Roulette (curve) in this case, the point lies on the circle then the roulette is a cycloid. A related concept is a glissette, the curve described by a point attached to a given curve as it slides along two (or more) given curves. Formally speaking, the curves must be differentiable curves in the Euclidean plane. The "fixed curve" is kept invariant; the "rolling curve" is subjected to a continuous congruence transformation such that at all times the curves are tangent at a point of contact that moves with the same speed when taken along either curve (another way to express this constraint
The Rolling Bridge which may still be seen at Fort Nelson, Portsmouth. Certain types of bascule bridges roll on an arc; an example is the Pegasus Bridge. The Rolling Bridge The Rolling Bridge is a type of curling movable bridge completed in 2004 as part of the Grand Union Canal office and retail development project at Paddington Basin, London. Despite the connotation of its name, it is more accurately described as ""curling"". The Rolling Bridge was conceived by Thomas Heatherwick. The bridge consists of eight triangular sections hinged at the walkway level and connected above by two-part links that can be collapsed towards