Ice age

Independently of these debates, the Swiss civil engineer Ignaz Venetz (1788–1859) in 1829, explained the dispersal of erratic boulders in the Alps, the nearby Jura Mountains and the North German Plain as being due to huge glaciers. When he read his paper before the Schweizerische Naturforschende Gesellschaft, most scientists remained sceptical.[18] Finally, Venetz managed to convince his friend Jean de Charpentier. De Charpentier transformed Venetz's idea into a theory with a glaciation limited to the Alps. His thoughts resembled Wahlenberg's theory. In fact, both men shared the same volcanistic, or in de Charpentier’s case rather plutonistic assumptions, about earth history. In 1834, de Charpentier presented his paper before the Schweizerische Naturforschende Gesellschaft.[19] In the meantime, the German botanist Karl Friedrich Schimper (1803–1867) was studying mosses which were growing on erratic boulders in the alpine upland of Bavaria. He began to wonder where such masses of stone had come from. During the summer of 1835 he made some excursions to the Bavarian Alps. Schimper came to the conclusion that ice must have been the means of transport for the boulders in the alpine upland. In the winter of 1835 to 1836 he held some lectures in Munich. Schimper then assumed that there must have been global times of obliteration (“Verödungszeiten“) with a cold climate and frozen water.[20] Schimper spent the summer months of 1836 at Devens, near Bex, in the Swiss Alps with his former university friend Louis Agassiz (1801–1873) and Jean de Charpentier. Schimper, de Charpentier and possibly Venetz convinced Agassiz that there had been a time of glaciation. During Winter 1836/7 Agassiz and Schimper developed the theory of a sequence of glaciations. They mainly drew upon the preceding works of Venetz, of de Charpentier and on their own fieldwork. There are indications that Agassiz was already familiar with Bernhardi's paper at that time.[21] At the beginning of 1837 Schimper coined the term ice age (“Eiszeit“).[22] In July 1837 Agassiz presented their synthesis before the annual meeting of the Schweizerische Naturforschende Gesellschaft at Neuchâtel. The audience was very critical or even opposed the new theory because it contradicted the established opinions on climatic history. Most contemporary scientist thought that the earth had been gradually cooling down since its birth as a molten globe.[23]

In order to overcome this rejection, Agassiz embarked on geological fieldwork. He published his book Study on glaciers ("Études sur les glaciers") in 1840.[24] De Charpentier was put out by this as he had also been preparing a book about the glaciation of the Alps. De Charpentier felt that Agassiz should have given him precedence as it was he who had introduced Agassiz to in depth glacial research.[25] Besides that, Agassiz had, as a result of personal quarrels, omitted any mention of Schimper in his book.[26]

Altogether, it took several decades until the ice age theory was fully accepted. This happened on an international scale in the second half of the 1870s.[27]