The method of making these rockets is thus:--Have a cone turned out of hard wood two inches and a half in diameter, and as much high; round the base of it drive a line; on this line fix four spokes, each two inches long, so as to stand one opposite the other; then fill four nine-inch one-pound cases with any strong composition, within two inches of the top: these cases are made like tourbillons, and must be rammed with the greatest exactness. The rockets being filled, fix their open ends on the short spokes; then in the side of each case bore a hole near the clay; all these holes, or vents, must be so made that the fire of each case may act the same way; from these vents carry leaders to the top of the cone, and tie them together. When the rockets are to be fired, set them on a smooth table, and light the leaders in the middle, and all the cases will fire together and spin on the point of the cone. These rockets may be made to rise like tourbillons, by making the cases shorter, and boring four holes in the under side of each at equal distances; this being done they are called _double tourbillons_. _Note._--All the vents in the under side of the cases must be lighted at once, and the sharp point of the cone cut off; at which place make it spherical. WHEELS. Wheel-cases are made to any length; which must always depend on the size of the wheel, but must not exceed the length of each angle. Charge for wheel-cases, from 2 oz. to 4 lb. lb. oz. Meal-powder 4 0 Saltpetre 1 0 Brimstone 0 8 Charcoal 0 4 The filings in this composition may be varied by using a portion of sea-coal, glass-dust, saw-dust, &c., or a combination of the whole. SLOW FIRE FOR WHEELS. lb. oz. Saltpetre 0 4 Brimstone 0 2 Meal-powder 0 1-1/2 or, 1 oz. of brimstone may be used with 1 oz. of antimony. DEAD FIRE FOR WHEELS. oz. dr. Saltpetre 4-1/4 0 Brimstone 0-1/4 0 Lapis-caliminaris 0 2 Antimony 0 2