Round dish in silver. 
Hallmarks: flower corresponding to the period 1768-17774 for small Parisian pieces of silver; helmeted head turned to the right corresponding to the same period; silversmith's hallmerk for Jacques Pierre Marteau registerede in 1757 and  deceased in Apris 1779. The letter date is a crowned "H" for the period going from July 1771 to July 1772. 
Diameter: 29 cm.
Weight: 703 grams.