ual number--it will
still be easy to show that the whole amount of one of these was not
equal to even a fifth part of a library composed of printed books.

Every one who has had any thing to do with publication, is well aware of
the great difference between the space occupied by the written and that
filled by the printed letters. It is well known that the volumes of
ancient libraries consisted of rolls, which generally were written only
on one side. Thus the written surface of one of these volumes would
correspond to but half the written surface of one of our books, of which
every page is covered with letters. A library, then, composed of 100,000
rolls, would contain no more matter than one of our libraries composed
of 50,000 manuscripts. It is well known, also, that a work was divided
into as many rolls as the books which it contained. Thus the Natural
History of Pliny, which in the _Princeps_ edition of Venice forms but
one folio volume, would, since it is divided into thirty-seven books,
have formed thirty-seven rolls or volumes. If it were possible to
compare elements of so different a nature, we should say that these
rolls might be compared to the sheets of our newspapers, or to the
numbers of our weekly serials. What would become of the great library of
Paris were we to suppose its 824,000 volumes in folio, quarto, &c., to
be but so many numbers of five or six sheets each? Yet this is the rule
by which we ought to estimate the literary wealth of the great libraries
of ancient times; and "hence," says M. Balbi, "notwithstanding the
imposing array of authorities which can be brought against us, we must
persist in believing that no library of antiquity, or of the middle
ages, can be considered as equivalent to a modern one of 100,000 or
110,000 volumes."

No one of the libraries of the first class now in existence dates beyond
the fifteenth century. The Vatican, the origin of which has been
frequently carried back to the days of St. Hilarius in 465, cannot with
any propriety be said to have deserved the name of library before the
reign of Pope Martin V., by whose order it was removed in 1417 from
Avignon to Rome. And even then a strict attention to exactitude would
require us to withhold from it this title until the period of its final
organization by Nicholas V. in 1447. It is difficult to speak with
certainty concerning the libraries, whether public or private, supposed
to have existed previous to the fifteenth ce