Page:Climatic Cycles and Tree-Growth - 1919.djvu/15

 the summer of 1918 and the measurements and tabulation finished soon after. I wish gratefully to acknowledge the courtesy of the editors of the Astrophysical Journal and the Bulletin of the American Geographical Society for permission to use illustrations and extracts from articles of mine which they have published. Plate 9 and figure 31 in the text are from the former journal. Thanks are also extended to Professor Ellsworth Huntington for the use of several text-figures which first appeared in my chapter of his work (1914).

TREES SUITABLE FOR CLIMATIC STUDY. During the course of this investigation the wood and growth of numerous species of trees have been examined with reference to their adaptability to the purposes herein described. The collections visited include several in London, especially one in the South Kensington Museum, fossils in the Jermyn Street Museum, the lumber-yards of Messrs. W. W. Howard Bros. & Company, tree sections and fossils in the geological museum at Berlin, fossils in the lignite beds of Grube Ilsa near Dresden, and fossils chiefly in Munich and Vienna. In