568 E. HUXTIXGTOX- — SOLAR HYPOTHESIS OF CLIMATIC CHANGES 



ditions, may not liave Yaried greatly and rapidly during past eras. It is 

 now incumbent on ns to test the matter in one more way. AYe must see 

 what would happen if the present solar changes and the related terres- 

 trial phenomena were to be greatly intensified. 



Let us see how closely the earth^s conditions would conform to those 

 of a Glacial period if the disturbances of the sun's atmosphere which we 

 know as sun-spots and tlie apparently associated disturbances of the 

 earth's atmosphere became more intense than at present. Our assump- 

 tion is simply that in their waning these various phenomena did not 

 reach so low an ebb as at present, and that in their waxing they became 

 decidedly moje intense than today. Figures 7 and 12 may be taken as 

 typical of the way in which the conditions of such a time would be dif- 

 ferent from those now prevalent. These maps show, in the first place, 

 that the total number of storms, or rather the total storminess, for KuU- 

 mer's figures include both the number of storms and the length of their 

 courses, would be greater in times of many sun-spots than in times of 

 few. Then, according to our assumption, the degree of storminess dur- 

 ing a Glacial period would be several times as great as now. The second 

 thing that the maps show is that the distribution of storms would be 

 different from what it now is. If the conditions thus indicated increased 

 in the proportion demanded by our assumption, the result would appar- 

 ently be the production of two main storm belts, both in America and 

 Europe. In America one would be a boreal belt of great severity lying 

 in southern Canada, or perhaps slightly farther north. If it were con- 

 centric with the magnetic pole, it would swing around over southern 

 Greenland. It is quite possible, however, that during its course across 

 the Atlantic Ocean it would be bent to the east and become the northern 

 European belt. This, if it grew more intense than at present, would 

 probably spread out so as to cover Scotland and much of Scandinavia, 

 northern England, and the Xorth Sea. The second, or subtropical belt, 

 might have its most southerly point as far south as latitude 25° or 30° 

 in xlmerica. Although less severe than the boreal belt, the storminess 

 might be quite as great as in the present storm belt. Between the trop- 

 ical and boreal storm belts would lie a region of comparatively few storms. 



The double storm belt in America. — The idea of two distinct stoim 

 belts separated by a zone of few storms is so important that it requires 

 further elaboration. Evidences of it can be seen in the present distribu- 

 tion of storms both in America and Europe. To begin with America, the 

 main storm belt, as shown in figure 3, has its center in the northern 

 United States and southern Canada. A southern belt, almost merged 

 with the first, but nevertheless plainly discernible, has its center in more 



