364 H. A. Hazen—Projection of Lines of Equal Pressure. 
teen degrees lower at Dodge City than at Denver. At Salt 
Lake City, on the elevated plateau west of the Rocky Mountains, 
there is a still greater difficulty, as the temperature seems to 
run too high. 
TABLE ITI. 
Elevation. Elevation. 
cera Signal Barome- = Signal Barome- 
Service. tric. Service. tric. 
Bismarck 1704’ 1740’ ||Leavenworth 813 840 
J 1333? 1400 ||Los Angeles 320 
Boise City 2877 2799 fason 1800? 1610 
Brackettville 1026? 1140 North Platte 2838 2838 
Camp Grant 4823? 4900 ‘|| Phoenix 1800? 1150 
Ca 2500? 2500 i 5779 6148 
Cheyenne 6057 6093‘ ||Pike’s Peak 14151 14021 
Co 1750? 1900 Prescott 5700? 5230 
Deadwood 4600 Red Blu 33 410 
Denver 5269 5265 Sa 76 100 
Dodge City 2486 2555 ~—‘||Salt Lake City 4362? 4365 
ort Buford 1970 St. Paul 796 825 
ort Craig 4622 4570 Santa Fé 6851 7020 
rt Davis 5203 4900 Silver City 6896 5920 
Fort Gibson 511 541 tockton 2000? 3100 
Fort Keogh 2536? 2480 U , 461 o 
Fort McKavitt 2050? 2230 ‘|| Virginia City 5480? 5830 
Fort Sill 1100? 1198 || Visalia 348 378 
j son 1760 Winnemucca 4335 4390 
Fredericksburg 1614? 1720 |/Yankton 1275 1210 
wa Mesilla 4050 |'Yuma 155? 240 
3d. Even if elevations were known, there seems to be no 
formula of reduction which can be applied to the varying con- 
ditions of the temperature and movements of the atmosphere. 
In order to obtain a satisfactory method of reduction, the 
following plan has been adopted, based upon the theory that 
the fluctuations of pressure are in part dependent upon the 
temperature at the base and summit of a mountain. 
rrange in a table a column for temperatures running from 
—30° to 80° in a vertical line, and a horizontal row of pressures, 
limited by the minimum and maximum pressures at the eleva- 
ted station under consideration. 
ar, we can construct a table which shall represent the proper 
reduction of all observations at the upper station. 
