The Common Wedge and Its Iron Sheath
A wedge immobilized by its socket, and the wedge's marvelous power under percussion
The page treats the wedge as a mechanical power. In the upper diagrams a wedge penetrates a narrow slot but is stopped by a cap that catches against an obstacle, and a second wedge is set in an iron sheath within a hollow bored into a block of stone. The accompanying text explains that the wedge's power becomes very great through percussion, serving to divide united things and unite divided ones, and that, though of the nature of a screw, it far exceeds it.
On this page
Common wedge immobilized by its socket
A common wedge is held fast where its cap or socket (its 'female') catches against an obstacle on the object it enters, so that it can penetrate no further. The wedge is shown part-way into a narrow slot.
Wedge in an iron sheath for splitting stone
A hollow is bored into a block of stone and lined with a metallic sheath, and a wedge is positioned above the opening ready to be driven in for splitting the stone.
The wedge's power through percussion
Struck by percussion the wedge exerts marvelous power: dividing united things, uniting divided ones, impressing bas-relief in metal, pressing liquids out of the places where they arise, and drying wet things. Though of the nature of a screw, it exceeds the screw by a great deal.