510 on the paradox of value.] [Footnote 6: That is, "the amount which can be developed upon the basis of the flowage of the streams for a period of two weeks in which the flow is the least," all the rest being allowed to escape unused.
Van Hise, "Conservation of Natural Resources," p.

119.] [Footnote 7: These and other figures in this section relate to the year 1913.] [Footnote 8: Coal has been mentioned above, sec.

9.].