ZENITH observation chronometer in original wooden box, Switzerland around 1920, 3-piece construction mahogany box, inserted brass case, bezel screwed down, silvered dial with Roman numerals, 40-hour power-reserve- indicator at 12, constant second at 6, blued original hands, gold-plated 19´´´ pocket watch- movement, 15 jewels, compensation- balance with Breguet balance-spring, measures approx. 15 x 12 x 9, original key enclosed, condition 2-3