Let one of the holes be circular, the other square, and the third an oval; then it is evident, that any cylindrical body, of a proper size, may be made to pass through the first hole perpendicularly; and if its length be just equal to its diameter, it may be passed horizontally through the second, or square hole; also, if the breadth of the oval be made equal to the diameter of the base of the cylinder, and its longest diameter equal to the diagonal of it, the cylinder, being put. in obliquely, will fill it as exactly as any of the former.