38 CLIMATIC CYCLES AND TREE-GROWTH. 
On page 114 will be found the Eberswalde means from 1830 to 1912. 
Only one center occurs later than that date of beginning, namely, 
1833. The others were mostly between 1821 and 1827. The means 
of this group are plotted in figure 8 and also shown more in detail in 
figure 9. These means have been corrected for age and reduced to 
1820 30 40 1850 60 20 £0 90 1900 1910 
i : 6 ; ‘ Mms. 
7 4.00 
Nos. 1-6 wh VV - ; re 
URN Ave TLAN woh 
WONG 
Nos 7-13 er | - is vi 
vrs MW. \wh \. Baa 
iG ae ime 
A A 
Nos. 1-13 Vv x h 
v v 4 7. Bre 
mua KT 
Nos. 1-18 
reget Ard wa caw i taal ie Y Sy cava y u 1.00 
0 
A. Me 
Nos. 1.18 1100 |, JNA AU Fé \ 
smoothed we ra F Fg/ HN At! \Y 
“uve Lo of NZ] ne oe 
Fia. 9.—Sunspots and growth of trees at Eberswalde, Germany. 
percentages of a mean line reading 2.57 mm. in 1830 and 0.54 mm. in 
1910. These in turn have been smoothed and plotted in figure 23. 
In considering the significance of the agreement above noted, one 
should, in my opinion, keep in mind first the unusually homogeneous 
environment of these particular trees and the great care they have 
received, and second, the suggestion they contain of eventually defining 
distinct meteorological districts in which homogeneous effects are noted. 
A small pine of 60 rings from the Hartz Mountains was examined in the 
