Roulette (curve) application of this is that a square wheel could roll without bouncing on a road that is a matched series of catenary arcs. Roulette (curve) In the differential geometry of curves, a roulette is a kind of curve, generalizing cycloids, epicycloids, hypocycloids, trochoids, and involutes. Roughly speaking, a roulette is the curve described by a point (called the "generator" or "pole") attached to a given curve as that curve rolls without slipping, along a second given curve that is fixed. More precisely, given a curve attached to a plane which is moving so that the curve rolls, without slipping, along
Rolling stock of the South Manchuria Railway Mantetsu system. The numbering system is unclear for Period 1. Some locomotives – the 2-6-4 tank locomotives later designated Dabui-class, the 2-8-0 tender locomotives that became Sorii-class, and the 2-8-0 tender locomotives that became Sorini class – were numbered starting at 1, but there was no system of type classification. The first system of type classification for locomotives consisted of a letter of the Roman alphabet to indicate the wheel arrangement based on the American names used for the given arrangement. If a second class of locomotive of the same wheel arrangement was introduced, this was indicated by a class