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The Pocket Watch (A brief guide)
The Pocket Watch (A brief guide)
The earliest sundials known from the archaeological record are shadow clocks (1500 BC or BCE) from ancient Egyptian astronomy and Babylonian astronomy. Sundials were used in Ancient Egypt, Iraq, Greece and Rome. They are also mentioned in the Old Testament (—the "dial of Ahaz" mentioned in Isaiah 38:8 and Kings 20:11. "Then the prophet Isaiah called on the Lord, and the Lord made the shadow go back the ten steps it had gone down on the stairway of Ahaz.").
Over time sundials gradually became more accurate and they remained a common use way of telling the time until the early 19th century.
About 1400 BC the Egyptians invented the water clock. It consisted of two containers of water, one of which was higher than the other. Water flowed along a tube from the higher container to the lower at a steady rate. Rings were marked on the inside of the lower container and when the water level reached one it meant another hour had passed.
The first known mechanical clock (though still powered by water) was made in 723 A.D. by monk and mathematician I-Hsing. It was an astronomical clock and he called it the "Water Driven Spherical Birds-Eye-View Map of The Heavens". This clock operated by dripping water that powered a wheel which made one full revolution in 24 hours. An iron and bronze system of wheels and gears made the clock turn. This system caused the chiming of a bell on the hour.
By the 9th century AD, a mechanical timekeeper had been developed, but without an escapement mechanism (the mechanism that controls the transfer of energy from the power source to the counting mechanism).
The oldest working clock in Europe, and quite possibly the world, can be found in Salisbury cathedral. It was commissioned by Bishop Erghum and dates from about 1386. There was apparently a mechanical clock already working in Milan, Italy, by 1335, but the Salisbury clock is the oldest of its kind known to still be working.
Did you know?
Which came first. The fob watch, fob chain or fob pocket?
In the 18 century dress styles changed. Men wore coats which showed more of the waistcoat and breeches. The watch was often placed for safety in a small concealed pocket in the band of the breeches. The word 'fob' has its origins from Germany meaning 'of deception and secrecy'. and the pocket became referred to as the fob pocket. The watch chain was merely called a watch chain or string. Eventually fob was was applied to the chain as well as to the watch and to specific trinkets suspended from the chain because that became the general area these items where placed. So the pocket came first, then the watch and chain where referred to fob watches and chains after the pocket.
In 16th-century Europe timepieces made the transition in size between clocks and began to be worn on the body. The movement was made of iron or steel and held together with tapered pins and wedges, until screws began to be used after 1550. Many of the movements included striking or alarm mechanisms. The shape later evolved into a rounded form. Still later in the century there was a trend for unusually shaped watches, and clock-watches shaped like books, animals, fruit, stars, flowers, insects, crosses, and even skulls.
Styles changed in the 17th century with men wearing watches on the body instead of as pendants (the woman's watch remained a pendant into the 20th century). This is thought to have occurred in 1675 when Charles II of England introduced waistcoats. To fit in the pockets, the shape evolved into the typical round shape with no sharp edges. Around 1610 glass was used to cover the face. Watch fobs began to be used as well, the name originating from the German word fuppe, a small discreet pocket and the watch and chains began to be referred to as items contained in that pocket
Until the second half of the 18th century, watches were luxury items. An example is the 18 Carat Gold Pocket Watch By Jean Antoine L’epine (pictured left). By the end of the 18th century, however, watches (while still largely hand-made) were becoming more common; special cheap watches were made for sale to sailors, with paintings of maritime scenes on the dials.
The Movements
The Movements
Verge
Verge
Up to the 1720s, almost all watch movements were based on the verge escapement, which had been developed for large public clocks in the 14th century. This type of escapement involved a high degree of friction and no jewelling. As a result, a verge watch could rarely achieve a high standard of accuracy. Later on some Verge had jewels. Pictured opposite is a very unusual Clamshell verge.
Cylinder Escapement
Cylinder Escapement
Developed by the Abbé de Hautefeuille in the early 18th century and applied by the English maker George Graham.
George Graham
Cylinder Escapement by Thomas Grignion.
