That heart in its hard pulsations sounded to me like the carpenter hammering on her coffin-lid: I marvel that she did not take it for a death-watch tapping to warn her of her end.

But no: Simon held his hand against his heart to keep it quiet: he was so very fearful the pitapating would betray him.
Never mind, Simon; don't be afraid; she is fast asleep already; and her snore is to thee as it were the challenge of a trumpeter calling to the conflict..