... already existing, mitigate the extremes of atmospheric temperature, humidity, and precipitation, restore dried-up springs, rivulets, and sources of irrigation, shelter the fields from chilling and from parching winds, arrest the spread of miasmatic effluvia, and, finally, furnish a self-renewing and inexhaustible supply of a material indispensable to so many purposes of domestic comfort, and to the successful exercise of every art of peace, every destructive energy of war. [Footnote: The preservation of the ... — The Earth as Modified by Human Action • George P. Marsh