74. Vacheron & Constantin. An 18K gold manual wind concealed 20 dollar coin watch Vacheron & Constantin. Montre de poche en or jaune 18K (750) dissimulée dans une pièce de 20 dollar mouvement mécanique Date: Circa 1970 Movement: 17-jewel Cal.1003/1 manual wind, adjusted to heat, cold, isochronism and 5 positions, No.728267 Dial: Sunburst champagne, black baton hour markers, black pointed baton hands Case: Brushed and polished inner hinged case with snap on back, outer case in the form of a United States of America 20 dollar coin dated 1904, winding crown at 1, hinged front opened via push button in milled band at 3, Signed: Case, dial & movement Size: 35mm Weight: 32,15g Coin watches were first produced in the 1920s, and rose in popularity throughout the 20th century. During the 1920s, watches were incorporated into daily objects such as cigarette cases, lighters and lipstick holders. Makers such as Cartier, Rolex, Patek Philippe, Piaget and Vacheron Constantin have produced coin watches. Real coins are utilised, with some examples with fitted lugs added on to be worn on the wrist.