Slow-match

Slow-match, generally rope steeped in a solution of saltpetre and lime-water, and burning at the rate of one foot per hour. Port-fires are very similar, but burn an inch a minute. They were used for firing guns before the introduction of friction tubes, and sometimes for firing military mines, &c. They have been superseded by Bickford's fuze, a train of gunpowder enclosed in two coatings of jute thread waterproofed. There are two kinds, the ordinary (a slow match), burning at the rate of 3 or 4 inches a minute, and the instantaneous (a quick match), burning at the rate of 30 yards per second, and distinguished from the former by yellow threads crossed on the outside.