Procure a piece of girth from 12 to 18 inches in length. Double it, and fold it down about 1-1/2 inch, similar to the fold of a letter, and then turn back one end of the girth, and it will form two compartments. Then take some gum and dissolve it in water; boil it till it is quite melted, and very thick; add coarse powdered glass, sufficient to make it into a very thick paste; place two upright rows of the glass composition in the inside of one of the folds, about as wide as the thickness of a lath, and as high as a half-crown laid flat; and when they are dry, sew the first fold together on the edge, and then the second at the opposite end, so that one end may be open. Then, in the centre of the two rows, put about a grain of fulminating silver, and paste a piece of cotton or silk over it. Make a hole at each end of the girdle, and hang it to a hook in the door-post, and the other hook on the door, observing to place the silk part so that it may come against the edge of the door when opened, which will cause a report as loud as a small cannon. The fulminating silver may be purchased at any of the operating chemists. DETONATING BALLS. Procure some glass globes, between the size of a pea and a small marble, in which there must be a small hole; put into it half a grain of fulminating silver. Paste a piece of paper carefully over the ball to prevent the silver from escaping. When you wish to explode one put it on the ground, and tread hard upon it, and it will go off with a loud noise. These balls may be made productive of much amusement in company, by placing a chair lightly on them; for whoever sits down upon them will cause them to explode. These globes may be procured at the barometer-makers. THE DETONATING TAPE. Is made of binding, about three-eighths of an inch in width. Observe the same directions as given for the girdle; you may either explode it yourself, by taking hold of each end, and rolling the ends from each other sharply, or give one end to another, and pull together. DETONATING CARDS. Take a piece of card about three-fourths of an inch in breadth and 12 in length; slit it at one end, and place in the opening a quarter of a grain of fulminating silver; close the edges down with a little paste, and when dry you may use it by lighting the end in a candle. Having given the method by which these loud reports are produced, we shall mention some other effects to be produced by the silver, capable of affording much amusement. For instance, by placing about a quarter of a grain of the silver in the midst of some tobacco in a pipe, or between the leaves of a cigar, and closing the end again, to prevent the powder from falling out; when lighted, it causes a loud explosion; for heat, as well as friction, will equally do.