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 264 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. I also think, however, that for reasons quite unconnected with the sliding-press, this pattern of room ought to be imitated in libraries hereafter to be built, and when this is the case, it must inevitably bring the Museum press after it. It will therefore be worth while to describe this style of building, in order that the mutual adaptation of it and of the sliding-press may be clear. It consists of three storeys lighted entirely from the top. It is therefore necessary for the transmission of light from top to bottom that the floors of the two upper storeys should be open; and they are in fact iron gratings. It follows that the floor of the highest storey must form the ceiling of the second, and the floor of the second the ceiling of the third. Here is the key to the sliding-press system. The beams or rods which I have described as projecting from the presses that line the wall already existed in the shape of the bars of the grating, and did not require to be introduced. Nothing was needful but to provide them with flanking ribs projecting at right angles, from which, as you see in the photographs, the additional press could be suspended by rollers, admitting of easy working backwards and forwards, and then the