BAINFALL AND COMMERCE AND rOLITICS. 159 



fluences on man's political and business relations are not more fre- 

 quently considered. 



One of the fundamental needs of man, in fact a prime necessity, is 

 a sufficient food supply. When food is abundant and hunger is satis- 

 rled there is a surplus of energy to expend on other human affairs, 

 and this, I presiime, most people will admit is the primary condition of 

 prosperity. 



The food-supply at present is obtained almost entirely from the soil, 

 and its growth is intimately dependent on weather conditions. The 

 relation of the food-supply to the weather has been investigated to 

 some extent, and it is found that the factors which most powerfully in- 

 fluence the food-product are temperature and moisture, which latter is 

 derived from rainfall. The annual change in temperature is com- 

 paratively regular and certain, so that the factor which, by its changes, 

 most powerfully influences the food-product, is the rainfall. 



J. T. Wills investigated the relation of the rainfall to the wheat- 

 product per acre in south Australia for the six winter months (the 

 growing season there), and found that for the seven best years there 

 was a yield of 12.4 bushels of wheat with 18.5 inches of rain; for the 

 next best years there were 10.0 bushels of wheat with 15.4 inches of 

 rain; and for the six worst years there were 6.6 bushels of wheat with 

 13.5 inches of rain. The product of wheat in the fiM case was nearly 

 twice as great as in the last. If such a relation holds for the United 

 States, it is easy to understand what great effect a general drought may 

 have on the food product. If the amount of wheat raised in the United 

 State were reduced one half or even one third by a year of deficient 

 rainfall, it is easy to imagine an enormous strain on the business of the 

 sountr}^, and with a succession of such years the effect might mean dis- 

 aster. Such a deficiency in the wheat supply, with wheat at 80 cents 

 a bushel, would mean for a single year a direct loss in wealth of more 

 than $100,000,000 ; it would mean that nearly all the wheat which is 

 usually shipped abroad would be needed at home; it would mean that 

 thousands of railroad cars and ships which ordinarily transport this 

 grain would lie idle; that hundreds of men who usually handle this 

 grain in transport would be out of employment; that farmers in large 

 numbers would be unable to meet their obligations; and consequently, 

 that banks and business of all kinds would suffer. 



But the deficiency in rainfall would not affect the wheat alone ; every 

 product of the soil would likewise suffer. Eawson has worked out a 

 simple formula in the case of Barbadoes by means of which the amount 

 of sugar to be exported the next year can be calculated with great 

 accuracy from the rainfall of the current year. This calculation is 

 accurate within six per cent, in most cases. Similar calculations for 

 Jamaica have been made by Maxwell Hall. He shows that 56 inches of 



