258 
present borders. Malaspina Glacier has 
shrunk more than the Bering, but even 
this is far nearer the maximum than the 
glaciers of Prince William Sound toward 
the west, or those of the Inside Passage to 
the southeast, or those of the interior to 
the north. In the same region with Mala- 
spina Glacier, the expansion of the Nuna- 
tak-Hidden Glacier, of a century or more 
ago, extended to within 10 or 15 miles of 
the earlier maximum. 
From these facts it is evident that lo- 
eally, near the center of the coastal area of 
Alaskan glaciation, the present day gla- 
ciers are only a little short of their former 
maximum. This may be due to recent ex- 
tensive uplift of the mountains in which 
these glaciers have their source, or to other 
Jocal causes; or the entire history of Alas- 
ikan glaciation may be related to changes 
in elevation, and wholly unrelated to those 
causes that gave rise to the development of 
continental glaciation in Europe and east- 
ern North America. We are not now in 
possession of a sufficient body of fact to 
warrant further discussion of this problem. 
CONCLUSION 
This brief analysis makes it clear that 
up to the present time only a beginning has 
been made in the research in the field of 
Alaskan glaciers and glaciation. Hnough 
has been done, however, to show the exist- 
ence of interesting and important prob- 
lems, to permit a few of them to be set 
forth in conerete form, and to discover 
facts that have a bearing upon some of 
them. But there is so much yet to be 
learned, so many more facts are needed, 
there is so wide a field that is wholly un- 
known, and the period of observation is so 
limited that any one who undertakes to 
consider the general problems of this broad 
and complicated field can not but feel ap- 
palled at the limitations surrounding his 
SCIENCE 
[N.S. Vou. XXXV. No. 894 
attempt. At best, with all the help that 
he can obtain from the work of others, he 
can only hope to make a step toward the 
understanding of the conditions and prob- 
lems of this great field. I do not delude 
myself with the belief that in this address 
I have done more than this. 
RaupH §. TARR 
CORNELL UNIVERSITY 
PROFESSOR GEORGE DAVIDSON 
In San Francisco on December 1, 1911, 
Professor George Davidson quietly ended a 
long life of active and valuable service to his 
country. Men of science the world over are 
expressing their sorrow at his passing, but 
everywhere there swells also the strong note 
of pride and satisfaction in the magnificent 
example which he has given of what may be 
accomplished by the devotion of a clean, strong 
life to a chosen field of work. Beginning his 
independent scientific observations in 1843 as 
magnetic observer for Girard College, he de- 
voted sixty-eight years of virile manhood to 
geodesy, geography and astronomy. For fifty 
years of this long period he was uninterrupt- 
edly in the service of the United States Coast 
and Geodetic Survey. Three years after his 
retirement in 1895 from the survey he was 
elected to the professorship of geography in 
the University of California, with which insti- 
tution he was connected to the time of his 
death. This change in his nominal employ- 
ment made, however, no serious break in the 
continuity of his life of study and research. 
The exceptional character of his mental and 
physical virility is strikingly shown by his 
election to the faculty of the University of 
California at the age of 73—eight years be- 
yond the limit usually fixed for the retirement 
of college professors. 
Few men can read the brief sketch which 
follows without some feeling of surprise that 
the life of a contemporary should reach so far 
back into the history of another generation. 
Born in Nottingham, England, on May 9, 
1825, in early boyhood he was brought to the 
United States by his parents, who settled in 
