| 摘要 |
A staircase having a small base area is formed with one or more stringers and a plurality of horizontal treads placed along the stringer, the leading edges of alternate treads being set back from the usual tread edge and the setbacks alternating from side to side along the treads. The arrangement permits the treads in their unset back regions to overhang one another while the setback regions permits the foot to clear each tread in passing through the tread thereabove or therebelow. The arrangement permits a steep staircase to be negotiated with ease.
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