Show History From Trees Tree For a n quarter of a century Dr D Douglass of the Un University of Arizona ArIzona Arizona Ari ArI- zona has studied the rings which mark the annual growth g of trees He demonstrated that the rin rings s formed each year vary in in width in direct proportion to the amount of ot rainfall n a a wet year produces a thick ring and vice versa Tree growths in the giant sequoias of California were traced back three thousand years Doctor Douglass made an unbroken annual calendar back to A. A D. D By the study of timbers taken from pueblos he be gave exact dates of ever events ts tsIn In the history of those Indian peoples back as ns far as the Eighth century |