574 E. HUXTINGTOX SOLAR HYPOTHESIS OP CLIMATIC CHANGES 



the severity of the winds, for it woukl establish high barometric gradients, 

 down which the winds wonkl sweep viciously. The gro^i:h of the glacial 

 area would cause the region of high pressure also to increase in size, and 

 thus the l)oreal storm belt vrould l)e pushed equator ward and would main- 

 tain its position along the ice-front. As long as the smi maintained its 

 high degree of activity the storms would continue and the glaciers would 

 grow. Then when the solar disturbances ceased the terrestrial storms 

 would also decrease in severity, the two cyclonic belts of each hemisphere 

 would tend to merge, precipitation and cloudiness would decrease, and 

 the sun would have an opportunity to melt the accumulated ice. 



The glacial precipitation of the Alps. — The severest test and the great- 

 est confirmation of any hypothesis is found in the extent to which it ex- 

 plains highly specialized facts which were not known or were not consid- 

 ered when it was framed. Several such facts appear at once as soon as 

 our cyclonic hypothesis is applied to the glaciation of past times. They 

 are not in any respect new, but were not thought of in framing the hy- 

 pothesis. They came to mind only when the line of reasoning which has 

 just been followed had been brought to the present point. Then they 

 stood out so clearly that what I am about to say will probably be only a 

 repetition of what has already occurred to most readers. Therein lies 

 their importance. A knowledge of the hypothesis here discussed would 

 lead to the expectation that certain peculiar phenomena pravailed during 

 times of glaciation. "When we inspect the history of Glacial periods as 

 worked out by geologists those phenomena stand out as among the most 

 dijBficult to explain. The first is Penck's conclusion that in the Alps, but 

 not necessarily elsewhere, the snowfall during the Glacial period can not 

 have been appreciably heavier than now. The upper surface of the 

 ancient glaciers at their point of origin never rose higher than the present 

 surface. Hence he infers that there can never have been more snow than 

 today, and that the expansion of the Alpine glaciers must have been due 

 entirely to the lowering of the temperature. A glance at figure 10 shows 

 that during that particular period of maximum sun-spots the amount of 

 storminess over the Alps did not increase nearly so much as in many 

 other places. In fact it remained almost stationary. In figure 11 we see 

 that the storminess of the Alps increased somewhat, but the area of in- 

 crease is small and its intensity is not great. There is a strong proba- 

 bility that if the general conditions which prevail at times of sun-spot 

 maxima should greatly increase, the Alpine area of excess would either 

 be absorbed in the surrounding area of deficiency or would remain nearly 

 neutral — that is, not appreciably difl^erent from what it is today. This 



