For ancient manuscripts or autograph works of famous authors large prices were often paid. Aristotle is said to have given three talents (about £750) for an autograph manuscript of Speusippus, and a manuscript of Virgil's second book of the _Aeneid_, thought to be the author's own copy, sold for twenty _aurei_, more than £20 in modern value; see Aul. Gell. III. 17, and II. 3. _Cost of new books._ _Slave scribes._ But ordinary copies of newly published works, even by popular authors, appear to have been but little more expensive than books of this class are at the present day. The publisher and bookseller Tryphon could sell Martial's first book of _Epigrams_ at a profit for two _denarii_--barely two shillings in modern value; see Mart. XIII. 3. It may seem strange that written manuscripts should not have been much more costly than printed books, but when one considers how they were produced the reason is evident. Atticus, the Sosii and other chief publishers of Rome owned a large number of slaves who were trained to be neat and rapid scribes. Fifty or a hundred of these slaves could write from the dictation of one reader, and thus a small edition of a new volume of Horace's _Odes_ or Martial's _Epigrams_ could be produced with great rapidity and at very small cost[14]. Little capital would be required for the education of the slave-scribes, and when once they were taught, the cost of their labour would be little more than the small amount of food which was necessary to keep them alive and in working order. Cicero (_Att._ II. 4) speaks of the publisher Atticus selling manuscripts produced in this way by slave labour on a large scale. _Librarii._ The name _librarius_ was given not only to the booksellers, but also to slave librarians, and to scribes, the latter being sometimes distinguished by the name _scriptores librarii_. _Librarii antiquarii_ were writers who were specially skilled in copying ancient manuscripts. The word _scriba_ commonly denotes a _secretary_ rather than what we should now call a _scribe_. In Athens a class of booksellers, [Greek: bibliographoi], appears to have existed as early as the fifth century B.C.; see Poll. VII. 211. The name [Greek: bibliopôlai] was subsequently used, and adopted by the Romans. THE TECHNIQUE OF ANCIENT MANUSCRIPTS[15]. _Parchment and vellum._ _Erasures._