GENERAL REVIEW QUESTIONS. 167

 

In what respects do the river-systems of Africa resemble
those of the Americas?

Why are the waters of lakes with no outlets generally
salt?

Name the great fresh-water lake-systems of the world.

State the composition of ocean-water. What is its
density? Its boiling-point? Its color?

How do the five oceans compare with one another in
area?

Distinguish between inland seas, border seas, and gulfs
and bays, and fiords.

What facts are known respecting the shape of the bed of
the Atlantic Ocean? Of the Indian Ocean? Explain the
origin of the ooze-deposits on the ocean’s beds.

By what are waves caused? Upon what does their
height depend ? 5

How are tides caused ?

Distinguish between ebb, flood, spring, and neap tides.

Where does the parent tidal wave originate?

In what part of the ocean are tides the highest?
Why?

What are the main causes of constant oceanic currents ?

In what respects do the currents in the three central
oceans resemble one another?

The Atmosphere.

What is the-composition of the atmosphere?

By what instrument is the pressure of the atmosphere
measured ? :

What proof have we that the greater weight of the at-
mosphere lies within a few miles of the earth’s surface?

Define climate. Enumerate the circumstances which
influence the climate of a country.

Why are the vertical rays of the sun warmer than the
oblique rays?

In what different ways does the atmosphere «eceive its
heat from the sun?

Explain the origin of winds.

Why should the general direction of the atmospheric
circulation be between the equator and the poles?

Name the different wind zones of the earth.

What is the origin of land and sea breezes ?

What resemblance do land and sea breezes bear to
monsoons?

Describe some of the peculiarities of cyclones.

What facts have been discovered in regard to the great
storms of the United States?

Enumerate the circumstances upon which the rapidity
of evaporation depends.

State the general law for the occurrence of precipi-
tations. 2

Under what circumstances will a heavy deposition of
dew occur?

Name the primary forms of clouds.
forms.

Explain the peculiarities of the rainfall in each of the
wind zones.

Why is the rainfall on mountains heavier than that on
plains? :

Define snow line. On what three circumstances does the
height of the snow line depend ?

Describe the formation of a glacier.

The. secondary

 

 

Enumerate the principal electrical and optical phenom-
ena of the atmosphere.

What is the probable cause of the earth’s magnetism ?

Define volt, ohm, ampére. What analogies exist between
the flow of water in a pipe and an electric current?

Plant Life and Animal Life.

Why should the distribution of light, heat, and moisture
form the best basis for the distribution of vegetation?

Define flora. Distinguish between the horizontal and
the vertical distribution of vegetation.

State the limits of each of the horizontal zones of
vegetation. ,

What is the characteristic feature of the flora of each of
these zones?

State the conditions requisite for the existence of forests;
of prairies; of steppes; of deserts.

Enumerate the principal cultivated plants of the torrid,
temperate, and polar. zones.

Define fauna.

Upon what is the existence of animal life dependent?

What is the cause of the change noticed in the fauna in
passing from the equator to the poles, or from the base to
the summit of a high tropical mountain?

Enumerate the characteristic tropical fauna ; the temper-
ate fauna; the arctic fauna.

What is the characteristic peculiarity of the fauna of
each of the continents?

Enumerate the proofs of the probable unity of the
human race.

Naine the portions of the world inhabited by each of the
primary and secondary races.

Minerals.

Name the principal useful metals.

Enumerate the most important natural fuels.

In what parts of the world are valuable deposits of coal
found ?

Name the most important gold-fields of the earth.

Physical Features of the United States.

What is the area of the United States, exclusive of
Alaska?

Describe the surface structure of the United States.

Describe the drainage-systems of the United States.

What are the causes of the difference in the temperature
of the eastern and western coasts?

Between what extremes of mean annual temperature are
the United States included?

In what wind zone is the United States situated ?

Name the four principal regions of vegetation.

Enumerate the chief agricultural productions of the
country.

What large animals are found in the United States?

Name the chief mineral productions.

What is the area of Alaska? o

What are the principal indentations of its coast?

Name the principal islands of Alaska.

Describe the river-system of the Yukon.

Name the principal trees of Alaska. Name its principal
fur-bearing animals. Its principal food-fishes.