had engraved upon a Diamond a portrait of Don Carlos, intended for a betrothal present or gage d'amour to
Anna, daughter of the Emperor Maximilian II. This work was actually
seen by Clusius during his residence in Spain in the year 1564. Birago
had also engraved on Diamond the arms of Spain as a signet for the same
ill-fated prince.
The
discovery of the method of executing such engravings is assigned by
Paolo Morigia, in his ' Nobilite di Milano,' to Trezzo, the famous
cameo-artist of that city, and his first essay on this stone was the
coat of arms of the Emperor Charles V. : adding that Birago, a pupil of
Trezzo's, afterwards engraved on a Diamond the portrait of Don Carlos,
the Prince of Spain. iElius Everhard Vorstius, physician to Maurice of
Nassau, and therefore a contemporary and trustworthy authority, in his
Preface to 'Gorlsei Dactyliotheca ' (published first in 1601) repeats
Morigia's statement as to Trezzo's (Treecia's) being the first
inventor, and having cut on a Diamond the arms of Philip II. Gori ('
Hist. Dactyl.,' 186) says that Jacobus Thronus (who, judging from his
name, was a Hollander) engraved " eximia arte " on a Diamond,
the arms of Philip's consort, Queen Mary of England. In the very
miscellaneous collection belonging to a Mr. Peter (sold at Christie's,
June, 1859), Lot 206, is: "A gold ring, set with a large square
Diamond, engraved with the arms, crown, and cypher, of Mary Queen of
Scots." *
To
come to more reoent times : in Her Majesty's collection of gems is
preserved the signet-ring of Charles II. when Prince of Wales, bearing
for device the ostrich-
