88 
And then that, though there is a strong parallelism of 
the Treves-growth with that of other parts of the region 
investigated, this parallelism is not in any way perfect. 
J do not give the facts brought out in this lecture as 
well established proof of a regularity in the weather. The 
only thing [I would claim for them is that they are full 
of promise. 
And they lead us to put definite questions, which in 
my opinion is one of the main points in scientific research. 
To take one instance: what does the fact mean that this 
12l/, years period may disappear in one place, and the 
same time clearly show in another? 
VIII. And now, to bring this talk to a close, a few 
words about the particular fitness of California for this 
particular branch of research. (California has many trees, 
but especially California has her very very old trees. 
Think of the enormously improved chances of success if 
our series instead of embracing 2 centuries, would embrace 
ten times as long a time. Now trees of 2000 years must 
exist here. Î was even told that actual count of the rings 
has proved the existence of trees of 4000 years! That 
is, provided that we admit that, here in California too, 
there never grows more than one ring in a year. À single 
tree of such an age, if favorably situated, | mean situated 
in such a position and in such a soil that it proves to be 
especially sensitive to some of the meteorological factors, 
or at least showing large fluctuations, may prove a real 
gold mine for the meteorologist. Through the courtesy 
of Prof. Mc Adie of San Francisco, I am anabled to 
show the representation of the rings of a Sequoia of 1244 
years old. 
Several of the principal historical events have been noted 
against the rings that grew at those times. The drawing 
cannot be well seen from your places, but those that are 
interested may see it after the lecture. 
