tuation, until after a discovery or
development has brought them face to face with it.

Because of the vital importance of the reserve factor in mineral
valuation, geologic aid and advice are extensively sought by both public
and private organizations. Mining geologists are playing an important
part in the application of the national income tax. A larger number are
acting for private companies in appraisals required by this tax. Many
geologists are used in making valuations for state taxes, and in two
cases the state geological surveys have complete charge of appraisals.
These appraisals include not only examinations of specific properties,
but general surveys of large regions, to ascertain possible values of
undeveloped lands and to establish broad principles of valuation based
on a consideration of all the physical factors in the situation.

CHAPTER XVI

LAWS RELATING TO MINERAL RESOURCES

This heading is likely to suggest mining law and the vast literature
devoted to it. Mining law has mainly to do with questions of the
ownership and leasing of mineral deposits. In addition, there are laws
relating to the extraction of mineral products, including those having
to do with methods of mining and with safety and welfare measures. There
are laws affecting the distribution of mineral products, such as those
relating to tariffs, duties, international trade agreements, and many
other matters. There are laws relating to underground water, to shore
lines, and to various geologic engineering fields.

In the formulation of these laws, as well as in the litigation growing
out of their infraction, basic geologic principles are involved; and
thus it is that the geologist finds much practice in the application of
his science to legal questions. It will be convenient to consider some
of the laws relating to mineral resources under three headings: first,
ownership and control; second, extraction; and third, distribution.

I

LAWS RELATING TO OWNERSHIP AND CONTROL OF MINERAL RESOURCES

Large use of mineral resources is of comparatively recent date. Some of
the mineral industries are not more than a decade or two old and the
greater number of them are scarcely a century old. In the United States
the mineral industry dates mainly from the gold rush to California in
1849. The formulation of laws relating to the ownership of minerals has
on the whole followed rather than preceded the development of the
mineral industrie