ested,
"snow has to be measured, as well as rain."

"Certainly," the Forecaster answered, "otherwise we wouldn't be able to
tell the precipitation of a region at all. There is a regular instrument
for it, called a shielded snow-gauge. This is like a rain-gauge, boys,
only it stands ten or twenty feet above the ground, to avoid surface
drifting. The snow caught is melted and expressed as so many inches of
precipitation. Sometimes the depth of snow is measured by thrusting a
measuring stick down to the ground.

"Of course, that's not nearly all that the Weather Bureau has to do with
snow. In the northern states, especially of the Pacific Coast, snow
surveys are of great importance. The Weather Bureau often sends men to
determine the amount of snow that has fallen over a given area, in order
to find out how much water may be expected. This is needed in flood
forecasts and irrigation projects. Some of our men, boys, can tell you
thrilling tales of their expeditions on snow-shoes up snow-covered
slopes where there is never a trail.

"Railroads whose tracks run through the regions of heaviest snowfall
build snowsheds to keep their lines from being buried in avalanches, and
these sheds are built to withstand pressures calculated by the Weather
Bureau. Where drifting occurs and the railroad tracks are being covered
with the drifting snow, it is the combined snow and wind records of the
Weather Bureau which form the basis for the work of the
rotary-snow-plow.

"Even so, boys, the value of the work of the Weather Bureau in snow
surveys is very small compared with the importance of frost warnings.
These save the country tens of millions of dollars every year,
especially in the fruit sections."

"You mean by smoking them?" queried Ross. "Father heard about that a
couple of years ago and bought a lot of fire-pots for his orchard."

"How did he succeed?" asked the Forecaster.

"He didn't succeed at all," the boy answered. "There were only two bad
frosts that spring, and both times the evening before had been so warm
that no one suspected that there would be frost before morning. The one
night that he did start the fires, it turned warm towards midnight and
we wouldn't have needed the fires any way. Old Jed Tighe, who's got the
biggest fruit farm here, has made fun of Father's fire-pots ever since."

"Now, if your father had received the Weather Bureau's frost warnings in
advance," the Forecaster said, "he wouldn't have waste