448 POPULAR SCIENCE MONTHLY. 



cessive or deficient temperatures were indicated at cities within districts 

 of too high or too low temperature, respectively. Similarly, the de- 

 pressing effects upon trade of too much, or too little, precipitation were 

 found in those portions of the country where there had been an excess 

 or a deficiency of rainfall. So close were these relations in some weeks 

 that it was possible to state in degrees, or in inches, the amount of 

 the excess or deficiency of temperature or of rainfall which were 

 needed to stimulate or to depress trade (e. g., the third week in June; 

 and the weeks ending September 21 and April 14). So close an agree- 

 ment is, however, exceptional. A careful study for the year in question 

 of all the trade reports in which mention was made of weather control, 

 and a close comparison of these reports with the temperature and rain- 

 fall charts, failed to give any such exact results as were hoped for. 



The final outcome of this consideration may be briefly stated as 

 follows: As the result of the experience of many years, trade is in a 

 condition of such very close and delicate adjustment to the average 

 weather of any particular month, or even week, that 'seasonable,' i. e., 

 normal weather, other things being equal, usually means 'seasonable' 

 trade. The case is not unlike that of a row of card houses which, when 

 left undisturbed, i. e., under normal conditions, stand, but when in- 

 terfered with by any unexpected or abnormal influence, fall down. Thus, 

 when meteorological conditions are unseasonable, trade at once reflects 

 the change, and suffers. Trade is, however, subject to many and widely- 

 varying controls; hence the problem of the particular controls which 

 affect it in any one week is a very complex one, and the key is not 

 always, or sometimes even at all, to be found in local weather conditions. 

 The trade of a city is often largely dependent upon orders coming from 

 a distance. Hence, although the weather in the city may be unfavor- 

 able, and local trade depressed, orders from the tributary district may 

 suffice to overcome this depression, and keep trade up to its usual 

 standard, and vice versa. Again, while seasonable weather promotes 

 active trade among the inhabitants of a city, the farmers round about 

 may take advantage of this opportunity to work in their fields, and 

 trade in the country districts suffers because the farmers are too busy 

 to make purchases. Furthermore, the relation between temperature 

 and precipitation on the one hand, and crops on the other (and hence, 

 indirectly, the control of weather over trade) cannot be expressed in any 

 simple way. This is partly because the effect of the weather of any 

 one week upon crops, and upon trade, depends largely on the weather of 

 the preceding weeks. Thus, if there has been enough rain, high, or even 

 unusually high, temperatures may be needed to promote the growth 

 of crops, while on the other hand, if the rainfall has been deficient, high 

 temperatures may be very injurious. The proper distribution, in time 

 and in amount, of temperature and precipitation in their relation to 

 crops is a subject which itself still needs much careful study. 



