National Geographic : 1929 Dec
THE KEY TO THE SECRET OF THE SOUTHWEST-CHARRED RINGS OF BEAM HH39(SEE TEXT, PAGES 767-770) This fragment, photographed in reflected light, shows some of the pre-Columbian tree diary entries. The ring indicated bythe arrow records rain fall conditions in 1247; the one designated by a star tells of conditions in 1275. The closeness with whichtimbers ofthesame age corroborate each other's testimony about common experiences would delight a trial lawyer's heart. Photographs by Dr. A. E.Douglass MATCHING THE STORIES THE TREE RINGS TOLD To make them readily accessible for comparison, one with another, each tree-ring specimen was carefullyplotted. The long black lines onthese orig inal field records represent severe drought years; the shorter ones, less severe drought years. The lower plot, ofspecimen HH39 (see above) from Showlow, brought joy to the expedition members when its principal drought years were found to coincide with those inthe upper plot, made up oftimber records previously dated.