Sentence:  When the flames at last began to flicker and subside, his lids fluttered, then drooped ; but he had lost all reckoning of time when he opened them again to find Miss Erroll in furs kneeling on the <WSD>hearth</WSD> and heaping kindling on the coals, and her pretty little Alsatian maid beside her, laying a log across the andirons. 
Meaning of the word marked with <WSD> tags:  A brick, stone or cement floor to a fireplace or oven.