In the world of mechanical watches, precision reigns supreme. And while the Swiss COSC sets the modern standards for the certification of chronometers, observatory certification was once considered the most prestigious certificate for the accuracy of mechanical watches. Among the most famous was the Kew Observatory, known for its extensive regime of chronometer tests. His "observatory test" tested watches for 44 days in many positions and extreme conditions compared to the relatively short 15-day COSC test. The auctions sold for Bonhams watches were not one, but two very rare Rolex tested by Kew A, which are perhaps the most accurate watches that were placed under the hammer for its time.
Two Kew A watches tested for Rolex auctioned Bonhams watches
Rolex Oyster Speedking
Lot 21 is a Rolex hand-wound stainless steel wristwatch. The tested movement of Kew A has been rated "particularly good". Of the 136 watches that have managed to obtain the prestigious Kew A certificate, only 16 have achieved a particularly good ranking, making it one of the rarest watches ever produced by Rolex. According to the Hodinkee report, the pre-sale value of the Oyster Speedking was estimated at $ 7,600 to $ 10,000. The watch was sold on December 12, 2018 at a price of $ 30,347.
Chronometer of the Rolex Oyster Observatory
Image: Bonhams watch auction
The next watch in lot 22 was a very rare 18-carat gold-plated wristwatch made by Rolex around 1951. 18-carat gold case. According to Bonhams, the 4156 movement obtained the Kew A certificate on its fourth attempt via Teddington, placing it under the last batch of watches to pass before stopping issuing certificates. The watch was priced at SGD 54 191 on December 12, 2018 in London, New Bond Street.