I think time is amazing. Time is the only factor that we can not change. We could change elevation, move left or right, go forward or backwards, yet we can't change time. What is done is done. Make the most of what time you have, you never know when it is going to run out. The clocks that I like the most are the mechanical ones.

Do you believe in time travel? If you think NO, then you are wrong. Step outside on a clear night and look upwards to the starlite sky. What do you see? You see history! The light you see originated from stars 100 of years ago.

In 1971, physicists conformed "time dilation" when they put four supremely accurate atomic clocks on board jet liners and sent them around the world. Sure enough, the speeding clocks were just slightly out of step - by about 150 billionths of a second - with identical clocks that stayed put.

Here is a paper that my brother, Anthony Rossetti, wrote about how time was attempted to be measured in early days.

Time… There is no real definition of time. Trying to tell someone what 'time' is can be very complex. Webster's dictionary lists time as: "A nonspatial continuum in which events occur in apparently irreversible succession from the past through the present to the future." People have been trying to measure and record time, the passage of an event from one to another, for centuries. Several different methods have been invented to measure time more accurately, but they have all had their drawbacks. This paper will discuss the methods used to measure time.

The earliest method of telling time consisted of observing the rise and setting of the sun (Spon,3). When the sun was visible, sundials were used to indicate the time. Sundials create a shadow on a plate that had markings which divided the day into 12 hours. The sundials were adequate only during the day. Sundials had a large disadvantage since the sun is in different positions of the sky determined by the season and also the person's latitude. Several sundial types have been invented which eliminated any dependence on the season and the sun's altitude (Ward 21). Several methods were utilized to measure time when the sun was not shinning. Early methods of telling time at night were the usage of sandglasses, an oil-burning lamp, candles, and water flow meters (Spon,3). Water flow meters had a resurgence of popularity in the 1700's only because of their simplicity in design. A particular technique of interest to tell time at night was the use of food spices. Placed at the hour markings of a clock, different spices would be set. The owner was able to tell the time by reaching up and finding the hour hand. After finding the hour hand, the owner following the hour hands position, would scrape at the face of the clock. With some spice on his finger, the time could be determined by the taste on their finger.

The observation of stars allowed another way for time to be revealed. The positional measurements of stars allowed accurate times to be measured. The usage of a Nocturnal, something similar to a star map, was very common during the 1700's. Another method of telling time at night required the use of string. The angle created by two strings aligned to aim at two different stars would tell the user the time. (Spon, 3)

Mechanical Clocks, invented around 1450, are believed to have originated in Italy. Mechanical Clocks are ones that employ an oscillator or some other escapement, to govern a set amount of time (Cipolla 38). The first mechanical clocks built were costly and very large devices. The cost of the clocks only permitted kings and very wealth citizens to purchase them. The spread of mechanical clocks was rapid mostly due to their intriguing complex design (Spon, 3). A clock was usually installed in a town's tower, which enabled every citizen to observe the time. Artists employed clocks in their paintings to symbolize "the fleeting nature of life" (Thompson 418). Owners of clocks and watches would have paintings of themselves with the timepiece visible in the foreground (Thompson 418).

The first public clocks were very unreliable for several different reasons, and required that someone maintain the clock's movement at all times. A person employed to check the clock's movement, would compare its time with a sundial. It was not uncommon for the early clocks to lose or gain a quarter hour each day. Mostly due to the unreliability of these public clocks and their tendency toward inaccuracy, they only possessed an hour hand.

Galileo observed in 1590 that the swing of a pendulum was an accurately timed event. The pendulum would always swing at certain intervals, which were not dependent on the height of the swing and the weight of the pendulum (Ward, 26). A pendulum clock, would actually count the number of swings. The only problem with the pendulum was that it needed to be lightly pushed throughout its swings to sustain a continuous swinging. 100 years after Galileo's discovery of the pendulum, Huygens invented a device that would push the pendulum through some of its swings. With the discovery of the pendulum, and Huygen's escape movement, time could be accurately measured. The pendulum resulted in the minute hand to be employed on the face of clocks. It is interesting to note that the hour hand was larger then the minute hand (Cipolla 43).

The pendulum did not fix all the problems associated with clocks . The temperature of the outside air had a factor in the length of the pendulum (Ward 26). If the temperature would change by 10 degrees, the time lost, or gained, was calculated to be as much as 2.5 seconds a day (Ward 28). The use of mercury in the pendulum as a weight allowed an accurate distance to be preserved at all temperatures. The mercury, when warm, would move up the pendulum and counteract the expansion of the pendulum rod. Methods of using zinc and steel were also employed and are still used today. The zinc and steel, when connected to each other in rods, would cancel the expansion of one by the contraction of the other.

Another problem for clocks that used pendulums were the changing air resistance to the pendulum. The barometric pressure of the air also had an observable effect on the pendulum (Ward 29). The actual weight of the hands on a clock had a dramatic effect on the pendulum's timing. The clock hands required little pressure to be moved when they were at a position between noon and 6 o'clock. To force the hands upward, much more force was needed.

As brass was introduced into new clock mechanisms, clocks became cheaper and several house started to own them. Because of the mass of the weights alone, clocks, bolted to walls, were not movable (Cipolla 48). Several owners of clocks only purchased clocks because of the social status that a clock gave a person. Clock owners knew little of how the clock functioned but would usually let others believe that they knew how the clock functioned.

