At home in the world

The scientist and explorer Alexander von Humboldt was surely one of the most curious men who ever lived. His interest was piqued by everything under the sun and beyond it: Humboldt made important contributions as a botanist, geologist, astronomer, geographer and mountaineer, and he helped create the fields of geomagnetism, climatology, oceanography and ethnography. His expedition of scientific discovery through South America, Mexico and the Caribbean, from 1799 to 1804, made him one of the most famous intellectuals in the world; Emerson likened him to Aristotle and Julius Caesar. There are mountains named after Humboldt in Nevada, Colorado, Venezuela, China, New Zealand and Antarctica. Even the moon has the Humboldtian Sea.

Yet somehow, perhaps because he was the last great generalist, never lighting on one subject long enough to make it his own, his name has lapsed into obscurity. Gerard Helferich, an editor and publisher, has written a vivid, solidly researched biography to rectify that. “Humboldt’s Cosmos� is a fascinating snapshot of European thought at the cusp of the Romantic era and the uncompromising rationalism of modern science.

In Humboldt’s mind, nature inspired transcendental awe as much as it generated data. His studies of the native peoples of the Americas were as influential as his work in biology and the earth sciences: Although he was a Prussian with an aristocratic “von,� and his commission came from the king of Spain, he was an idealistic democrat, one of the earliest foreign observers to acknowledge the intellectual accomplishments of the Incas and Aztecs.

Helferich is a well-informed introducer of the book’s many fields, from early theories about the formation of volcanoes to the history of the Spanish conquest, but his book succeeds best as a thrilling tale of adventure travel. There was never a wilder place than South America when Humboldt and his doughty sidekick, a French physician named Aime Bonpland, descended its malarial, crocodile-infested rivers and climbed its furiously active volcanoes, always with their precision scientific instruments in tow.

When they climbed Chimborazo, near Quito, which was thought at the time to be the tallest mountain in the world, Humboldt’s party set an altitude record that would stand for decades. Their trail sometimes narrowed to less than a foot across, with a steep, snow-covered slope on one side and on the other “an abyss a thousand feet deep, with huge rock formations projecting from the bottom. They had no climbing equipment, and at some places the ridge rose so steeply that they had to pull themselves up with their bare hands, which bled on the sharp rocks.� Even under these arduous circumstances, Humboldt paused periodically to take readings with his thermometer and barometer.

At the conclusion of his five-year odyssey, Humboldt came to the United States, where the process of his lionization began. He dined with President Thomas Jefferson both at the White House and at Monticello, where they talked philosophy and natural history, forming a friendship that would continue by correspondence until Jefferson’s death. Dolly Madison wrote in a letter to her sister that “all the ladies say they are in love� with the “charming Baron von Humboldt� (though he was otherwise inclined, apparently; after a series of passionate liaisons with younger men, he followed a chaste life, to devote himself to science).

In Europe, Humboldt was royally feted (though Napoleon dissed him at his coronation, telling him curtly that the empress, too, collected plants), achieving a level of renown that would never be eclipsed by any scientist who followed him. He devoted the remainder of his long life to publishing the discoveries he had made in the New World, culminating in a ponderous volume called “Cosmos,� which attempted to synthesize all human knowledge in a grand, overarching system. It also had a more practical purpose: Humboldt was among the first to foresee the coming importance of science in human affairs. He predicted that those societies that best put the discoveries of science to industrial use would prosper, a prophecy that has been amply fulfilled. His hope that the world would be harmonized by “a community of knowledge� is an ideal still waiting to be realized. *