Some files from www.archive.org:
Catalogue and price-list of fine imported and American machinery, tools, materials, and supplies for machinists, jewellers, watchmakers ..
Precision time measures : their construction and repair : a manual of the theory and mechanical laws governing the construction of timekeeping machines and accepted methods of their maintenance and repairs
"Junghans Aviation Clocks: A Historical Look at Timekeeping in Flight - Reading's (Updated 06.08.2019)"
Junghans clocks have a long-standing history of being used in zeppelin and aircrafts. The company's precision and reliability in timekeeping made them a popular choice for aviation. In fact, Junghans clocks were used in the Hindenburg, the famous zeppelin that flew from Germany to the United States in the 1930s. Today, Junghans continues to produce high-quality timepieces that are both functional and aesthetically pleasing. Whether you're an aviation enthusiast or simply appreciate fine craftsmanship, a Junghans clock is a timeless addition to any collection.