There writers insist much on the necessity of taking into account, in estimating the relations between precipitation and evaporation, the abstraction of water from the surface and surface-currents, by absorption and infiltration an element unquestionably of great value, but hitherto much neglected by meteorological inquirers, who have very often reasoned as if the surface-earth were either impermeable to water or already saturated with it; whereas, in fact, it is a sponge, always imbibing humidity and always giving it off, not by evaporation only, but by infiltration and percolation.

The surface-earth around the trunk of a tree may be made almost impervious to water, by flagstones and cement, for a distance as great as the spread of the roots; and yet the tree will not suffer for want of moisture, except in droughts severe enough sensibly to affect the supply in deep wells and springs.

These, with their curves, can be carefully staked out, the surface-earth between the stakes to the depth of four or five inches carted to the rear of the place near the stable, or the place where the stable is to be. Of the value of this surface-soil we shall speak presently, and will merely remark in passing that it is amply worth the trouble of saving.

The mountains are very high and steep about Carson, Eagle and Washoe Valleys very high and very steep, and so when the snow gets to melting off fast in the Spring and the warm surface-earth begins to moisten and soften, the disastrous land-slides commence.

In the course of ten minutes part of the layer of surface-earth was removed, revealing the bluish-clay soil in which gold was usually found; the pan was filled with this "pay-dirt," as it was called, in contradistinction to the "surface-dirt," which didn't "pay," and was taken down to the stream, where Larry washed it out under the eye of McLeod; but he did it clumsily, as might be expected, and lost a considerable amount of valuable material.

The roof of the entrance is at first a mere shell, formed by the thin crust of rock on which the surface-earth and trees rest high overhead; but this rapidly becomes thicker, as shown in the section of the cave, and thus a sort of outer cave is formed, the real portal of the glacière being reached about 60 feet above the bottom of the slope.

The mountains are very high and steep about Carson, Eagle and Washoe Valleys very high and very steep, and so when the snow gets to melting off fast in the Spring and the warm surface-earth begins to moisten and soften, the disastrous land-slides commence.