means that a load of about two million tons is removed from each square mile of land; the corresponding rise of pressure means the addition of a similar load. Such a storm, and to a less degree every other storm, strikes a blow upon the earth's surface, first by removing millions of tons of pressure and then by putting them on again.[133] Such storms, as we have seen, are much more frequent and severe when sunspots are numerous than at other times. Moreover, as Veeder[134] long ago showed, one of the most noteworthy evidences of a connection between sunspots and the weather is a sudden increase of pressure in certain widely separated high pressure areas. In most parts of the world winter is not only the season of highest pressure and of most frequent changes of Veeder's type, but also of severest storms. Hence a meteorological hypothesis would lead to the expectation that earthquakes would occur more frequently in winter than in summer. On the Chinese coast, however, and also on the oceanic side of Japan, as well as in some more tropical regions, the chief storms come in summer in the form of typhoons. These are the places where earthquakes also are most abundant in summer. Thus, wherever we turn, storms and the related barometric changes seem to be most frequent and severe at the very times when earthquakes are also most frequent. [Illustration: _Fig. 12. Seasonal distribution of earthquakes. (After Davisson and Knott.)_ solid line ---- Northern Hemisphere. dashed line .... Southern Hemisphere.] Other meteorological factors, such as rain, snow, winds, and currents, probably have some effect on earthquakes through their ability to load the earth's crust. The coming of vegetation may also help. These agencies, however, appear to be of small importance compared with the storms. In high latitudes and in regions of abundant storminess most of these factors generally combine with barometric pressure to produce frequent changes in the load of the earth's crust, especially in winter. In low latitudes, on the other hand, there are few severe storms, and relatively little contrast in pressure and vegetation from season to season; there is no snow; and the amount of ground water changes little. With this goes the twofold fact that there is no marked seasonal distribution of earthquakes, and that except in certain local volcanic areas, earthquakes appear to be rare. In proportion to the areas concerned, for example, there is little evidence of earthquakes in equatorial Africa and South America.