Instructions to rain-fall observers of U.S. Geological Survey

In the prosecution of the general "survey of the arid lands for purposes of irrigation," authorized by Congress to be undertaken by the U. S. Geological Survey, a determination of the amount of water supplied by the natural rain and snow fall in different localities is of fundamental importance. To obtain this knowledge the Geological Survey must depend in large measure upon the residents, to whom the benefit of the work will accrue, for their voluntary cooperation in making; the necessary observations.