Sentence:  “Put that cannon up once, and I'll answer for it that no Injin faces it. 'Twill be as good as a dozen sentinels,” answered Joel. “As for mountin', I thought of that before I said a syllable about the crittur. There's the new <WSD>truck</WSD>-wheels in the court, all ready to hold it, and the carpenters can put the hinder part to the whull, in an hour or two.” 
Meaning of the word marked with <WSD> tags:  A small wheel or roller, specifically the wheel of a gun carriage.