Used to fracture and split natural stone blocks.
A method used in quarrying to reduce large masses of stone to smaller size.
By using a hammer drill, a row of shallow holes is made along the line where a break is desired.
The feathers consist of two iron strips, flat on one side for contact with the wedge and curved on the other to fit the wall of the drill hole.
They are placed in the hole and the plug (a steel wedge) is placed between them.
They are sledged lightly in succession until a fracture appears.