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Alexander von Humboldt, 1769–1859

German naturalist Alexander von Humboldt lived to see the new direction taken by geographic studies, which his own work had initiated. By the time of his death, thematic mapping had already passed its golden age.

Portrait of Alexander von Humboldt. From vol. 1 of Evert A. Duyckinck’s Portrait Gallery of Eminent Men and Women of Europe and America . . . (New York: Johnson & Miles, ca. 1873) [General Library Collection].

Alexander was the younger brother of the successful Prussian diplomat and linguist Wilhelm von Humboldt (1767–1835), the founder of Humboldt University. But he was not destined to live in his brother’s shadow. Born in Berlin to privileged aristocracy during Frederick the Great’s reign, Humboldt was nine when his father died, and the brothers were reared, according to biographers, in an emotional wasteland by a puritanical mother: work and achievement ruled over love and play. As a result, the boys became as close as twins.
            While Wilhelm’s studiousness put him on the fast track in training for a high public office, Alexander’s restlessness and outdoor wanderings—collecting and labeling beetles, flowers, shells, and stones were favorite pastimes—led his mother to choose for “the little apothecary” a more bureaucratic career. In 1789, he matriculated at Göttingen University, where he met and formed a strong friendship with naturalist-ethnologist-revolutionary Georg Forster, who had accompanied his father on Captain James Cook’s second voyage of exploration around the world. After spending time with Forster, traveling to London and back through revolutionary Paris, Humboldt seemed to have found his calling: thereafter he pursued a relentless, self-imposed program of study, both curricular and extracurricular, to become a scientific explorer himself. He studied commerce, geology, botany, foreign languages, anatomy, astronomy, and scientific instruments as if possessed by a demon. Among his prominent instructors were geologist Abraham Gottlob Werner, anatomist Justus Christian Loder, and astronomers Franz Xaver von Zach and Johann Gottfried Köhler. Throughout his life, Humboldt would meet and correspond with an unprecedented number of important figures in a wide range of disciplines.
            In 1792, Humboldt received his first official employment as assessor of mines for the Prussian Ministry of Industry and Mines. This service to the state he viewed as an apprenticeship only, but he performed it so diligently—his first report, which weighed in at 150 pages, won him an immediate promotion to chief inspector—that he probably would have become superintendent. Yet, though he seemed to enjoy dashing around the country on official business, improving mining conditions and output, and even setting up the country’s first workers’ training school, the bureaucrat continued to fan the scientific flame. He could not be deterred from conducting muscle-electricity experiments and publishing a botanical book, activities that ultimately brought him into the Weimar circle of German literary giants Johann Wolfgang von Goethe and Friedrich Schiller, whose interests included natural science. When his mother died in the fall of 1796, Humboldt was finally freed from family career expectations, and he had suddenly through inheritance become a millionaire. So, in February 1797, he resigned from his mining job and began calculating his next move. What opportunity would present itself?

Humboldt’s signature. From a letter to an unidentified correspondent, dated 8 December 1840 [General Manuscripts Collection, Manuscripts Division].

In short order he was living in his brother’s house in Paris, where Wilhelm was taking a sojourn of his own to follow his cultural interests and indulging himself in the intellectual and social life of the city, which had become an international meeting-ground of top-flight thinkers. While visiting Louis Antoine de Bougainville, France’s first circumnavigator, Humboldt learned of the government’s plans for a new, five-year scientific expedition round the world on land and sea. The venerable explorer was in charge and invited Humboldt to join its staff. But the news was too good to last, for a new war soon was breaking out and the expedition plans were shelved.
            Disappointed but still desiring to do something stimulating and challenging, Humboldt joined forces with Aimé Bonpland (1773–1858), the now-defunct expedition’s first-rate botanist, and the two ultimately walked from the Pyrenees to Madrid on a six-week journey of their own. Bonpland would prove to be the perfect companion (then and later)—always positive, level-headed, healthy, and humorous. During the trek Humboldt assiduously took scientific readings (astronomical and barometric) with his instruments, and his resulting topographic profile of the peninsula, the first of its kind, proved that central Spain was a high plateau.
            In Madrid, his connections got him an introduction to the king and queen at court, where he explained his desire to visit Spanish-American colonies and the possible benefits that might result. Indeed, King Carlos IV thought a good geologist in New Spain might discover rich mineral deposits and readily agreed to lend his support: Humboldt and Bonpland were given unlimited permission to explore Spanish territory and passports that would open any door they encountered. Humboldt could not believe his sudden good fortune. One of the largest territories on the earth, stretching from Cape Horn to California, including most of the West Indies and all of Central America, as well as one-third of what is now the continental United States, was offered up for his scientific exploration! Most of that terrain was terra incognita, and no foreign scientist had been given such free rein there. He was determined to make the most of this unique opportunity, which he would finance from his own pocket.

