"But you're older'n me." "Not so much, as years go," Tom rejoined.

"For that matter, if you go on with your cigarettes you'll be an old man before I get through with being a young man.

Fill up your chest, Alf; expand it---like this." As he expanded his chest Reade looked a good deal more like some Greek god of old than a twentieth century civil engineer.
Alf puffed and squirmed in his efforts to show "some chest." "That isn't the right way," Tom informed him.

"Breathe deeply and steadily.

Draw in your stomach and expand your chest.