Abstract: A self-stabilising support for a structure, e.g. a chair, is disclosed, which comprises: a first pair of legs (1), means connected to the first pair of legs for supporting the structure, e.g. the upper part of the chair (3); a second pair of legs (2); a bearing acting between the first pair of legs (1) and the second pair of legs (2) and allowing the second pair of legs to pivot with respect to the first pair of legs about an axis whereby the four legs of the first and second pair can, by suitably pivoting the second pair of legs with respect to the first pair, be firmly planted on an uneven surface to support the said structure. The bearing is damped so that it does resist sudden movement between the first and the second legs about the bearing but a sustained force causes pivoting movement of the second pair of legs about the bearing.