The rain gauge records of the country have been made but for a brief period, and the stations have been widely scattered, so that no very definite conclusions can be drawn from them, but so far as they are of value they fail to show any increase. But if it be true that increase of the water supply is due to increase in precipitation, as many have supposed, the fact is not cheering to the agriculturist of the Arid Region. The permanent changes of nature are secular; any great sudden change is ephemeral, and usually such changes go in cycles, and the opposite or compensating conditions may reasonably be anticipated. For the reasons so briefly stated, the question of the origin and permanence of the increase of the water supply is one of prime importance to the people of the country. If it is due to a temporary increase of rainfall, or any briefly cyclic cause, we shall have to expect a speedy return to extreme aridity, in which case a large portion of the agricultural industries of the country now growing up would be destroyed. The increase is abundantly proved; it is a matter of universal experience. The observations of the writer thereon have been widely extended. Having examined as far as possible all the facts seeming to bear on the subject, the theory of the increase of rainfall was rejected, and another explanation more flattering to the future of agriculture accepted. The amount of water flowing in the streams is but a very small part of that which falls from the heavens. The greater part of the rainfall evaporates from the surfaces which immediately receive it. The exceedingly dry atmosphere quickly reabsorbs the moisture occasionally thrown down by a conjunction of favoring conditions. Any changes in the surfaces which receive the precipitation favorable to the rapid gathering of the rain into rills and brooks and creeks, while taking to the streams but a small amount of that precipitated, will greatly increase the volume of the streams themselves, because the water in the streams bears so small a proportion to the amount discharged from the clouds. The artificial changes wrought by man on the surface of the earth appear to be adequate to the production of the observed effects. The destruction of forests, which has been immense in this country for the past fifteen years; the cropping of the grasses, and the treading of the soil by cattle; the destruction of the beaver dams, causing a drainage of the ponds; the clearing of drift wood from stream channels; the draining of upland meadows, and many other slight modifications, all conspire to increase the accumulation of water in the streams, and all this is added to the supply of water to be used in irrigation.