 1619. He determined the circumference of the earth to be about 23,000 miles (it is actually 24,901.55 miles).

Ibn-Batuta (1304-1369 or 1377) is known as the "Muslim Marco Polo." In 1325 he traveled to Mecca for a pilgrimage and while there decided to devote his life to travel. Among other places, he visited Africa, Russia, India, and China. He served the Chinese Emperor, the Mongol Emperor, and the Islamic Sultan in a variety of diplomatic positions. During his life, he traveled approximately 75,000 miles, which at the time was farther than anyone else in the world had traveled. He dictated a book which was an encyclopedia of Islamic practices around the world.

Ibn-Khaldun (1332-1406) wrote a comprehensive world history and geography. He discussed the effects of the environment on humans so he is known as one of the first environmental determinists. He felt that the northern and southern extremes of the earth were the least civilized.

By translating important Greek and Roman texts and by contributing to the knowledge of the world, Islamic scholars helped provide the information which allowed the discovery and exploration of the New World in the fifteenth and sixteenth centuries.

William Morris Davis is often called the "father of American geography" for his work in not only helping to establish geography as an academic discipline but also for his advancement of physical geography and the development of geomorphology.

Life and Career

Davis was born in Philadelphia in 1850. At the age of 19, he earned his bachelor's degree from Harvard University and one year later earned his masters degree in engineering. Davis then spent three years working at Argentina's meteorological observatory and subsequently returned to Harvard to study geology and physical geography.

In 1878, Davis was appointed an instructor in physical geography at Harvard and by 1885 became a full professor. Davis continued to teach at Harvard until his retirement in 1912. Following his retirement, he occupied several visiting scholar positions at universities across the United States. Davis died in Pasadena, California in 1934.

Geography

William Morris Davis was very excited about the discipline of geography; he worked hard to increase its recognition. In the 1890s, Davis was an influential member of a committee that helped to establish geography standards in the public schools. Davis and the committee felt that geography needed to be treated as a general science in primary and secondary schools and these ideas were adopted. Unfortunately, after a decade of the "new" geography, it slipped back to being rote knowledge of place names and eventually disappeared into the bowels of social studies.

Davis also helped to build geography up at the university level. In addition to training some of America's foremost geographers of the twentieth century (such as Mark Jefferson, Isaiah Bowman, and Ellsworth Huntington), Davis helped to found the Association of American Geographers (AAG). Recognizing the need for an academic organization composed of academics trained in geography, Davis met with other geographers and formed the AAG in 1904.

Davis served as the AAG's first president in 1904 and was reelected in 1905, and ultimately served a third term in 1909. Though Davis was very influential in the development of geography as a whole, he is probably best known for his work in geomorphology.

Geomorphology

Geomorphology is the study of the earth's landforms. William Morris Davis founded this subfield of geography. Though at his time the traditional idea of the development of landforms was through the great biblical flood, Davis and others began to believe that other factors were responsible for shaping the earth.

Davis developed a theory of landform creation and erosion, which he called the "geographical cycle." This theory is more commonly known as the "cycle of erosion," or more properly, the "geomorphic cycle." His theory explained that mountains and landforms are created, mature, and then become old.

He explained that the cycle begins with the uplift of mountains. Rivers and streams begin to create V-shaped valleys among the mountains (the stage called "youth"). During this first stage, the relief is steepest and most illregular. Over time, the streams are able to carve wider valleys ("maturity") and then begin to meander, leaving only gently rolling hills ("old age"). Finally, all that is left is a flat, level plain at the lowest elevation possible (called the "base level.") This plain was called by Davis a "peneplain," which means "almost a plain" for a plain is actually a completely flat surface). Then, "rejuvenation" occurs and there is another uplift of mountains and the cycle continues.

Though Davis' theory is not entirely accurate, it was quite revolutionary and outstanding at its time and helped to modernize physical geography and create the field of geomorphology. The real world is not quite as orderly as Davis' cycles and certainly erosion occurs during the uplift process. However, Davis' message was communicated quite well to other scientists through the excellent sketches and illustrations that were included in Davis' publications.

Alexander von Humboldt was born in Berlin, Germany in 1769. His father, who was an army officer, died when he was nine years old so he and his older brother Wilhelm were raised by their cold and distant mother. Tutors provided their early education which was grounded in languages and mathematics.

Once he was old enough, Alexander began to study at the Freiberg Academy of Mines under the famous geologist A.G. Werner. Von Humboldt met George Forester, Captain James Cook's scientific illustrator from his second voyage, and they hiked around Europe. In 1792, at the age of 22, von Humboldt began a job as a government mines inspector in Franconia, Prussia.

When he was 27, Alexander's mother died, leaving him as substantial income from the estate. The following year, he left government service and began to plan travels with Aime Bonpland, a botanist. The pair went to Madrid and obtained special permission and passports from King Charles II to explore South America.

Once they arrived in South America, Alexander von Humboldt and Bonpland studied the flora, fauna, and topography of the continent. In 1800 von Humboldt mapped over 1700 miles of the Orinco River. This was followed by a trip to the Andes and a climb of Mt. Chimborazo (in modern Ecuador), then believed to be the tallest mountain in the world. They didn't make it to the top due to a wall-like cliff but they did climb to over 18,000 feet in elevation. While on the west coast of South America, von Humboldt measured and discovered the Peruvian Current, which, over the objections of von Humboldt himself, is also known as the Humboldt Current. In 1803 they explored Mexico. Alexander von Humboldt was offered a position in the Mexican cabinet but he refused.

