Deceptive Vision. The following sleight, which we take from the MagiciAn's own Book, shows bow easily the eye may be deceived. Take a piece of pasteboard, an inch and a hair in width, and fire inches in length, and divide it by inked lines into thirty squares, then cut it from corner to corner, so as to form two triangles. After this, cut off the top of these triangles at c and d, (at the fourth square from the right angle,) after which, arrange the pieces in the manner represented below:

On counting the squares in the first figure, there appear to be thirty, but the other arrangement of the same card seems to contain thirty-two. It does so, however, only in appearance, but it is only a very correct eye that can detect the imperfection.