This large observation watch No. 83193 crafted by A. Lange & Söhne was sold to the Zeppelin yard at Friedrichshafen in 1935. It was used for airship navigation and air traffic control. The Physics Institute of the Clausthal-Zellerfeld Mining Academy and the Berlin Society for Time Measurement belonged to the scientific community that purchased further exemplars of this observation watch type.

1A quality gilt movement (calibre 57): five screwed gold chatons, engraved balance cock with diamond endstone, large compensation balance with gold screws, gold pallet lever, movement diameter: 25 lignes
Silver-plated dial with subsidiary seconds and UP/DOWN power-reserve indicator, signed: A. Lange & Söhne, Glashütte b. Dresden, 83193
Silver case with gold hinges and gold crown

HISTORY OF THE UP/DOWN POWER-RESERVE INDICATOR

MANUFACTORY

TIMEPIECES

POINTS OF SALE

THE ZEPPELIN OBSERVATION WATCH.