An Englisch brass universal sundial by W & S Jones – Holborn- London. Circa 178-1790
.A Universal ring dial or Equinoctial ring sundial. An Universal ring dial, of the 18th century crafted of Brass 23 cm in overall diameter. This is a relatively example of the classic pendant ring dial, useable anywhere on earth and without the need for a compass. Only the date and one’s latitude are needed to determine the apparent solar time and even the North. The latitude can be determined by using the quadrennial degree scale at the backside for measuring the solar meridian altitude. The outer meridian ring is divided from 90º South latitude through 0° ( S/N) to 90º Nord latitude, readable against the index on the sliding pendant ring. It has on the backside the solar altitude scale, with 0-90 degrees, to be used with a shadow-casting straw or pin. The inner hinged equatorial ring is divided every 10 minutes of time, full circle, for twice twelve hours. The central bridge carries the shadow casting pin hold slider, adjustable to the correct solar declination using the date scale and/or the Zodiacal scale. The Zodiac scale is based on the Gregorian calendar. Declination scale numbered 20°, 10°, AE , 10°, 20°. The brass is with a fine mellow patina. Diameter: 9 inches (23 cm).
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Van Leest Antiques
Van Leest Antiques, based in Utrecht in the Netherlands, specialises in antique scientific and medical instruments. Their collection covers mainly scientific and medical antique instruments: barometers, globes and planataria, nautical instruments, anatomical models, and pharmacy items. Toon Van Leest travels regularly in Europe and visits trade fairs, auctions, and antique dealers to collect stock and to find pieces to fulfil his clients' unusual requests.
As well as being an avid antique collector and dealer, Toon Van Leest is also a dentist. He believes that antiques are a stable investment, not reliant on trends or fashion, and have truly lasting value. Above all, he says, antiques are timeless and never lose their beauty.