William trained twelve of his monks to be excellent writers, and to these was committed the office of transcribing the Holy Scriptures and the treatises of the Fathers. Besides these, there were in the _scriptorium_ of Hirschau a large number of lesser scribes, who wrought with equal diligence in the transcription of other books. In charge of the _scriptorium_ was placed a monk “well versed in all kinds of knowledge,” whose business it was to assign the task for each scribe and to correct the mistakes of those who wrote negligently. William was Abbot of Hirschau for twenty-two years, and during this time his monks wrote a great many volumes, a large proportion of which were distributed to supply the wants of other and more needy monasteries. There was often difficulty, particularly in the less wealthy monasteries, in securing the parchment required for their work. It is evident from such account-books as have been preserved, that throughout the whole of Europe, but particularly in the north of the Continent and in England, parchment continued to be a very costly commodity until quite late in the thirteenth century. It was not unnatural that, as a result of this difficulty, the monastic scribes should, when pressed for material, have occasionally utilised some old manuscript by cleaning off the surface, for the purpose of making a transcript of the Scriptures, of some saintly legend, or of any other religious work the writing of which came within the range of their daily duty.