For sale we have a very charming 1920s Zentra German Art Deco square tank watch, in a Swiss silver case with engraved bezel design, with an early Felsa manual wind movement.
 
This is a neatly designed and eye-catching tank style watch from the 1920s in a good silver case. The bezel engraving is particularly eye catching, along with the champagne dial with subtle shine. The Arabic numerals, 24 hour marking and thermally blued hands make this stand out. An affordable and fun addition to a vintage watch collection.
 
Zentra are a German watch company, who were founded in 1927 in Berlin. Most cases tended to be German, whilst movemenets were German (PUW) or Swiss (A.Schild or Minerva). They advertised with the slogans "die Uhr mit dem Reifezeugnis" (the watch with a certificate of maturity and "die treue Gefahrtin" (the faithful companion), clearly demonstrating a focus on reliability. 
They moved to Cologne post WWII and remaned ZentRa Uhren GmbH. They produced for men and women, targetting the emerging middle class, whilst also expanding into neighbouring countries.
 
The tank style case measures 25.5mm x 25.5mm with a lug-to-lug measurement of 33mm. 
The case is Swiss hallmarked Silver and is square with a polished finish and engraved bezel. The bezel has a chequered design to the sides, with an arrow shaped design to the top and bottom. The lugs have a rounded design to the ends which creates a very neat case. To the rear is a polished case back which is hinged to the top, with the hinge functioning well. To the right of the case is the original silver crown with rounded coin edge finish.
 
The case is hallmarked with the 0.900 Swiss fineness grade, with the bear marking. The 0.900 grade was higher than the Swiss standard of 0.875. It was never introduced into Swiss law, but was a popular grade in the US and Europe as it was the standard used for coins. It has the serial number 88075, with an unidentified makers mark.
 
The dial has a champagne base tone which has some areas of darkened patination. It is an unusual tone for the era with a subtle satin shine adding intrigue. A cut railroad track follows the outside of the dial, with 24 hour signing separating the segments. Inside are the Arabic hour markers which have a black outline and lume in-fill to the centre in a deep cream tone. The sub-second dial is square, keeping continuity with the dial and case. It has exaggerated Arabic numerals for the 10 second graduations, with a circular centre and railroad track. The dial is signed with the Zentra 3 below 12 O’clock.
 
The hands are thermally blued with lume in-fill. The lume has been replaced with a well-matched modern alternative. The thermally blued finish is excellent and signs brightly in the light. 
 
The watch is on a 16mm genuine leather strap for fixed lugs. It has an unbranded Stainless buckle.
 
The movement is an early Felsa 7 jewel movement. It has a gold tone finish, with Zentra “3” signing on the it. The service history is unknown, but the movement is in good condition cosmetically and functionally. It has a daily variation of + 60 seconds a day, with a strong amplitude.
 
Please see the images as these compliment and aid the description provided below.
A further condition report is below.
 
Dial: 
The dial is in good original condition with some areas of darkened patination. It has black painted Arabic numerals, with modern well matched lume in-fill.
 
Hands: 
The hands are original. They are thermally blued with lume in-fill. The lume has been replaced with a well-matched modern alternative. The hands are in very good condition, signing brightly in the light. The sub-second hand is a gold tone and has been replaced.
 
Glass: 
The acrylic crystal is a replacement and is in good condition with some scratching associated with age on the right hand side.
 
Crown: 
The crown is original and is formed of silver. It has light surface scratching.
 
Case:
The case is Silver and is square with a polished finish and engraved bezel. It has light surface scratching associated with age and some light denting as is common with silver of this age. It has light tarnishing.
 
Caseback:
The case back is Silver and is in good original condition. It has a polished finish and light surface scratching associated with age.
 
Strap: 
The watch is on a 16mm genuine leather strap for fixed lugs. It has an unbranded Stainless buckle.
 
Movement: 
The movement is an early Felsa 7 jewel movement. It has a gold tone finish, with Zentra “3” signing on the it.
 
The service history is unknown, but the movement is in good condition cosmetically and functionally. It has a daily variation of + 60 seconds a day with an amplitude of 265 degrees and a beat error of 7.8m/s.
 
Case dimensions: 
Case width: 25.5mm
Case width with crown: 27mm 
Case length: 25.5mm 
Case length lug to lug: 33mm
Case Depth: 9mm
Lug width: 16mm