One if by land, and two if by sea

1. The words used by Henry Wadsworth Longfellow in his poem “ Paul Revere's Ride ” to describe the signal used to guide the “midnight ride of Paul Revere” at the start of the Revolutionary War . Revere had ordered two lanterns to be placed in a Boston church tower to warn his confederates that the British were on the move. Longfellow embellished the story a little.