TREE RECORDS: GEOGRAPHICAL DISTRIBUTION 87 



by graphic Hann. The curve extends from 1551 to 1921 and the part 

 since 1750 is shown in figure 6. It has a distinct similarity to the 

 typical Sierra Nevada curve farther south. Its cycles are 6.7, 11.8, 

 13.7 (oc. -J), and 28.6 (3), which conforms to the usual ones of the 

 Coast zone. 



Professor Fritz also sent a partial section of pine tree from a point 

 at about 5,400 feet altitude in Lassen County, near Susanville. This 

 single tree-record begins at 1588 and ends in 1922. An analysis 

 obtained in the usual way gives as cycles, 16.4 (2, oc. -£), 20.2 (oc. -J-), 

 24.2 (oc. i), and 29.5. 



CALAVERAS GROUP OF PINES (CVP) 



The collection of this group of increment-cores at the edges of the 

 Calaveras Grove of big trees on July 4, 1924, has been described in a 

 previous chapter, page 53. The additional cores, taken near Murpheys, 

 showed a larger growth average of 1.71 mm. as compared to 1.25 of the 

 trees near the grove, but otherwise appeared to give much the same 

 record, and all were included in one group of 14. 



Mr. Hawkins measured these, using the long-plot method. An 

 attempt was made in this group to standardize the individual records 

 by using different gear ratios on the plotting instrument, but it was 

 not felt to be entirely satisfactory, on account of the different average 

 size of different parts of a single record; for instance, the larger central 

 growth in early years of the tree can not be properly allowed for, and 

 yet it is usually too good to discard. The average was undoubtedly 

 improved by this change of gears, and there were so many trees in the 

 group that it did not seem necessary to do any further standardizing. 

 The mean of the 14 trees, 1621 to 1923, smoothed by a graphic Hann, 

 is shown in large part (1750 to 1923) in figure 6. It is at once evident 

 that this belongs to the inner collection of homogeneous Sierra Nevada 

 curves. The cycles in this curve are 6.8 (2), 7.6 (2), 10.4, 14.6 (oc. £), 

 21.2 (2), and 30.2, which are of the Arizona type. 



BIG CREEK GROUP (BC) 



After the sequoia trip of 1919, it was realized that no pine records 

 had been secured in California to aid in the cross-dating between 

 Arizona and California. Accordingly, in 1920, at the request of Mr. 

 Paul Redington, district forester at San Francisco, the ranger on Big 

 Creek very kindly sent me five excellent v-cuts from pine stumps at 

 an elevation of about 5,500 feet on Big Creek, a northern tributary of 

 King's River. This river is just north of the General Grant National 

 Park and the large areas from which the greater part of the sequoia 

 records had come. 



These pine specimens cross-identified among themselves exceed- 

 ingly well, and there was no trouble in recognizing a number of Flag- 

 7 



