LIST OF ILLUSTRATIONS. V 



IG. Actual tree growth compared with growth calculated from rainfall 113 



17. Five-year smoothed curves of rainfall and tree growth at Prescott 113 



18. Actual rainfall compared with rainfall calculated from growth of trees, Aiizona 114 



19. .\nnual growth of trees at Flagstaff since 1385 A.D 116 



20. 500-year curve of tree growth, 20-year means 117 



21. A possible 150-year period 117 



22. Mean curve of the 21-year cycle 117 



23. Variations of the 11-year cycle 118 



24. Comparison of eleven 4-year cycles in tree growth, rainfall, temperature, and inverted sun-spot numbers. . . 119 



25. Sun-spots and the growth of trees at Ebcrswalde, Germany 120 



26. Ideal curves illustrating correction for age 125 



27. Ideal curve illustrating correction for longevity _. 127 



28. CiuT^e of growth and correction for age of yellow pine in New Mexico 128 



29. Curve of growth of 50 yellow pines over 280 years of age 129 



30. Variation in radial growth by decades 131 



31. Curves of growth of American trees 133 



32. Curves of growth of western yellow pine in New Mexico and Idaho 135 



33. Rainfall of Idaho compared with that of New Mexico 136 



34. Ideal diagram to illustrate the dropi)ing of rings ._ 148 



35. Sequoia washingtoniana, corrective factor for age dm-ing first 250 years of life 150 



36. Sequoia washingtoniana, corrective factor for age, plotted by centuries 151 



37. Sequoia washingtoniana, corrective factor for longevity 152 



38. Curve of growth of the Sequoia washingtoniana in California 153 



39. Effect of flaring buttresses on the measurement of rings of growth 154 



40. Annual rainfall at selected stations in California 158 



41. Monthly distribution of precipitation in California 160 



42. Rainfall at Portersville compared with growth of Sequoias at Dillonwood 161 



43. Annual growth of 1 1 1 Sequoias at Hume 162 



44. Growth of trees at Hume, and rainfall at Fresno 163 



45. Mean monthly distribution of rainfall compared with distribution in exceptional years 164 



46. Conservation factor in the relation of growth and rainfall, method 1 166 



47. Conservation factor in the relation of growth and rainfall, method II 166 



48. Tree growth in California calciJated from rainfall 167 



49. Rainfall by months in favorable and unfavorable years 170 



50. Changes of cUmate in California and western Asia during historic times 172 



51. Storm frequency, 1878-1887 191 



52. Storm frequency, January 194 



53. Storm frequency, February 194 



54. Storm frequency, March 195 



55. Storm frequency, April 195 



56. Storm frequency. May 196 



57. Storm frequency, ,Iune 196 



58. Storm frequency, July 197 



59. Storm frequency, August 197 



60. Storm frequency, September 198 



61 . Storm frequency, October 198 



62. Storm frequency, November 199 



63. Storm frequency, December 199 



64. Storm frequency. Year maps for 1878-1887, after Dunwoody, and 1899-1908, after Kullmer, showing shift 



of storm track 201 



65. Changes in storm frequency by months according to longitude 202 



66. Changes in storm frequency by months irrespective of longitude and latitude 202 



67. Changes in storm frequency by months according to longitude in latitude 50°-55° 202 



68. Changes in storm frequency by months according to longitude in latitude 45°-50° 203 



69. Changes in storm frequency by months according to longitude in latitude 30°-35° 204 



70. Changes in storm frequencv bv months according to longitude in latitude 25°-30° 204 



71. Summary of differences in storm frequency, 1878-1887 and 1899-1908 204 



72. Changes of climate in California for 2,000 years 209, 231 



73. Diagrammatic sections of wall and deposits at Copan Ruins 214 



74. Relation of terraces and ruins at Copan 214 



75. The Relation of sun-spots and tree growth in the 11-year cycle 239 



76. The sun-spot cycle and terrestrial phenomena 240 



77. The com crop of the United States, 1901, a "lean" year 244 



78. The com crop of the United States, 1906, a "fat" year 244 



79. The corn crop of the United States, 1908 245 



80. The com crop of the United States, 1909 245 



81. Variations of the solar constant and monthly departures from mean temperature at Arequipa 246 



82. Monthly departures of temperature in South Equatorial regions, showing agreement 247 



83. Monthly departures of temperature in North and South Equatorial regions, showing disagreement 248 



84. Monthlv departures of temperature in North .'Vmerica compared with Arequipa in Peru 249 



85. The Relation of volcanoes, sun-spots, and terrestrial temperature 252 



86. Geological changes of climate and movements of the Earth's crust 256 



87. Map of Pleistocene glaciation 266 



88. Paleogeography and glaciation of early Permic times 267 



89. Map of Proterozoic glaciation 270 



90. Chart of geological climates. Paleometeorology 285 



