Alexander Humboldt (1769 - 1859)

    Alexander von Humboldt (1769–1859) was a Prussian naturalist, geographer and explorer. Born in Berlin, he trained in botany, geology, mining, and surveying methods of measurement. From 1799-1804, accompanied by the French botanist Aimé Bonpland, Humboldt undertook a five-year scientific journey through Spanish America, traveling in present-day Venezuela, Colombia, Ecuador, Peru, Cuba, and Mexico before visiting the United States. His Personal Narrative of this and other travels made him one of the most famous of 19th century explorers.

    As well as collecting thousands of plant specimens, Humboldt made physical measurements such as temperatures, elevations, magnetic forces and atmospheric conditions. By comparing vegetation at different elevations and in different parts of the world, he showed that climate and geography shape the distribution of plants. His 1802 attempt to climb Chimborazo [below, left] in Ecuador in 1802 took him higher than any recorded European climber had previously reached. His diagram of Chimborazo of life zones and plant communities [below, right] remains famous as one of the first to present a mountain as a connected ecological system.

    He was one of the first naturalists to observe that human interventions such as deforestation and irrigation could alter local climates. later life he attempted to unite the scientific knowledge of his age in Cosmos, an ambitious description of the physical universe. His ideas influenced scientists and writers including Charles Darwin, and his name survives in numerous species, geographic features and scientific institutions.

    His travel books had many readers, including the young Charles Darwin. Darwin made frequent reference to Humboldt's work in his own, "Voyage of the Beagle", and his sister remarked that, by much reading of Humboldt,  he had "... got his phraseology and the kind of flowery French expressions he uses."

    Darwin sent a copy of his Journal of Researches to Humboldt, who answered, "You told me in your kind letter that, when you were young, the manner in which I studied and depicted nature in the torrid zones contributed toward exciting in you the ardour and desire to travel in distant lands. Considering the importance of your work, Sir, this may be the greatest success that my humble work could bring." Darwin called Humboldt's "Personal Narrative" one of the two most influential books on his own work, alongside Lyell's Principles of Geology.