In the centre of the block of the sun drive a spindle, on which put a small hexagonal wheel, whose cases must be filled with the same charge as the cases of the sun; two cases of this wheel must burn at a time, and begin with those on the fells. Having fixed on all the cases, carry pipes of communication from one to the other, and from one side of the sun to the wheel in the middle, and from thence to the other side of the sun. These leaders will hold the wheel steady while the sun is fixing up, and will also be a sure method of lighting both cases of the wheel together. A sun thus made is called a _brilliant sun_, because the wood-work is entirely covered with fire from the wheel in the middle, so that there appears nothing but sparks of brilliant fire; but if you would have a transparent face in the centre, you must have one made of pasteboard of any size. The method of making a face is, by cutting out the eyes, nose, and mouth, for the sparks of the wheel to appear through; but instead of this face, you may have one painted on oil paper, or Persian silk, strained tight on a hoop; which hoop must be supported by three or four pieces of wire at six inches distance from the wheel in the centre, so that the light of it may illuminate the face. By this method may be shown, in the front of the sun, VIVAT REGINA, cut in pasteboard, or Apollo, painted in silk; but, for a small collection, a sun with a single glory and a wheel in front will be most suitable. Half-pound cases, filled ten inches with composition, will be a good size for a sun of five feet diameter; but, if larger, the cases must be greater in proportion. DETONATING WORKS. WATERLOO CRACKERS. Take a slip of cartridge-paper, about three-quarters of an inch in width, paste and double it; let it remain till dry, and cut it into two equal parts in length, (No. 1 and 2,) according to the following pattern: +-----------------+---+-------+--------+ | No. 1. Glass. | S | Glass.| No. 2. | +-----------------+---+-------+--------+ Take some of the glass composition, and lay it across the paper as in the pattern, and put about a quarter of a grain of fulminating silver in the place marked S, and while the glass composition is moist, put the paper marked No. 2, over the farthest row of glass. Over all, paste twice over the part that covers the silver a piece of paper; let it dry, and when you wish to explode it, take hold of the two ends and pull them sharply from each other, and it will produce a loud report. DETONATING GIRDLE.