The
History of Clocks At best, historians know that 5000 - 6000 years ago, great civilisations in the Middle East and North Africa started to examine forms of clock-making instead of working with only the monthly and annual calendar. Little is known on exactly how these forms worked or indeed the actual deconstruction of the time, but it has been suggested that the intention was to maximise time available to achieve more as the size of the population grew. Perhaps such future periods of time were intented to benefit the community by allotting specific lengths of time to tasks. Was this the beginning of the working week? Using the Sun Sundial Clocks Another ancient Egyptian 'shadow clock' or 'sundial' has been discovered to have been in use around 1500 BC, which allowed the measuring of the passage of 'hours'. The sections were divided into ten parts, with two 'twilight hours' indicated, occurring in the morning and the evening. For it to work successfully then at midday or noon, the device had to be turned 180 degrees to measure the afternoon hours. The Egyptians also used the 'Merkhet', the oldest known astronomical tool, which is believed to have been developed around 600 BC. Two merkhets were used to establish a north-south line which was achieved by lining them up with the 'Pole Star'. This enabled the measurement of night-time hours, when certain stars crossed the marked meridian. By 30 BC, 'Vitruvius' describes thirteen different sundial styles being used across Greece, Asia Minor, and Italy, inherently demonstrating how the development must have grown to be more complex. Water Clocks Look at the picture right. Water drips from the higher container to the lower container. As the water level rises in the lower container, it raises the float on the surface of the water. The float is connected to a stick with notches, and as the stick rises, the notches turn a gear, which moves the hand that points to the time. 'Water clocks' were among the
earliest time keeping devices that didn't use the observation
of the celestial bodies to calculate the passage of time. The
ancient Greeks, it is believed, began using water clocks around
325 BC. Most of these clocks were used to determine the hours
of the night, but may have also been used during daylight. An
inherent problem with the water clock was that they were not
totally accurate, as the system of measurement was based on
the flow of water either into, or out of, a container which
had markers around the sides. Another very similar form was
that of a bowl that sank during a period as it was filled of
water from a regulated flow. It is known that water clocks were
common across the Middle East, and that these were still being
used in North Africa during the early part of the twentieth-century. Dividing the Year into
Months and Days Dividing the Day into
Hours, Minutes, and Seconds Somebody finally figured out that by dividing the whole day into 24 hours of equal length (12 hours of the day plus 12 hours of the night), the time could be measured much more accurately. Why was the day and night divided into 12 parts? Twelve is about the number of moon cycles in a year, so it is a special number in many cultures. The hour is divided into 60 minutes, and each minute is divided into 60 seconds. The idea of dividing the hour and minute into 60 parts comes from the Sumerian sexagesimal system, which is based on the number 60. This system was developed about 4,000 years ago. Mechanical Clocks 'George Graham', in 1721, invented a design with the degree of accuracy to 'one second a day' by compensating for changes in the pendulum's length caused by temperature variations. The mechanical clock continued to develop until they achieved an accuracy of 'a hundredth-of-a-second a day', when the pendulum clock became the accepted standard in most astronomical observatories. Pendulum Clocks The pendulum swings left and right, and as it swings, it turns a wheel with teeth (see the picture to the right). The turning wheel turns the hour and minute hands on the clock. On the first pendulum clocks, the pendulum used to swing a lot (about 50 degrees). As pendulum clocks were improved, the pendulum swung a lot less (about 10 to 15 degrees). One problem with pendulum clocks is that they stopped running after a while and had to be restarted. The first pendulum clock with external batteries was developed around 1840. By 1906, the batteries were inside the clock. As you already learned, a clock only shows 12 hours at a time, and the hour hand must go around the clock twice to measure 24 hours, or a complete day. To tell the first 12 hours of the day (from midnight to noon) apart from the second 12 hours of the day (from noon to midnight), we use these terms: A.M.--Ante meridiem, from the
Latin for "before noon" Quartz is a type of crystal that looks like glass. When you apply voltage, or electricity, and pressure, the quartz crystal vibrates or oscillates at a very constant frequency or rate. The vibration moves the clock's hands very precisely. Quartz crystal clocks were invented in 1920. Europe In Italy, during the early-to-mid fourteenth-century, large mechanical clocks housed in towers began to appear in several of the large cities. These clocks appear to have been plagued by the same problem as that of the 'water clock', that of regulating the mechanisms and maintaining the accurate time. This appears to have been due to the oscillation period of the escapement depending on a driving force which had sufficient friction in the drive mechanism. A technological advance came with the invention of the 'Spring-powered' clock, around 1500-1510, credited to 'Peter Henlein' of Nuremberg (Germany). These were instantly popular although the spring-powered clock did have one problem, that of slowing down when the mainspring unwound. In the sixteenth-century, and even through until the nineteenth-century, these clocks were mainly the reserve of the wealthy, when the reduced size meant it could now be put on a mantle shelf or table. The development of the spring-powered clock was the precursor to accurate time keeping Time Zones
