METEOROLOGICAL TABLES 



25 



METEOROLOGY. 



The principal features in the distribution and total amount of rain- 

 fall in several localities which may be included within the arid regions 

 are given below. The data concerning the maximum and minimum 

 temperatures and rate of evaporation afford a means of estimating the 

 actual usefulness or availability of water supply for the native vegeta- 

 tion. Thus, for example, evaporation is so great and humidity of the 

 air so small, in the southernmost stations given, that the effectiveness 

 of the rainfall in meeting the needs of plants is diminished fifty or even 

 sixty per cent. Of the localities named below, El Paso, Fort Win- 

 gate, Chihuahua, and San Luis Potosi may be included in the Chihua- 

 huan desert, and the other places within the Nevada-Sonoran desert. 



METEOROLOGICAL TABLES. 



The following tables give the mean rainfall and the absolute maxi- 

 mum and minimum temperatures for 16 stations, 13 in the United 

 States and 3 in Mexico. All data for the United States stations are 

 from records in the U. S. Weather Bureau. Data for two Mexi- 

 can stations, San Luis Potosi and Chihuahua, are taken from the 

 Monthly Bulletin of the Central Meteorological Bureau of Mexico for 

 1901. The rainfall record for Torres, vSonora, Mexico, was cour- 

 teously furnished by Mr. T. Oldendorff, agent of the Sonora Railway 

 at that point. The figures for this station were copied from the report 

 made daily to the manager of the railway. 



* 15 years' observations 



