46 CLIMATIC CYCLES AND TREE-GROWTH. 
delightfully mild summers. The latter have occasional thunder-storms 
whose waters quickly run down the mountain slope. Thus conserva- 
tion plays an important part in the growth of these trees by rendering 
the winter precipitation more important than the summer and by per- 
mitting the moisture to remain long in the swampy places. 
Three groups were obtained from this general region in 1915. The 
first of these’ came from the uplands above Camp 6 close to the west 
line of section 17, township 13 south, range 29 east. This region 
may be found on the Tehipite Quadrangle of the United States Geo- 
logical Survey. The group includes Nos. 1 to 5. No. 1 was a splen- 
did tree, about 19 feet in its greatest diameter, growing at the upper- 
most limit of the logging area. Its growth was rapid, and yet it 
was an extremely sensitive tree, showing beautiful variations from 
year to year. No. 2 was obtained a little lower down and is mentioned 
here because it has been used as the standard of the whole sequoia 
group, having probably a more perfect record than any other tree 
measured. Its center was about 300 B. C. No. 5 was a small tree 
which was cut just at the time I came within hearing distance. I 
thought that two blasts of dynamite were set off and found afterwards 
that only one charge of dynamite had been used to break through the 
last support of the mighty tree; the other report was the tree itself 
crashing to the ground. Yet this was a small tree, only some 12 feet 
in diameter, and its age was about 700 years. It proved of particular 
value to the whole sequoia group, because it was the only tree on which 
was obtained the ring of the current year, thus permitting a very 
important correction to be made in the dating of rings. This had an 
important bearing on the relationship of rings to rainfall. 
The second group included Nos. 6 to 11, and was made about a 
mile to the north and 700 feet lower altitude in the swampy basin whose 
outlet was similarly toward the northeast. No. 6 grew at the edge 
of the little brook running through the basin and its rings proved later 
very uncertain in identity, because its habit was complacent, 7. e., the 
rings were nearly all alike in size.1 No.7 was an improvement on it, 
and No. 8, which was still farther from the creek, was perhaps the best 
of this group of 6. It gave a very fine cross-identification with the first 
group. No. 11 was also very close to the creek near the outlet of the 
basin and, as with No. 6, it was impossible to be sure of the identifica- 
tion, owing to its complacent character. 
The third group consisted of 4 trees from Indian Basin, about 10 
miles northwest of the Redwood Basin and 3 miles north of Hume. 
This basin is a broad, flat, fertile area with an outlet toward the 
northeast. Four trees were obtained there which Huntington had 
already counted. Nos. 12 and 13 came from the flat middle area of the 
basin. No. 12 was not included in the final averaging because its rings 
1Since the trip of 1919 the identification of No. 6 has been fully established. 
