specially suited for flat countries.
Long lines of wall, broad dykes, huge reservoirs, by means of which
large tracts may be laid under water, form the natural resort in such
a case; and to such defences as these alone, in addition to her armies,
could Babylonia look in case of a quarrel with the Medes. On this side,
however, she for many years felt no fear. Political arrangements and
family ties connected her with the Median reigning house, and she looked
to her northern neighbor as an ally upon whom she might depend for aid,
rather than as a rival whose ambitious designs were to be watched and
baffled.

Babylonia lay open also on the side of Arabia. Here, however, the nature
of the country is such that population must be always sparse; and the
habits of the people are opposed to that political union which can alone
make a race really formidable to others. Once only in their history,
under the excitement of a religious frenzy, have the Arabs issued forth
from the great peninsula on an errand of conquest. In general they are
content to vex and harass without seriously alarming their neighbors.
The vast space and arid character of the peninsula are adverse to
the collection and the movement of armies; the love of independence
cherished by the several tribes indisposes them to union; the affection
for the nomadic life, which is strongly felt, disinclines them to
the occupation of conquests. Arabia, as a a conterminous power, is
troublesome, but rarely dangerous: one section of the nation may almost
always be played off against another: if "their hand is against every
man," "every man's hand" is also "against them;" blood-feuds divide and
decimate their tribes, which are ever turning their swords against each
other; their neighbors generally wish them ill, and will fall upon them,
if they can take them at a disadvantage; it is only under very peculiar
circumstances, such as can very rarely exist, that they are likely even
to attempt anything more serious than a plundering inroad. Babylonia
consequently, though open to attack on the side of the south as well
as on that of the north, had little to fear from either quarter. The
friendliness of her northern neighbor, and the practical weakness of her
southern one, were equal securities against aggression; and thus on her
two largest and most exposed frontiers the Empire dreaded no attack.

But it was otherwise in the far south-west. Here the Empire bordered
upon Egypt, a rich