White Fire.—Gunpowder two parts, steel filings one part; for a pale white add a little camphor. Raspings of ivory give a flame of a silver colour, somewhat dazzling to the eyes.

Red Fire.—Gunpowder two parts, iron-sand of the first order one part. Greek pitch produces a flame somewhat red, but more inclined to a bronze colour.

Common black pitch produces a dusky flame, like a thick smoke, very essential in producing a medium of intolerable obscurity.

Sulphur, mixed in a moderate quantity, makes the flame appear of a blue cast.

Sal ammoniac and verdigris produce a flame inclined to green.

Raspings of yellow amber give to the flame a lemon colour.

Crude antimony a kind of russet colour.

33. For Jets of Fire.

When the inner diameter of the cases is not more than six lines the following must be the proportions.