The Story of Time (Nita Berry)

["connected by a narrow 'neck'. The upper Sandglass\/hourglass vessel was filled with fine sand, which trickled slowly into the lower vessel through the neck. It emptied the upper vessel in a precise measured period of time. Time intervals could also be measured by checking the amount of sand that had trickled through. The sandglass was inverted to restart its time measurement. No doubt, the measurement of time depended on the size of the glass vessels, the amount of sand and the narrowness of the neck. The top vessel could be filled with enough sand to flow through the neck for one hour. That is why the sandglass came to be called the 'hourglass'. On the pulpits, preachers often placed an hourglass which ran for a whole hour. Everybody could see how much longer sermons would last, and not surprisingly, many made use of this time to snatch forty winks on a Sunday morning in church! On ships, hourglass was invaluable in measuring time and even speed during voyages. Ships kept four hourglasses which timed the length of one watch, that is, a period during which part of a ship's crew are on duty. The hourglass was turned over at the end of each four-hourly watch. Another sandglass on board lasted only 28 seconds. It was used to time a length of line thrown overboard with a log at its end. The ship's speed could be calculated by counting 49","Christopher Columbus the knots on the rope that ran out during (1451-1506) these 28 seconds. The knots were tied at intervals of about 47 feet. Even today, sailors measure the speed of their ships in knots or nautical miles per hour. A land mile, as you know, measures 5,280 feet, but a nautical mile is longer, measuring 6,080 feet. The term 'knot' probably came from the old way of measuring the speed of the ship with a sandglass and knotted rope. It is said that Christopher Columbus made all his long voyages with only one 'clock' on board\u2014a half-hour sandglass! Someone must have kept constant and careful watch on it to measure time. Today, if you want to boil an egg for three minutes and you have an egg-timer or three- minute sandglass, you cannot really go wrong. Start the sand 'clock' as soon as you have dropped the egg into boiling water on the fire. When the sand has run through from one glass vessel to the other, the egg is hard- boiled. But if you are impatient and do not wait for the sand to run right through, you will have to eat a rather 'gooey' egg. If, on the other hand, the egg keeps boiling after the sandglass has run through, you will have to chew a very hard-boiled egg indeed! Some popular indoor games too use sand- glasses to set a time limit. A watch would, no doubt, be more accurate, but a sandglass 50","is an easy and interesting way of keeping Candlestick clock\u2014candle is track of the minutes. marked in hours The Chinese adopted a rather peculiar and laborious way of telling time. They knotted a rope at equal distances. This rope was wetted and set alight at one end. The time taken by the fire to reach from one knot to the next marked a unit of time! King Alfred spent much of his life fighting off the Danes from England. He probably needed to know the time often during his campaigns. In fact, he was the first person outside China to use the fire technique in 870 a.d. to measure the minutes, though in his own way. He invented a 'candlestick clock' which had notches marked down the entire length of the candle. It was placed inside a wooden lantern to protect it from any gusts of wind. King Alfred estimated that the candle took exactly four hours to burn down completely. If it were half burned, it meant that two hours had elapsed. The smaller markings on the candle, three for every hour, gave smaller indications of time as the candle burned from notch to notch. When it had burned out completely, another candle was lit at once, so the 'clock' ran continuously. You can well imagine King Alfred spending long hours keeping vigil against enemy attacks, by watching his clock burn steadily in the dark. All this while, even as people devised the 51 1","AUtl strangest ways to tell time, others were trying to know more and more about the Garden sundial large number of stars in the sky every night. The science of astronomy was gradually developed through the study of stars and planets. A new way of telling time, by following star movements and patterns closely in the sky, was discovered. The Pole Star or Polaris was noticed to remain constantly above the North Pole. The earth's axis of rotation pointed northwards towards it. Polaris seemed to remain almost still in the sky while everything else revolved around it once in 24 hours. Star watchers used two of the stars in the Plough constellation as 'Pointers'. These seemed to travel round Polaris once in 24 hours. It was logical that time intervals could be measured by noting how much the Pointers had moved. In fact, any star could be used in this way on a dark and clear night. In those faraway days, instruments called 'nocturnals' were deve- loped to help tell the time through stars. It was not till much later, around the thirteenth century, that the mechanical clock was invented. Till that happened, people relied on devices like water-clocks, sundials and 'nocturnals' to measure the passing of the hours. However, these were not accurate timekeepers and were inconvenient to use because of their bulk and immovability. 