Persia from the Earliest Period to the Arab

40 HISTORY OF PERSIA.
sluices required for the irrigation of the fields. One
direct advantage was certainly obtained by this plan,
that it enabled the chief ruler to know on what
amount of revenue he could count ; and, though the
people at large often, doubtless, suffered from the
selfish oppression of the satraps, who took care to
pay themselves handsomely while they provided for the
royal demands, they secured this advantage, that the
central government was directly interested in sup-
porting them against proconsular rapacity. Obviously,
the wiser and gentler the rule of the satrap, the better
chance for the crown to secure its demands from the
actual cultivators of the soil.
The next point Darius considered was the establishment
of efficient checks on the satraps themselves, and
here he devised a scheme well fitted for this purpose,
consisting as it did in the threefold power of the satrap,
or civil governor, of the commander of the troops, and
of his own secretary, the duties of each office being
so arranged as to prevent the concentration of these
powers in any one person. Thus neither of the two
former could plan or carry out an insurrection without
being outwitted by a minister, who in the province was
rightly deemed to be the king's " eye " and " ear." The
provinces, too, themselves were liable to the inspection
of another officer, who, with an armed force, acted
directly for the king in the redressing of grievances.
It is hardly necessary to add that the success of such
a system depended greatly on the personal vigour of
the sovereign; and, hence, that it rapidly degeneiated
under the later Persian princes, till at length the same
person ofien secured all the three offices himself, the