150 AGRICULTURE ON THE PACIFIC SLOPE 



sprouted, may be ruined by a spell of dry weather. 

 If the farmer could have known that such a dry spell 

 was coming, he would have waited to sow until later 

 in the season. But how could he know ? 



We have long tried to find out how we may predict 

 the weather a long time ahead, but we have been unable 

 thus far to forecast it with any certainty for more than 

 one or two days ahead; except that in most of the arid 

 states there is almost a certainty that, outside of the 

 mountains, there will be no rain of any practical conse- 

 quence during from three to six months of summer. 

 Yet rains do sometimes come, and finding the crops 

 stacked in the open fields they may do a great deal of 

 damage. 



Forecasting the weather. The enormous importance 

 of knowing beforehand what the weather of a season 

 is going to be has brought about many attempts 

 to discover a sure method of forecasting it. Until 

 within the last fifty years, almanacs claimed to give 

 good weather predictions for every month of the year, 

 in advance. Such predictions were guesses based 

 upon the average records of past years, often colored 

 by a foolish belief in the influence of the phases of the 

 moon. Many farmers believejn this influence ex 



although accurate observations for many years have 

 failed to show any truth in this belief. It is now thought 

 that the study of the sun's changes (as to light, heat, and 

 magnetism) may help us to understand the weather 