52","With the invention of the ingenious mechanical clock, keeping time started to become really accurate and more simplified. 53","The Clock Goes Tick-Tock It was a wintry morning in Pisa, Italy, in the sixteenth century. A young student of seventeen years sat motionless in the Pisa cathedral. He looked worried and unhappy, and hardly glanced at the book of psalm that lay in his hands. He was in a dilemma. He wanted to study mathematics, his first love. His father insisted that he study medicine. He had little interest in the subject, although he had already started studying it at the University of Pisa. His father was, indeed, difficult to disobey! As the lad pondered over his problems, his gaze shifted to the high ceiling of the cathedral. Some repair work was being carried out there, and a lantern swung to and fro. He began to watch it with interest as it swung in wide arcs. Suddenly, his eyes widened. The arcs were becoming smaller 54","","Galileo Galilei and smaller, but big or small, they seemed to (1564-1642) take the same amount of time to swing. It was strange indeed! Galileo, for that was the lad's name, sat up straight in excitement, and felt his pulse. Its regular beat was his best time-keeper, and he began to time the lantern's swings. He was right. The lantern always required the same amount of time to complete a swing, no matter how long the range of its swing. Galileo did things thoroughly. He ran home in excitement to try out his own experiments. He fixed one end of a string to the branch of a big tree in his garden. He hung an iron weight from its other end. He now pulled the string back and released it. He had made a simple pendulum, like the lantern in the church. He next replaced the iron weight with a much lighter wooden one. This too took the same amount of time to swing to and fro, in a regular motion. Galileo thought hard. His experiment confirmed that the time taken for one swing remained the same, regardless of the weight attached. However, the time taken for the pendulum to swing did vary according to the length of the string. Galileo, who later went on to study mathematics and become a famous scientist, had discovered the laws of the pendulum. This early experiment made him realize later that the pendulum, which was a weight fixed to a 56","rod or .cord, could be used to regulate the The pendulum escapement movements of a clock once it was put in motion. After all, it had the astonishingly useful habit of swinging to and fro at the same speed according to its length. However, seven decades passed before a Dutch scientist, Christian Huygens, adopted Galileo's idea to build the first pendulum clock with a regulating movement. Galileo's remarkable discovery ushered in the era of accurate timekeeping. However, the first mechanical clocks had already appeared a few centuries earlier. Although it is difficult to say exactly when, water-clocks with moving parts were in use in China 500 years before, as we earlier saw. Around the thirteenth century A.D. the first mechanical clocks appeared in monasteries in Europe, and were operated by monks. They were enormous structures, often weighing several tonnes, and were made by unknown ironsmiths. These early contraptions did not have hands or a dial. They did not even strike the hour. They were used to alert somebody or to toll a bell that called monks to prayer. Their movements were simple and noisy, driven as they were by weights and wheels. Called 'turret clocks', these first clocks were nearly always placed on church or bell towers, so that everybody could see or at least hear them in the town. They were not of much use when they were out of sight or earshot for 57","German anybody who wanted to move about and still rack know the time. However, despite their crude clock working, they managed to work for many years, although they did not always tell the German correct time! novelty clock The word 'clock' or 'clok' as it was called in Middle English, goes back to this time. It was taken from the French word cloche which means a bell. French was widely spoken by the English upper classes, and many English words were 'borrowed' from it. Bells were, therefore, associated with clocks in those early days of mechanical timekeeping. In fact, even before mechanical clocks existed, churches and monasteries rang bells to tell the common folk that it was time for prayers. The devout would stop all their activities, to say their prayers. Some of these prayers for which bells were rung were called sexts and nones. These terms were taken from Latin, and meant the sixth hour and the ninth hour, when prayers were said. So the ringing of prayer bells also indicated the time. Even when mechanical clocks with dials and hour hands were made they struck the hours and were used in the same way as prayer bells. So it is little wonder that all timekeepers were called clocks or cloches. The French themselves, strangely enough, call a clock horloge, which has nothing to do with bells but indicates 'hours'. 