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THE ANNUAL RAINFALL AND TEMPERATURE 

 OF THE UNITED STATES.* 



Geo. a. Lindsay. 



A record of the annual temperature and rainfall of var- 

 ious stations scattered over a large territory, having 

 wide variations of climate cannot give a very accurate 

 idea of the mean annual temperature of the whole region, 

 or of the total volume of precipitation upon its surface. 



In ''A Report on Missouri Rainfall"^ for the years 

 1878-1887 inclusive, Professor Nipher has shown the aver- 

 age number of cubic feet per second of water in the var- 

 ious forms of precipitation which fell upon the surface of 

 the state during those years. 



In the following work, which was also begun by Pro- 

 fessor Nipher, and completed by the writer, an attempt 

 has been made to compute the total precipitation on the 

 main body of the United States, exclusive of Alaska, and 

 the outlying possessions; and also to find the average an- 

 nual temperature of the same region as a whele. It would 

 seem that this, or some similar method, is the proper way 

 of expressing the climate of an entire country, such as 

 the United States. 



Twenty-eight manuscript maps, covering the fourteen 

 years 1891-1904, were obtained from the office of the 

 Weather Bureau at Washington. Half of these indicated 

 the precipitation in inches per year, and the other four- 

 teen the mean annual temperature. The figures for these 

 had been marked on the maps at the points of observa- 

 tion, and lines passing through points having equal pre- 

 cipitation, and lines of equal temperature had also been 

 drawn upon the maps by the weather officials. These 



* Read before The Academy of Science of St, Louis, June 5, 1911. 

 1 Trans. Acad. Sci. St. Louis. 5 : 383. " 



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