With him a chuckle meant as much as a riotous outburst of merriment from another, and he could enjoy greatly without any noticeable muscular disturbance of his face.

And not always was his smile a reflection of humorous thought.
There were times when it betrayed another kind of thought more forcefully than speech.
Because he understood fairly well and knew what he was, the present situation amused him.

He could not but see what an error in judgment Miss Standish had made in selecting him, when compared with the intoxicating thrill she could easily have aroused by choosing one of the young engineers as a companion in her evening adventure.

He chuckled.
And Mary Standish, hearing the smothered note of amusement, gave to her head that swift little birdlike tilt which he had observed once before, in the presence of Captain Rifle.

But she said nothing.