374 FARM AND SCHOOL PROBLEMS. 



The following references are given to assist the teacher in 

 getting such information as may be desirable to assist in the 

 study of climatology in its relation to agriculture and the general 

 business interests of the country. 



Among the publications of the weather bureau, the following 

 are worthy of special mention : 



1. The Monthly Weather Review. 



2. Bulletin of the Mount Weather Research Observatory. 



3. Climatological Data. 



4. Bulletins by experts of the service. 



5. Library of the Weather Bureau, numbering about 28,000 books. 



6. Annual Report of the Chief of the Weather Bureau. 

 1. Snow and ice bulletins during winter. 



Every teacher should write to the U. S. Department of Ag- 

 riculture Weather Bureau and ask for the List of Publications 

 of the Weather Bureau that are available for distribution. 



Need of Moisture. 



According to observations made by scientists in England, 

 Germany and America, it has been determined that a plant in 

 growing will transpire and evaporate from 200 to 500 pounds of 

 water for each pound of dry matter produced. 



The leading crops are named in the following table in the 

 order of the amount of water required to produce one pound of 

 dry matter. 



Barley estimated at from 310 pounds to 774 pounds of water. 



Oats " " " 402 " " 665 " 



Buckwheat " " " 371 " " 664 " " " 



Red Clover " " " 249 " " 453 " 



Wheat " " " 225 " " 359 " 



Corn " " " 233 " " 272 " 



A study of this table will enable us to determine from a 

 study of the annual rainfall map of a region, together with other 

 weather conditions, what are the crops best adapted to that region. 



It is very apparent that the evaporation of water from the 

 tissue of plants will vary in amount in different climates and in 

 different soils. More water is required in an arid than in a 



