Iceland, Sicily, St. Helena; part of Sumatra,
Java, Japan; and the Sandwich Islands, seem to have been upheaved by
volcanic agency; Hawaii, the largest of the last-named group, contains
an area of four thousand square miles, and rises eighteen thousand
feet above the ocean.

What are Earthquakes?

Shakings or vibrations of the ground; sometimes accompanied by rents,
and rockings or heavings of the surface, so as to overthrow buildings,
and swallow up towns and large tracts of country. They are attended
with a terrible subterranean noise, like thunder, and sometimes with
an eruption of fire or water, or else of smoke or winds.

_Subterranean_, underground.

What is supposed to cause them?

An electrical action between the atmosphere and some deep sub-strata;
or the sudden formation of gaseous matter beneath the surface of the
earth by internal volcanic fires. Many hot countries, where much
electrical disturbance takes place, are very subject to them:
earthquakes almost always precede volcanic eruptions; an open volcano,
also, probably diminishes the force of earthquakes, by the vent which
it affords. Earthquakes, at different times, have been productive of
the most terrific effects: towns and cities have been swallowed up,
and thousands of people destroyed by them. The island of Jamaica is
remarkable for the earthquakes which frequently happen there.

_Precede_, to go before.

_Vent_, opening.

_Terrific_, full of terror, dreadful.

Where is Jamaica situated?

In the West Indies,--a large group of fertile islands which lie
between North and South America. Jamaica is the principal one of those
which belong to the English.

CHAPTER XVII.

ARCHITECTURE, SCULPTURE, USE OF MONEY, NAVIGATION.

What is meant by Architecture?

The art of building or erecting edifices fit for the habitation of
man, to defend him from the weather, and for his domestic comfort and
convenience; for devotion, trade, and other purposes, and for the use
of civilized life in every capacity.

_Capacity_, state, condition.

Is not this an art of great antiquity?

It is almost as ancient as human society; the changes of the seasons
first led men to build themselves huts or cabins, into which they
might retire for shelter; in process of time, their manner of building
gradually improved, and habitations were constructed of more stately
forms and elegant proportions, and greater skill and variety