The prone position is, however, the better one for the book, and the respective levels of the edges of the book and the edges of the boards are designed for this position. When the books were set up on end, the discrepancy between the levels of the book edges and the board edges was never rectified, and the result is that a large amount of damage has been done. When a large book is set up on end, the weight of it rests entirely upon the lower edges of the boards, and the lower edges of the book itself are up in the air above the shelf by so much as the projection of the edges of the boards beyond them. The result is that the whole of the weight of the vellum or paper of the book pulls upon the bands of the back in their weakest direction, from within and more particularly from the top, thereby pulling the back inwards. The mass of the book falls forward slantingly, until the lower edge of the front of it rests upon the shelf. It is difficult to describe, but my sketch will show what I mean, and the truth of it can be easily seen in almost any library of old books that are kept “on end”; the edges will be found grubby from resting on the shelf, and the top of the back will be found pulled forward. [Illustration: FIG. 70.--Inside of heavy book fallen forward, by reason of being kept upright.] Valuable books that are kept upright should have the edges of the boards level with the edges of the leaves, and then this disastrous pull would not occur. A remedy, however, may be found by means of a piece of wood cut the same size as the lower edge of the book so as to fit closely into the hollow between the outer edges of the boards and the lower edges of the leaves. Such a slip will neutralise the drop of the leaves, and preserve the proper form of the backs of heavy books. But before the upright position was finally adopted for books, and their titles were put on their backs, the front edge or “forage” of the leaves was always kept outwards, in view, and on this space or long panel all sorts of devices and letterings were put. Leaves of a book, pressed tightly together, provided too tempting a space to be ignored, to say nothing of the usefulness of giving the name or title of the book, or the device of its owner, or even a decorative design. So on fine mediæval books and also on later books, following the earlier manner in their own way, we find all sorts of designs on book edges. It is not a subject which has attracted much attention as yet, but it probably will in time, and there is already enough known about it to show that much valuable knowledge is lying hidden up in it. For instance, if a book, otherwise likely, has the words “Rex in Æternum Vive” painted in gold on the edges, it is a positive sign that it issued from the workshop of Thomas Berthelet, printer and binder to Henry VIII. [Illustration: FIG. 71.--Forage decoration in colour. Tenth century.]