CYCLONIC STORMS IN TEMPERATURE LATITUDES 515 



Table 6 



Correlation Coefficients 'between Storminess in the Main Storm Track Area of 



North America for the 30 Years from 1883 to 1912 and Sun-spots 



du7'ing various Years and ComMnations of Years 



Storminess of a given year and sun-spots of the third year previous. . +0.074 



Storminess of a given year and sun-spots of the second year previous. -{-0.220 



Storminess of a given year and sun-spots of the first year previous . . . -f 0.409 



Storminess of a given year and sun-spots of the same year +0.486 



Storminess of a given year and sun-spots of the first year later +0.463 



Storminess of a given year and sun-spots of the second year later. . . . +0.232 

 Storminess of a given year and sun-spots of the same year, together 



with preceding and succeeding years +0.530 



Storminess of a given year and sun-spots of the same year, together 



with preceding year +0.465 



Storminess of a given year and sun-spots of the same year, together 



with succeeding year +0.535 



Cyclonic storms and volcanic eruptions. — Turning back now directly to 

 the curves of figure 9, we see that during the entire period of 38 years 

 covered by both curves the only distinct disagreements are 1881, 1886, 

 and 1892, to which we ought probably to add 1883. The cause of these 

 may be found either in the volcanic eruptions or meteorological accidents, 

 already discussed, or in some other cause as yet unknown. We can test 

 . them as to volcanic eruptions, but not in other respects. Such a test gives 

 a negative result. Volcanoes, as we have seen, appear to have a direct in- 

 fluence on the earth^s temperature. Therefore, if storms depend primarily 

 on conditions of temperature acting through barometric pressure and 

 winds, we. ought to be able to trace the influence of volcanic eruptions in 

 the storm curve. This does not seem to be possible, as may be seen in 

 figure 9, where stars indicate eruptions according to the data of Hum- 

 phreys given in figure 1. The eruption of Krakatoa, in 1883, falls two 

 years after the most notable year of disagreement between sun-spots and 

 storms. The eruption of Tarawera, in 1886, coincides with an anomalous 

 increase in storminess; that of Bandai San, in 1888, corresponds with a 

 decrease which is normal, if we assume that sun-spots and storms are 

 really due to the same cause. The outburst of Bogoslof, in 1890, comes 

 at a time when the storms increase in number, but it is noticeable that 

 the increase is more than would be expected on the basis of solar relation- 

 ship. The eruption of Awoe, in 1892, on the contrary, is accompanied by 

 a decrease. The four remaining volcanic eruptions occur when the num- 

 ber of storms is small. It may be worth noting that 1903 is a somewhat 

 abnormal year, for the number of storms remains lower than would be 

 anticipated, yet the storminess increases somewhat and is thus in har- 



