A short dictionary entry defining the heddle as the set of knotted cords forming loops that guide the warp threads and, by moving up and down, open the shed for the shuttle. It explains how many heddles are needed for plain weave and twills (including blanket twill and satin twill) and mentions the Jacquard. It also describes an illustrated mechanism (Fig. 2478) in which a twilling cam acts on levers to move the heddles in sequence.