Generating Cycles in a Century of Prices 57 



crops passed through cycles of approximately eight 

 years in length. 



The first relevant facts have already been adduced. 

 The yield per acre of representative crops in the United 

 Kingdom — wheat, oats, and barley — passed through 

 cycles of eight years with maxima at about 1882, 1890, 

 1898, 1906, 1914, and these cycles were synchronous 

 with those of France and the United States. (The 

 graph is given in Figure 16.) 



In presenting the next remarkable piece of evidence 

 I make use of a thoughtful, long neglected paper ^ on 

 "A Comparison of the Fluctuations in the Price of 

 Wheat and in the Cotton and Silk Imports into Great 

 Britain," by the late J. H. Poynting, at one time Pro- 

 fessor of Physics in Binningham.^ Having in mind, 

 doubtless, the essays of Stanley Jevons, the author ex- 

 pressed cautiously the opinion that ''the attempt to 

 prove the sunspot origin of variations of the harvests 

 and crops has probably led us somewhat away from the 

 proper Hne of inquiry. This, it seems to me, should be- 

 gin with such a manipulation of the statistics as to show 

 the true fluctuations whatever they may be, with the 

 effects of wars, increase of conmierce, etc., as far as 

 possible eliminated." ^ Accordingly Professor Poynting 

 set about devising a method to reveal the essential 

 fluctuations in the price of wheat in England from 1760 

 to 1875. Here is his description of the method: 



1 Journal of the Royal Statistical Society, March, 1884. 



2 "Poynting belonged to the rare type of men who are more critical 

 of their own work than of that produced by others. The number of his 

 papers is therefore comparatively small, but each of them marks some 

 definite and generally important step." Schuster and Shipley, Britain's 

 Heritage of Science, p. 161. 



^ Journal of the Royal Statistical Society, March, 1884, p. 35. 



