Lost time is never found again, the popular saying holds. Since man first became aware of the concept of time, or of the fact that the present is different from the past and from the future, he has sought ways to record and better use this one-way current.

Throughout history different methods have been applied to account for the passage of time. Mostly, these have relied on the movement of the sun across the day sky or of the advancing of the stars and planets for longer periods of time. However, it was only in relatively recent history of human development that time became so important that it needed to be measured most precisely and by one single standard. This called for the invention of what was to become the mechanical clock that we all know.

The earliest predecessors of today’s mechanical clocks were the public clocks made in Italy and later in England in the 14th century. It would take another two hundred years before a German, Peter Henlein, invented the small portable clock. This device became the very first precursor of the indispensable for us all modern watch.

From clocks to watches: the development of the watch

The initial stages of clock craftsmanship produced time measuring devices, which only measured the passing of hours. They had no hand to indicate minutes throughout the duration of each hour and hence had only one hand. In 1580, the legendary medieval Italian scholar known as Galileo, realized the importance of the pendulum for measuring time. In his student years, he noticed that a lamp swinging always needed the exact same amount of time to make a complete swing. Irrespective of how long the extent of the swing was, Galileo proved scientifically that this rule of the pendulum could, be used for controlling clocks. Some eighty years later, Christiaan Huygens - a Dutch astronomer and physicist - experimented and expanded on Galileo’s invention. Around the year of 1656, he became the first to apply the pendulum method in clocks to measure time. Shortly after Christian Huygens' contribution, clock making experienced a surge and clocks with short pendulums were often coated in a wooden box and became commonly hung on walls. As clock popularity increased and greater precision was called for, the hand indicating the minutes was introduced shortly in about 1670. By the turn of the century, the whole mechanical gear was completely enclosed from all sides with the introduction of the front glass shield.

The essence of the mechanical clock and watch.

In the early stages of clock making, the apparatus of clocks was entirely made of iron. During the last decade of the sixteenth century, brass was also introduced as a clock mechanism material. Some thirty years later, in late 1620’s, brass was established as the preferred material for the less precise parts, but steel was used for the more refined elements.

To the ordinary person, the image of the inside of a mechanical clock is a somewhat perplexing. It is a multitude of gears, all interconnected and interdependent, and it is not all so simple to make out which is what. Quite simply however, all the gears and wheels are moved by a wound spring or a weight connected to the main wheel. It is essential that the gears be perfectly shaped to ensure a smooth and steady motion of the hands of the clock.

As already mentioned, Peter Henlein must be credited with the very useful transformation of the clock into a watch. The earliest watches were made in his native Germany. Rather bigger than their contemporaries, these timepieces were carried around in the hand as they were more or less 12 centimeters in diameter and measured some 8 cm in depth. Essentially, the motor of these portable clocks was the so-called “main spring.” The main spring stores the energy it has gained during winding. The more the mainspring is wound, or bent, the more energy it gains and stores. It then passes this energy on to the gears and eventually on to the hands of the time keeping device.

Early shortcomings of watch construction

    The primary shortcoming in the early craftsmanship of watch making had to do with the inconsistency in the torque put forth by the main spring. When fully wound, the main spring would exert more force than at any other time. This presented a crucial difficulty for accurate time keeping. Luckily, still early in the forming years of clock and watch development, a solution was found. In around 1540, Yakob the Czech of Prague invented a grooved pulley in the shape of a cone, known as the fusee, which was used with a barrel enclosing the main spring. Thus enclosed, the main spring rotates the barrel with it. At the same time, a small chain is wound on the barrel with its other end winding about the fusee. If the main spring is wound to the maximum, the chain pulls on a bigger radius. When precise relationship between the main spring and fusee radii has been set, an invariable stable torque is produced. A related facility shortly introduced was the so-called “going barrel.” It allowed the watch to keep going while it is being wound - a feature modern watch users are all familiar with.

