A. Lange & Sohne WWII B- Uhr Beobachtungsuhr with " Deutsches Uhrenmuseum Glashutte Certificate". The watch was presend for assessement. This watch was professionally fully serviced before being offered at our shop. Certificate details: Description: Silberne Beobachtungsuhr Marke ALS Manufacturer: A. Lange & Sohne Movement ; Kal. 48 Movement No; 204 732 Case Ne; 204 732 A. Lange & Söhne, Glashitte Buyer: Deutsche Seewarte Hamburg, Zweigstelle Gesundbrunnen Date of Sale:31.01.1945 Sales Price: 237,-- RM Additional Comments: Movement diameter 48 mm, silver case, degree of fineness 0.900, case shape,. Jürgens", ALS brand, 16 jewels, nickel steel compensation balance, with up and down movement (gear- reserve indication), 35 hour power reserve, silver-plated dial, Arabic numerals, Steel bulb pointer, Plexiglas, test acceptance in production stage 3 on 20.04.1944, Assessment: Die Identität der Uhr mit den oben gemachten Angaben wird bestätigt: YES The watch was presented for assessment: YES Documents, copies of the archive register: 2 sheets EVW Watches guarantees the authenticity of every watch we sell. Look at the pics,that told more than 1000 words Worldwide express shipping. Will be send registered and insured Please look at our other watches to. You can see all of our listings by scrolling down to the "seller information section" and clicking on the "VIEW CURRENT LISTINGS" button Express History: "At the beginning of the Second World War, when the demand for B-watches grew strongly and Lange & Söhne could not keep up with the deliveries, companies known for their precision work were obliged to reassemble and fine-tune calibre 48 for the Wehrmacht. These companies included: Wempe Hamburg, Huber Munich and Berlin, Alpina Berlin, Felsing Berlin, Schieron Stuttgart, Metall Lago Wien and Prell Gera. Series production of the B-watches began at A. Lange & Söhne in October 1940 with the movement number 200,000. The production of this movement, cal. 48 with the movement number 204732, was based on an order placed by Howaldtswerke AG Kriegsmarinewerft Kiel on February 20, 1944. The movement design and case document the uniform equipment of the B-watches of cal. 48 that was planned for the start of production. However, until 1945, various material substitutions had to be made, especially for the silver case, due to the wartime economy. Even the standard escapement with the special lever used from the beginning of production was no longer used in all movements at the end of the war in 1945. In the course of the production period up to 1945, reassembly was also entrusted by the military clients to various companies. Calibre 48 was developed by the company A. Lange & Söhne on military orders from 1937 to 1940. The Oliw 90 calibre, which had already been developed in the 1920s, served as the basis for this calibre, which had encountered regulation problems due to its flatness and which was not transferred to series production. In order to meet the requirements of max. 1 sec. rate deviation in 24/h, the movement was enlarged, redesigned and equipped with a power reserve indicator. The differential gear for the power reserve display is located between the upper and lower plate, next to the mainspring barrel. For the attachment of the end curve of the Breguet hairspring used in caliber 48 to the balance cock, the hairspring stud attachment, which was already registered in 1920 for the company A. Lange & Söhne in Germany as DRGM No. 748971 and patented in Switzerland under No. 90340, was used. The notch in the balance cock and the fitted, triangular stud made it possible to fix the end curve without a lug that would disturb the observation of the hairspring. The responsible departments of the Navy and the Air Force required the blanks, which were to be reassembled by subcontractors, to be supplied by Lange & Söhne in various stages of production, from individual parts to complete blanks, as required. According to the current state of knowledge, the companies listed below were assigned additional reassembly work on B-watches by the responsible military authorities in the period from 1941 to 1945. This had become necessary due to the limited possibilities for completing these watches in Glashütte. The production of caliber 48 B-watches and B-chronometers was resumed in Glashütte shortly after the end of the war. In 1968, the production of B-watches in the VEB Glashütter Uhrenbetriebe was discontinued."