52 CLIMATIC CYCLES AND TREE-GROWTH 



of badly compressed rings near the outside. A good radius was 

 selected and a conspicuous ring was traced across from the new radius 

 to the old and its position on the old accurately determined. It 

 proved very easy to extend the dating on the new radius back to this 

 ring, and with this good start the entire dating of this tree proved 

 very satisfactory, in spite of the complacency of its growth. 



We returned to the Park and the next day I cut radials 32 to 35 at 

 Converse Hoist. These supplemented the two obtained the year before 

 in that vicinity by going higher up on the ridges for Nos. 32 and 35 

 and nearer the creek for 33 and 34. 



This locality is a very interesting one, because it contains the 

 stump D-21, which had 3,200 rings in it, whose central rings were 

 shown in Plate 1. Very old trees are rare. I have examined many 

 hundreds of stumps, made estimates of their age, and in many cases 

 have counted the rings. There were in these forests many trees over 

 2,000 years of age, but probably very few over 3,000. Only 3 stumps 

 of this age are known so far. Two estimates of the General Grant 

 tree gave 2,000 and 3,000 years of age, and its true age is thus taken 

 as 2,500 until some better opportunity comes for getting its number of 

 rings. The Centennial stump nearby was estimated to have some 

 1,800 rings and the large stump with raised center at Wigger's probably 

 is 1,500 years of age. 



FOURTH SEQUOIA TRIP. 1924 



The fourth sequoia trip in July 1924 had two objectives; first, the 

 improvement of the general sequoia record, and second, the securing 

 of certain indicators needed in the problem of correctly dating large 

 numbers of prehistoric tree-sections from the ancient ruins of the 

 Southwest. Such dating would not only help the archaeologist, but at 

 one stroke would also extend the superb yellow-pine climatic record 

 by more than 300 years at least. The general problem of dating 

 unknown tree-records will be taken up at another time. It is sufficient 

 to say here that one way to accomplish such dating is by cross-identifi- 

 cation between the pines of the Arizona region and the sequoias of 

 California. This apparently would be easy by comparison of the 

 occasional common deficient years, perhaps eight per century, except 

 that in about one-fourth of such cases the Arizona deficient year 

 occurs one year late. For example, the small sequoia rings for 1846, 

 1812, 1541, and other years in California come in 1847, 1813, 1542, 

 and so forth, in Arizona. The attempt is, therefore, now being made 

 to discover in the pines or sequoias, or both, some internal signs by 

 which to know just when this difference of one year is to be expected. 

 Hence, in approaching this problem from the sequoia point of view, it 

 seemed best to go to other sequoia groves and see if some indication 

 of this occasional discrepancy could be discovered. 



