planning further changes in the direction of conservation. Conservational measures do not all require sacrifice of the individual to the public, nor of the present to the future generations. An exercise of public power is not in all cases essential to the advancement of conservation. The respective limits of the fields of public and private endeavor are not sharply defined, and vary from place to place and time to time, depending upon local conditions and special requirements.
In general, the sphere of private interest includes measures which will bring adequate commercial return. The interest rate is the limiting and controlling factor. When it is possible—by improvement of methods of mining, better planning, better preparation of coal, better transportation and distribution, or better utilization—to secure a larger average return on the investment, or to insure return through a longer period of years, self-interest naturally requires the introduction of such methods as rapidly as financial conditions allow.
Even some of the improvements in labor and welfare conditions have been introduced in this way, with a view to securing a more permanent and more efficient labor supply, and thereby aiding the enterprise from the commercial standpoint.
Within the sphere of government activity lie the removal of unnecessary restrictions on private initiative, and such conservation measures as involve some sacrifice of individual returns—in other words, a reduction of the normal interest rate. Exercise of government power may be directly helpful within the field of private endeavor without materially sacrificing private interests; but beyond this point there are additional large possibilities of conservational activity which are clearly beyond the control of private interests. The introduction of any of these latter changes would evidently be so far-reaching in effect, and would require such broad readjustments not only within but without the mineral industry, that the necessity or desirability is not in all cases so clear as in the case of measures already introduced for private interest.