Louis Agassiz (1807–73)
1795 Scottish geologist James Hutton argues that erratic boulders (rock fragments that are different from the underlying rock) in the Alps were transported by moving glaciers.
1818 In Sweden, naturalist Göran Wahlenburg publishes his theory that ice once covered Scandinavia.
1824 Danish–Norwegian mineralogist Jens Esmark theorizes that glaciers were once larger and thicker and had covered much of Norway and the adjacent seafloor.
1938 Serbian mathematician Milutin Milankovic´ publishes a theory to explain the recurrence of ice ages based on changes in Earth’s orbit around the Sun.