They are elevated above the brick pier, and roll in towards each other.

它们被抬高到砖墩上方，并相互滚动。

The boiler in which the steam is generated is situated outside the main building; the machinery and engine rest on a brick pier, fifteen feet above the floor, within the body of the building.

产生蒸汽的锅炉位于主楼外；机器和发动机放置在建筑物主体内的砖墩上， 距地面 15 英尺。