58 CLIMATIC CYCLES AND TEEE-GKOWTH 



Of the 8 radials cut (Fl-33 to 40), 5 had an age of 500 years. Only 2 

 such trees had been found before. Thus by one day 's work a reliable 

 500-year record was obtained (see Plate 6). 



Burnt centers — All this seemed so encouraging that on August 28, 

 1922, another visit was made to this locality for the purpose of collect- 

 ing " burnt centers." It had long been hoped that the tree record 

 could be carried back before 1,400 a. d. by finding stumps or logs of 

 earlier origin which in some way had been preserved. For example, 

 a tree blown down by the wind might be buried and thus preserved, 

 or it might have fire injury which would cause the central parts of the 

 stump to fill with pitch and thus withstand weathering. So on this 

 visit the larger burnt stumps were sought and partial radials cut from 

 their centers. Out of 5 so collected, numbers Fl-95 to 99, one was 

 too complacent for dating, 2 began about 1500 and 2 began before 

 1400 a. d. Of these two, one undoubtedly started by 1350, but the 

 very center had rotted away and no real gain was made. Yet these 

 two were thoroughly filled with pitch and presented records which 

 match in a remarkable manner certain dated beams from the pueblo 

 buildings of the Hopi Indians. 



In the summer of 1920 two other 500-year trees were reported to 

 me at about the same time. On June 17 a radial from Fl-41, a 66- 

 inch stump in the northwest corner of Fort Valley, was cut. This 

 very old tree stood at the edge of the flat valley floor, in good soil, 

 near large outcroppings of volcanic rock, on which the Southwestern 

 Forest Experiment Station stands. Mountains protected it to the 

 west, north, and east, but not especially on the southwest and south- 

 east, and southwest winds are sometimes very strong. 



On the following day another stump of even larger size was visited 

 near the top of Woody Mountain, 10 miles to the south. This was 

 numbered Fl-42. By courtesy of Mr. T. A. Riordan, president of the 

 Arizona Lumber and Timber Company, a full section of this splendid 

 tree was cut and shipped to Tucson. Each of these 500-year trees 

 was somewhat complacent; in fact, they and the still older tree men- 

 tioned below have decidedly less sensitive records than the previous 

 7 trees of that age. Five of these 7 had come from the university 

 section, some 3 miles east of Woody Mountain, and 2 collected in 1906 

 had come from about 2 miles west of the same mountain. 



A 640-year pine — In early July 1923, Forest Assistant Merker 

 and Forest Examiner M. Westveld discovered a pine stump in the 

 canyon a mile up-stream (south) from Fisher's Tank and about 5 

 miles southeast of Flagstaff. By their first count this tree was 640 

 years of age when cut and subsequent examination confirmed that 

 figure. By courtesy of Mr. G. A. Pearson, director of the Southwestern 

 Forest Experiment Station, a large half section was cut for me and 



