COLLECTION OF SECTIONS. 27 
THE SECOND FLAGSTAFF GROUP OF SEVEN SECTIONS. 
In 1911 the writer visited Flagstaff again and made a trip into the 
forest where cutting was going on, in order to procure a few additional 
samples of the yellow pine which would check the recent part of the 
tree-record previously obtained and bring it up to date for comparison 
with rainfall values. The location was about 12 miles southeast of 
town and from 6 to 12 miles east of the region from which the first 
Flagstaff group was obtained. Seven cuttings 
were procured from the edges of stumps, thus 
Year 
1900 1905 _ 1910 
bringing away a triangular pyramid of wood, rf i 
which included the outer 50 to 100 rings. sal np VJ 
Figure 4 shows how well the second group = ¥ jo|_Nov. 1 to Nov. 1 
checks the first and indicates that even asmall § , 
group of trees, no more than 7 in number, is “= |%%* f20 
sufficient to give results of considerable accu- v A N Is 
racy. Indeed, we may go further and say that 1.0 
a single tree under favorable conditions may seat 
give results of very great value. This is evident ie be 
in figure 5, where the 7 sections from the last 7 10 : 
Flagstaff group are plotted separately, the most ae: 
rapid grower at the top, just below the rainfall Set | V > & 
curve, and the slowest-growing tree at the eis “4 
bottom. All rise alike because the conditions 1 a 
of rajnfall in 1900-10 were more favorable than ses |/ N43 
in the preceding decade, but all (especially the Wee = 
curve of section 4) show a more or less close nicl 
relation to the rainfall at Flagstaff, even though a NF 0.6 
that town was some 12 miles away. The great meus e 
sinuosity which a quick-growing tree may show P08 
is well illustrated in section 4 in the great dif- 0.0 
ferences between successive years. A lack of See. 8 8 
. : : . . 0.0 
sinuosity is shown in section 5 at the bottom. |. 5 Growth of indi 
This difference supports the conclusion already vidual trees compared 
reached that slow-growing trees are of less value ees 
than rapid ones in the determination of climatic 5a 
cycles. The results of the measures of this group serve as a check 
on the preceding measures and are shown in the figures just referred to. 
They are, therefore, not tabulated in this book. 
THE PRESCOTT GROUP. 
Prescott is located in the northerly part of the Bradshaw Mountains, 
at an elevation of 5,200 feet. The rocky subsoil is largely granite 
disintegrated at the surface and worn into steep hillsides, deep gorges, 
and picturesque masses of rounded boulders. The ridges are sharp 
and rugged, and the general contour is very irregular. There are very 
