Sentence:  Three chairs of the steamer type, all maimed, comprised the furniture of this roof-garden, with (by way of local colour) on one of the <WSD>copings</WSD> a row of four red clay flower-pots filled with sun-baked dustnb.... 
Meaning of the word marked with <WSD> tags:  The top layer of a brick wall, especially one that slopes in order to throw off water.