the issuing of storm warnings, the display of weather and flood
signals for the benefit of commerce, agriculture, and navigation
(see Chapter XVI).

THE FOREST SERVICE has in its keeping the great national forests
(see Chapter XV).

THE OFFICE OF PUBLIC ROADS AND RURAL ENGINEERING administers the
work of the federal government for road improvement, and studies
farm engineering problems such as those relating to sanitation and
water supply (see Chapters XVII and XX).

REGULATORY POWERS OF THE DEPARTMENT OF AGRICULTURE

The Department of Agriculture has certain important powers of
regulation and control. Animals are inspected at market centers to
discover the presence of disease, and localities infected are
quarantined.

In 1915 more than 15 million sheep were inspected and nearly 4
million dipped to cure scabies. As a result nearly one and one
half million square miles of land were released from quarantine.
In the same year more than a million square miles were released
from quarantine against scabies in cattle.

In quarantining a state, or portion of a state, the Department
acts by authority of laws passed by Congress under its power to
regulate interstate and foreign commerce (Constitution, Art. I,
Sec. 8, cl. 3). By the same authority, all cattle for export and
all imported from foreign countries are inspected and those