28 CLIMATIC CYCLES AND TREE-GROWTH. 
few isolated peaks. The mountains are covered with pines from their 
crests to a little below the level of the city. 
This Prescott group was obtained in 1911 for the purpose of testing 
the conclusions derived from the Flagstaff trees some years earlier. 
Year 1870 1880 1890 1900 1910 
1.0 Nal A AS [SX Trees 1-10 
AR eMac 
2.0 NAA 
1.0 ee 7wA\ 1» ne & Group II 
2.0 
; $00 
a0 LN VWI Th Group III 
eo INA Gard \ A! AV verges 
B 0.0 
< 20 
NSE 
0.0 
2.0 
hee \ NM Mean of 
1.0 a4 NA ok A>~f>» Eom aa. yg 
WY |" ™|/ | 
0.0 
1870 1880 1890 1900 7910 
Fic. 6.—Annual growth of trees near Prescott, Arizona. 
It consists of 67 trees selected in 5 subgroups depending on their 
nearness to town. The farthest was 10 miles southeast and the 
- nearest was 1 mile south. It was apparent that the agreement between 
growth and precipitation increased as the location of the actual rain- 
fall station was approached. The nearest subgroup, containing 10 
