The battle flamed in fifteen minutes into extraordinary violence.

Harry had never before heard such a continuous and terrific thunder.

It seemed that the drums of his ears would be smashed in, but over his head he heard the continuous hissing and whirring of steel and lead.

The Northern riflemen were at work, too, and it was fortunate for the Invincibles that they were able to lie down, as they poured their fire into the bushes and woods on the opposite bank.
The volume of smoke was so great that they could no longer see the position of the enemy, but Harry believed that so much metal must do great damage.

Although he was a lieutenant he had snatched up a rifle dropped by some fallen soldier, and he loaded and fired it so often that the barrel grew hot to his hand.