"“Well,” returns his wife, considering, “George seems to me to be getting not a little impatient and restless. I don’t say but what he’s as free as ever. Of course he must be free or he wouldn’t be George; but he smarts, and seems put out.”

“He’s extra-drilled,” says Mr Bagnet. “By a lawyer. Who would put the devil out.”

Mr. Bagnet and Mr. George are ex-troopers. So "extra drill"
presumably refers to punitive marching after end of regular day.