The pair were persuaded to visit Washington, D.C. by an American counselor and they did so. They stayed in Washington for three weeks and von Humboldt had many meetings with Thomas Jefferson and the two became good friends.

Von Humboldt sailed to Paris in 1804 and wrote thirty volumes about his field studies. During his expeditions in the Americas and Europe, he recorded and reported on magnetic declination. He stayed in France for 23 years and met with many other intellectuals on a regular basis.

Von Humboldt's fortunes were ultimately exhausted because of his travels and self-publishing of his reports. In 1827, he returned to Berlin where he obtained a steady income by becoming the King of Prussia's advisor. Von Humboldt was later invited to Russia by the tsar and after exploring the nation and describing discoveries such as permafrost, he recommended that Russia establish weather observatories across the country. The stations were established in 1835 and von Humboldt was able to use the data to develop the principle of continentality, that the interiors of continents have more extreme climates due to a lack of moderating influence from the ocean. He also developed the first isotherm map, containing lines of equal average temperatures.

From 1827 to 1828, Alexander von Humboldt gave public lectures in Berlin. The lectures were so popular that new assembly halls had to be found due to the demand. As von Humboldt got older, he decided to write everything known about the earth. He called his work Kosmos and the first volume was published in 1845, when he was 76 years old. Kosmos was well written and well received. The first volume, a general overview of the universe, sold out in two months and was promptly translated into many languages. Other volumes focused on such topics as human's effort to describe the earth, astronomy, and earth and human interaction. Humboldt died in 1859 and the fifth and final volume was published in 1862, based on his notes for the work.

Once von Humboldt died, "no individual scholar could hope any longer to master the world's knowledge about the earth." (Geoffrey J. Martin, and Preston E. James. All Possible Worlds: A History of Geographical Ideas., page 131).

Von Humboldt was the last true master but one of the first to bring geography to the world.

Eratosthenes was born around 276 B.C.E. at a Greek colony in Cyrene, Libya. He was educated at the academies of Athens and was appointed to run the Great Library at Alexandria in 240. While serving as head librarian and scholar, Eratosthenes wrote a comprehensive treatise about the world, called Geography. This was the first use of the word, which literally means "writing about the earth" in Greek. Geography also introduced the climatic concepts of torrid, temperate, and frigid zones.

Having heard of a deep well at Syene (near the Tropic of Cancer and modern Aswan) where sunlight only struck the bottom of the well on the summer solstice, Eratosthenes determined that he could discover the circumference of the earth. (Greek scholars knew that the earth was indeed a sphere). To calculate the circumference, Eratosthenes needed two things. He knew the approximate distance between Syene and Alexandria, as measured by camel-powered trade caravans. He then measured the angle of the shadow in Alexandria on the solstice. By taking the angle of the shadow (7°12') and dividing it into the 360 degrees of a circle (360 divided by 7.2 yields 50), Eratosthenes could then multiply the distance between Alexandria and Syene by 50 to determine the circumference.

Remarkably, Eratosthenes determined the circumference to be 25,000 miles, just 100 miles over the actual circumference at the equator (24,901 miles). While Eratosthenes made mathematical errors in his caculations, these fortunately canceled each other out and yielded an amazingly accurate answer.

A few decades later, the Greek geographer Posidonius thought Eratosthenes' circumference was too large. He calculated the circumference on his own and obtained 18,000 miles, 7,000 miles too short. During the middle ages, most scholars accepted Eratosthenes' circumference though Christopher Columbus used Posidonius' circumference to convince his supporters that he could quickly reach Asia by sailing west from Europe.

In old age, Eratosthenes became blind and died of self-induced starvation in either 192 or 196 B.C.E. He had thus lived to be about 80 to 84 years old.

"The purpose of geography is to provide 'a view of the whole' earth by mapping the location of places." – Ptolemy, 150 CE

"Synoptic discipline synthesizing findings of other sciences through the concept of Raum (area or space)." – Immanuel Kant, c. 1780

"Synthesizing discipline to connect the general with the special through measurement, mapping, and a regional emphasis." – Alexander von Humboldt, 1845

"Man in society and local variations in environment." - Halford Mackinder, 1887

"How environment apparently controls human behavior." - Ellen Semple, c. 1911

"Study of human ecology; adjustment of man to natural surroundings." - Harland Barrows, 1923

"The science concerned with the formulation of the laws governing the spatial distribution of certain features on the surface of the earth." - Fred Schaefer, 1953

"To provide accurate, orderly, and rational description and interpretation of the variable character of the earth surface." - Richard Hartshorne, 1959

"Geography is both science and art" - H.C. Darby, 1962

"To understand the earth as the world of man" - J.O.M. Broek, 1965

"Geography is fundamentally the regional or chorological science of the surface of the earth." - Robert E. Dickinson, 1969

"Study of variations in phenomena from place to place." - Holt-Jensen, 1980

"...concerned with the locational or spatial variation in both physical and human phenomena at the earth's surface" - Martin Kenzer, 1989

"Geography is the study of earth as the home of people" - Yi-Fu Tuan, 1991

"Geography is the study of the patterns and processes of human (built) and environmental (natural) landscapes, where landscapes comprise real (objective) and perceived (subjective) space." - Gregg Wassmansdorf, 1995