ILLUSTRATIONS. 5 
TEXT-FIGURES. 
PAGE. PAGE. 
1. Effect of monthly distribution"of pre- 23. Six European groups, standardized 
cipitation on thickness of rings of BG BINOORER deco a's ida Widen ed 75 
growth; Prescott, Arizona.........- 19 | 24. Three European groups, standardized 
2. Monthly and yearly precipitation at ONG SMOOMIE .\65 20 noc ov eesioeads'ee 77 
veda and size and character of 25. Comparison between 57 north Europe 
DOMES, Srasstet ss 3 Ges nic je:s. 0 +o Ree 21 trees (smoothed) and sunspot num- 
3. aanal growth of trees at Flagstaff bers. The trees are from England, 
from 1385 to 1906, A. D............ 25 Norway, Sweden, and north Germany 77 
4, Comparison of two Flagstaff groups. 26. Dates of large rings in 80 European 
Variations in annual rainfall according trees compared with sunspot curves. 
to month of beginning annual means. 26 Ordinates give number of trees in 
5. Growth of individual trees compared total of 80 showing maxima in re- 
with precipitation at Flagstaff...... 27 Bpective YEAaTS...65..eccecescssecos 78 
6. Annual growth of trees near Prescott, 27. Tree growth at Windsor, Vermont, 
DMPMMLMAME Sc 5 alc £'X-<'s. pialadiacesa o1k op. a encore 28 showing measures uncorrected: same 
7. Annual rainfall and growth of trees standardized and smoothed, and sun- 
(Group V) at Prescott. Dotted line spot numbers displaced 3 years to left 78 
=rainfall. Solid line=growth..... 29 | 28. Smoothed quarterly rainfall (upper 
8. The nine European groups.......... 31 curve), sunspot numbers (center), 
9. Sunspots and growth of trees at Ebers- and tree growtb (lower) at Windsor, 
walde, Germany..............-0005 38 Vermont, 1835 to 1912............. 79 
10. Growth of old European ‘ies: A. Six 29. Correlation curves of solar cycle, rain- 
Norwegian trees, mostly from inner fall, and tree growth at Windsor, Ver- 
fjords. B. Eight trees from Dalarne, mont, 1835 to 1912.............6. 80 
oe EARS ECS ea Se 40 | 30. Schuster’s periodogram of the sunspot 
11. Oregon group. Curve No. 1, actual MUNI EOS <in's ois ore sleek eo Rc ipiecoas Siena 86 
tree growth; No. 2, trees growth de- 31. Diagram of theory of differential pat- 
partures, smoothed; No. 3, sunspot tern in periodograph analysis...... 91 
numbers displaced 2 years to left.... 43 | 32. Smoothed curve of Arizona pines show- 
12. Cross-identificationin first fivesequoias ing the half-sunspot period for 120 
. and gross rings in No. 1............ 48 POE Sicnsd Cea tens auch eeneeae awe 102 
13. Correlation between tree growth and 33. Changes in the 11-year period in 500 
rainfall in smoothed curves; Flagstaff. 65 years. Solid line, Arizona pine; 
14, Early test of correlation between tree dotted line, sequoia................ 103 
growth and rainfall by years; Flagstaff 66 | 34. Correlation curves in the 1l-year cycle 104 
15, Relation of tree growth and rainfall at 35. Early curve of Arizona pines from 1700 
Prescott. Tree growth and rainfall to 1900 A. D. (No. 4) compared with 
MIQUIMUNNOD Ss cCs a dlc se x tia w'ei ciel 8 atie 3's 68 double and triple sunspot cycles com- 
16. Five-year smoothed curves of growth Benes ST GS, as ae oes ceeelenk 105 
RUE BOIONMIE 5 Al dte.d s1k54, 45 oe wleroed 68 | 36. Double sunspot period in tree growth 
17. Accumulated rain and smoothed tree at inner fjords of Norway; lower curve 
MOPED eos bdloke ak hdio-eyc: a nin:s 09645 ale 68 a 22.8-year cycle...........2.eees 105 
18. Actual tree growth and growth calecu- 37. Double sunspot rhythm in sequoia, 
TQUOO TOOME LA's s/s ore roads cleans 68 D-12 about 300 A. D.............. 105 
19. Actual rain and rain calculated from 38. Triple sunspot cycle in a single tree 
NOR MOOWM cask <e a lect iad «va egcwre 68 from northern Norway. Lowercurve, 
20. Huntington’s early curves of sequoia a Sdsyear CyOlO. 6... ..ccecceces cues 106 
growth and rainfall compared with 39. D-22 at 750 to 660 B. C., showing a 
‘growth calculated by a conservation DHOOL PENOGs si ov actccses weaecaves 106 
POM: «slots: oa Pe cite eee meee 71 | 40. Two differential patterns of Hunting- 
21, Comparison of Fresno rainfall (after tons preliminary 2000 year sequoia 
Huntington) and sequoias D-1 to5.. 71 record. The most prominent cycle is 
22. Sunspot numbers and annual rings in about 105 years in length, shown in 
spruce tree from south Sweden...... 75 the upper diagram................. 109 
