ay in text / WNC he be ak 
dias 
Avia f\ 
SRA ee 
a fel Wy NI AV] y\ 
EY Os Sa 
CORRELATION WITH RAINFALL. 71 
pond, but of the moving type, as if a belated supply from the snows 
came to hand and then passed on. The tree was assumed to receive 
moisture from the current year and from the first and second preceding 
years; and whichever of the three was greater, that one had the more 
effect. The application of this formula is shown in figure 20. 
1850 1860 1870 1880 1890 1900 
1910 
T T T T T 
0 n 1 1 n n 
Fie. 20.—Huntington’s early curves of sequoia-growth and rainfall compared with growth calcu- 
lated by a conservation formula. 
But on identifying the rings in the trees collected from that locality 
in 1915, and especially on finding the soft, delicate parts of the 1915 
ring on D-5, it seemed fairly certain that the curve of growth given 
in figure 20 is one year in error through the omission of a finalring. The 
growth, then, which appeared to be 1902, for example, and for which a 
pronounced conservation was necessary, really came the year before, 
p 
PS 
\ 
Gren WARET Te 
aos Pel, DORARA ze 
10 pot T ty 
y Rainfall cate v 
AN - eee TreeGrowth~|~ 
1850 60 7 60 90 7300 7 
~ 
Millineters 
Tree Growth 
Years 
Fie. 21.—Comparison of Fresno rainfall (after Huntington) and sequoias D-1 to 5. 
and less conservation or none was needed. The comparison of the 
same rainfall curve with the old sequoias of the present series is given 
in figure 21. In this the agreement is not as good as at Prescott, but 
there is marked similarity in many details. My curve from very old 
Ss 
is 
