After six months in New Amsterdam, Trinidad, Humboldt had examined everything that lacked the feet and the fear to run away from him. He had measured the colour of the sky, the temperature of lightning flashes, and the weight of the hoarfrost at night ... [he] dug holes, dropped thermometers on long threads down wells, and put peas on drumheads. The quake would certainly begin again, he said cheerfully. Soon the whole town would be in ruins. (p. 56)
Alexander von Humboldt grows up in the shadow of his brilliant elder brother: their father is carrying out an experiment, raising one son as a man of culture and the other as a man of science. Young Alexander quickly works out that whenever things were frightening, it was a good idea to measure them. (p. 16). As a teenager, he's his own experimental subject for studies involving Galvinism (it wasn't easy to explain to the doctor what had been going on): from an early age, he goes through life certain that the trick of it is not to let anything get to him. Humbolt lives a swashbuckling life on the frontiers of science and geography: climbing mountains, rowing up the Orinoco, discovering oceanic currents, observing silver-miners at work beneath the unsettling mask of an ancient god.
Carl Friedrich Gauss is another infant prodigy, though born rather than moulded: he counts prime numbers when he's nervous. Numbers didn't seduce one away from reality, they brought reality closer, made it clearer and more meaningful in a way it had never been before. (p. 71) Awkward with people, he's wholly at home in the mathematical world: he finds himself wondering if the occasional anomalies he notices in physical laws are a sign of God's negligence.
The novel's mostly told from the two men's viewpoints, plus that of Humboldt's assistant the long-suffering Bonpland ("Oh hallelujah," he says when Humboldt interrupts a bout of altitude-induced vomitting to announce that they have now climbed higher than anyone in human history). It's a fascinating account of two very different lives in science, of two men gripped by scientific fervour and the need to know who go about their quest for knowledge in very different ways. There are parallels, congruences, differences and similiarities. Humboldt is uninterested in women (there's a hint, late on, that he's homosexual, but he doesn't do anything about that either): Gauss marries, but finds himself thinking of orbital eccentricities on his wedding night.
Humboldt's science is eighteenth-century science, with outmoded ideas: the sun would never burn out, it would renew its phlogiston and shine for ever (p. 187). He lectures on light-extinguishing ether and regards evolution as the greatest insult to mankind. Gauss, by contrast, seeks eternal truths: Whatever was hiding out there in holes or volcanoes or mines was accidental, unimportant. That wasn't how the world would become clear. (p. 212) And later, One didn't need to clamber up mountains or torment oneself in the jungle. Whoever observed the needle [an iron needle suspended in a galvanometer] was looking into the interior of the world. (p. 233)
Humboldt is the celebrity scientist, a supreme self-publicist: see to it that you get it into the newspaper. The world needs to learn of me. I doubt very much that I am of no interest to it. (p. 41). He's lauded in courts and sent on expeditions to distant lands, though he seldom has the freedom he craves, the freedom to study whatever captures his interest. Gauss, meanwhile, sits in a dark room in Göttingen, watching his needle, boxing his son's ears when the boy opens the door and disturbs the air.
Gauss enlists Humboldt's help in measuring magnetic variations: the two men strike up a kind of friendship, though neither understands the other, and indeed they grow to feel sorry for one another -- Gauss for Humboldt's lack of freedom, Humboldt for Gauss's hermit-like, confined existence. Only gradually, though, does Humboldt begin to appreciate that Gauss's mathematical certainties, his laws and rules and numbers, enable him to see further:
... all of a sudden he could no longer have said which of them had travelled afar and which of them had always stayed at home. (p. 252)
This is a rivetting insight into the scientific mind, and into the characters of two very different men. It's also beautifully written: kudos to the translator for a smooth, poetic, subtle rendition.