Sentence:  “... It's for life, Miss Archer, it's for life,” Lord Warburton repeated in the kindest, tenderest, pleasantest voice Isabel had ever heard, and looking at her with eyes charged with the light of a passion that had sifted itself clear of the baser parts of emotion—the heat, the violence, the unreason—and that burned as steadily as a lamp in a <WSD>windless</WSD> place. 
Meaning of the word marked with <WSD> tags:  Devoid of wind; calm.