Thomas Mudge (Horologist)
Lever Escapement
Lever Escapement
Towards the end of the 18th century, the lever escapement (invented by Thomas Mudge in 1755) was put into limited production by a handful of makers including Josiah Emery (a Swiss based in London) and Abraham-Louis Breguet. With this, a domestic watch could keep time to within a minute a day. Lever watches became common after about 1820, and this type is still used in most mechanical watches today. A lever movement generally offers a more cost effective to repair.
Abraham-Louis Breguet
Types of pocket watch cases
Types of pocket watch cases
The three main styles of pocket watch, the hunter-case pocket watch, the open-face pocket watch and the half-hunter.
Open-face watch
Open-face watch
An open-faced, or Lépine, watch, is one in which the case lacks a metal cover to protect the glass. It is typical for to have the pendant located at 12:00 and the sub-second dial located at 6:00. Occasionally, a watch movement intended for a hunting case (with the winding stem at 3:00 and sub second dial at 6:00) will have an open-faced case. Such watch is known as a "sidewinder." Alternatively, such a watch movement may be fitted with a so-called conversion dial, which relocates the winding stem to 12:00 and the sub-second dial to 3:00. After 1908, watches approved for railroad service were required to be cased in open-faced cases with the winding stem at 12:00.
Hunter case watch
Hunter case watch
A hunter-case pocket watch is a case with a spring-hinged circular metal lid or cover, that closes over the watch-dial and glass, protecting them. The name originated from England where in fox hunting, it was convenient to be able to open their watch and read the time with one hand, while holding the reins of their 'hunter' (horse) in the other hand. It is also known as a "savonnette", after the French for soap (savon) due to its resemblance with a round soap bar.
The majority of antique and vintage hunter-case watches have the lid-hinges at the 9 o'clock position and the stem, crown and bow of the watch at the 3 o'clock position. Modern hunter-case pocket watches usually have the hinges for the lid at the 6 o'clock position and the stem, crown and bow at the 12 o'clock position, as with open-face watches. In both styles of watch-cases, the sub-seconds dial was always at the 6 o'clock position.
Half-hunter case watch
Half-hunter case watch
An intermediate type, known as the half-hunter (or demi-hunter), is a case in which the outer lid has a glass panel or hole in the centre giving a view of the hands. The hours are marked on the outer lid itself; with this type of case you can tell the time without opening the lid. Opposite is a superb example of a Patek Philippe 1/2 hunter.
Types of watch movements
Types of watch movements
Key-wind
Key-wind
The first pocket watches had key-wind and key-set movements. A watch key was necessary to wind the watch and to set the time. Some watches of this period had the setting-arbor at the front of the watch, so that removing the crystal and bezel was necessary to set the time. Others where more accessible by having a flip up cover of glass or metal.
Stem-wind
Stem-wind
Invented by Adrien Philippe in 1842 and commercialised by Patek Philippe & Co. in the 1850s, the stem-wind removed the key. The first stem-wind and stem-set pocket watches were sold during the Great Exhibition in London in 1851 and the first owners of these new kinds of watches were Queen Victoria and Prince Albert. Stem-wind are the most common type of watch-movement found in both vintage and modern pocket watches.
Stem-wind, pin-set movements
Stem-wind, pin-set movements
These pocket watches had a small pin or knob next to the watch-stem that had to be depressed before turning the crown to set the time and releasing the pin when the correct time had been set.
Stem-wind, lever-set
Stem-wind, lever-set
Mandatory for all railroad watches after roughly 1908, this kind of pocket watch was set by opening the crystal and bezel and pulling out the setting-lever. Once the lever was pulled out, the crown could be turned to set the time. This was preferred by railroads, as lever setting watches make accidental time changes impossible.
Jewelled movements
Jewelled movements
A jewel in a mechanical watch is a small, shaped piece of a hard mineral. Ruby and sapphire are most common. Diamond, garnet, and glass are also seen. Starting in the early 20th century, synthetic jewels were almost universally used. The most common types of jewels are hole jewels which are disks with a carefully shaped and sized hole. The pivot of an arbor rides in this hole. The jewel provides a smooth and hard surface and when properly lubricated, very low friction. Greater jewel counts are often associated with better quality watch movements. While it is true that expensive movements often have higher jewel counts, the jewels themselves are not the reason for this. The jewels themselves add essentially no monetary value, and beyond 17 offer a negligible improvement in timekeeping ability and in movement life. Most of the cost of a more expensive watch is associated with better quality finishing and, more importantly, with a greater number of adjustments.
