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ANNUAL REPORT SMITHSONIAN INSTITUTION, 193 5 



as on the doings of animals and birds. Thus Brooks quotes from an 

 almanac of 1870 : " When you see 13 geese walking injun file and 

 toeing in you can deliberately bet yure last surviving dollar on a 

 hard winter, and grate fluktuousness during the next seazon in the 

 price of cowhide boots." 



Undeterred by the difficulties, G. F. McEwcn, of the Scripps Insti- 

 tution of Oceanography in California, has for some time been fore- 

 casting rainfall by empirical methods, and at first attained con- 

 siderable success, largely on the basis of a short series of ocean tem- 

 peratures. These, however, as he has recognized, have not of late 

 made good their early promise; and he is driven to using sun-spot 

 numbers, a cycle of 5 or 6 years, and a complex method of smoothing 

 in the hope of attaining reliability. 



Figure 13. — Atlantic icebergs and the previous oscillation. 



A less difficult task confronts the International Ice Patrol Service 

 of the United States in their desire to obtain advance information 

 of the amount of Arctic ice drifting into the western North Atlantic. 

 I do not know what progress has been made, but the dependence on 

 the previous North Atlantic oscillation, with which there is a coeffi- 

 cient of 0.60, would appear to suggest a useful starting-point 

 (fig. 13). 



In Europe the only seasonal forecasts known to me that have a 

 scientific foundation, and have been made for a number of years, are 

 those of Sweden and Russia. In Sweden Wallen has for 18 years 

 made predictions for rainfall and for the height of water. Regard- 

 ing rainfall, he smooths by taking the sums of consecutive 12 

 months; and then, assuming that the nature of the fluctuations so 

 disclosed will not change suddenly, he forecasts that the total rain- 

 fall of some definite period, usually 6 months or a year, will be 

 greater, or less, than it was in the previous year. Now a moment's 



