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. The blocks of these two mutations, are turned out of one piece of wood, whose length from F to P is fifteen inches. L a block five inches diameter, in which are fixed eight spokes, each two feet four inches in length; at the end of each spoke tie two four ounce cases as shewn by Nᵒ. 6; all these cases must be fired at the same time, by a pipe brought from the end of one of the cases on the fifth mutation. Let the distance between the spokes at L and those in the fifth mutation be seven inches. M, the nave of the seventh mutation, whose diameter must be five inches and a half; in this nave fix eight spokes, and on the front of them two circular fells, one of four feet eight diameter, and one of three feet eleven inches diameter; on these fells, tie sixteen eight ounce or pound cases, in the same manner as represented by Nᵒ. 7, and carry leaders from one to the other, so that they may be all fired together; this mutation must be fired by a leader brought from the tail of one of the cases on the sixth mutation. Eighth and Ninth Mutation. The blocks of these may be turned out of one piece, whose length from P to D must be twelve inches. O, the block of the eighth mutation, which must be six inches diameter, and in it fixed six spokes, each three feet in length; these spokes must be strengthened by a hexagon fell within three or four inches of the ends of the spokes; close to the end of each spoke, in the front, fix a five-pointed brilliant star; then seven inches below each star tie two ten inch eight ounce cases, so that the upper ends of the cases may rest on the fells, and their ends on the spokes; each of these cases must be placed parallel to the opposite fell, see Nᵒ. 8. NNN, &c. are the cases, and kkk, &c. the stars.