One yard burns in the open air thirteen seconds.
30. What is the use of quick-match?
To fire stone and heavy mortars, and sometimes in proving pieces. It is extensively used in priming all kinds of fire-works, such as fire and light balls, carcasses, rockets, priming-tubes, &c., and in conveying fire very rapidly from one portion of a piece of fire-work to another.
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31. When used for discharging cannon, how is the quick-match set fire to?
By a slow match, port-fire, or any other convenient material.
32. When used to prime carcases, &c., how is it set on fire?
By the flame from the piece.
33. What is Valenciennes composition?
A compound of 50 parts of nitre, 28 of sulphur, 18 of antimony, and 6 of rosin.