260 
of the National Academy of Science in 1874, 
and many others. He was president of the 
Geographical Society of the Pacific since its 
organization in 1881. He received the degree 
of Ph.D. from Santa Clara College in 1876; 
Se.D. from the University of Pennsylvania in 
1889, and LL.D. from the University of Cali- 
fornia in 1910. Norway conferred upon him 
the Cross of the Royal Order of St. Olaf in 
1907, and the American Geographical Society 
awarded him the Charles P. Daly medal in 
1908. 
In California he was frequently called upon 
to give advice in the great engineering prob- 
lems of San Francisco and of the state. He 
served as regent of the University of Cali- 
fornia from 1877 to 1884, and was a member 
of many state commissions. It was largely 
through his suggestion and influence that 
James Lick finally decided to build and endow 
the great Lick Observatory. 
Professor Davidson is also favorably known 
for his accurate astronomical work. He was 
in charge of the solar eclipse expedition to 
Alaska in 1869 and took his 63-inch equatorial 
to the top of Santa Lucia (over 6,000 feet) 
to observe the total eclipse of 1880. He had 
charge of the American Transit of Venus 
Expedition to Japan in 1874 and of the party 
to New Mexico for the transit of 1882. The 
Davidson Observatory in Lafayette Park, San 
Francisco, where he made many valuable ob- 
servations, was established and maintained by 
him for twenty years. His remarkably fine 
drawing of Saturn is a monument to his acute 
eyesight and to his delicate skill in delineation. 
The name of Davidson is inseparably con- 
nected with the foundations of accurate map 
work in the state of California. His long 
study of the coast line is embodied in the 
many survey charts and in the final edition of 
his “Coast Pilot,” which was published in 
1889. The north-flowing current now known 
as the Davidson inshore eddy, was discovered 
by him and studied particularly in regard to 
its effect upon harbor improvements. 
The only base lines in California, the lines 
upon which all the distances involved in the 
extensive triangulation of the state depend, 
SCIENCE 
[N.S. Vou. XXXV. No. 894 
were located and accurately determined by 
Professor Davidson, the Yolo base line being 
twice measured by him in 1881 and the Les 
Angeles base line three times in 1888-89. A 
recent report of the Coast and Geodetic Sur- 
vey puts the probable error in this work as 
about the one-ten-thousandth part of one per 
cent. The location of the northeastern boun- 
dary line of California, the 120th meridian, 
was finally determined by him in 1873, and the 
diagonal boundary of 405 miles from Lake 
Tahoe to the Colorado River was located and 
marked under his supervsion in 1893. This 
line is interesting because at each end it ter- 
minates in a body of water. 
This fragmentary account affords but an 
imperfect idea of the breadth and scope of the 
work of Professor Davidson. The fact that 
in all the many problems of his main work his 
scientific accuracy stands practically unchal- 
lenged is due to his wonderful capacity for 
untiring effort, to his acute eyesight as an 
observer, and to his fixed habit of patiently 
and conscientiously verifying every observa- 
tion. 
In the seventies, when reoccupation of some 
of his old stations by later parties threw some 
doubt on his observations fixing the exact 
position of Mt. Tamalpais, he boldly asserted 
that his work was right, that the mountain 
might have moved, but that he had correctly 
determined its location at the time. After 
the earthquake of 1906 there was made a care- 
ful and extensive survey of central California, 
which, compared with the surveys before and 
after the earthquake of 1868, confirmed the 
accuracy of Professor Davidson’s original ob- 
servations and also his explanation of the 
apparent discrepancies. 
Simple and unassuming in appearance, he 
bore the mark of one accustomed to command, 
and possessed a strong and dominating person- 
ality. The men who served under him learned 
at once to obey unquestioningly his slightest 
order, yet his warm-hearted and generous 
nature caused them to be strongly attached to 
him. It has been said that his life work 
extended through sixty-eight years of active 
manhood, and rightly so, although one in- 
