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
Rolling stock of the South Manchuria Railway etc. of a given wheel arrangement. This was followed by a unit serial number in Roman numerals. The first two katakana indicated the wheel arrangement, derived from the American naming system: Self-moving rolling stock powered by something other than steam used a different system, which indicated the type of powerplant. Railway cranes were also classified like this. The third katakana in the class name was the class number, derived from the first syllable of the corresponding Japanese number: When the operation and management of the Manchukuo National Railway and of the North China Transportation Company were transferred to Mantetsu, their