58","From the beginning, these clocks were Rolling clock designed to tell the time by dividing the day from the 17th century into 24 equal hours. This was based on the ancient Egyptian time division of one day. The Falling ball clock hours were further divided into two lots of 12 of the 17th century hours each for every day, that is, 12 hours of daytime and 12 hours of night. However, we really do not know why the divisions fell in the middle of the day and the night\u2014falling after noon and after midnight. People had further divided each hour into 60 minutes, and each minute into 60 seconds. The figure 60 was probably taken from the ancient Babylonian counting system which used 60 in much the same way as we use 10. However, the earlier mechanical clocks did not bother about marking smaller divisions for minutes on their dials, or using a minute hand. This was just as well, considering that they were not very accurate anyway! Some of these early clocks still exist. The oldest surviving clock in England is at the Salisbury Cathedral, and is over 500 years old. It has an ornate dial, with 24 hours marked on its face in two lots of 12 hours each. This clock struck the hours. The mechanical clock was indeed a big leap from the age of sundials and sandglasses. It worked in a rather clever way. A weight was attached to a cord wrapped around a drum. As the weight hung down, the cord unwound, turning the drum. This in turn moved a series 59","American acorn clock of toothed wheels or gears. The wheels turned made about 1850 a pointing hand on the dial to tell the hour. This does sound easy enough, but in actual practice, it was quite difficult to make. This was because the hand had to move steadily and go right round a circle once in every 12 hours, without changing speed. For this, a mechanism called an 'escape wheel' was later provided, which served as a kind of brake. This prevented the hour hand from whizzing around the dial. Although these clocks were most useful, they did lose at least half an hour everyday. So we cannot say that they were very reliable timekeepers. Luckily there were no trains or aeroplanes to catch in those days! It is likely that the speed at which the parts of these clocks moved was altered slightly by hot or cold weather, as also by oiling or rusting of these parts. Late in the fourteenth century, the first clocks appeared in homes. They were simply smaller versions of these large public clocks, and were rather plain structures, with no protective cases. They usually stood on a pedestal which had an opening to accommodate their weights. These domestic clocks must have taken pride of place in the homes that possessed them. You can imagine how their owners probably invited much envy! For they could now see the time at home always\u2014rather than 60","having to rush out every time to the public clock, in rain or hail, to see if the school bell was about to ring! Do you know that many of the things we take for granted today began as great luxuries? When you were much younger, you must have had a few, favourite clockwork toys to play with, which you wound with a key or knob. Once these were wound and set down, remember how the clockwork mouse ran or the train moved with a loud whirr! You might have even had a musical box that played a gay tune once it was wound. All these simple, mechanical toys are driven by clockwork. They are provided with a coiled","Portable clock spring, which is a thin steel ribbon that bends to form a tight coil when you wind it. When released, the spring begins to uncoil and turns gear wheels, which in turn drive a spindle or axle around. This makes the toys move or play. You may be wondering what all this has to do with clocks or with time. Actually, many clocks and watches are powered by coil springs in much the same way as clockwork toys. It was at the beginning of the sixteenth century that the first spring-driven clocks were made. Peter Henlein, a German lock- smith, had the ingenious idea of ridding clocks of their heavy weights which made them impossible to carry or shift around. He began to make small clocks that measured four or five inches in diameter and about three inches in depth. These were the first portable timepieces, carried by hand, and represented one of the greatest strides in the history of timekeeping. The secret of these 'travelling timepieces' was that they were driven by a spring instead of by weights. Just as weights in a clock made the drum turn around, so the coiled spring made the wheel turn round. In principle, they worked in just the same way. A difficulty did crop up with these early spring-powered clocks. In a weight-driven clock, the driving weight always remained the same. However, if you have seen a spring