The resulting five-year expedition (1799–1804) to the Americas that Humboldt undertook with Bonpland took virtually the rest of his life to fully digest and describe. The two men would cover six thousand miles, from 52° N to 12° S, and bring back forty-five cases of specimens (sixty thousand items!), as well as a mass of astronomical, geological, meteorological, botanical, and oceanographic data. The expedition would lay the groundwork for a new direction in geography.
            On June 5, 1799, the two men left the Spanish port of Corunna, bound for Havana aboard a packet-boat named Pizarro. Stocked with the most advanced scientific instruments he could acquire, Humboldt planned to measure and observe everything, including atmospheric temperature and pressure, ocean temperature and currents, terrestrial magnetism, the distribution of plants and animals, rocks and strata, humidity and other climatic conditions. The ship put in for a few days at Tenerife in the Canary Islands so the men could explore the volcano Pico de Teide, which had recently been active. (See Humboldt’s profile of the mountain, opposite.) During the Atlantic crossing, the ship’s crew and passengers suffered from a serious outbreak of typhoid fever, and so they changed course to land at the first South American port they could find. That was Cumaná, Venezuela, where they anchored on July 16. It was a serendipitous altering of plans for Humboldt and Bonpland, who had miraculously escaped the epidemic: they would begin their explorations in South America.

“Cuadro fisico de las Islas Canarias. Geografia de las Plantas de Tenerife.” Copperplate profile chart, with added color, 17.5 × 39.4 cm. From vol. 1 of Humboldt’s Viage á las regiones equinocciales del nuevo continente: Hecho en 1799 hasta 1804, por Al. de Humboldt y A. Bonpland (Paris: En Casa de Rosa, 1826) [Rare Books Division].

           Leopold von Buch (1774–1853) studied with Humboldt and published a multivolume description of the Canary Islands in 1825, which included an atlas. Note that Humboldt credits Buch’s observations in the caption to the chart.

For the next two-and-a-half years (to February 1803), Humboldt and Bonpland’s itinerary took them through what is now Venezuela, Colombia, Ecuador, and Peru. Their interior route also took them through different stages of human civilization—from the coastal towns with eighteenth-century amenities to remote regions where tribes lived in extremely primitive states, unchanged since Columbus’s first footsteps on the continent and ruled by a small number of Franciscan missionaries. In a 1,500-mile exploratory loop, they canoed past the cataracts of the Upper Orinoco River and confirmed the existence of the Casiquare Canal, the world’s only natural waterway connecting two huge river systems (Orinoco and Amazon). (See Humboldt’s map of the province of Verina, below left.)
            In 1801, they journeyed overland from Cartagena to Bogotá and then, crossing the Andes at almost twelve thousand feet, to Quito, where Humboldt spent half a year examining the major volcanoes. He was at the physical peak of his life and earned universal fame by climbing Chimborazo, which was considered the highest mountain in the world at the time. By his own instrument’s reading, he estimated that he reached an altitude of 19,286 feet before an impassable ravine forced them—Humboldt, Bonpland, and local friend Carlos Montúfar—to turn back. (See Humboldt’s landmark profile of the mountain, below right.) Today, Chimborazo’s height is given as 20,565 feet. In his old age, this climb still ranked among Humboldt’s proudest achievements. Interestingly, because of Chimborazo’s height and location near the equator, its summit is the furthest point from the earth’s center.

“Map of the Eastern Part of the Province of Verina, between the Oronooko the Abura & the Rio Meta Compiled from Astronomical Observations & Materials Collected on the Spot by Alexander Humboldt.” Copperplate map, 16.8 × 26 cm. From vol. 3 of Humboldt’s Personal Narrative of Travels to the Equinoctial Regions of the New Continent, during the Years 1799–1804, trans. from the French by Helen Maria Williams (London: Longman, Hurst, Rees, Orme, and Brown, 1818) [Rare Books Division].

