Is a standing piece called the cross fire. This mutation consists of eight spokes fixed in a block; near the end of each of those spokes, must be tied two four ounce cases of white charge, one across the other, so that the fires from the cases on one spoke, may intersect the fire from cases on the other. Seventh Mutation Is a fixed wheel, with two circular fells, on which are placed sixteen eight ounce cases of brilliant fire, in the form of a star: this piece is called a fixed star of wild fire. Eighth Mutation. This is a beautiful piece, called a brilliant star piece, it consists of six spokes, which are strengthened by two fells of a hexagon form at some distance from each other; at the end of each spoke, in the front, is fixed a brilliant star of five points; and on each side of every star is placed a four ounce case of black or grey charge; these cases must be placed with their mouths side ways, so that their fires may cross each other. Ninth Mutation Is a wheel piece; this is composed of six long spokes, with a hexagon vertical wheel at the end of each; these wheels run on spindles in the front of the spokes; all the wheels are lighted together: two ounce cases will do for these wheels, and may be filled with any coloured charge. After having spoke of the several parts of the regulated piece, each by their proper names and colour of fire, I shall next proceed with the proportion of every mutation, together with the method of conveying the fire from one to the other, and the distance they stand one from the other on the spindle. First Mutation Must be a hexagon vertical wheel, fourteen inches diameter; on one side of the block, whose diameter is two inches and a quarter, is fixed a tin barrel A, see fig. 53, Nᵒ. 1; this barrel must be a little less in diameter than the nave; let the length of the barrel and block be six inches. Having fixed the cases on the wheel, carry a leader from the tail of the last case into the tin barrel through a hole made on purpose two inches from the block; at the end of this leader let there be about an inch or two of loose match, but take care to well secure the hole wherein the pipe is put, to prevent any sparks falling in, which would light the second mutation before its time, and confuse the whole piece. Second Mutation