As the books were to stand upright on a shelf, not to lie on their sides on a desk, it was necessary to attach the chain in a different manner. A narrow strip of flat brass was passed round the left-hand board (fig. 74) and riveted to it, in such a manner as to leave a loop in front of the edge of the board, wide enough to admit an iron ring, an inch and a quarter in diameter, to which one end of the chain was fastened. The book is placed on the shelf with the fore-edge turned outwards, and the other end of the chain is fastened to a second ring, rather larger than the former, which plays along an iron bar (fig. 75). For the two upper shelves these bars, which are 1/2 in. in diameter, are supported in front of the shelf, at such a distance from it as to allow of easy play for the rings (fig. 73). Each bar extends only from partition to partition, so that three bars are needed for each shelf. For the lowest shelf there are also three bars, set two inches behind the edge of the shelf, so as to keep the rings and chains out of the way of the desk. The bars for the upper shelves rest in iron sockets screwed to the woodwork at the juncture of the horizontal shelves with the vertical divisions and ends respectively. The socket fixed to the end of the bookcase which was intended to stand against the wall is closed by an iron plate (fig. 76), so that the bar cannot pass beyond it. At the opposite end, that which would usually face the alley between the two rows of bookcases, the bars are secured by lock and key in the following manner. A piece of flat iron is nailed to the end of the bookcase, just above the level of the uppermost shelf (fig. 77). Attached to this by a hinge is a hasp, or band of iron, two inches wide, and rather longer than the interval between the two shelves. Opposite to each shelf this iron band expands into a semicircular plate, to which a cap is riveted for the reception of the head of the socket in which the bar rests (fig. 77); and just below the middle shelf it drops into a lock and is secured by a key (fig. 73). A second hasp, similarly constructed, secures the lowest of the three bars; but, as that bar is behind, and not in front of, the shelf to which it belongs, the arrangements described above are reversed. One lock and key serves for the ironwork belonging to the three shelves. [Illustration: Fig. 77. Iron bar, with part of the iron plate or hasp which is secured by the lock and keeps the bar in place: Hereford.]