Before buying a spring-driven clock, try to wind it to see if it has a broken mainspring. If the key turns and you hear the mainspring slip, the spring has broken at the outer end and there would probably be little or no damage to the gears. If the mainspring is fully wound, there is probably no damage either (exceptions sometimes include carriage clocks and French clocks). If the winding key turns easily and there is no load, the mainspring has broken near the inner end and there would probably be considerable damage to the gears. Be sure that parts are not missing, such as the pendulum or weights (if the clock was designed to have them). Consider the age of the clock before buying. The older the clock, the more desirable and collectible it is. However, clocks made before about 1870 are usually more difficult to repair because the industry lacked good technology in the machines that were used to manufacture clock parts. Parts were finished and fitted by hand. The parts fit together less accurately than parts in newer clocks, which can create problems during repair. Some of the finest timepieces I have seen, in terms of quality and technology, were made between 1910 and 1950. Newer clocks have very accurately made parts, but manufacturers have increasingly been finding ways to lower production costs, frequently at the expense of quality, which is why I do not like most clocks made after 1985. What
To Look For With clocks, what you see is most definitely not all you get. It is important to look at the entire clock, not just the beautiful case but also the mechanical heart within. Here's some quick advice: Avoid so-called marriages, i.e., clocks whose authentic movement was removed and replaced with another not its own Always try to buy the best in the price range you can afford (this also makes it easier to trade up at some time for a more expensive and more desirable piece) If you are a beginner, decide
early on about the form of the collection (e.g., you may want
to specialize in carriage clocks, novelty clocks, 18th century
English clocks, etc.) Compared to other collecting fields, prices for antique clocks are relatively modest. A clock by a top maker will generally cost much less than a painting by a top artist of the same period. An 18th century English bracket clock by a good maker can be purchased at auction for less than £10,000 (approximately $15,000). A collector can start with a French 19th century French decorative mantel clock or a French striking carriage clock from the latter part of the 19th century with a repeat facility or an alarm, which will cost around £600 (or $900). As is the case with all antiques, rarity and condition are very important and affect price. Christie's London sold a Queen Anne ebony miniature table clock with pull quarter repeat for more than £350,000 or more than $500,000 (December 2000). Introduction
to clocks The value of a clock depends on its maker, the movement, the case and its condition. Plain carriage clocks are available from about £200, and a late 19th-century long-case from around £800. Unlike many other types of antiques, clocks are 'working' antiques. You can appreciate them for their visual appeal and technical mastery - and they also serve as timekeepers. If you're a novice collector thinking of investing in a clock, it's probably best to buy one in working order. Most clocks can be repaired, but restoring a 'bargain' can be a laborious and expensive business, and unless the problem is very straightforward it's often cheaper in the long run to buy a clock that's been properly overhauled and restored to working order by a skilled clockmaker. Most clocks are relatively easy to date and identify because they were signed by their maker on the dial and movement, and records of most makers have survived. A clock's visual appeal, however, lies largely in its case, which usually reflects the style of furniture of the period. There are three key elements which you should access before buying a clock: the mechanism, or movement; the dial; and the case. Movements The escapement. This is the part of the movement that controls the speed at which a clock runs. The verge or balance wheel escapement. The balance wheel escapement was used on lantern clocks until c.1760. The oscillating balance wheel releases the two pallets of 'flags' on the vertical bar, which engage the toothed wheel. The verge escapement is similar but has a short pendulum. The anchor escapement. This was first used in long-cases from c.1670, and became standard for long-cases and brackets. The anchor engages with the teeth of the escape wheel. Clocks with an anchor may have a long or short pendulum. Pendulums Dials The dial is the face of the clock and is attached to the movement by a number of brass 'feet'. A dial has an important bearing on price. Clocks with replaced dials are much less desirable. There are four main