"Pocket Dial By Trap, Germany, C.1700"
Round-shaped pocket or travel sundial model, constructed in turned ivory, and with a floating compass. The dial bears the signature/label of David Trap, illustrated with a biblical scene, and is dated to around 1650. These ivory pocket dials are rarely signed. In addition, the signature of David Trap is very rare. For a similar example see the dial kept at the Oxford History of Science Museum, inventory number 49543. The dial measures 5 cm in diameter. Good condition 
Le Magazine de PROANTIC
TRÉSORS Magazine
Rivista Artiquariato