The meteorologist needs no geologic evidence that the storm track was shoved equatorward by the growth of the ice sheet, for he observes a similar shifting whenever a winter's snow cap occupies part of the normal storm tract. The geologist, however, may welcome geologic evidence that such an extreme shift of the storm track actually occurred during the Pleistocene. Harmer, in 1901, first pointed out the evidence which was repeated with approval by Wright of the Ireland Geological Survey in 1914.[42] According to these authorities, numerous boulders of a distinctive chalk were deposited by Pleistocene icebergs along the coast of Ireland. Their distribution shows that at the time of maximum glaciation the strong winds along the south coast of Ireland were from the northeast while today they are from the southwest. Such a reversal could apparently be produced only by a southward shift of the center of the main storm track from its present position in northern Ireland, Scotland, and Norway to a position across northern France, central Germany, and middle Russia. This would mean that while now the centers of the lows commonly move northeastward a short distance north of southern Ireland, they formerly moved eastward a short distance south of Ireland. It will be recalled that in the northern hemisphere the winds spiral into a low counter-clockwise and that they are strongest near the center. When the centers pass not far north of a given point, the strong winds therefore blow from the west or southwest, while when the centers pass just south of that point, the strong winds come from the east or northeast.