Make a circular hole in the shutter of a window, from whence there is a prospect of some distance; in this hole place a magnifying glass, either double or single, whose focus is at the distance of five or six feet; no light must enter the room but through this glass. At a distance from it, equal to its focus, place a very white pasteboard, (what is called a Bristol board, if you can procure one large enough, will answer extremely well;) this board must be two feet and a half long, and eighteen or twenty inches high, with a black border round it: bend the length of it inward to the form of part of a circle, whose diameter is equal to double the focal distance of the glass. Fix it on a frame of the same figure, and put it on a moveable foot, that it may be easily placed at that distance from the glass, where the objects appear to the greatest perfection. When it is thus placed, all the objects in front of the window will be painted on the paper in an inverted position, with the greatest regularity, and in the most natural colours. If you place a swing looking-glass outside the window, by turning it more or less, you will have on the paper all the objects on each side the window. If, instead of placing the looking-glass outside the window, you place it in the room above the hole, (which must then be made near the top of the shutter,) you may have the representation on a paper placed horizontally on a table, and draw at your leisure all the objects reflected. Observe, the best situation is directly north; and the best time of the day is noon. _The Magnifying Reflector._ Let the rays of light that pass through the magnifying glass in the shutter be thrown on a large concave mirror, properly fixed in a frame. Then take a third strip of glass, and stick any small object on it; hold it in the intervening rays at a little more than the focal distance from the mirror, and you will see on the opposite wall, amidst the reflected rays, the image of that object, very large, and beautifully clear and bright. _To tell by a Watch Dial the Hour when a Person intends to rise._ The person is told to set the hand of his watch at any hour he pleases, which hour he tells you; and you add in your mind 12 to it. You then desire him to count privately the number of that addition on the dial, commencing at the next hour to that at which he intends to rise, and including the hour at which he has placed the hand, which will give the answer: for example. A intends to rise at 6, (this he conceals to himself;) he places the hand at 8, which he tells B, who, in his own mind, adds 12 to 8, which makes twenty. B then tells A to count twenty on the dial, beginning at the next hour to that at which he proposes to rise, which will be 5, and counting backwards, reckoning each hour as one, and including in his addition the number of the hour the hand is placed at, the addition will end at 6, which is the hour proposed; thus,