unwind, you will notice that it pulls much 62","faster when it is fully wound than when it has Pocket watch nearly uncoiled. This irregular movement would make the clock move unsteadily too. However, in about 1525 A.D., a Swiss clockmaker overcame this rather serious defect by inventing the 'fuses'. This was a clever arrangement which used a spiral- shaped drum to regulate the movement of the spring. Those portable clocks had dials placed on their uppermost sides. They possessed an hour hand, and were exposed to the air. Their mechanisms were made wholly of iron. Later brass was used, and steel for the more delicate pieces. It was only later, in the seventeenth century, that glass covers were made, and the mechanism enclosed in brass cases. The clock began to have a profound effect on society as people became conscious of time. It was not long before watches evolved from portable clocks, in the sixteenth century itself. At first, these were hung on belts or worn round the neck. By the next century, it had become most fashionable in Europe to carry a pocket watch or 'watch fob', as it was called. This was a short ribbon or chain attached to a watch which hung out of the pocket in which the watch was kept. Later, the more watches one carried in waistcoat fob pockets, the more fashionable one was considered! Right till world war the first and the development of wristwatches, watches for 63","Grandfather clock men had, in fact, to be carried about in pockets. Galileo had prepared the way for the invention of the modern clock with his discovery of the laws of the pendulum. The spring-driven clock or watch used a 'verge' which depended for its accuracy on being pushed with the same force all the time. Lots of little things like heat and cold of the day could affect its regular working. Christian Huygens used the pendulum as the time controller in clocks, instead of the verge. After all, the regular movement of the pendulum would not be affected by small changes in the pull of the spring. The idea worked, and suddenly there was a great demand for clocks. Clocks were made with short pendulums to hang on walls.The next step was to enclose the pendulum and weights, and the long case or stately 'grandfather clock' was born! The pendulum commonly used in clocks, a cord or a chain, has an 'escapement' device which gives small, regular pushes to the pendulum to keep it swinging. Each time the pendulum swings aside, one tooth of a gear wheel turns past the escapement. This takes exactly one second in many grandfather clocks, and produces the familiar 'tick-tock'. Most grandfather clocks tell the time not only by hour, minute and second hands, they also have a deep chime. They usually chime every 15 minutes, with a different chime. 64","On the hour they chime the number of hours. These chimes are triggered off when cogs in the clockwork mechanism go past a certain point. Clocks became more and more decorative. In fact, clockmaking became a specialized craft. Skilled workers migrated from country to country, as watchmaking and clock- making became an international trade. Cuckoo clocks which sung out the time to the call of a 'cuckoo' arrived! Although the pendulum made clocks more accurate, it could not be used for watches. A pendulum works only if it hangs straight, and not if it lies on its side, nor if it is moved around. Watches that told the correct time were developed with the help of two new inven- tions\u2014the hairspring and the lever escapement. They are still commonly used in millions of clocks and watches today, despite the modern technology of our newest timepieces. Cuckoo clock 65","Time Moves On Industrialization, which began in the eighteenth century, changed the face of the globe. With the use of new materials like iron and steel, new energy sources, and the invention of many remarkable machines that increased production, the world became a much more complex place. Suddenly, old leisurely ways of life were gone. Important developments in transport and communication like the steamship, the automobile, the airplane, radio and telegraph made it more urgent than ever to live life according to the clock. All this while, the clock had been used for the most ordinary purposes\u2014like getting to school or to work on time, or catching a train. It did not need to be accurate to within more than half a minute or so for these every- day things.","With the twentieth century, time had to be John Harrison much more exact. After all, it had to keep pace (1693-1776) with the new science and technology that was sweeping the modern world. Accuracy no longer meant keeping time to the half minute or even second. Even one-hundredth of a second mattered in fields like astronomy! Timekeeping had already become a science with the introduction of chronometers for sailors in the eighteenth century. These gave the right time to within a very few seconds. It was indeed a matter of life and death to have good clocks on board the ships. In the olden days, even for long sea voyages, there were only crude instruments and rough tables to find positions at sea. There were no proper clocks. Many a ship was wrecked and sailor drowned because of unknown locations, as there were no reliable clocks. As your geography book must have told you, the intersection of latitude and longitude gives the exact position of any place. Sailors could figure the latitude they were in, by measuring the position of the Pole Star. However, to find their longitude, they needed the exact time. Realizing the gravity of the problem, the British Admiralty offered a prize of 20,000 pounds to anyone who made a reliable clock that worked well at sea. It was a challenge. John Harrison was a carpenter, but a genius with clocks. At that time, the hairspring and lever escapement had not been invented. 