This is the earliest example of an automation dial for telling time on a watch known. The hour of the day is displayed through a traveling aperture that additionally points to the minute engraved on the dial. Other types of automation dials include Sun & Moon and Differential. This design is called a wandering hour (also known as “Chronoscopes” or “Floating Hour Dial”).
It was made by William Knottesford of London, circa 1665 – 1675, prior to the invention of the spiral balance spring.
The watch has a very interesting past. It was in the collection of the renowned horologist and author Theodore Patrick “T.P.” Camerer Cuss sometime during the 1960s and described in two publications by him: “Watches with Unusual Dials,” The Antique Collector, October 1969, and Early Watches (Country Life Collectors’ Guides), a small book published in 1971.
Brian Loomes in his book, Clockmakers of Britain 1286-1700, states that William Knottesford was born in about 1644 and died in 1698. He apprenticed to Henry Child in January 1657, made Free in 1664, and became Master of the Clockmakers' Company in 1693.
Thankfully, the watch is in fine condition and still retains its original pair case. The inner “box” is gold, matching the gold dial, and the outer is leather with gold pique work. Exceedingly few gold-cased watches survive from this early period, and the same can be said for original leather outer cases. The engraving on the dial depicts the Greek Mythology story of the goddess Diana discovering Callisto's pregnancy by Jupiter.
Knottesford’s finishing is very high quality. The gold dial is secured with six posts, and the arbors on the wheels and pinions are sculpted.
Additional References and recommended reading:
Brian Loomes, Clockmakers of Britain, 1286-1700, Mayfield Books, 2014