James Geikie (1839-1915) was the leading British authority on Pleistocene geology, developing the theory that during ice-ages mild inter-glacial periods interrupted the glacial period as a whole. He originated the current belief that human habitation continued in Europe throughout the glacial period. Geikie undertook classes at the University of Edinburgh while working in a printer's office. In 1861 he took up a position, with the Geological Survey, mapping glacial drift deposits in Central Scotland. This was supervised by his brother Archibald Geikie (1835-1924) whom he succeeded as the second Murchison Professor of Geology and Mineralogy at the University of Edinburgh.