67","Chronometer He set to work to design a clock with a kind of pendulum that would keep accurate time through rough sea passages and changes of temperature. After much painstaking effort, he succeeded in making unbelievably accurate clocks which were better than some of our modern watches. The chronometer, which he made in 1760, after many years of experiments, showed an error of only 15 seconds in five months! Harrison's clocks are still working. They are kept in the National Maritime Museum at Greenwich. It was a long time before anybody could improve on them, for they were so good. Unfortunately, the prize money was given to him with the greatest reluctance. He was merely given small sums to carry on his work. It is a sad story that Harrison was an old man by the time he received half the prize. And it was not till matter was taken up by the King and Parliament that he received the full amount. By the nineteenth century, shipping was growing in importance because of increased trade and transport. Chronometers became readily available for ships. They were mounted in a special brackets to keep them level on a rolling sea. They were cheap and accurate timekeepers, and made the seas safer for mariners. Meanwhile, pocket watches were being fitted into specially made bracelets or leather 68","straps. Women began to wear them like pieces of jewellery. Wristwatches became popular with men with the first world war, when soldiers found it difficult to reach inside bulky uniform jackets to check the time. All kinds of clever, new ideas were now coming up for timepieces. Today, we use mainly three types of clocks and watches\u2014mechanical, electrical and electronic. Mechanical clocks and watches are spring-driven, electric clocks are powered by electricity and electronic ones are quartz- based. Although these are accurate timekeepers, they can gain or lose time if run continuously. Most mechanical watches have to be wound every day by hand. Some are self-winding. They contain a swinging weight which is geared to the coiled mainspring. When you move your hand, the weight turns and winds the spring. So you need not bother about winding. This ordinary watch is really a complicated bit of mechanism, containing about 211 different parts. It is powered by its mainspring which is about two feet long when straightened out. When you wind the watch, you tighten the coil of the mainspring, rather like a clockwork toy. F^ rom th, e mainspri.ng, the power t.r1avels S1.prwinign-ddirnivgekneycloc2k. Mainspring through a series of four wheels, called the | Cerrtrewhee. 4. ^cape^wheei 'train' to the delicate balance wheel. The train 7. Balance wheel 69","moves the hands on the dial while the balance wheel, the heart of the watch, regulates its movements. It acts like the pendulum of a clock, and spins back and forth steadily. The hairspring, a coiled steel wire, no thicker than a hair, lies inside the balance wheel. Around the balance wheel, tiny screws of gold or steel control the speed of the watch by their position and weight. An escapement wheel regulates the movement of the balance wheel. This is the sound that causes a watch to tick. The wheels in the watch rest on pivots which are in constant friction. To withstand this, the pivots rest on tiny bits of precious stones like ruby, garnet or sapphire, which are next only Electric clock to diamonds in hardness. These are called the 'jewels' of a watch, and their number is inscribed on its outer case or dial. More jewels mean less friction to wear out or slow down moving parts in the watch. So it is an indication of quality. MERCURY Ever since man knew enough about CELL electricity to make use of its power, he tried to apply it to clocks and watches. The simplest way to do this, he found, is to have electric currents replace the weight or spring as a source of power. Most electric clocks are BALANCE driven from the ordinary mains supply, which WHEEL is called 'alternating current'. Usually, the current flowing in wires changes direction Inside of an electric clock exactly 50 times a second. This keeps clocks 70","correct without any regulation. Of course, one The front of a quartz must beware of power cuts or even voltage crystal clock fluctuations! The back view Electronic watches are most popular today. They have batteries