A South German turned ivory cup and cover 17th century

the conical base of ridged lobes rising to a gadrooned baluster form stem with stepped florettes, a ring of foliate points below the gadrooned cup, divided horizontally into three registers, the conforming lid surmounted by a ring below a crown-form beneath a spiralling openwork finial with encircling ramp surmounted by a smaller crown.

Cup leans slightly. Some small age cracks throughout, including three short blackened cracks to one gadroon on central register of cup. Small losses and cracks throughout pierced openwork. Some pits and discolored areas due to natural impurities in the ivory, including part of top finial, part of stem, and a hole in bottom of cup. Ring below cup slightly offset. Otherwise minor small chipping, surface abrasions, and variations in color. Glued crack to openwork at aperture in center of the underside of base. Stains in crevices. Spiral finial possibly associated.
In response to your inquiry, we are pleased to provide you with a general report of the condition of the property described above. Since we are not professional conservators or restorers, we urge you to consult with a restorer or conservator of your choice who will be better able to provide a detailed, professional report. Prospective buyers should inspect each lot to satisfy themselves as to condition and must understand that any statement made by Sotheby's is merely a subjective qualified opinion.
NOTWITHSTANDING THIS REPORT OR ANY DISCUSSIONS CONCERNING CONDITION OF A LOT, ALL LOTS ARE OFFERED AND SOLD "AS IS" IN ACCORDANCE WITH THE CONDITIONS OF SALE PRINTED IN THE CATALOGUE.

This impressive ivory goblet closely relates to a cup and cover turned by Emperor Leopold I in 1618 when he was as Archduke of Austria, now preserved in the Danish Royal Kunstkammer at Rosenborg Castle in Copenhagen (Gundestrup 1991, pp. 261-262, DKK 23.81).  That example bears the signature Leopoldus Archiduc Austriae fecit 1618 and the Austrian coat of arms, and like the present cup features a high conical base comprised of ridged lobes, a densely gadrooned stem, a cup in three registers, and a pierced crown.  The finial of the present cup is similar in design to a late 16th century candlestick turned in Dresden and today preserved in the Bayerisches Nationalmuseum in Munich (Maurice 1985, p. 79, no. 88).

The lathe made it possible for artists to achieve sculptural forms which would be impossible to create by hand; the operator applied tools to subtract material from a solid medium rotating rapidly on an axis powered by a treadle or a flywheel.  Innovations to this basic process in the late 16^th century vastly widened the formal possibilities: multiple axes, elliptical motion, elaborate rotating chucks, and complex cutting tools allowed for the production of spiraling, asymmetrical, undercut, and often paper-thin elements.

The form of a spiralling tower with encircling ramp in turned ivory has been compared to a kind of miniature Tower of Babel, as indeed it strains the limit of possibility and evokes a sense of audacious, hubristic height.