The other basic jewel types are cap jewels, roller jewels, and pallet jewels.
7 Jewels
7 Jewels
A jewelled watch with a lever escapement should contain at least 7 jewels.
11 Jewels
11 Jewels
With American makers, it was common on low-end movements to jewel to the third wheel on only the top (visible) plate of the watch. This gives a total of 11 jewels, but looks identical to a 15 jewel watch unless the dial is removed.
17 Jewels
17 Jewels
More highly jewelled watches contain 17 jewel and is considered to be fully jewelled.
19 Jewels
19 Jewels
Watches with 19 jewels, particularly those made by Elgin and Waltham, will often have a jeweled mainspring barrel or a 19 jewel watch will have additional cap jewels on the escape wheel.
21 jewels
21 jewels
21 jewel watches commonly have cap jewels on both the pallet fork and escape wheel. 23 jewel watches will have a jeweled barrel and fully capped escapement.
Complicated movements will often have additional jewels which do serve useful purposes.
Adjusted movements
Adjusted movements
Pocket watch movements are occasionally engraved with the word "Adjusted", or "Adjusted to a number (3-5 etc) positions". This means that the watch has been tuned to keep time under various positions and conditions. There are eight possible adjustments:
Dial up. Dial down. Pendant up. Pendant down, Pendant left. Pendant right. Temperature (from 34–100 degrees Fahrenheit). Isochronism (the ability of the watch to keep time, regardless of the mainspring's level of tension).
Positional adjustments are attained by careful poising of the balance-hairspring system control control of the shape and polish on the balance pivots. Positional adjustments are achieved through repeated trials on a timing machine. Adjusting a watch to position requires many hours of labor, increasing the cost of the watch.
Early watches had problems through temperature change and various parts changed/expanded in size, and the hairspring would lengthen/shorten. The problem was completely solved through the use of special alloys for the balance and hairspring which were immune to thermal expansion. The most common method of achieving good time time with a hairspring is through the use of the Breguet overcoil. which places part of the outermost turn of the hairspring in a different plane from the rest of the spring. This allows the hairspring to "breathe" more evenly and symmetrically. Two types of overcoils are found - the gradual overcoil and the Z-Bend.
References
Header Picture - Man Holding A Watch by Maso di San Friano "Watch, Mechanical", Science and Technology, How It Works, 19 (3rd ed.), Marshall Cavendish, 2003, p. 2651, ISBN 0-7614-7333-5 in How it Works, ISBN 0-7614-7314-9.Campbell, Gordon (2006), The Grove encyclopedia of decorative arts, 1, Oxford University Press, p. 253, ISBN 0-19-518948-5.Juan F. Déniz, The first transparent watch, Antiquarian Horology March 2018 Milham 1945, pp. 133–37.Perez, Carlos (2001). "Artifacts of the Golden Age, part 1". Carlos's Journal. TimeZone. Archived from the original on 2007-02-18. Retrieved 2007-06-06. Milham 1945, pp. 213–15. "Pocketwatch". Encyclopedia of Antiques. Clocks and Watches. Old and Sold. "Lépine watch", Glossary, Fondation de la Haute horlogerie. "About Watch Cases and Crowns". Vintage Watch Straps. March 2016. Retrieved 7 June 2016. John E. Lodge, "New triumphs in age-old quest for perfect timepiece" in Popular Science, Vol. 119, No. 6 (December 1931), p. 53. "Foundation de la Haute Horlogerie". hautehorlogerie.org. hautehorlogerie.org. October 19, 2016. Van Horn, Carl (2003). Work in America. M–Z. ABC-CLIO. p. 236. ISBN 1-57607-676-8. Passy, Charles (9 March 2015). "Can a pocket watch outshine the Apple Watch?". MarketWatch. Retrieved 14 October 2016.
Did you know?
The small pocket on a pair of jeans was originally invented to take a pocket watch.
"It appears on the oldest pair of waist overalls — the original name for jeans — in the Levi Strauss & Co. archives that date back to 1879," said Tracey Panek, a historian for Levi Strauss & Co.
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