to power them. They are regulated not by a spinning balance wheel, but by a vibrating tuning fork. Battery-operated electromagnets set off the vibrations, which are passed on to the gear-wheels, to move the hands of the watch. More recently, nature has been tapped to discover a most accurate tuning fork\u2014a quartz crystal. It has been discovered that when an electric current is passed through a quartz crystal in little waves, the crystal vibrates at a special speed\u201432,768 times a second. Clocks and watches regulated by electric impulses with a crystal are amazingly accurate to a second in fifty years! Man has made an even more astounding discovery! He has dug deeper into nature to use the very smallest particles of matter called atoms. Since the 1940s, scientists knew that the electrons of atoms oscillate with a rhythm so regular that they could be used to tell time. Thus, a very sophisticated clock known as the 'atomic' clock has been developed, which allows the astonishing splitting of seconds. These clocks generally use atoms of caesium, a silvery-white metal. Some of the latest ones are so precise that they gain or lose less than one second in 30,000 years! 71","An atomic clock Atomic clocks are being used as a standard of time at some 50 timekeeping stations round the world. They are also being used in sophisticated navigation systems and space communications. They have ushered in a new era in the field of time measurement. Indeed, they are better timekeepers than our earth itself! Different countries specialize in making different kinds of clocks. Britain has long been famous for its chronometers as also chime- clock movements. The chimes of the world's most famous clock, Big Ben, in London, have been broadcast live for decades by the BBC. The Black Forest of Germany was famed for its beautiful cuckoo clocks, handcarved in wood. Watchmaking has been a national industry in Switzerland, ever since the appearance of the wristwatch. In fact the Swiss always led in the production of high grade watches. Special feature watches such as alarms, calendars, automatics and chronographs were made almost exclusively in Switzerland. Today, over half a billion watches pour out of the world's assembly lines every year. Japan's Seiko group is the world's largest timepiece manufacturer. In a 1.8 hectare plant, 1,200 robots screw parts into inexpensive quartz crystal watches. Every two seconds a new watch\u2014standard or digital\u2014pops off the assembly line! 72","Nature too has its clocks. Fifty years ago, an Radioactive clock\u2014the age of American chemist, Willard Libby, found a some elements like carbon is natural timekeeper in everything that had measured by their decay. It takes existed in the last 50,000 years. This was the 100 million years for the part A carbon-14 atom, which decays at a known rate. to decay; another 100 million Scientists can now tell the age of an Egyptian years for part B and another mummy or a fossil by determining their levels 100 million years for part C. of carbon-14. Relics too could be dated to give history more accurate dates. What is more, there are natural cycles within our bodies that can perceive time all on their own. If you were stranded on an island with no clocks around, your body would fall naturally into a 24-hour pattern of sleep and wakefulness, with meals thrown in at regular intervals. This is the body's clock it work. Biologists call it the 'circadian rhythm'. If we break this rhythm for any period of time, many disorders in the body can result. If you have been on a long flight across several time zones, you will know what 'jet lag' means. You feel groggy and out of sorts. It usually takes the body many days to readjust to a new day- night pattern. 73","The Great Calendar Stone A Calendar A world without clocks would surely be a topsy-turvy place. Imagine what a world without calendars would be like! There would be no way of keeping track of the weeks, months or years as they went past, or of anything else, for that matter. You would not have the foggiest notion of how old you were. At school you would not be promoted after a year, but would probably sit in the same class always! No birthday parties, no festivals, not even plans for vacation\u2014after all, these are all measured by a calendar. What a muddle everything would be! Did you know the word 'calendar' comes from calendarium, the Latin word for 'account book'? It means the division of the year, like a set of accounts, into days, weeks and months. A calendar does indeed regulate all our affairs\u2014at home, at work, even in the fields, 74","and it also reckons time for religious and Australian memory sticks scientific purposes. The Incas of South America used Calendars have been around a long while. knotted ropes known as 'quipu' We saw how man found ways to measure time to remember things. long before he had invented any instruments to do so. Early in history, he began counting time by days, months and seasons, which were all natural time units. He thus had the first beginnings of a