Alexander von Humboldt: Scientist-Explorer

                     Humboldt and Bonpland at Mt Chimborazo. Painting by Weitsch, 1810

    Much of our present understanding about nature was first conceived by a few naturalists at the end of the eighteenth century. From among those early scientists one primary person emerged: Alexander von Humboldt. He gained international renown for  traveling to remote regions unexplored by scientists and measuring, collecting, or observing everything: plants, rocks, earth magnetism, air temperatures, elevations, and indigenous humans. He wrote profusely and spoke frequently in many public appearances always stressing the complex interconnectedness of nature.      
    Born in Berlin (then the capital city of Prussia) in 1769 to a lower tier aristocratic and wealthy family, Humboldt had exposure to the best teachers in many subjects concerned with the natural environment. His primary training led him into geology and work as inspector of mines and later director of mines for the government of Prussia. During this time as an administrator he conducted research on vegetation and the Earth’s magnetism.     
    A  major turning point for Humboldt came when his mother died in 1796 and he inherited the family wealth. This boon allowed him to leave his job at the Ministry of Mines and devote his life to travel and research. He began by buying the many necessary scientific instruments needed for an extended expedition. He acquired an enormous collection of state of the art equipment that he considered essential, and much of which had to be duplicated to allow for possible losses or damage. He was prepared for measurements of gases, liquids, and solids, earth magnetism, and atmospheric electricity. He bought the necessary quadrants, chronometers, theodolites, and altimeters for mapping locations and elevations. He had the instruments necessary for making astronomical observations.          
    Between 1799 and 1804 Humboldt, starting at the age of twenty-nine, traveled extensively in Latin America, beginning with Cuba, exploring and describing the area for the first time from a modern scientific point of view. With his royal passport from the king of Spain he had unrestricted access to colonial regions and local administrators. Throughout this journey he was accompanied by an accomplished botanist and physician, Aimé Bonpland. Along with Bonpland and locally hired porters and guides, Humboldt ventured into the rainforests of the Amazon and Orinoco Rivers. He climbed mountain after mountain in Venezuela, Colombia, Peru, Ecuador, including Chimborazo, a volcanic peak then thought to be the highest (20,548 ft) in the world, but is still the highest peak north of Peru and all the way to Alaska.      
     To be sure this was an arduous journey with hardship, sickness, and few comforts, but Humboldt’s motivation never faltered. Author Andrea Wulf describes Humboldt and three companions crawling single file along a narrow ridge with steep drops on both sides while climbing Mount Chimborazo. “The icy wind numbed their hands and feet and ice crystals clung to their hair and beards.” As they climbed past the 17,000 elevation they struggled to breathe in the thin air. They ended their climb 1000 feet below the peak when they encountered a impassable crevasse.     
   The two men made many discoveries and produced accurate maps everywhere they went, many of which were not superseded for more than a century. Humboldt and Bonpland were the first to determine that the Orinoco River, which flows northward in Venezuela, was connected at its headwaters to the Negro River which flows southeastward into the Amazon.     
    While in Latin America Humboldt collected about 60,000 plants of which 3,000  had never been identified and given scientific names. He studied the electric eels, piranhas, and various monkeys of the tropical rainforest. His studies of the composition of guano led to its use as a fertilizer in Europe. By measuring water temperatures offshore on the west side of South America he identified the west coast cold ocean current that is now called the Humboldt current. Of all his scientific measurements Humboldt felt that his most important contribution was the measurement of Earth’s magnetism and locating the magnetic equator.     
    After South America Humboldt and Bonpland traveled to Mexico, then made a six-week visit to the United States (1804) where they were the guests of honor at a celebration in Philadelphia. They also went to Washington for a meeting with President Jefferson, who told Humboldt of the expedition beginning that year by Lewis and Clark to carry out a similar scientific exploration.      
    Humboldt settled in Paris and worked steadily writing his thirty volume Voyage de Humboldt et Bonpland over a period of twenty-one years. This detailed report of his Latin American studies focused on the natural history of the regions, history of their discovery, and culture of the pre-Colombian civilizations of Latin America. It became a best seller even among the general public, and the first printing of the first volume was sold out in a few months. He also wrote two monographs on the economic structure of Mexico and Cuba, focusing on the plantation economy of Cuba that depended on slavery. Humboldt was repulsed by the cruelty of slavery which he actively opposed with practical ideas for its abolition. On his visit to the United States he again commented on the great harm done by slavery.            
    Humboldt’s other major work, Kosmos, began to take shape as he gave public lectures in 1827-29 when he was at the peak of his career. The idea of Kosmos was to convey not only a graphic description of the physical world but proposed a unifying concept as well. This important work motivated a holistic perception of the universe as one interacting entity. Humboldt said his Kosmos was born in the Andes and took twenty-five years to complete.     
    Humboldt’s creative mind reached beyond merely reporting his findings. He drew innovative conclusions that have had a lasting effect on the natural sciences. Perhaps his most significant contribution was support for the then new idea of interconnectedness of all elements of Earth’s environment: plants, animals, soil, and climate. His focus on this important concept gave birth to ecology, the study of ecosystems as entities rather than studying only a single part of the environment. Humboldt also stressed the need for interaction and collaboration among scientists to gain a more complete picture of the environment.     
    Another of Humboldt’s contributions was the advent of a new field of study called plant geography. From his many travels in different climates he observed that the distribution of plants strongly correlated with climate. For example, humid tropics on different continents all have similar plants, albeit of different species. The same pattern exists in each climate and can be seen with changes in elevation as well, which Humboldt observed as he climbed various mountains in the Andes. It was partly on this knowledge of plant zonation according to climate that Vladimir Köppen based his famous map of world climates in 1884.   
     As a scientist-explorer Humboldt became widely imitated. The young United States in the early nineteenth century had just acquired a vast area of land named the Louisiana Purchase, and President Thomas Jefferson made plans to send Lewis and Clark to explore, map, and collect plants all the way to the Pacific northwest. The U.S. government initiated surveys led by Frémont, King, Hayden, Powell, and others. Humboldt’s example became the objective for these early surveys.     
    Humboldt’s enormous status and popularity in the nineteenth century is illustrated by the great number of places and things named for him—more than any other person. In North America alone there are thirteen towns, four counties, mountains, bays, a river in Nevada, a state park and Humboldt State University in California, as well as city parks in Chicago and Buffalo. The state of Nevada was almost named Humboldt. If we look at South America and Europe the list of honors expands enormously. Nearly 300 plants and more than 100 animals are named after him, not to forget Mare Humboldtianum on the moon!

Sources
Helferich, Gerard. Humboldt’s cosmos: Alexander von Humboldt and the Latin American journey that changed the way we see the world. New York: Gotham Books. 2004.

Magee Judith. Alexander Humboldt. (a chapter in The Great Naturalists). Robert Huxley, ed. London: Thames & Hudson, 2007.
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Gulf, Andrea, The Invention of Nature: Alexander von Humboldt’s new world. New York: Alfred A. Knopf. 2015.