N/A. English: Plate 9. A. Periodogram of the sunspot numbers, 1755-1911. Corrugations show periods. The numbers give length of period in years. The white line is the year 1830 and shows phase. B. Differential pattern used in making the periodogram, consisting of the sunspot curve mounted in multiple. C. Same pattern photographed out of focus to show discontinuities in the vertical lines. D. Sweep of sunspot numbers, 1755-1911. E. Differential pattern of sunspot numbers made by the periodograph process. 1919. Andrew Ellicott Douglass 353 Climatic Cycles and Tree-Growth Plate 9

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Size: 1985px × 2518px
Photo credit: © The Picture Art Collection / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: ., /, /., 1919., andrew, douglass., ellicott