effort to secure adequate
supplies of timber from the farm woodlands, sawmills and logging
camps. The automobile industry now uses considerable hickory in
the wheels and spokes of motor cars.

Most of the stock used by the vehicle industry is purchased
green. Neither the lumber nor vehicle industry is equipped with
enough kilns for curing this green material. The losses in
working and manufacturing are heavy, running as high as 40 per
cent. Many substitutes for ash, oak and hickory have been tried
but they have failed to prove satisfactory. On account of the
shortage and the high prices of hickory, vehicle factories are
using steel in place of hickory wherever possible. Steel is more
expensive but it can always be secured in quantity when needed.
Furthermore, it is durable and very strong.

Thus we see that our resources of useful soft woods and hard
woods have both been so diminished that prompt reforestation of
these species is an urgent necessity.

CHAPTER VI

THE GREATEST ENEMY OF THE FOREST--FIRE

Our forests are exposed to destruction by many enemies, the worst
of which is fire. From 8,000,000 to 12,000,000 acres of forest
lands annually are burned over by destructive fires. These fires
are started in many different ways. They may be caused by sparks
or hot ashes from a locomotive. Lightning strikes in many forests
every summer, particularly those of the Western States, and
ignites many trees. In the South people sometimes set fires in
order to improve the grazing. Settlers and farmers who are
clearing land often start big brush fires that get out of
their control. Campers, tourists, hunters, and fishermen are
responsible for many forest fires by neglecting to extinguish
their campfires. Sparks from logging engines also cause fires.
Cigar and cigarette stubs and burning matches carelessly thrown
aside start many forest fires. Occasionally fires are also
maliciously set by evil-minded people.

The officers of the National Forests in the West have become
very expert in running down the people who set incendiary fires.
They collect evidence at the scene of the fire, such as pieces of
letters and envelopes, matches, lost handkerchiefs and similar
articles. They hunt for foot tracks and hoof marks. They study
automobile tire tracks. They make plaster of Paris impressions of
these tracks. They follow the tracks--sometimes Indian fashion.
Often there are peculiarities about the tracks which lead to the