types of dial: Brass dials. These are the earliest type of dial, used on lantern, bracket and long-case clocks. These have the hours engraved onto a detachable chapter ring. Painted metal dials. These are found on most clocks after c.1800. They became increasingly elaborate in the 19th century. Painted wooden dials. These are found on English dial clocks, tavern clocks and continental clocks. If authentic, the wood will show some signs of cracking caused by changes in temperature. Enamelled metal dials. These are common on carriage clocks and other types of French clock. They're made from enamel fired on top of thin copper. Hands. Early clocks only have one hand (for hours), but from c.1660 most have both a minute and an hour hand. Second hands are usually shown on a subsidiary dial. Hands are usually made from blued steel, although gilded brass is found from c.1790. Until c.1740 the hour hand was elaborate, while the minute hand was longer and simpler. Replacement hands are acceptable if they're in the right style. Cases. The case houses the dial and the movement. Knowledge of materials and styles is useful in dating a clock and in assessing its value. Wooden cases. These were introduced in the 17th century. Many cases are covered with thin veneers of wood. The most common woods are ebony, walnut, mahogany and rosewood. Wooden cases may be decorated with marquetry (patterns made from different woods), lacquer, applied metal mounts, brass inlay (on rosewood cases), or a combination of tortoiseshell and brass (boulle work). Metal cases. Brass is the most common metal: all carriage clocks are brass-cased. Old brass is uneven and shows marks left by the casting process, while modern rolled brass is of uniform thickness. Brass cases may be elaborately engraved or decorated with enamel colours. Signatures. Most clocks are signed, although a signature isn't always a guarantee that the clock was made by the maker whose signature it bears. 19th century clocks may be signed by the retailer rather than the maker. Genuine signatures are usually found in the following places: until 1690, along the bottom of the dial plate; from 1690 to 1720, on the chapter ring; after 1720, on the chapter ring, on the boss in the arch or on an applied plaque. Bracket
clocks A brief history The English bracket clocks you're most likely to come across are those with mahogany veneered cases. Large numbers were produced from the late 18th and early 19th century, mainly in London, and you can still find clocks of this type for about £3,000 to £6,000. It's also easy to find French 19th-century clocks, which were made in a wide variety of shapes. Many of these incorporate such lavish decoration that you may need to take a second look before you realise they're clocks at all. Early brackets Early (pre-1700) bracket clocks, such as this one from about 1695, are usually the most valuable. You can generally identify them by their ebony or walnut cases and elaborately decorated square dials.
Regency clocks
French bracket clocks Bracket clock tips
Makers
Mahogany brackets
Both elaborate and simple cases were made from mahogany. The 1875 clock here has a fairly simple one, but the clocks illustrated here show some of the more elaborate variations. Carriage
clocks French carriage clocks Features to look for are:
Signs of quality:
Repeat buttons Engraved cases Makers
Subsidiary dials
Longcase
clocks Value pointers If a clock has an unusual or attractively painted dial, or an elaborate marquetry or lacquered case, it will cost more than a run-of-the-mill version. Size can also have a bearing on price. Smaller longcases are usually more expensive than larger ones, and for good reason. In the past, rooms had higher ceilings than modern homes, and longcase clocks tended to be designed in proportion. So don't forget to check that a longcase will fit before you buy it! Names to look out for Mahogany longcases Parts of a longcase:
Dials - the changing face
Originally square, dials became arched in about 1720. Most longcases have brass dials, like the main picture here, or painted ones. Brass dials are usually 30cm (12in) in diameter and have an applied chapter ring (the band showing the numbers) and applied spandrels (corners). Walnut longcases Marquetry longcases
Novelty
and skeleton clocks Mystery clocks
Automaton clocks Value Skeleton clocks This typically elaborate clock (with its protective glass dome removed) dates from about 1870. It was made by J Smith & Sons and is worth £6,000 to £12,000.
The protective measures for antique clocks are no more stringent than for other antique furniture. Avoid:
Do:
Restoration More
Information Antiquarian Horological
Society Association Française des
Amateurs d'Horlogerie Ancienne (AFAHA) British Horological Institute National Association of Watch
& Clock Collectors (NAWCC) • Visit the clock collection of various museums: Austria: Uhrenmuseum der Stadt
Wien, Vienna • Christie's specialists are always available to help you form a clocks collection Collector's Dictionary of Clocks and Watches by Eric Bruton A Connoisseur's Guide to Antique Clocks & Watches by Ronald Pearsall Encyclopedia of Antique American Clocks by Robert W. Swedberg & Harriett Swedberg Watch and Clockmakers' Handbook, Dictionary and Guide by F.J. Britten Collectable Clocks 1840-1940 by Alan and Rita Shenton British Longcase Clocks by D. Roberts Carriage Clocks by Charles Allix The Collectors Dictionary of Clocks by Alan Lloy
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