The Wedge

This piece was an automatic lock of true wedge shape with "harpoon" points. Once driven through the mortise holes in the chair and rail and over the tie-bar, the wedge locked the entire structure and itself in, binding the rails vertically while permitting them to expand and contract. The only way to force the wedge out was to compress the harpoon points with a tool and drive it out.

Click image for larger view of tie-bar and wedge. (741K) (From Gibbon Catalogue)

Letter from Robert Grimshaw to William H. Wahl, Informing that a brief is being prepared by himself and Mr. Gibbon concerning the re-opening of the rail case before the Committee on Science and the Arts. Will attend the meeting of the CSA and "be "loaded for bear" and prepared to be cross-examined in the matter." 1/29/1892 (747K)