books except large and heavy folios, which would probably
require a small, and only a small, addition of thickness.

I have recommended that as a rule the shelves be fixed, and have given
reasons for the adoption of such a rule. I do not know whether it will
receive the sanction of authorities. And I make two admissions. First,
it requires that each person owning and arranging a library should have
a pretty accurate general knowledge of the sizes of his books. Secondly,
it may be expedient to introduce here and there, by way of exception,
a single movable shelf; and this, I believe, will be found to afford a
margin sufficient to meet occasional imperfections in the computation of
sizes. Subject to these remarks, I have considerable confidence in the
recommendation I have made.

I will now exhibit to my reader the practical effect of such
arrangement, in bringing great numbers of books within easy reach. Let
each projection be three feet long, twelve inches deep (ample for two
faces of octavos), and nine feet high, so that the upper shelf can be
reached by the aid of a wooden stool of two steps not more than twenty
inches high, and portable without the least effort in a single hand.
I will suppose the wall space available to be eight feet, and the
projections, three in number, with end pieces need only jut out three
feet five, while narrow strips of bookcase will run up the wall between
the projections. Under these conditions, the bookcases thus described
will carry above 2,000 octavo volumes.

And a library forty feet long and twenty feet broad, amply lighted,
having some portion of the centre fitted with very low bookcases suited
to serve for some of the uses of tables, will receive on the floor from
18,000 to 20,000 volumes of all sizes, without losing the appearance of
a room or assuming that of a warehouse, and while leaving portions of
space available near the windows for purposes of study. If a gallery
be added, there will be accommodation for a further number of five
thousand, and the room need be no more than sixteen feet high. But a
gallery is not suitable for works above the octavo size, on account of
inconvenience in carriage to and fro.

It has been admitted that in order to secure the vital purpose of
compression with fixed shelving, the rule of arrangement according
to subjects must be traversed partially by division into sizes. This
division, however, need not, as to the bulk of the library, be more th