48 THE CLIMATOLOGY OF THE UNITED STATES. 



be from 250 to 300 a year and sometimes more. Of 

 course there always exists in California the liability of 

 a severe earthquake, but though showers have taken place 

 there lately, they are not likely to develop into any such 

 severe and frequent electrical storms as are experienced 

 elsewhere. Changes in our own climate are also quite 

 plain : for several years our proverbial April weather has 

 been a stranger. We have not had mild days with typi- 

 cal April showers and bright blue skies alternating in rap- 

 id succession, as formerly, but instead, we have had cold 

 rainy Aprils more like November, with a few instances of 

 unseasonable heat ; and again, our winter season formerly 

 preserved its characteristics in a regular and orderly man- 

 ner. The snow came and the cold came and remained in 

 quite an even way. We were accustomed to have sleigh- 

 ing through a large part of the winter, and we expected a 

 short thaw of two or three days in the early part of January 

 known as the January thaw, but of late years we have had 

 very little continuous sleighing here, some years having very 

 little snow and at other times having the larger part of it in 

 one or two heavy storms. Our thaws have occurred every 

 few days, nearly every snowstorm being followed within a 

 day or two by one ; cold waves and warm spells alternating 

 in rapid succession. The present season has possessed more 

 or less the true winter features, but we have had an alterna- 

 tion of many very severe storms, very cold waves, and warm 

 spells. On the whole, the winter has been a cold one with 

 considerable of the old time regularity in its snowfalls, 

 but nearly as changeable as others of late. This change- 

 able and uncertain weather of the last few years has caused 

 an unusual amount of sickness everywhere. The influences 

 bringing about these changes have also manifested them- 

 selves in other ways. 



The most important agents of climatic change within the 



