Let a tumbler be half-filled with water; put a sixpence in it; and holding a plate over the top, turn the glass upside down. The sixpence will fall down on the plate, and appear to be a shilling; while at the same time a sixpence will seem to be swimming in the water. If a shilling is put in the glass, it will have the appearance of a quarter of a dollar and a shilling; and if a quarter of a dollar were put in, it would seem to be half a dollar and a quarter of a dollar. MAGIC RAT TRAP. Prepare a pasteboard circle, upon one side of which draw a figure of a cage, and on the other side that of a rat. Near the outer edge of the circle fasten two strings opposite each other. So that they may be held between the fore finger and thumb in such manner that the circle may be made to revolve rapidly. When it is set in motion the transition is so quick, that it presents the appearance of a rat in the cage. [Illustration] TO SHOW THE VELOCITY OF MOTION. Take a long hollow stalk or reed, suspend it horizontally by two loops of single hairs; by striking it with a sharp quick stroke at a point nearly in the centre, between the hairs, it may be cut through without breaking either of them. The hairs in this case would have been ruptured, if they had partaken of the force applied to the stalk; but the division of the latter being affected before the impulse could be propagated to the hairs, they must consequently remain unbroken. A smart blow, with a slight wand or hollow reed on the edge of a glass tumbler, would break the wand, without injury to the glass. Lay a small piece of money upon a card placed over the mouth of a glass tumbler, and resting upon the rim of the glass. The card may be withdrawn with such speed and dexterity, that the piece of money will not be removed laterally, but will drop into the glass. THE EXPLODING BUBBLE. If you take up a small quantity of melted glass with a tube, (the bowl of a common tobacco pipe will do,) and let a drop fall into a vessel of water, it will chill and condense with a fine spiral tail, which being broken, the whole substance will burst with a loud explosion, without injury either to the party that holds it, or him that breaks it; but if the _thick_ end is struck even with a hammer, it will not break. THE MAGIC PICTURE. Take two level pieces of glass, (plate glass is the best,) about three inches long and four wide, exactly of the same size; lay one on the other, and manage to leave a space between them by pasting a piece of card, or two or three small pieces of thick paper at each corner. Join these glasses together at the edge by a composition of lime slacked by exposure to the air, and white of an egg. Cover all the edges of these glasses with parchment or bladder, except at one end, which is to be left open to admit the following composition: Dissolve by a slow fire six ounces of hog’s-lard, with half an ounce of white wax; to which you may add an ounce of clear linseed oil.