[f. JACK sb.1, in various senses: cf. JACK-CHAIN.] A kind of thin rope or line used for various purposes: see quots.
1615. E. S., Brit. Buss, in Arb., Garner, III. 642. Every string must be fifty fathom long, and about the bigness of a jack-line.
1665. J. Wilson, Projectors, I. Dram. Wks. (1874), 227. I shall be an alderman,… I think a brass jack-line would hang as well o’ my shoulders as on another man’s.
1686. Plot, Staffordsh., 337. A round wooden box which receives a Jack-line, that goes also through another box which turnes a second spindle above in the Chimney.
1794. Rigging & Seamanship, I. 64. Jack-line is made of bar hemp, and has 9 threads, 3 in a strand.
1851. Illustr. Catal. Gt. Exhib., 514. Sash and jack-lines, made from Indian spun hemp.
1858. Kipping, Sails & Sail-making, 57. Through these eyes a small-sized rope is reeved; and this is called the jack-line.
