He reserved this form of emphasis for supreme moments.

He was possessed of a dramatic temperament and appreciated at its full value the effect of a climax.

The climax had not yet arrived, hence his self-control.
"Exactly so," said the Sergeant, determined to be agreeable.
"What's that ?" "They don't seem to be here, sir," replied the Sergeant, staring up into the trees.
"Where ?" cried the Superintendent, following the direction of the Sergeant's eyes.

"Do you suppose they're a lot of confounded monkeys ?" "Exactly--that is--no, sir, not at all, sir.

But--" "They were to have been here," said the Superintendent angrily.