PRINCIPLES OF COMMERCIAL GEOGRAPHY 109
life-saving service, gives weather and flood warnings, maintains
lighthouses and signal stations, and sets up a quarantine. It
guards against the migration and importation of pests, as is illus-
trated by the presence on the plains of Canada of officers whose
duty is to enforce laws for the suppression. of noxious weeds.
The attempted extermination of the gypsy moth by the state of
Massachusetts is a further example, as is the stringent control
exercised by the Department of Agriculture over the foot and
mouth disease by which the cattle and dairy industry is threat-
ened. Under this head falls sanitation, as organized by govern-
ment authority at Habana, Panama, and Manila.
Government also promotes transportation. It gathers scien-
tific information dealing with routes, practicable roadways, the
resources of adjacent territory, and the development of termi-
nal points. The Pacific Railway surveys of the decade 1850-
1860 offer an example, and also the land grants made to the
Union Pacific and other transcontinental roads in the years of
construction following the Civil War. Governments often sub-
sidize lines of marine shipping, and they have given much aid
in the construction of canals. River and harbor improvements
belong under this class of government activities affecting com-
merce, as does the extensive development of earth roads and
highways. Great Britain, Norway, Switzerland, France, Italy, or
indeed any advanced European nation, is conspicuous for its
building of roads; and the United States, though far behind
in this particular sphere, owing to the newness of the country,
is now extending this important aid to commercial operations.
Government mails and telegraphs are further factors in trade.
Governments constantly investigate natural resources, such as
mines, soils, and climate. It is enough to name, in the United
States, the Department of Agriculture, with its Soil Survey, its
Bureau of Plant Industry, its experiment stations, and other activ-
ities ; or the United States Geological Survey, its topographic
mapping, and its study of general and economic geology. In
addition may be named the Reclamation Service, for irrigating
the arid lands: and the Forest Service, for forest protection
