“…Gregory's Presidential address on 14 October 1915 reflected the increasing public alarm at what had initially been expected to be a short war, 'Geological factors affecting the strategy of the war and the geology of the potash salts' (Gregory 1916a), which appeared also in summary in Gregory (1915cGregory ( , d, 1917Gregory ( , 1917a. Briefly, Gregory surveyed the mineral resources of the principal protagonists in the war, emphasizing that Germany had more than a half of the European coal reserves which, being the main source of energy at the time, was very important.…”