           Humboldt’s map of some of the remote areas in Venezuela that he and Bonpland explored at the beginning of their five-year expedition.

“Journey towards the Summit of Chimborazo, Attempted on the 23rd June 1802. By Alexander de Humboldt, Aimé Bonpland & Carlos Montúfar.” Copperplate profile chart, 24 × 37.4 cm. From vol. 3 of Humboldt’s Personal Narrative of Travels to the Equinoctial Regions of the New Continent, during the Years 1799–1804, trans. from the French by Helen Maria Williams (London: Longman, Rees, Orme, Brown, and Green, 1822) [Rare Books Division].

           One of the most famous of Humboldt’s charts and maps, a landmark linking of plant life to altitude.

"Map of the Different Channels by Which the Precious Metals Flow from the One Continent to the Other.” Copperplate map, 15 × 28.7 cm. From vol. 4 of Humboldt’s Political Essay on the Kingdom of New Spain, trans. from the French by John Black (London: Longman, Hurst, Rees, Orme, and Brown, 1811) [Rare Books Division].

            Because of his own mining experience, Humboldt showed particular interest in raw materials of the New World and devoted a large part of his examination of statistical records to the subject of precious metals. He provides numerous tables of data in the work, and one of the amazing numbers he calculates is the sum value of all the gold and silver shipped to Europe from America since the time of Christopher Columbus:

Taking also the 186,000 marcs of gold, which have passed as spoil into the hands of the conquerors at 25 millions, it follows that the quantity of gold and silver imported into Europe from America, between 1492 and 1803, amounts to five thousand four hundred and forty-five millions of piastres, or to twenty eight thousand five hundred and eighty-six millions of livres tournois.*

* £1,166,775,322 Sterling [his emphasis, vol. 3, pp. 431–32].


While traveling through Peru, the group crossed the magnetic equator, where the compass needle balances between north and south; Humboldt’s measurement of the spot’s magnetic intensity would become a standard reference for future geomagnetic readings. From Lima, in the fall of 1802, he sent home samples of guano for analysis. Peruvian farmers had known of its great fertilizing properties for centuries, but Humboldt was the first to draw European attention to its value. On Christmas Eve, they embarked for Guayaquil from Callao, and during the voyage the ever-observant scientist measured the temperature and flow of the current they followed north. Though Humboldt did not discover it, the Humboldt Current, still shown on modern maps, is his most lasting legacy.
            Reaching Acapulco in March 1803, the men spent the next year exploring Mexico. Based in Mexico City, Humboldt spent much of his time doing research in government offices, archives, and libraries as background for the first regional geographic essay ever written, his Essai politique sur le Royaume de la Nouvelle-Espagne (Political Essay on the Kingdom of New Spain, 2 vols., 1811). (See his thematic map of the worldwide flow of precious metals, opposite.) He made journeys to climb or measure the surrounding volcanoes, explored silver mines, corrected numerous latitude and longitude errors on maps, and even studied Aztec artifacts. In March 1804, the three men—Montúfar had become an inseparable companion—were in Havana to pick up scientific collections sent there for safe-keeping, and they then boarded a Spanish frigate bound for Philadelphia. Humboldt was reluctant to depart from the New World without meeting Thomas Jefferson, a man whose promotion of liberty he admired, and learning of his plans for exploring the West of North America which the country had just acquired from France in the Louisiana Purchase.
           While waiting for a formal invitation from the president, Humboldt became the toast of the American Philosophical Society, founded by Benjamin Franklin, the U.S. version of London’s Royal Society. In a Philadelphia news item, he learned of the arrival of some of his manuscripts and collections at his brother’s house in Paris, which he had sent three years earlier! During his stay in Washington, D.C. (June 1–13), Humboldt was invited everywhere by everyone, including Secretary of State James Madison and Secretary of the Treasury Albert Gallatin. He lunched with Jefferson at his unfinished Executive Mansion on his second day, and the two got on so well that Jefferson offered Humboldt free use of his personal residence and invited him to Monticello. Having already dispatched Lewis and Clark on their epic western journey, Jefferson sought from Humboldt the latest cartographic and statistical information he had developed on New Spain, now the country’s newest neighbor. The scientist was happy to oblige: he had fallen in love with the young country.
            On June 30, 1804, Humboldt and Bonpland, with Montúfar, boarded the French frigate La Favorite in Philadelphia for the return to Europe, arriving in the Garonne River off Bordeaux on August 1. After a five-years’ absence, Humboldt was soon back in Paris, having spent approximately a third of his fortune on one of history’s most extraordinary and defining scientific expeditions.

