Alphabeti verè naturalis Hebraici brevissima delineatio : quae simul methodum suppeditat, juxta quam qui surdi nati sunt sic informari possunt, ut non alios saltem loquentes intelligant, sed & ipsi ad sermonis usum perveniant
A 1667 Latin treatise by Franciscus Mercurius van Helmont, printed in Sulzbach, teaching Hebrew letter sounds and mouth positions so that deaf students could learn to speak. The engravings show a profile head in a hooded cap, with a numbered band on the headdress and a framed panel below holding stylised Hebrew-style letterforms. A designer might take the strict side-profile diagrams, the boxed letter panels and the numbered grid as a model for clear instructional labelling.
