32 SOUTHERN CALTFORNIA ACADEMY. OF SCLENGES 
has ascertained that the primary is itself a spectroscopic 
double with a period of four days, and a high velocity of reyo- 
lution round a common center of gravity. Third, these two 
bodies appear to be moving in a large orbit, comparable to 
that of Jupiter, round a third massive, dark body, whose ex- 
istence is inferred from the otherwise unaccountable pertur- 
bations of the primary which has alternate motions in the line 
of sight of advance towards, and recession from, our own sys- 
tem. Finally, the bright companion, immensely more distant, 
slowly circling in a vast orbit about the other three bodies. 
Thus the familiar North Star, which to the unaided eye is a 
single point of heht, becomes a double with a bright compan- 
ion in a telescope of moderate power, then the spectroscope 
reveals the dupleity of the brighter component, and further 
research transforms the latter into a triple system consisting 
of one bright and two dark bodies, and around all three re- 
volves the bright telescopic companion—altogether forming an 
exceedingly complex quadruple star. 
Tree Growth and Sun Spots 
The meeting of December 30 was reported as follows in the 
Evening News 
Exceedingly interesting was the session of the astronomical section 
of the Academy of Sciences held last evening at the residnece of Treas- 
urer S. J. Keese, whose pleasant parlors were thrown open for the 
occasion. After several views of Lake Tahoe and vicinity were exhib- 
ited by Mr. Keese, Chairman William H. Knight introduced Prof. BE. A. 
Douglass of the University of Arizona, formerly assistant astronomer 
of the Lowell Observatory at Flagstaff, where he engaged in original 
research work of a novel nature. 
Here Professor Douglass becaine deeply interested in tree growth as 
attsted by the annular rings disclosed in cross-sections of giant pins 
from 300 to 500 years old. By examining the cross-sections of many 
large logs, the professor was enabled to compare them with each other, 
and note the fact that all alike showed large growth in the years 
following rainy seasons, and meager growth in dry seasons. He thus 
found a sure criterion of rainy inl ee years for periods reaching back 
to the century before Columbus discovered America. 
Finally, searching for the cause of that periodicity, he noted the fact 
that it accorded fairly well with the alternating maximum and minimum 
sun spot periods, thus bringing out the hidden relations of sun spot 
activities, seasons of unusual rainfall, and vigorous or feeble tree 
growth. W. A. Spalding, who has been engaged in noting the corre- 
spondence between sun spot activity and seismic disturbances, regarded 
the discovery of Professor Douglass as a remarkable corroboration of 
his own views as expressed in a lecture given before the academy 
several months ago. 
B. R. Baumgardt, president of the academy. who has recently returned 
from Europe, received an ovation from the club. He spoke at length 
of many of the interesting astronomical relics he had seen in Europe. 
