It seemed that they intended to wear out the defenders by the sheer persistency of their cannon fire.
Ned became so hardened to the bombardment that he paid little attention to it.

Even when a ball fell inside the Alamo the chances were several hundred to one that it would not hit him.

He had amused himself with a mathematical calculation of the amount of space he occupied compared with the amount of space in the Alamo.

Thus he arrived at the result, which indicated comparatively little risk for himself.
The shrewdest calculations are often wrong.

As he passed through the convent yard he met Crockett, and the two walked on together.