My efforts were in vain.

At last I directed my staff officers to set fire to the camps.
This drew the fire of the enemy's guns located on the heights of Columbus.

They had abstained from firing before, probably because they were afraid of hitting their own men; or they may have supposed, until the camp was on fire, that it was still in the possession of their friends.

About this time, too, the men we had driven over the bank were seen in line up the river between us and our transports.

The alarm "surrounded" was given.