meant by a tubular boiler?--by a forced draught?--by a
switch?--by an automatic coupler?

Ascertain from a railway official the various danger-signals as
indicated by lights, flags, and whistle-blasts.

Why should not crated furniture and coal have the same freight rate?

What is meant by a pool?--by long haul and short haul?--by rebate?

If the rate on a given weight of merchandise is one dollar and fifty
cents for five miles, should it be three hundred dollars for one
thousand miles?

FOR COLLATERAL READING AND REFERENCE

Hartley's Railroad Transportation.

American Railways.

[Illustration: DISTRIBUTION OF VEGETATION]

CHAPTER VII

FACTORS IN THE LOCATION OF CITIES AND TOWNS

The population of the world is very unevenly distributed. Not far from
nine-tenths live in lowland plains, below an altitude of 1,200 feet, in
regions where food-stuffs grow. The remainder live mainly in the
grass-producing regions of the great plateaus, the mining regions or the
flood-plains and grassy slopes of the higher montane regions.

=Communal Life.=--In each of these regions, also, there is a very unequal
massing of population. In part, the various families live isolated from
one another; in part, they gather into cities and villages. In other
words the population of a habitable region may be classed as _rural_ and
_urban_. In the United States and western Europe, agricultural pursuits
encourage rural life, each family living on its own estate. In Russia,
the agricultural population usually cluster in villages.

The farmer or freeholder who owns or controls his estate, exemplifies
the most advanced condition of personal and political liberty. Only a
few centuries have elapsed since not only the land but also the life of
a subject was the property of the king or the feudal lord, and in those
days about the only people living in isolation were outlaws. In most
cases the communal system, best exemplified in Russia, marks an
intermediate stage between a low and a high state of civilization; in
other instances it is necessary in order to insure safety. German
farmers in Siberia usually adopt the village plan for this reason.

For the greater part, the non-agricultural population of the civilized
world is massed in villages and cities for reasons that have nothing to
do with either civilization or self-defence. The causes that bring about
the massing of urban population are many and their operation is complex.
In g