White Bluffs spokesman. [volume] (White Bluffs, Wash.) 1907-1938, 1927-06-17
TREE RINGS CLEWS TO
HISTORY AND WEATHER
Life Story Is Revealed in
Own Cross-Section.

gtOn.-AnnOuncement by Or.
A. q. Douglass of the University Of
Arizona that the study of the sequence
of tree rings is likely to be of value
in longtime weather forecasting re-
calls that tree rings already have fur
nished valuable clews to dating pre-
Columbian history of America.
This method was used in con1unc-
ton with pottery types in fixing the
time when Pueblo Bonito, New Mex
leo, fourished as the metropolis OF
America in the years before l492.
Trees Our Oldest Inhabitants.
DR.. Neil M. Judd, leader Of the Ma
tional Geographic society expeditions
to Pueblo Bonito, with whom Doctor
Douglass elaborated in applying his
method to the Pueblo Bonito ruins,
writes:
1.-THE Oldest living things in Amer
lea are its big trees, the sequoias of
the Sierra Nevada. The pines and
jumpers of Arizona and New Mexico.
are much younger than the sequoias;
but, like the latter, they are older
than any other living thing in their
own neighborhood. Some of these up
land trees are between four hundred.
and five hundred years Of age, and it,
is not at all improbable that still old
er ones may be found.
1.-THE life history of almost every
tree is revealed by its own-cross sec
ton, this years growth being record
ed by new ring. If any given year
has been one Of scanty rainfall, the
particular ring for that year will be
relatively thin; and, conversely, If the
rainfall has been abundant, there will
be corresponding increase in the
thickness of the annual ring.
periods of drought or excessive
moisture, it has been learned, tend to
repeat themselves at fairly regular In
tervals, resulting thus in more or
less orderly sequence of thick and thin,
annual rings which do not vary, to
any marked degree, in all the trees
of any one district.
Certain of these ring series pos
sesses individual features that quick
ly identify them, no matter in what
locality they may be found, and these
are naturally utilized by the investi-
gator as keys to the problem he is
seeking to solve. And what is true of
living trees is likewise true of dead
trees, and beams or roofing timbers
from prehistoric ruins, like Pueblo
Bonito.
'From the foregoing it will be OBJ
vious that If any overlapping series
of annual rings can be discovered
that is, If given sequence Of rings
can be found both in beam from,
Pueblo Bonito and in tree still liv-
ing-it will be possible to date the
former with reasonable exactness.
Tree Calendars missing Link"
"Such a direct connection, however,
with no intervening links in our time
chain from the beams of prehistoric
Pueblo Bonito to the living trees Of
northern New Mexico, is rather be-
yond the range Of possibilities; the
explorers task is rarely quite so easy
as that.
sit seems necessary, therefore, In
the present case, to find connecting
link in this time chain, and that was
the especial object Of subsidiary .ex-
petition authorized by the research
committee Of the National Geographic
society in connection with the explora-
ton of Pueblo Bonito.
cootiorc froy,o 40
earthed during the explorations Of two,
seasons we're examined by Doctor
Douglass with very instructive re-
suits. These beams, taken from the,
eastern portion of Pueblo Bonito, air
seem to have been cut within period
of IL years. I
"Some timbers exposed in the north
western quarter of the ruin, however,
were cut several years earlier, thus
corroborating the archaeological evil
dence previously presented"