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 long. To allow the passage of boats, the hydraulic pistons are activated and the bridge curls up until its two ends join, to form an octagonal shape measuring one half of the waterway's width at that point. The bridge won the British Structural Steel Design Award. While its designer refers to this particular structure as "The Rolling Bridge" on his website, this should probably be regarded as the name for this particular bridge rather than a term to refer to its type, which could be more accurately described as a "curling bridge". This name is used by some to refer