Sentence:  One of the most important inventions, one that was received with acclaim by the American manufacturer, and one which actually reduced his labor cost on spooling no less than ten per cent. at one clip, is a tiny little thing that is held in the palm of the hand. This is the Barber <WSD>knotter</WSD>. When a thread breaks, the attendant places the two ends together in the machine and by the mere pressure of her thumb ties the knot much better than she could do it without the <WSD>knotter</WSD>. 
Meaning of the word marked with <WSD> tags:  A machine or device that makes knots.