In thirty volumes, published over the next thirty years (1805–1834), Humboldt would exhaust most of the rest of his fortune to mine his epic story for all of its ramifications. There were three main categories of publications that fell under the general umbrella title of Voyage aux regions équinoxiales du Nouveau Continent fait en 1799, 1800, 1801, 1802, 1803 et 1804, par A. Humboldt et A. Bonpland: (1) scientific works containing botanical, zoological, astronomical, geological, and meteorological data, with two atlases; (2) treatises on the economy and geography of Mexico and Cuba; (3) miscellaneous, more “popular” volumes, including an incomplete narrative of his travels (1799–1801) and Vues des Cordillères, which was a strange hodgepodge of Aztec art and descriptions/illustrations of mountains. For titles in the first category, Humboldt sought scientific collaboration with contemporary experts in these subjects; he wrote all the volumes in the other two groups himself, in French.
            As stated in the preface to his travel narrative, Humboldt’s general purpose was “to collect such facts as are fitted to elucidate a science, of which we have possessed scarcely the outline, and which has been vaguely denominated natural history of the world, theory of the Earth, or physical geography” [his emphasis, vol. 1 (1814), p. iii of the Helen Maria Williams translation]. He noted that maritime voyages and circumnavigations had been in vogue, but they did little to promote scientific knowledge of the earth sciences. Widely translated, Aspects [or Views] of Nature (1808) was his most popular work. He was sixty-five when the final volume of the great opus appeared. (Bonpland, for all his trusted abilities during the long trip, proved unhelpful on the writing end. He returned to South America in 1816, initially as a professor in Argentina. But life went downhill for him, and he died in 1858 in a remote village now called Bonpland, where he had been living in a mud hut surrounded by his beloved plants.) 
            Lionized when he returned, Humboldt settled down in Paris. For fifteen years, he held to a schedule of morning work and evening salon hopping. Apparently, he needed only three or four hours of sleep per day. He maintained a prodigious correspondence (wrote between one thousand and two thousand letters each year, but in an appalling scribble); was a great, often sarcastic conversationalist—more like a noisy lecturer—and knew every scientist and socialite of note. Moreover, as a living legend, Humboldt began to see his role as an inspirer and supporter of young scientific talent. Among those he championed then, and later, were geographer Heinrich Berghaus (1797–1884), organic chemist Justus Liebig (1803–1873), geologist Charles Lyell (1797–1875), and naturalist Louis Agassiz (1807–1873). A planned expedition to Russia was stymied by Napoleon’s wars; another, to India, by the British East India Company. But the adventurous Humboldt still managed to climb Mount Vesuvius in 1822, and in April 1827, he spent forty minutes at the bottom of the Thames River in the diving bell used by the British civil engineer Isambard Kingdom Brunel during the construction of the Thames Tunnel.

