natter published in 1754 "a treatise on the ancient method of engraving on precious stones compared with the modern", london; it was also published in french in the same year as "traité de la méthode antique de graver en pierres fines". in natter gave practical instructions in gem-engraving, and strongly advised beginners to copy from the antique. godefrid kraft of danzig is mentioned by him, as a pupil of his in engraving. the "treatise" did much for his reputation, but in financial terms proved troublesome.