The Furniture Restorer Who Can Date a Chair by Its Joinery

Adam Bowett, one of Britain's leading furniture historians and practising restorer, can determine a chair's approximate date of manufacture within a decade by examining its joinery alone, without reference to style, timber, or surface finish. The type of joint, its execution, and the tools used form a chronological signature as reliable as a hallmark.

The evolution of chair joinery follows technological and economic pressures. Seventeenth-century chairs used through-mortise-and-tenon joints secured by wooden pegs, borrowed from timber framing. The joints are robust, often over-engineered, and the peg holes are typically offset to draw the joint tight, a detail called drawboring.

By the early eighteenth century, chairmakers adopted blind mortise-and-tenon joints. The change reflects improved glue technology and the influence of Dutch and French design favouring cleaner lines. The mortises of this period show the scalloped bottom left by a brace and bit, a distinctive tool signature.

The introduction of the mortising machine in the mid-nineteenth century produced joints with flat, uniform bottoms and parallel sides immediately distinguishable from hand-cut work. Machine-cut tenons show circular saw marks rather than the rippled surface of a hand tenon saw.

Dowel joints appeared from the 1840s, offering faster assembly at reduced strength. The presence of dowels in a chair claiming to be eighteenth century is an immediate red flag. Screw and bolt joints indicate twentieth-century production, with thread pitch and head type narrowing the date range further.

When evaluating antique chairs, examine joinery before surface. Turn the chair over, look at the underside, and if possible inspect a joint. The joinery tells truth that refinishing may have obscured. A genuine eighteenth-century chair with original joinery is significantly more valuable than a restyled Victorian piece. Study at https://www.furniturehistorysociety.org