The last phase of Humboldt’s life began when he moved permanently to Berlin in 1827 and took up residence in a first-floor apartment at 67 Oranienburger Strasse. (See the illustration of his library, below.) At that time, Prussia was a repressive police state. A close friendship with King Frederick William III protected Humboldt from conservative enemies at court. But he had many friends outside of government. From the fall of 1827 through April 1828, he delivered sixty-one lectures on physical geography at the University of Berlin, which his brother had founded in 1810. With echoes of Sir Francis Bacon, Humboldt argued that knowledge had to be derived from verifiable experience, but that scientific facts (data) could also appeal to the imagination. Delivered in fluent German, from bare outlines without notes, the lectures were hugely popular with the public. They became the basis of his final great work, Kosmos.
            In April 1829, Humboldt used a sudden invitation to go to Russia to consult about the new metal called platinum as an opportunity to realize his other grand dream: an expedition through Asia. But he was now thirty years older than when he toured New Spain, and exceedingly famous; he could not travel incognito or in peace. In St. Petersburg, he was treated as a personal guest of Czar Nicholas I, and, as an unfortunate result, his expedition became more of a traveling circus with its entourage of officials. In a whirlwind of about six months’ duration, the party covered approximately 9,700 miles (some by river), passed through 658 post-stations, and used more than 12,000 post-horses! Knowing the geology of the Ural Mountains, Humboldt predicted that diamonds would be found there, and shortly afterward they were, the first outside of the tropics. He was back in Berlin just after Christmas. The net achievement of the trip was not a publication—Humboldt’s modest work about it would not appear for many years—but impetus for establishing a chain of geomagnetic observation stations around the world to develop international scientific collaboration. Gradually, in pieces, this would be accomplished, particularly with the support of the British government, which eventually equipped stations across its vast empire.
            After his brother died in 1835, leaving him deeply bereft, Humboldt devoted himself to his master work about the entire material world, titled (in its English translation) Cosmos: A Sketch of a Physical Description of the World. His goal, of course, was to stimulate further scientific inquiry, but he also hoped to promote the enjoyment of nature using a vivid, accessible style—in short, to communicate intellectual excitement. The first volume appeared in 1845 when he was seventy-six, the second when he was seventy-eight, the third at eighty-one, and the fourth at the age of eighty-nine! The fifth volume, unfinished at his death, was published from Humboldt’s notes and with a lengthy index in 1862. Humboldt viewed nature as a unified whole of which humanity was part, and he thought that scientific knowledge was part of a country’s wealth, a natural resource that needed support and development. Called the last great work of the last universal man, Cosmos was spectacularly received.
            Fate was not so kind. Having known, literally, all the great men of his time—even having become one himself—Humboldt died penniless and possession-less: he had to deed everything he owned to his valet to pay his back wages.

♦ ♦ ♦

If he were alive today, Humboldt would be a strong supporter of the environment, urging global ecological studies, for he saw clearly the interrelationship of humankind and nature. In the preface to the first edition of Views of Nature, he wrote: “Everywhere the reader’s attention is directed to the perpetual influence which physical nature exercises on the moral condition and on the destiny of man” (p. x of the 1850 London edition, translated from the German by E. C. Otté and Henry G. Bohn). Thematic maps now play an important role in such studies. In fact, though Humboldt may not have understood it then, thematic maps have continued to do his work.

Title page of vol. 1 of Humboldt’s master work, Kosmos: Entwurf einer physischen Weltbeschreibung von Alexander von Humboldt . . . , 5 vols. (Stuttgart and Tübingen: Cotta, 1845–1862) [Rare Books Division].

“Vulkanischen erscheinungen der Erdoberfläche” (plate 12). Lithograph map, with added color, 20.2 × 28 cm. From Traugott Bromme’s Atlas zu Alex. v. Humboldt’s Kosmos in zweiundvierzig tafeln mit erläuterndem texte (Stuttgart: Krais & Hoffmann, [1851]) [Rare Books Division].

            The atlas was published as a companion volume to Humboldt’s Kosmos, with forty-two thematic maps and plates by Bromme and explanatory text drawn from Humboldt and others. This map focuses on volcanic activity around the world: eruptions (red dots), regions (green circles), and ranges (colored lines)—most seem familiar to us today. Inset maps highlight Italy/Sicily, Java, and Iceland. The catastrophic eruption (1881) of Krakatoa in Indonesia is thirty years away, but the large yellow circle around Indonesia and part of Australia shows the destructive reach of Mount Tambora’s explosive eruption on April 11, 1815. Its magnitude has been given a 7 on today’s Volcanic Explosivity Index, the highest rating of any volcanic eruption since the Lake Taupo (New Zealand) eruption circa AD 180.

“Alexander von Humboldt in seiner Bibliothek.” Chromolithograph copy of watercolor drawing by Eduard Hildebrant, 1856 (Berlin: Storch & Kramer) [Graphic Arts Collection].

            Rooms in Humboldt’s apartment at 67 Oranienburger Strasse in Berlin, where he lived from 1827 to the end of his life.

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Quantitative Thematic Maps
Qualitative Thematic Maps
Theme Maps (Fanta "Z")