Admitting then that impressions from type could be taken on both sides of a sheet, the mere fact that a single leaf was so printed in two editions of the same ancient work, is no proof whatever that the said impressions were made with a press such as was used by the printers at Mentz, the invention of which became a necessity in order to complete the Typographic Art. What it does prove, is, that the printer of the _Speculum_, with the appliances then at his command, preferred the easier, simpler, and _safer_ method of printing on one side only. But in the consideration of this subject there are other questions which ought not to be overlooked;--_e. g._ For what special purposes, and for whom, were the _Donatuses_ and _Block-books_ printed? Certainly not for the public at large. The _Donatuses_,--small elementary _Latin_ grammars,--would be for a few of the superior monastic schools of the day; and the _Biblia Pauperum_, _Ars Memorandi_, _Speculum Salutis_, &c., were avowedly for “the assistance of poor preachers,”--“propter pauperes predicatores.” Editions of these works would therefore be small in number, and the time taken in their production would not be an object of much account. Mr. Ottley supposes (p. 283) that they would not exceed 20, 40, or 60 copies each. The market for them, consequently, might very easily be overstocked. Now as regards the most ancient _Speculums_ printed in Holland, it is by no means improbable, that, as two editions in Latin and two in Dutch followed one another in quick succession, the printer did overstock the market, and had to cease work in consequence. It is at any rate certain, that the cuts were laid aside for a length of time, and were not reprinted until 1483, when Veldener, then printing at Culembourg, issued an edition in small 4to., sawing the pictorial headings in two in order to suit his purpose. This branch of the subject is of some importance in its bearings on the question of the origin of block printing in Holland, and will be more fully considered in a subsequent chapter.