The object of this paper is to give a short account of the sliding-press or hanging book-press now in use at the British Museum, and to suggest the importance of its introduction elsewhere where possible, and of regard being had to it in forming the plans of libraries hereafter to be built. Every successful library is destined to be confronted sooner or later with the problem how to enlarge its insufficient space. Without considerable financial resources such enlargement has hitherto been absolutely impracticable, and even where practicable has rarely been carried into effect without a long period of makeshift, discomfort, and disorganisation, for which the enlargement itself affords only a temporary remedy. The great advantages of the sliding-press in this point of view are two: it allows expansion within the edifice itself, without the necessity of additional building, and it enables this expansion to be effected gradually out of the regular income of the library without the need of appealing for the large sums which would be required by extensive structural additions to the existing edifice. I may assume that all present have seen, or will see, the photographs of the Museum sliding-press exhibited to the Conference, with the accompanying description. I may therefore be very brief in my account of it here, and simply characterise it as an additional bookcase hung in the air from beams or rods projecting in front of the bookcase which it is desired to enlarge, provided with handles for moving it backwards and forwards, working by rollers running on metal ribs projecting laterally from the above-mentioned beams or rods, and so suspended from these ribs as absolutely not to touch the ground anywhere. These are its essential characteristics, without which it would be indeed an additional book-press, but not a hanging-press or sliding-press. In recommending this system of additional accommodation, I by no means wish to insist upon this special form as the only one adapted for the necessities of a library. I have no doubt that in very many libraries the arrangement of the projecting beams or rods would be inapplicable, and that it would be better to resort to the original form of the idea, from which the Museum derived its own application of it—the idea, namely, of a skeleton door made in shelves, hinged upon the press requiring expansion, running on a wheel resting upon a metal quadrant let into the floor, and opening and shutting like any ordinary door. I have merely to affirm that for the Museum the adaptation we have made is a very great improvement; but this is due to the peculiar construction of the rooms to which the new press has hitherto been chiefly confined. Rooms of this pattern do not generally exist in public libraries, and where they are not found I am inclined to think that the plan which I have just described, the prototype of the Museum sliding-press, may be found the more advantageous.