halanx in the center. This army moved along down the eastern bank of
the Tigris, the scouts pressing forward as far as possible in every
direction in front of the main army, in order to get intelligence of
the foe. It is in this way that two great armies _feel_ after each
other, as it were, like insects creeping over the ground, exploring
the way before them with their _antennae_. At length, after three days'
advance, the scouts came in with intelligence of the enemy. Alexander
pressed forward with a detachment of his army to meet them. They
proved to be, however, not the main body of Darius's army, but only a
single corps of a thousand men, in advance of the rest. They retreated
as Alexander approached. He, however, succeeded in capturing some
horsemen, who gave the information that Darius had assembled his vast
forces on the plain of Arbela, and was waiting there in readiness to
give his advancing enemy battle.

Alexander halted his troops. He formed an encampment, and made
arrangements for depositing his baggage there. He refreshed the men,
examined and repaired their arms, and made the arrangements for
battle. These operations consumed several days. At the end of that
time, early one morning, long before day, the camp was in motion, and
the columns, armed and equipped for immediate contest, moved forward.

They expected to have reached the camp of Darius at daybreak, but the
distance was greater than they had supposed. At length, however, the
Macedonians, in their march, came upon the brow of a range of hills,
from which they looked down upon numberless and endless lines of
infantry and cavalry, and ranges after ranges of tents, which filled
the plain. Here the army paused while Alexander examined the field,
studying for a long time, and with great attention, the numbers and
disposition of the enemy. They were four miles distant still, but the
murmuring sounds of their voices and movements came to the ears of the
Macedonians through the calm autumnal air.

Alexander called the leading officers together, and held a
consultation on the question whether to march down and attack the
Persians on the plain that night, or to wait till the next day.
Parmenio was in favor of a night attack, in order to surprise the
enemy by coming upon them at an unexpected time. But Alexander said
no. He was sure of victory. He had got his enemies all before him;
they were fully in his power. He would, therefore, take no advantage,
but w