The invention of the spring replaced the pendulums in household clocks. The spring allowed small clocks to be created, which may be considered large watches. These spring run devices were worn around the owner's neck (Ward 31). The spring type clocks had several disadvantage over pendulums… One of the disadvantages was a change in torque from the unwinding spring. In 1940, Lenardo da Vinci (talk about a mistake that Tony made) devised a method of applying continuous torque, independent of the spring's tension (Ward, 32).

What did a public clock mean to its town or city? "The installation of a public clock signified the city's openness to innovation, of its wealth, and the vigor of its administration" (Rossum 157). Before the invention of clocks, bells were signs of how the town was doing in terms of its economy. The size of a bell would indicate the importance of the town's citizens. The citizens of the town usually paid for town clocks by the imposition of a clock tax. By order of the king, if you could hear the clock ring its bell or if you used the clock, you were required to pay taxes for the maintenance (Rossum 155). For the reason that clocks represented the town's excellence, no expense was spared in the building of clocks (Rossum 143). As new towns and churches were built, clocks were the main peace of the construction, the bells of the town and churches were incorporated into their design. The clock would ring the town's bell the number of times that corresponded to the hour (Cipolla, 43). King Charles V required that all churches ring their bells when the clock bell rang to spread the time of day throughout the country (Rossum 143). Citizens believed that having a clock would attract more merchants their town's fairs, cause people to live an orderly life, and the town would gain in popularity. The actual truth about the early clocks was that they rarely worked, and clock keepers had to be employed constantly. If the clock was broken, the clock keeper was to move the hands and ring the bell at the appropriate times (Cipolla, 42). Kings believed that clocks were invented to allow the citizens of honorable cities to live orderly lives and to call sleepers and idlers to virtuous works (Cipolla, 45).

Charles Lindbergh, the first person to fly solo across the Atlantic Ocean, changed the way individuals view aviation. Charles flight caused him to become an instant hero and worldwide celebrity. Lindbergh only flew across the Atlantic because there was a reward for the first pilot(s) to achieve this impossible feat. In 1695, a similar unmanageable feat existed. The government of England challenged all clockmakers to design and build a clock that would have no more than a two-minute error during a ship's six-month voyage (Ward, 37). Keeping accurate time on a ship was difficult and believed to be impossible. The ship's movement in bad weather could wreak havoc on any time instrument of the day. John Harrison, a Yorkshire carpenter, devoted his entire life to the development of a clock that would maintain accurate time on a ship at sea. From 1728 till 1759, Harrison would develop four separate clocks that were improvements on previous ones (Ward 37). During testing of John Harrison's first clocks, the earth's gravity varying in different locations was John's largest problem. (Earth's gravitational force noticeably less at higher elevations.) With Britain and Spain at war, John would have to wait before he could test his clocks again on the open sea. Testing his clocks on the shore and replicating severe sea conditions, Harrison developed ways of canceling out the forces imposed on a clock's spring (Ward,37). A fourth time keeper was completed in 1759 which had the best performance Harrison had previously achieved. The fourth time keeper was considerably smaller than its predecessors, being little more then five inches in diameter. A trip to Jamaica and back to England was the fourth clocks first test. Upon arriving in Jamaica, the discovery that the clock was off by no more than 5 seconds allowed John to claim the prize. With an error of five seconds, the ship's position could be determined within 1.5 miles (Ward 38). A second test was performed because it was unbelievable that a clock could be as accurate as the one that John Harrison had built. The second test proved that during a 5-month period at sea, the clock lost no more than fifteen seconds. John Harrison won his award and became a world-wide clock maker. Clocks constructed today use the same internal movements that John Harrison created for his clock. Harrison clock's, considered to be highly secretive, were soon a requirement on voyages to North America. If a ship was pirated, the crew was to throw their clock overboard so that no one would discover the clock's internal workings (Ward 40).

The increase in knowledge of clocks during the 1400's and 1700's is beyond belief. There are several items that were left out of this paper such as the different types of escapements used and other oscillating motions such as a ball swinging vertically side-to-side. Even though better time pieces were continuously created, there was never one that pleased al the users of clocks. The knowledge of gravity varying on earth and the air resistance varying due to barometric pressure was unbelievable. A mass produced timepiece with interchangeable parts, and made by specialized workers, was important for the Industrial Revolution (Cipolla, 71). The precision needed in clocks enabled several other devices to be constructed, such as guns. I was trying to discover how early clocks were repaired if they were running slow. I discovered that instead of calculating the size of the gears, clock keepers would sometimes only get a new gear made that was either larger or smaller. The size of the gear was mostly a guess and an accurate gear was only achieved by chance. One concept that I was never able to understand was, "what is a second?" Today we define a second as a specified number of oscillations of an atom (9,192,631,770 oscillations of a cesium-133 atom) but a second was not defined in the same manner during the 1400's. Asking a professor about time, I was informed that sixty was the base number in the Babylonian math system. After completing this paper, I will never look at a clock the same way that I had once did. I hope that the history of the clock is as interesting to you as it is to me.

October 07, 2006