180 
son, the result was so important that it seemed 
necessary to test it further, by means of sim- 
ultaneous independent observations held at 
Mount Wilson and some other high altitude 
station remote from there, where an equally 
cloudless atmosphere existed. These dupli- 
cate observations would eliminate all errors 
due to local atmospheric conditions. Mr. 
Abbot made complete determinations of the 
solar constant of radiation for forty-four days, 
in Bassour, while his assistant, Mr. L. B. 
Aldrich, made similar measurements at Mount 
Wilson, Cal. The two observing stations 
were separated by a distance nearly equal to 
that of one third the circumference of the 
earth. Unfortunately some cloudy weather 
was encountered at each of the stations, but 
the records of about thirty days will be avail- 
able for comparison. If it seems necessary to 
make additional measurements it will be pos- 
sible to continue the work this year, during 
June, July and August. 
More than 200,000,000 barrels of oil, with 
a value of nearly $128,000,000, were produced 
in the United States last year, according to 
David T. Day, of the United States Geological 
Survey, in an advance chapter on petroleum 
from ‘Mineral Resources of the United 
States ” for 1910. The petroleum industry in 
the United States, says Dr. Day, has been 
characterized by a phenomenal increase each 
year for the last four years. Each year’s gain 
over that of the year before has been so re- 
markable as to lead to the belief that the 
limit of production had been reached, but the 
increase has continued rapidly. After vary- 
ing between 50,000,000 and 60,000,000 barrels 
annually in the decade between 1890 and 
1900, the. oil output was over 63,000,000 bar- 
rels in 1900 and increased to 88,000,000 bar- 
rels in 1902. In 1903 it passed the 100,000,- 
000-barrel mark, in 1904 it was over 170,000,- 
000 barrels, and in 1905 nearly 135,000,000 
barrels. After a slight decline in 1906 the 
output rose again, in 1907 reaching 166,000,- 
000 barrels. It was 178,000,000 barrels in 
1908, 183,000,000 barrels in 1909, and 209,556,- 
048 barrels in 1910, a gain of 14 per cent. 
over the record output of 1909. This brought 
SCIENCE 
[N.S. Vou. XXXV. No. 892 
the total output since the beginning of the 
petroleum industry to more than two billion 
barrels. The United States is now by far the 
greatest oil-producing country; in fact, it 
produces more than all the rest of the world 
together. In 1910 the wells of this country 
yielded nearly 64 per cent. of the total pro- 
duction, Russia scoring a very poor second 
with about 70,000,000 barrels, or 21 per cent. 
The production of other countries is com- 
paratively negligible, the third on the list, 
Galicia, contributing only 3.87 per cent. of 
the total. The excess of the petroleum pro- 
duction of the United States over the normal 
demand is shown by the fact that the 209,- 
556,048 barrels produced in 1910 brought a 
smaller return—$127,896,328—than the 183.- 
170,874 barrels in 1909, which was valued at 
$128,328,497. The even smaller output in 
1908, 178,000,000 barrels, was valued at still 
more—$129,079,184. As the production has 
increased the average price has gone down 
from more than $1 a barrel in 1900 to 61 cents 
in 1910. These repeated great increases in 
oil production have been due to the successive 
development of four great petroleum fields 
farther west than the old productive centers. 
By 1900 the country had adapted itself to the 
influx of oil from western Ohio and Indiana; 
then came in rapid succession the develop- 
ment of the Gulf field in Texas and Louisiana, 
the Mid-Continent field in Oklahoma and 
Kansas, and the Illinois field. Im the mean- 
time California’s production had been in- 
creasing so rapidly that it became the domi- 
nant feature of 1909 and 1910, outstripping 
the production of any other state and prom- 
ising to retain this supremacy in the future. 
The trade effect of these developments was 
largely discounted by the small proportion of 
gasolene and kerosene yielded by the Gulf and 
California oils and it was only when the su- 
perior character of the Mid-Continent oil 
was recognized that the middle western con- 
tributions began to be taken seriously in the 
general trade. Geographic and technical fac- 
tors put California petroleum at a disad- 
vantage compared with the eastern supply, 
