Alexander von Humboldt, German naturalist and explorer, c 1810.

Engraving by Ambroise Tardieu after an original portrait by Steuben. Baron Humboldt (1769-1859) is primarily remembered as an explorer and pioneer in geophysics and meteorology, but he also pursued interests in geomagnetism, botany and geography. He sought to describe natural inter-relationships, studying cohesion and universality in nature. From 1799 to 1804 he toured the Spanish colonies in South America, researching with the French botanist Aime Bonpland. They collected and analysed data in many fields including meteorology, geology, and oceanography.