[f. JACK sb.1 7: because used in roasting-jacks.] A chain each link of which consists of a double loop of wire, resembling a figure of 8, but with the loops in planes at right angles to each other; the links are not welded.
1639. W. Cartwright, Royall Slave, I. ii. If you’l make use of any ornaments, I’ve a couple of jack-chains at your service.
1676. Wycherley, Pl. Dealer, I. i. Here you see … a great Lord [bowing] to a Fishmonger, or Scrivener with a Jack-chain about his neck.
1801. Trans. Soc. Arts, XIX. 125. Six lengths of jack-chain.
1892. Pall Mall Gaz., 23 Sept., 7/2. Much stronger than ordinary welded or jack chains.
