Sentence:  It was April 22, 1831, and a young man was walking down Whitehall in the direction of Parliament Street.nb.... He halted opposite the Privy Gardens, and, with his face turned skywards, listened until the sound of the Tower guns smote again on the ear and dispelled his <WSD>doubts</WSD>. 
Meaning of the word marked with <WSD> tags:  Uncertainty, disbelief.