Smithsonian Report. 1931. — Douglass 



Plate 1 



1. Arizona pine forest near Flagstaf! (hence forest interior); note freedom from uwlerbrush, a dry 



climate character 



2. Drought of 1573 to 1593 in tree 5 miles south of Flagstaff, showing "forest interior" type of rings, 

 that is, gentle changes from one ring to the next. Three dots mark the year 1600; 1590, 1580, etc., 

 are marked by one dot. 



3. Drought of 1276 to 1299 in Oraibi beam from lower (dry) forest border showing abrupt change from 

 ring to ring. The very large ring, second from the left end, is 1275; 1299 is the last extreme drought 

 year. 



Ring Types in Arizona Pines 