In the very early clocks, a wheel with a heavy rim called “the balance,” or a foliot - a weighted crossbar - was fitted to maintain the pace of the clock apparatus. Because it did not have a regular constraint, it was quite impossible to mark out its oscillation phases precisely. Therefore, the oscillation period and the pace of the clock were affected by the driving force. Luckily, the introduction of the fusee solved this problem.

Further Developments

    In 1675, Christiaan Huygens made the first watch with a “hair spring,” or a spiral balance spring. The hair spring was made of a small steel band and was bent into a spiral shape. Its inner end is attached to a small collar and the outer end is attached in a stud fastened to the movement. The hair spring essentially does to the balance what gravity did to the pendulum. When the balance is moved offside, it winds the spring, charging it with energy. In return, the hair spring unwinds and thus restores the energy to the balance.

In a theoretical situation of no frictional force, both in terms of inner spring friction and the minimal air friction, the balance would swing exactly the same distance from one side to the other and would swing ad infinitum. Because of frictional slow-down in real life circumstances, the main spring’s accumulated energy weakens. This is where the energy accumulated by the mainspring and transferred to the balance by the wheel train and escapement helps to sustain the rate of the swings. Traditionally, the masters of watch making in Europe used only hardened steel as the material of the watch club-toothed wheel. The wheel’s outer surface was finely ground and polished to ensure reliability and high quality. Its refined shape guarantees minimum motion loss between the wheel and the pallets.

The Popularization of the Watch

    As watches became more and more popular, especially among the higher classes, they became an indispensable fashion accessory for those who could afford them. Naturally, they started being adorned with precious stones and were positioned as jewellery items. In a typical traditional manner, jewellery watches are of uniform outer thickness about the diameter of which are made small holes. The holes act as the holders of the jewel bearings, which are fixed into them. This is an extremely delicate process dealing with holes measuring one tenth of a millimeter.

In 1780, the first self-winding pocket watch was officially registered in London, England. Almost a century and a half later in 1924, the English patented another development in watch making. It was the self-winding wristwatch, which includes an oscillating weight pivoted at the center of the rotation. This weight is attached to the barrel arbor by means of reduction wheels and gears. The later development of this device has the weight rotating completely, winding in either direction of the rotation movement.

Increased durability and facility of taking care of one’s watch meant increased interest in watch production. People needed more reliable time keeping indicators, and research in watch making increased. In 1906, the battery driven clock was invented. It used electrical current to control a set of dials. Some twelve years later, in 1918, the synchronous electric motor was introduced in clocks, which further increased their recognition as a common home accessory.

A big leap towards exactitude was made in 1929 with the use of quartz in time keeping devices. The quartz crystal, oscillating at frequencies of 100,000 hertz, can be compared and frequency differences can be established to an accuracy of one part in 1010. This allowed for tremendous precision in time measuring.

Today, as almost everything else that can make use of it, electric current is the preferred driving force in watches. Small pre-charged batteries are used to drive the electric timekeeping devices. Several different methods are commonly used in electric watches. One is the induction-powered device in which an electrical magnet pulls a magnetic balance towards it. Another is the galvanometer drive method. This type of drive is essentially a balance hair spring oscillator powered by the attraction between a coil and magnet. Yet another method employs the so called resonance drive. This type of drive uses an electrically powered minute tuning fork to provide the driving power. This particular mechanism is the one, which can most accurately be referred as the electronic watch. It is the most precise out of the devices described above as it functions at a higher frequency than that used in balance type watches. Using a transistor instead of mechanical contact, the electronic watch produces almost no friction, ensuring increased precision. Also, in such watches there is no slowing down of the driving mechanism because when the battery is exhausted, the watch just stops working.

As we entered the sci-fi age and are today bombarded with countless electronic and computerized gadgets and semi-intelligent devices, watches of all shapes and multiple features have appeared on the market. Many of these “timekeepers” show the time in digital format, some even say it out loud when we ask them to. Some watches continue to be regarded as jewellery items, some are combined in phones, some have integrated digital cameras, and some have it all. But no matter how altered the shape and how multipurpose the additional features of watches become, they are still being made for their essential historical reason - to tell time.