Five copies are known: two in the Bodleian Library; one in the University Library, Cambridge; one in Magdalene College, Cambridge; and one in the John Rylands Library, Manchester.
VIII The last of the eight books printed by Siberch of which complete copies survive is Papyrii Gemini Eleatis Hermathena, seu De Eloquentiae Victoria, printed on the 8th December, 1522. There are three different states of the title-page and six complete copies are known: University Library, Cambridge; British Museum; St John's College, Oxford; Archbishop Marsh's Library, St Patrick's, Dublin; Duke of Devonshire; Lincoln Cathedral Library.
To these eight books must be added the De octo partium orationis constructione libellus of Lily and Erasmus, two leaves of which were found in the book bound by Siberch which Mr Duff discovered at Westminster. This libellus, originally written by William Lily and revised, at Colet's suggestion, by Erasmus, was a popular school book of the period.
It was in the binding of the same book that the letter from Petrus Kaetz, a Dutch printer, was also found. This letter has many points of interest. Kaetz sends Siberch "25 prognostications and 3 New Testaments small," as well as a parcel to be delivered to Niclas [Speryng] and we may fittingly conclude our notice of Siberch with the tribute of a contemporary to his prospects as a printer:
Know, Jan Siborch (writes Petrus Kaetz) that I have received your letter as [well as specimens] of your type, and it is very good; if you can otherwise ... and conduct yourself well, then you will get enough to print.
(Translation by Dr Hessels, Jenkinson, C.A.S. VIII, 186.)
TRADE-MARK OF JOHN SIBERCH