348 



ENVIRONMENTAL CONDITIONS. 



Table 19. — Normal mean relative humidities, for the year and for the -period of the average 

 frostless season, mean relative humidities for the three summer months, 1908, and normal 

 mean vapor-pressures for the year and for the period of the average frostless season. — 

 Continued. 



Station. 



Texas — Continued: 



Amarillo 



Corpus Christi. 



El Paso 



Galveston 



Palestine 



San Antonio . . . 

 Utah: 



Salt Lake City. 

 Vermont : 



Northfield . . . ; . 

 Virginia: 



Lynchburg 



Norfolk 



Wytheville. ... 

 Washington : 



Seattle 



Spokane 



Tacoma 



Tatoosh Island. 



Walla Walla.... 

 West Virginia: 



Elkins 



Parkersburg. . . . 

 Wisconsin : 



Green Bay 



La Crosse 



Madison 



Milwaukee 



Wyoming: 



Cheyenne 



Lander 



Sheridan 



Yellowstone. . . . 



Mean relative humidity. 



Annual. 



p. ct. 

 59.3 

 82.1 

 38.8 

 85.2 

 73.8 

 66.6 



52.8 



77.6 



71.1 



78.6 



76.2 

 64.0 



64.8 



75.7 



74.0 

 72.2 



74.9 



53.7 



57.8 



For period 



of average 



frostless 



season. 



p. ct. 

 59.4 

 81.9 

 37.0 

 80.2 

 73.7 

 66.7 



40.9 



78.1 



72.8 

 79.1 



73.6 

 52.9 



54.6 



73.2 



70.6 

 69.5 



72.6 



52.9 

 47.9 



For June, 



July, and 



August 



1908. 



p. ct. 

 68 

 80 

 43 

 74 

 78 

 73 



45 



86 



77 

 79 

 90 



75 

 46 

 73 

 89 

 46 



83 

 73 



69 



71 



71 



61 

 58 

 62 

 61 



Mean vapor-pressure 

 of water. 



Annual. 



inch. 

 .262 

 .618 

 .243 

 .595 

 .467 

 .472 



.193 



.239 



.356 

 .410 



For period 



of average 



frostless 



season. 



inch. 

 .373 

 .676 

 .300 

 .622 

 .569 

 .540 



.250 



.423 



.498 

 .625 



The chart of plate 63 is markedly different from any of the moisture 

 charts heretofore considered, excepting that it somewhat resembles 

 some of those for precipitation. It is not very similar to any of the 

 temperature charts with which we have been concerned, but it appears 

 to partake of the general characteristics of both temperature and 

 moisture charts. In the East the zonation here shown is markedly 

 similar to that for temperature, the isobars having generally a west- 

 east direction. Each of these lines, however, is seen to bend rather 

 sharply southward in the middle of the country, so that the region 

 west of about the ninety-eighth meridian of west longitude is generally 

 characterized by isobars that have a north-south trend. The western 



