Ca. Ø57.5mm, ca. 134g, original leton case, back with raised flowers and leaves, fire-gilded, decorated withpletely preserved and original stone setting, central a large enamel plaque with painting of exceptionally fine quality, plaque perfectly preserved, case and movement matching with number No.715, verge movement in excellent condition, signed and numbered, signed enamel dial also in excellent condition, exceptional original hands withplete stone setting, intact and in museum condition. It is extremely rare to find these 'Leton' watches in such an original and outstanding condition. The size and quality of the enamel painting are also extremely rare. Tardy's 'Dictionnaire des Horlogers Francais' lists Jean Louis Argand in Geneva and Paris. Argand worked between 1760 and 1777.