VI 



ILLUSTRATIONS 



PAGE 



8. Mass diagram and residual mass 

 diagram 20 



9. Logarithmic plot compared with 

 non-logarithmic plot 21 



10. a. "Normal" distribution of data 



about mean 

 b, c. Frequency distributions 

 compared : 



standardized ring widths in 

 complacent and sensitive rec- 

 ords, 1750-1920. ... . # 22 



d. Frequency distribution : stand- 

 ardized ring widths in sensitive 

 records, Central Pueblo area. 

 Mean group curve (73 trees) 



e, f. Frequency distribution: ring 

 widths in datable though not 

 sensitive tree records 23 



11. Skeleton count and skeleton plot. . 24 



12. Standardizing 25 



13. Merging diagram 27 



14. a. Summation (integration) curve 



of sunspot numbers at 10.0 

 years 



b. Graphic representation of inte- 

 gration table 



c. Summation curve at 11.5 years. 31 



15. Plot of sunspot data to show 

 changing place of 11.4-year 

 maxima in successive 11-year 

 intervals 33 



16. Successive integration of FAM 

 (Flagstaff area mean curve), 1700- 

 1920 34 



17. Two methods of plotting cycles. . 36 



18. Cyclogram demonstration, first 

 part 37 



19. Cyclogram demonstration, second 

 part 38 



20. Cyclogram plot of sunspot num- 

 bers, 1750-1930 39 



21. Schuster's periodogram of sun- 

 spot numbers 42 



22. Important parts of the cyclograph 



a. Schematic elevation 



b. Analyzing plate 44 



23. Cycleplot, to show cutting line. 

 Standardized tree growth, G-5, 

 Eberswalde, Germany 45 



24. The analyzing plate changes 

 longitudinal displacement in posi- 

 tion of maxima to transverse 45 



25. Bartels' Harmonic Dial of inter- 

 national magnetic character figure 

 C (from Terrestrial Magnetism, 

 March 1935, by permission) 54 



26. Bartels' Summation Dial (from 

 Terrestrial Magnetism, March 

 1935, by permission) 55 



27. Comparisons between Bartels' 

 dials and cyclogram anslysis 57 



28. Plan of Stumpff's periodograph 

 (after Stumpff , slightly modified). 62 



29. Butterfly diagram (after Maun- 

 der) 66 



PAGE 



30. Monthly sunspot curve to show 

 reduced amplitude at minimum 

 (after Wolfer) 70 



31. a. Chrono-periodogram of Ab- 

 bot's radiation curves analyzed 

 cyclogram methods 



b. Abbot's cycles in same 



c. Frequency periodogram 

 monthly sunspot numbers, 

 1750-1934 73 



d. Chrono-periodogram of same . . 74 



32. Ultra-violet radiation compared 

 to monthly sunspot numbers and 

 the solar constant 76 



33. International magnetic character 

 figure C as related to opposite 

 longitudes on sun during a 27-day 

 period 79 



34. Effect of smoothing on natural 

 sequences and random sequences. 

 Flagstaff area — 20-year running 

 means 84 



35. Frequency periodograms by three 

 processes applied to the same data 

 (central Pueblo area; 15 groups — 



73 trees) 87 



36. Two-year reversal test, to show 

 similarity in Arizona area in short 

 cycles 88 



37. "Reversal" tests for short cycles 



a. Lesser maxima in two-year 

 reversal test; showing agree- 

 ment between groups in Ari- 

 zona area 



b. Two-year test; lesser maxima 

 summarized for three western 

 zones 90 



38. Two-year reversal tests on random 

 data 91 



39. Conservation in successive years 

 in Fort Defiance group, shown by 

 scatter diagram using departures 

 from a mean 92 



40. Successive year conservation in 

 departures from a smoothed curve, 

 Fort Defiance group 



(a) in natural data; (b) in random 

 data 93 



41. Frequency periodograms of 42 

 groups : 



(a) obtained by two independent 

 observers 



(b) weak and strong cycles com- 

 pared (as recorded by Schul- 

 man) 97 



42. Hellmann cycle in sequoias, A.D. 

 155 to 245, using "triple lag" 

 method 100 



43. Scrambled sequoia values tested 



by "triple lag" method 101 



44. Hellmann cycle in recent sequoia 

 records. Running means of three 

 successive cycles of 23 years 

 ("triple lag" method, incomplete 

 after 1891) 102 



