a duct that provides ventilation (as in mines)

a stairway whose steps move continuously on a circulating belt

support consisting of a place to rest the foot while ascending or descending a stairway

support consisting of a place to rest the foot while ascending or descending a stairway

support consisting of a place to rest the foot while ascending or descending a stairway

support consisting of a place to rest the foot while ascending or descending a stairway

support consisting of a place to rest the foot while ascending or descending a stairway

support consisting of a place to rest the foot while ascending or descending a stairway

a way of access (upward and downward) consisting of a set of steps

support consisting of a place to rest the foot while ascending or descending a stairway