The first four of these lines of investigation have to do with
preventive measures, and are those on which ultimately the greatest
dependence must be placed. The fifth is one in which the result seems at
first to be the most apparent. It has to do, not with prevention, but
with the cure of conditions which should not arise, or, at least, should
be greatly ameliorated.

During the last 19 years, 28,514 men have been killed in the coal-mining
industries.[2] In 1907 alone, 3,125 men lost their lives in coal mines,
and, in addition, nearly 800 were killed in the metal mines and quarries
of the country. Including the injured, 8,441 men suffered casualties in
the mines in that year. In every mining camp containing 1,000 men, 4.86
were taken by violent death in that year. In the mining of coal in Great
Britain, 1.31 men were killed in every 1,000 employed in the same year;
in France, 1.1; in Belgium, 0.94, or less than 1 man in every 1,000
employed. It is thus seen that from three to four times as many men are
being killed in the United States as in any European coal-producing
country. This safer condition in Europe has resulted from the use of
safer explosives, or the better use of the explosives available; from
the reduction in the use of open lights; from the establishment of mine
rescue stations and the training with artificial breathing apparatus;
and from the adoption of regulations for safeguarding the lives of the
workmen.

The mining engineering field force of the Geological Survey, at the head
of which is Mr. George S. Rice, an experienced mining and consulting
engineer, has already made great progress in the study of underground
mining conditions and methods. Nearly all the more dangerous coal mines
in the United States have been examined; samples of gas, coal, and dust
have been taken and analyzed at the chemical laboratories at Pittsburg;