Watchionary

The Age of the Moon refers to the duration between two consecutive new moons, typically presented on a watch dial as a range of 1 to 29½ days, reflecting the time it takes for the moon to complete one revolution around Earth.

Applied hour markers are numerals or ornaments that are crafted from sheets of metal and subsequently attached to the watch dial.

Arabic numerals refer to the number system, consisting of 1, 2, 3, and so on. They gained popularity on watch dials during the eighteenth century and offer more flexibility for creative expression than Roman numerals. Nowadays, many luxury watch manufacturers incorporate both Arabic and Roman numerals interchangeably on their timepieces.

An asthmomètre or asthmometer is a type of chronograph or sports counter that incorporates a specialised scale on its dial, measuring the frequency of respiratory activity in breaths per minute. Typically calibrated for 15 respirations, the chronograph hand is halted upon completion of the 15th breath and the dial displays the respiratory rate per minute.

An automatic watch movement is a mechanical type of movement that self-winds through the motion of the wearer's wrist. This movement incorporates a rotor, a weight that rotates as the wrist moves, thereby winding the mainspring, the watch's power source.

In a mechanical watch, the hairspring, also referred to as a balance spring, is an extremely delicate spring that drives the oscillations of the balance wheel, ultimately controlling the timekeeping of the watch. Its length and precise adjustment play a critical role in regulating a watch's accuracy.

It refers to a chronograph watch that typically features two subdials that are usually symmetrical, displaying the running seconds and the 30-minute scale of the chronograph.

Swiss Official Chronometer Testing Institute

A cabochon is a polished, precious or fine stone that is shaped into a dome and lacks facets. It is commonly used as a decorative element on watch dials and may also be found on crowns.

The Calatrava watch is named after the Calatrava cross. On April 27, 1887, Patek Philippe trademarked the 'Calatrava cross', a reference to the Spanish Catholic knights, who defended Calatrava (Nuova Castiglia) from Arabian invaders in 1158.

Calibre is a term that pertains to the internal mechanism or the movement of a watch or a clock. Initially, it was only used to denote the size of the movement. However, nowadays, it also signifies a particular model of movement that can be employed in various kinds of watches or clocks.

A celestial chart, commonly referred to as a sky chart, is a complex graphical illustration; it's a visual representation of the nocturnal sky. It helps individuals track the positions of stars and the moon as well as visualise the distinct phases of the moon.

The term refers to the process of engraving a metal surface with a graver to create recesses that are then filled with enamel.

The chronostop function lies between a chronograph and a minute counter. Its unique feature is that it remains continuously active while allowing resetting to zero at any point.

A cuvette is an additional cover found inside a watch caseback. It is often inscribed with the maker's signature or other engravings. It serves as an extra layer of defence against dust.

Cyclops is a term that refers to a small magnifying lens that is positioned on the crystal of a watch. It is primarily used to enlarge the date display for improved legibility.

Diamond-Like Carbon (DLC) is a high-performance carbon coating, frequently used on watch cases to obtain the black colour.

It's a complication that indicates the date of Easter, based on the following rule: the first Sunday after the full moon that appears following the vernal equinox. The patented mechanism is housed within the Caliber 89 watch.

In Italian, the word means 'right'. When referring to watches, it indicates that a timepiece is designed to be worn on the right hand.

Also called the Golden Ratio and expressed as a mathematical proportion of 1/1.6180, Divine Proportion represents a harmonious balance of uniform shapes. Commonly referred to as the 'golden section', this ratio serves as the foundation for the design of the Golden Ellipse.

Gadroon is a decorative moulding that features a sequence of convex flutes and curves, interconnected to produce an ornamental pattern.

Glucydur is an alloy that is characterised by its high elasticity, hardness, resistance to magnetism and anti-corrosion properties. It is widely used to manufacture monometallic balances, escapements and balance springs.

In a sundial, a gnomon refers to the component that projects a shadow.

Grisaille is a painting technique that employs a range of grey tones to create the illusion of sculpture or relief, often using dramatic modelling to achieve a three-dimensional effect.

A hunter-case pocket watch refers to a protective case that features a spring-hinged circular metal lid or cover that securely closes over the watch dial and the crystal. This design provides protection against dust, scratches and other forms of damage or debris.