when Nürnberg and Strasburg became the earliest centres of
this business.
The "rejuvenated art" was destined to suffer another
eclipse during the civil commotions which convulsed Europe,
but, though checked in its progress, it was not uprooted, and
in the eighteenth century it sprung up with a new vigor, which
challenged defeat. The engravings of this period were, to a
great extent, copies of the antique ; therefore numerous forgeries came into circulation, greatly to the discredit of the art
and artists. It has been estimated that for every celebrated
antique-engraved gem, a dozen copies exist, so well counterfeited that amateurs and collectors are often deceived ;
sometimes they even surpass the models in excellence of
workmanship.
Engravers. — It is the opinion of connoisseurs that the number of ancient engravers on gems must have been very large,
judging from the great number of their productions, though
Pliny names only a few, of whom Pyrgoteles, Apollonius,
Cronius, and Dioscorides were the best known ; to these may
be added Aulus, Cneius, Hyllus, and Solon, whose works are
found in modern collections. The most admirable engraving
of Dioscorides, who is, perhaps, the most skilful and celebrated
of the ancient school of art, is the head of Io, in the Piombino
cabinet. The signet engraved with the portrait of Augustus,
used by the earlier Roman emperors, was a work of this artist.
Many celebrated names are found in the list of modern
engravers, whose works have excited the admiration of connoisseurs and collectors. Prominent in this catalogue stands
that of II Vicentino (Valerio dei Belli), whose coffer of rockcrystal, representing scenes in the life of Christ, was purchased
by Pope Clement VIL, for two thousand gold scudi, equal to
more than thirty thousand dollars, and presented to Francis I.,
