CLIMATE OF THE SANTA CATALINA MOUNTAINS. 51 
than are now in hand. During the years 1907 to 1912 the percentage 
at Benson, Arizona (3,523 feet), was 60 per cent, that at Globe, Arizona 
(3,525 feet), was 42.1 per cent, the average of the two 51.0 per cent. 
The average of the percentages for Fort Huachuca (5,100 feet), Fort 
Apache (5,200 feet), and Bisbee (5,500 feet) is 55.5 per cent. Although 
these figures indicate that up to "3% 
5,000 feet there is about the same | 
percentage that holds at 2,400 feet aco 
(at Tucson), nevertheless at Flag- 
staff (6,907 feet) the summer rain sot 
was only 40.7 per cent of the total 
in the years mentioned. AtChlar- vol 
son’s Mill (7,200 feet) an incom- 
| | lod | | 
pleterecord indicates that in 1907, 
1909, and 1910 the summer rain 
3 
was far below the percentages for JAN. FEB MAR APR, MAY JUNE JULY AUG SEPT OCT Nov. DEC. 
Tueson for those years. AtGreer Fie. 4—Diagram showing monthly distribution 
(9, 200 feet), on the Mogollon Pla- of rainfall at Tucson. Averages of record for 
A 88 years, 1876 to 1913 inclusive. 
teau, the summer rain was a much 
greater percentage of the annual total in 1905 than it was at Tucson, 
while in 1906 and 1908 the percentages were nearly identical. It can 
only be said, therefore, that a much larger body of data is necessary to 
determine the possible change of seasonal distribution of rain due to 
altitude. The evidence at hand indicates that there is little probability 
of a marked influence. (See table 3.) 
TaBLE 3.—The average annual rainfall for 1907 to 1912, the average summer rainfall for the 
same years, and the percentage of the latter to the former for stations at different altitudes 
in central and southern Arizona. 
Station. Altitude. | Annual. | Summer.| Percentage. 
Feet Inches Inches Inches 
TUCSON 365 sida tiaes 2390 11.54 6.66 57.7 
Benson............- 3523 10.51 6.31 60.0 51.0 
Globe........... wialiese 3525 17.01 7.16 42.1 
Fort Huachuca...... 5100 15.53 9.24 59.5 
Fort Apache........ 5200 16.95 7.53 44.4 (55.5 
Bisbee............. 5500 20.68 12.95 62.6 
Flagstaff........... 6907 22.60 9.20 40.7 
ALTITUDINAL INCREASE OF RAINFALL. 
The measurements of summer rainfall on the Santa Catalina Moun- 
tains were begun in 1907 by the installation of a metal gauge at 7,600 
feet, where the record was secured until 1911, after which it was re- 
moved to a nearby ridge at 8,000 feet. During 1908 and 1909 readings 
were secured at the base of the mountain and at 6,000 feet, in 1910 at 
