Introduction 



Smoothed DEPARTURL5 OF 

 Annual RAiNfAuiNTHE uniteoStatesasaLInit 



1882 1890 1898 1906 1914 1922 



ANNUAL Rainfall in the Ohio Valley 



1842 1650 



1666 1874 1882 1690 



1906 1914 1922 



Figure 1 



Cycles in the annual rainfall of the Ohio Valley and in the annual rainfall of the 



United States as a unit. 



Cycles in the United States: y = — 1.99 + 0.86 sin (45°« + 42° 50'), origin at 1881; 



Cycles in the Ohio Valley: y = 41.19 + 4.13 sin (45°« + 310° 41'), origin at 1S39. 



and met is a source of difference between three types of 

 contemporary theories of cycles : 



In the first type there is a refusal to define the term, 

 economic or business cycle, otherwise than as a vague 

 general rhytlim, a series of changes which returns at an 



