In the early days of the study of glaciation the problem appeared to be a simple one: we are used to an ice-bound North Pole, and it was natural to assume that the boundary for some reason spread southwards to cover Scandinavia, Scotland, and even some of England. When it was further learnt that North America showed signs of extensive glaciation, this news fell naturally into place and scientists began to form hypotheses to account for a worldwide refrigeration. Quite soon, however, investigators in the countries concerned began to disagree as to the phases, and even the number, of glaciations: the centre of dispersal of the Scandinavian ice was found to be near the head of the Gulf of Bothnia; English geologists were inclined to favour only one glaciation, with certain retreats and advances; Boule would allow three glaciations, while Penck and Bruckner in their classical work on the Alps proved four in their region; Günz, Mindel, Riss, and Würm (with a short climatic improvement at the maximum); followed by the Bühl advance, Gschnitz Stadium and Daun readvance. But these Alpine phases cannot be followed into Italy. Gortani says (1): “Among us, too, Penck had disciples; and we, too, sought all means of adapting his system to the observed facts. But all attempts are vain because (a) nowhere are Günzian moraines to be found; (b) nowhere are to be found traces of more than one true interglacial with a warm climate and (c) the last two advances of the glaciers, where they have left separable traces, show themselves as two principal phases of one glaciation of medium intensity.”