What words describe make done in the book the foghorn

"The Fog Horn," the narrator and a man named McDunn work in a stone tower, far out from land, to alert ships passing through the fog of their proximity to land. The tower emitted red and white lights, as well as a "Voice," the deep cry that the Fog Horn sent out into the world. It was lonely work. On the night before it was the narrator's turn to return to land, McDunn tells him that he has something special to tell him about.