'Science Finally Sets 
I Bate of Pueblo Glory > 
j ———— —— — — < 
Civilization of Indians 
Flourished in 1067, 
Searchers Learn. 
The" curtain which has hidden the 
most baffling riddle of pre-Columbian 
| history of the United States—the 
dates of the building of scores of 
Important Indian ruins of the South¬ 
west—has been tom away by the 
: National Geographic Society, it is 
just announced, thereby effecting one 
of the greatest scientific discoveries 
j of the year. 
The key to, the problem was the 
J tree-ring calendar, together with the 
\ sun spots, dating back 1,200 years to 
1 700 A. D., when even the most ad¬ 
vanced scientists and explorers didn’t 
even suspect the existence of the 
vast American continents. 
The quest has been the work of 
years, involving two series of expedi¬ 
tions, and including the study of 
5,000 cross sections of living trees 
and timbers .In the ruins of wh&t 
constitutes probably the oldest Indian 
settlements in this country. The 
civilization of the giant apartment 
houses at Pueblo Bonito, New Mex., 
and at many other historic Indian 
ruins has long been known, but 
, archeologists have never heretofore 
I been able to answer the question: 
i “How old is it?” 
The variation of rainfall in the 
arid Southwest caused such marked 
, differences in the 'tree rings that 
• "certain sequences of years became 
i easily recognizable from tree to tree, 
county to county, even from State 
j to State,” according to Dr. A. E. 
*■ Douglass, who headed one of the 
k exploration parties, 
f “Just as the far-famed Rosette 
l Stone provided the key to the written 
NEIL M. JUDD. 
mysteries of ancient Egypt, so the 
collection of an unbroken series of 
tree rings has made clear the chron¬ 
ology of the Southwest,” Dr. Douglass 
said. 
“These researches have provided I 
the beginnings of & continuous : 
weather chart for 1,200 years. ) 
T" —gli this work we have learned : 
of some of the outstanding events ; 
In America which were contempora- , 
neons with the conquest of Spain by , 
the Moors, and we know that certain 
Pueblo Indian settlements were en¬ 
joying their golden ages when Will¬ 
iam the Conqueror faced Harold the 
Saxon at the Battle of Hastings. 
“The earliest beam we recovered 
from Pueblo Bonito was cut A. D. 
919 from a tree that was 219 years 
CONTINUED ON PAGE 4, COLUMN 4. 
r 
CONTINUED PNOM PAGE 1. 
old when Cut. Pueblo Bonito had 
reached its golden age in 1067 and 
was still occupied in 1127.” 
In many instances. Dr. Douglass 
report points out, one group name 
Is applied to several ruins. The “taik-j 
ative tree rings”- enabled the ex¬ 
plorers to date each ruin of the 
grOup Studied. Thus, in the Mesa 
Verde group, Cliff Palace is dated 
1073: O'h Tree House, liig; Spring 
House, 1115: Balcony House. 1190- 
1206: Square Tower HOuse, 1204, and 
Spruce Tree House. 1216 and 1262 
Speaking of the tree-ring calendar 
Dr. Douglass Said: “The ' method 
which we have Used in extending the 
historical calendar to the. Southwes' 
is the outcome of. a long attempt tc 
read the diaries of trees. A tree is 
hot a mechanical robot: it is a living 
thi:.g. and its food supply and ad¬ 
ventures through life all enter into 
its diary.'' 
T-j influence of s"- spots 6a ( 
weather has long been admitted; j 
hence their effects are registered in 
trees. 
Dr. Douglass found in Arizona pines 
evidence of ah eleven-year spot cycle 
for 500 years, except for an interval 
from 1650 to 1725. Puzzled at first, 
the explorer was gratified later when 
b English astronomer who was un¬ 
aware of this finding wrote him that 
there were ho sun spots between 1645 
and 1715,''thus establishing conclu¬ 
sively the accuracy of the tree diaries' 
The second series of expeditions, di- 
•ided into eight groups,' led by Neh 
M Judd, Were occupied chiefly in un¬ 
covering hundreds of art objects, 
tousehold utensils, and ceremonial - 
ppurtenances by digging up the > 
ruins of Pueblo Bonito in the Chaco 
Canyon . 
‘ In commenting on the significance i 
of the discoveries, Dr Gilbert Gros- \ 
'ehor, president of the National Geo- 
i graphic Society, said: 
s “A collateral finding of great inter¬ 
est yet to be developed is the possible 
,(relation between the weather cycles 
< clearly reveald in this tree-ring calen- 
j. , hr, of the southwestern United States 
id similar cyclic variations being fe¬ 
nded by a third National Geographic 
ciety expedition (in conjunction 
th the Smithsonian Institution) ah 
pedition Which still, is ifj the field 
a Mount Brukkafos. Southwest Af¬ 
rica. making daily observations 6f so¬ 
lar radiation ’* 
