Transactions of the American Society of Civil Engineers, vol. LXX, Dec. 1910 | Page 2

thousand in
the period 1881-90; and in the last decade this has been further reduced
to nearly 1 per thousand. It seems certain, from the investigations
already made by the Geological Survey, that better means of
safeguarding the lives of miners will be found, and that the death rate
from mine accidents will soon show a marked reduction.
Other statistics collected by the Geological Survey show that, to the
close of 1907, nearly 7,000,000,000 tons of coal had been mined in the
United States, and it is estimated that for every ton mined nearly a ton
has been wasted, 3,500,000,000 tons being left in the ground or thrown
on the dump as of a grade too low for commercial use. To the close of
1907 the production represents an exhaustion of somewhat more than
10,000,000,000 tons of coal. It has been estimated that if the production
continues to increase, from the present annual output of approximately
415,000,000 tons, at the rate which has prevailed during the last fifty
years, the greater part of the more accessible coal supply will be
exhausted before the middle of the next century.
The Forest Service estimates that, at the present rate of consumption,
renewals of growth not being taken into account, the timber supply will
be exhausted within the next quarter of a century. It is desirable,
therefore, that all information possible be gained regarding the most
suitable substitutes for wood for building and engineering construction,
such as iron, stone, clay products, concrete, etc., and that the minimum
proportion in which these materials should be used for a given purpose,
be ascertained. Exhaustion, by use in engineering and building
construction, applies not only to the iron ore, clay, and cement-making
materials, but, in larger ratio, to the fuel essential to rendering these
substances available for materials of construction. Incidentally,
investigations into the waste of structural materials have developed the

fact that the destructive losses, due to fires in combustible buildings,
amount to more than $200,000,000 per annum. A sum even greater
than this is annually expended on fire protection. Inquiries looking to
the reduction of fire losses are being conducted in order to ascertain the
most suitable fire-resisting materials for building construction.
Early in 1904, during the Louisiana Purchase Exposition, Congress
made provision for tests, demonstrations, and investigations concerning
the fuels and structural materials of the United States. These
investigations were organized subsequently as the Technologic Branch
of the United States Geological Survey, under Mr. Joseph A. Holmes,
Expert in Charge, and the President of the United States invited a group
of civilian engineers and Chiefs of Engineering Bureaus of the
Government to act as a National Advisory Board concerning the
method of conducting this work, with a view to making it of more
immediate benefit to the Government and to the people of the United
States. This Society is formally represented on this Board by C. C.
Schneider, Past-President, Am. Soc. C. E., and George S. Webster, M.
Am. Soc. C. E. Among representatives of other engineering societies,
or of Government Bureaus, the membership of the National Advisory
Board includes other members of this Society, as follows: General
William Crozier, Frank T. Chambers, Professor W. K. Hatt, Richard L.
Humphrey, Robert W. Hunt, H. G. Kelley, Robert W. Lesley, John B.
Lober, Hunter McDonald, and Frederick H. Newell.
In view, therefore, of the important part taken both officially and
unofficially by members of this Society in the planning and
organization of this work, it seems proper to present a statement of the
scope, methods, and progress of these investigations. Whereas the Act
governing this work limits the testing and investigation of fuels and of
structural materials to those belonging to the United States, the
activities of the Federal Government in the use of these materials so far
exceeds that of any other single concern in the United States, that the
results cannot but be of great value to all engineers and to all those
engaged in engineering works.
MINE ACCIDENTS INVESTIGATIONS.

Organization, and Character of the Work.--The mine rescue
investigations, carried on at the Federal testing station, at Pittsburg, Pa.,
include five lines of attack:
1.--Investigations in the mines to determine the conditions leading up
to mine disasters, the presence and the relative explosibility of mine gas
and coal dust, and mine fires and means of preventing and combating
them.
2.--Tests to determine the relative safety, or otherwise, of the various
explosives used in coal mining, when ignited in the presence of
explosible mixtures of natural gas and air, or coal dust, or of both.
3.--Tests to determine the conditions under which electric equipment is
safe in coal-mining operations.
4.--Tests to determine the safety of various types of mine lights in the
presence of inflammable gas, and their accuracy in detecting small
percentages of mine