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
Is thus made. Have a nave turned two inches and a half diameter, and three long; then let half an inch of that end which faces the first wheel be turned so as to fit easy into the tin barrel of the first mutation, which must turn round it without touching; on the other end of the block, fix a tin barrel B, Nᵒ. 2, this barrel must be six inches in length, and only half an inch of it to fit on the block. Round the nave fix five spokes, one inch and a half in length each; the diameter of the spokes must be equal to a two ounce former; on these spokes put five seven inch two ounce cases of spur fire, and carry leaders from the mouth of one to the other, that they may all light together; then from the mouth of one of the cases, carry a leader, through a hole bored slantways in the nave, from between the spokes, to the front of the block near the spindle hole; the end of this leader must project out of the hole into the barrel of the first mutation, so that when the pipe which comes from the end of the last case on the first wheel flashes, it may take fire and light the second mutation. To communicate the fire to the third mutation bore a hole near the bottom of one of the five cases, to the composition, and from thence carry a leader into a hole made in the middle of the barrel B; this hole must be covered with pasted paper.
Third Mutation
May be either an octagon or hexagon wheel, twenty inches diameter; let the nave be three inches and a quarter diameter, and three and a half in length; one inch and a half of the front of the nave must be made to fit in the barrel B. On the other end of the block fix a tin barrel C, Nᵒ. 3; this barrel must be six inches and a half in length, one inch of which must fit over the block. The cases of this wheel must burn two at a time; and from the mouths of the two first cases carry a leader, through holes in the nave into the barrel of the second mutation, after the usual manner; but besides these leaders let there be a pipe go across the wheel from one first case to the other, then from the tail of one of the last cases, carry a pipe into a hole in the middle of the barrel C; at the end of this pipe, let there hang some loose quick match.
Fourth and Fifth Mutation.
We shall here speak of those two mutations under one head, as their naves are made of one piece, which from E to F is fourteen inches; E, a block four inches diameter, with ten or twelve short spokes, on which are fixed eleven inch eight ounce cases; let the front of this block be made to fit easy in the barrel C, and cloath the cases so that they may all light together; and let a pipe be carried through a hole in the block into the barrel C, in order to receive the fire from the leader brought from the last case on the wheel. G, the nave of the fifth mutation, whose diameter must be four inches and a half; in this nave fix ten or twelve spokes one foot and a half in length each; these spokes must stand seven inches distance from the spokes of the fourth mutation; and at the end of each spoke tie a four ounce case, as shewn by Nᵒ. 5; all these cases are to be lighted together, by a leader brought from the end of one of the cases on Nᵒ. 4. Let F and H be of the same piece of wood as E and G; but as much thinner as possible, in order to make the work light.
Sixth and Seventh Mutation.