542 DISCUSSION: FORESTS, RESERVOIRS, AND STREAM FLOW 
Mr. Chitten- their thin needles do not make the heavy shade when on the tree, nor 
den. 
the thick mat when lying on the ground, that the broad leaves of the 
oak, beech and maple do. Instead of forming a spongy layer five or 
six inches thick, they are swept about by the wind and it is not un- 
usual to see the ground bare under the trees and all the needles lodged 
somewhere in drifts. Even when they lie where they fall the coat- 
ing is comparatively worthless so far as retaining moisture is con- 
cerned. On the other hand the foliage on this class of trees being as 
heavy in winter as in summer, the branches catch an immense amount 
of falling snow and hold it up in mid air for both sun and wind to 
work upon, and only those who have had experience of the absorbing 
power of the dry mountain air can form any idea of the loss from 
that source. Such as is melted falls upon that beneath, and breaking 
the surface sets in operation forces which are always ready to attack 
such substances. The theory that the shade protects the moisture laden 
soil means but little in such places. The law is doubtless in force 
with more or less strength wherever moisture falls and plants grow, 
but the class of trees that thrive here require a loose, sandy soil, and 
are often seen growing where there is no earth in sight at all clinging 
to the sides of the cliffs, so bare that the roots run along the surface 
entirely uncovered until they reach some crevice which they fill, and 
send tendrils down to draw sustenance from an unseen source. In 
such places the melting snow disappears quickly from the surface, and, 
except for their influence in keeping the soil light and porous so that 
the water can be absorbed readily instead of running off, it_ matters 
but little whether trees are there or not. No moisture remains upon 
the top of the ground long for shade to protect. It goes either into 
the air or else into the ground, and it is a well-known fact that a 
very large portion of water which finds its way down the steep sides of 
the Sierras disappears near its sources and is found again far below, 
either in springs, by means of artesian wells, or in the increased flow 
of the parent stream. Indeed, a number of very respectable rivers, 
not only in the mountains, but in some of the valleys, seem to owe their 
existence to such distant and hidden sources. If the trees have any 
direct power here it seems to be to draw from deep beneath the sur- 
face the moisture which has sunk into the earth and exhale gallons 
and gallons of it hourly. Any good-sized tree has been estimated to 
have a capacity of forty or fifty gallons every twenty-four hours, and 
a forest of such trees would effect very considerable results. 
“I should like to offer the opinion of Captain J. B. Overton, of 
Virginia City, Nevada, just here. He has had control of the water 
supply of that city for many years, and also conducted large opera-. 
tions in the mountains in cutting timber, wood and lumber for the 
mines. His experience covers a quarter of a century and extends 
over several townships of land, from which his men cut the timber. 
He says: 
“My experience proves to me that the wiig of the timber 
makes no difference in the amount of snow that falls, but that it 
drifts more and for that reason lasts about as late in the summer as 
it would before the removal of the shade. I do not think the streams 
get low any sooner or afford any less water. I am of the opinion that 
the trees absorb from the soil quite as much water as would be 
