Cycloid Cycloid A cycloid is the curve traced by a point on the rim of a circular wheel as the wheel rolls along a straight line without slipping. A cycloid is a specific form of trochoid and is an example of a roulette, a curve generated by a curve rolling on another curve. The cycloid, with the cusps pointing upward, is the curve of fastest descent under constant gravity, and is also the form of a curve for which the period of an object in descent on the curve does not depend on the object's starting position. The cycloid has been
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