ILLUSTRATIONS 



PLATES 



FACING 

 PAGE 



1. Cross-identification of MLK-179 

 and MLK-127. (See Plate 8) . . . . 1 



2. Pine forest, Northern Arizona: 

 Near San Francisco Peaks, Flag- 

 staff (1904) 2 



3. Pine (Ponderosa) forest, Northern 

 Arizona — Courtesy of U. S. Forest 

 Service 3 



4. Douglas fir site, Mesa Verde 4 



5. Giant sequoia: "Lady Alice" in 

 Balch's Park (1925) 5 



6. Complacent and sensitive se- 

 quences of rings: 



A. Complacent ring record, BE- 



133, pine 



B. Sensitive ring record, MV-23 



Douglas fir 8 



7. Cross-dating at 125 miles, JPB-17, 

 pine, and BK-2, Douglas fir 9 



8. Enlargements of specimens shown 

 in frontispiece 



A. MLK-179 



B. MLK-127 



C. Center of MLK-179 10 



9. JCD Signature in F-3992, Flag- 

 staff (charcoal) 11 



10. A. Forest interior ring type — 



Pine, FL-131, 3 miles north of 

 Flagstaff 

 B. Forest border ring type, PR-62. 

 Lower forest border, sensitive 

 rings : south-east of Prescott ... 12 



11. Tree roots and bed rock; Defiance 



Plateau 13 



12. A. Periodogram (1913) of sunspot 



numbers since 1760 

 B. Periodogram (1918) of variable 

 star, R Arietis, showing period 

 of 187 days (see appendix) 40 



13. A. Cyclogram by spectrometer 



process (1914) 



FACING 

 PAGE 



B. "Sweep" or cylindrical pat- 

 tern; the original plot, in- 

 verted, shows below the sweep . 4 1 



14. A. The cyclograph 44 



B. Analyzing parts of the cyclo- 

 graph . . 45 



15. A. Analyzing plate and mounting 

 B. Cyclograms of sunspot num- 

 bers, using centers of mass 48 



16. A. Multiple standard with discon- 



tinuous periods 



B. Arizona ring record, FAM, 1700 

 to 1920 at 21.0 years 



C. Analysis of Flagstaff tree ring 

 records (see chapter II, Cyclo- 

 gram Reading) 49 



17. Illustration of sunspot cycle by 

 changes in calcium flocculi — after 

 Adams and Nicholson 66 



18. Cyclograms of monthly sunspot 

 numbers, 1750 to 1931 67 



19. A. Cyclograms of Abbot's radia- 



tion curve, December 1918— 

 July 1930 



B. Cyclograms of magnetic char- 

 acter figure C. 1923-1933 



C. Cycle relief map of the mag- 

 netic character figure C, Jan- 

 uary 1932 to March 1935 78 



20. Cyclogram test to distinguish be- 

 tween natural and random se- 

 quences 79 



21. A. Eberswalde, Germany, ring 



sequence, G-6 

 B. Eberswalde specimen, G-2. . . . 122 



22. Cyclogram showing Hellmann 

 cycles between 1850 and 1900 in 

 Europe and North America 123 



23. Enlargement of cyclogram Plate 

 22 g, showing Hellmann cycle in 

 sequoias 124 



24. Cyclogram analysis of SS Cygni 

 (1918). Data cover 1896 to 1917... 125 



TEXT-FIGURES 



PAGE 



1. Circuit uniformity in a prehistoric 

 Douglas fir, MLK-127, from north- 

 eastern Arizona 8 



2. Cross-identity (similarity of 

 growth in each year) in Prescott 

 trees 11 



3. a. Cross-identity at 70 miles, Fort 



Defiance and Black Mesa 

 groups 

 b. Winter rainfall with 2i yr. lag 

 in smoothed values, and tree 

 growth 15 



PAGE 



4. Tree growth and river run -off 15 



5. Lynch's rainfall indices 1770 to 

 1930 (LRI) compared to Bear 

 Valley pine record (BV) and Grant 

 Park sequoia record (SVI) with a 

 pine (RB-7) showing good sequoia 

 record supplying data for the 

 period 1900-1934 16 



6. Point and column plots of same 

 data 18 



7. Smoothing methods compared 19 



