If the ground plan of this structure (fig. 5) be compared with that of the precinct of Athena and library at Pergamon (fig. 2), a striking similarity between them will at once be recognised; and, whatever may have been the destination of the building within the cloistered area, there can, I think, be little doubt that the library was contained in the five rooms beyond its limits to the east. They must have been entered from the cloister, much as those at Pergamon were. It is possible that Hadrian may himself have visited Pergamon, for Trajan had built an imperial residence there; but, even if he did not do this, he would accept the type from the great libraries built at Rome by Augustus. It should be mentioned that S. Jerome specially commemorates this library among Hadrian's works at Athens, and says that it was of remarkable construction (_miri operis_)[39]. From this brief digression I return to the public libraries of Rome. In the first place those built by Augustus had a regular organisation. There appears to have been a general director called _Procurator Bibliothecarum Augusti_[40]; and subordinate officers for each division: that is to say, one for the Greek books, one for the Latin books. These facts are derived from inscriptions found in _Columbaria_. Secondly, it may be concluded that they were used not merely for reading and reference, but as meeting-places for literary men. The Palatine libraries evidently contained a large collection of old and new books; and I think it is quite certain that new books, as soon as published, were placed there, unless there was some special reason to the contrary. Otherwise there would be no point in the lines in which Ovid makes his book--sent from Pontus after his banishment--deplore its exclusion. The book is supposed to climb from the Forum to the temple of Apollo: Signa peregrinis ubi sunt alterna columnis Belides et stricto barbarus ense pater Quaeque viri docto veteres coepere novique Pectore lecturis inspicienda patent. Quaerebam fratres exceptis scilicet illis Quos suus optaret non genuisse parens; Quaerentem frustra custos e sedibus illis Praepositus sancto iussit abire loco[41]. Where, set between each pair of columns from some foreign quarry, are statues of the Danaids, and their barbarous father with drawn sword; and where whatever the minds of men of old or men of to-day have imagined, is laid open for a reader's use. I sought my brethren, save those of course whom their father would fain have never begotten; and, while I was seeking for them in vain, he who was set over the room bade me leave that holy ground. The second couplet can only mean that old books and new books were alike to be found there. The general nature of the collection, and its extent, may be further gathered from the advice which Horace gives to his friend Celsus: