Wheat Prices and Rainfall 



[July, 



questions, particularly by trying to find out whether abnor- 

 mal temperature or rainfall recurs at regular intervals; i.e., 

 whether there is a regular sequence of weather, or cycle, as it is 

 called. 



Various astronomers and meteorologists have in recent years 

 thus discovered cycles, some of which may now be regarded as 

 well established. Of those that may conceivably produce a direct 

 or indirect effect upon our crops the two best known are probably 

 the sun-spot cycle and the Bruckner cycle. It has for long been 

 known that the number of spots occurring on the sun varies in 

 a regular manner, a maximum and minimum occurring at 

 intervals of about 11 years ; also that certain terrestrial 

 phenomena are influenced in the same way, indicating that sun- 

 spots affect the conditions on the earth, or perhaps it should 

 be said that both are due to the same cause. Dr. Bruckner 

 found some thirty years ago that a period of relatively warm 

 and dry years recurred on the Continent about every 35 years, 

 and similarly that the intervening years tended to be wet and 

 cold. Although we are altogether in the dark as to the causes 

 of such fluctuations in the weather, their influence must never- 

 theless make itself felt upon the growth of vegetation, and thus 

 it becomes a very important matter to detect them. 



It is conceivable that the weather of different parts of the 

 earth may be differently affected by a large number of cycles, 

 each of them due, maybe, to different causes. This makes it 

 exceedingly difficult to discover any regular sequence in the 

 weather or in the produce of agriculture by mere inspection of 

 records. Since the periods of these cycles are not of the same 

 duration, their beneficial or harmful influence does not recur 

 at the same moment of time : it will thus happen that the maxi- 

 mum effect of one cycle will sometimes coincide with an opposite 

 effect of some of the other cycles, and so its effect may be nullified. 

 It is therefore only when the maximum or minimum effects of 

 several influential cycles coincide in point of time, that their 

 combined result will show itself in a big crop or severe shortage ; 

 and this can only be expected to recur at comparatively long 

 intervals. Agricultural records have not been kept for a suffi- 

 cient number of years to exhibit a sequence of good or bad har- 

 vests that can be relied on as a guide to the future, as an event 

 known to have recurred only three or four times cannot be 

 accepted as sufficient evidence of a regular cycle. 



There is, however, one class of observations that is sufficiently 

 Ion*? to be of use for this purpose, and that is the price of wheat, 



