a change in surface conditions. Cultivated ground allows a much greater absorption than wild prairie soil, and therefore holds in storage and conserves the supply for springs and streams after flood seasons have passed. It is therefore probable that the extension of the methods of civilization has slightly reduced the intensity of floods in the plain regions, notwithstanding the cutting away of forests. It may be that deforestation has increased the intensity of floods in small constricted areas of mountain districts, which are usually small in comparison to the total area of each watershed; but where forests are cleared and kept clear, the hand of the husbandman keeps the surface so broken and permeable, or so covered with growing vegetation, that it is about as good a conserver of the rainfall as the forest- covered regions, and, except in areas too small to have an important effect on floods, Nature will at once begin to reforest a region that has been cleared. Certain it is that the hydrographs of the principal rivers of the United States do not show that the high waters are higher now or longer continued, or that the low waters are lower or of longer duration than they were half a century ago.
ABBE CLEVELAND, "Preparatory Studies for Deductive Methods in Storm and Weather Predictions," Washington, 1890. (United States Signal Office, Annual Report of the Chief Signal Officer for 1889. Appendix 15.)
BEBBER W. J. VAN, "Handbuch der ausübenden Witterungskunde. Geschichte und gegenwärtiger Zustand der Wetterprognose," Stuttgart, 1885-86, 2 vols. Vol. 1 is a history of weather forecasting from the earliest times; Vol. 2 an exposition of modern theory and practice.
GARRIOTT E. B., "Long-range Weather Forecasts," Washington, 1904. ( United States Weather Bureau, Bulletin 35.)
GARRIOTT E. B., "Weather Folklore and Local Weather Signs," Washington, 1903. ( United States Weather Bureau, Bulletin 33.)
MOORE WILLIS L., "Weather Forecasting: Some Facts Historical, Practical, and Theoretical," Washington, 1899. ( United States Weather Bureau, Bulletin 25.) Reprinted from The Forum, May, 1898.
SCOTT ROBERT II., "Weather Charts and Storm Warnings," 3d ed., London, 1887.