19. 19Y Patek Philippe. A fine lady's 18K gold manual wind wristwatch with sigma dial Model: Ellipse Lady Reference: 4458 Date: Circa 1970 Movement: 18-jewel Cal.16-250 manual wind, adjusted to isochronism, heat, cold and 5 positions, No.1392469 Dial: Sunburst blue, applied 18K gold baton hour markers, 18K gold pointed baton hands Case: Brushed and polished oval form, snap on back, No.2776143 Strap/Bracelet: Black crocodile leather Buckle/Clasp: Signed 18K gold buckle Signed: Case, dial & movement Size: 20mm Weight: 26,11gr When the Ellipse was first launched in 1968, its design was hailed as a striking combination of audacity and harmony. The balanced proportions were inspired by the "Golden Section," the divine proportions discovered by ancient Greek mathematicians.