calendar. Ancient tribes used a dawn-to-dawn reckoning to count the days. They probably called a number of days so many 'dawns' or 'suns'. In those far-off days, there were no fancy calendars like the one you have hung up in your room to keep track of the year. They simply used sticks with crude notches in them to count the days, or strings with knots in them to keep a record of so many full moons or even seasons. These were really our earliest calendars. The calendars used by all ancient civi- lizations were based on natural phenomena, or units of time such as the day, month and year. Two kinds of calendars came into use\u2014 the 'solar' calendar which was based on the earth's revolution round the sun, and the 'lunar' calendar, which was based on the movements of the moon. When you come to think of it, the intelligence of our ancients truly laid the foundation for our way of life today! Like many other things, the story of the calendar began in the great civilizations that 75","awakened nearly 5,000 years ago along the life-giving rivers of the Middle East\u2014in Sumer, between the Tigris and the Euphrates, and in Egypt, along the Nile. The ancient Egyptians introduced the use of a practical calendar in 4,200 B.C. They were the first people to measure the year with some exactness, although their first estimate was not quite right. They started with a lunar (monthly) calendar based on the appearance of the new moon every 29 or 30 days. As one year had 12 months, they calculated that this would give them a year of 360 days. It was a round figure that would have been most convenient for calendar-making, but as the Egyptians cleverly discovered, it was not very accurate. The annual flooding of the river Nile on its surrounding banks was most important to Egyptian farmers, for it brought renewed fertility to the land. Egyptian astronomers began to time this important event, which was celebrated as the ancient Egyptian New Year. They were observant men. They noticed that this flooding occurred every year when Sirius, the bright Dog Star, An ancient Egyptian calendar\u2014the 12 months are shown as discs.","first appeared in the early morning sky before Julius Caesar sunrise. The annual morning appearances of Sirius had an interval that was a few days (100 B.C.-44 B.C.) longer than the 360-day Egyptian year. The puzzled astronomers probably scratched their heads and mused. It was obvious that their year was a little short. Their scientific calculations were better, based on the more accurate 365-day solar year. The answer lay in extending the old year by adding on an extra five days. This was done at the end of the year, and the extra days were set aside for feasting and revelry during the Nile's annual government and administration. However, old habits die hard, and everyday life was still based on the old lunar year. So things remained. Soon, even the 365-day year was seen to be inadequate. Astronomers calculated that there were six hours missing in a year. The knowledge of the scholars of this period must indeed have been tremendous! It was around 240 B.C. that Ptolemy III, King of Egypt, tried earnestly to set the calendar right by adding an extra year every four years. He had come very close to finding the right solution\u2014but alas, it was not to be! The powerful clergy refused to accept his 'leap year' which would change their long calculations and the dates of all religious festivals, which were based on the old 77","Mayan calendar calendars. This same leap year was adopted 200 years later by the Roman General and ruler, Julius Caesar. Another highly developed civilization flourished in Central America, quite cut off from the rest of the world. The Mayas here worked out their own time scale with astonishing accuracy. Their early astronomers achieved this by means of stars and planets. Their calendar used a 'year' based on the movements of the planet Venus which they studied closely. You can see it shine brightly in the western sky after sunset. The Mayan astronomers drew up a 'Venus year' which had 18 months of 20 days each. However, they realized that this 360-day year was not quite right, and added another five days to each year. These five extra days were considered to be unlucky. The Maya people made the most elaborate calendars which they carved on stone. Indeed, these heavily worked stones with pictures and hieroglyphics 3,000 years old are the pages of their calendars for us to see even today. These calendars were very complicated, however, and their clumsy system of counting only made matters more difficult. Unfortunately, we do not know very much about this ancient civilization which was destroyed. The Babylonians and the Greek had their own calendars too. Studies of cuneiform tablets found in Mesopotamia show that its people 78","reckoned time as far back as 2700 B.C., somewhere near the invention of writing. Like the Egyptians, the ancient Babylonians were drawn to the movements of the stars and the changing seasons. They developed a year of 360 days, and divided it into 12 lunar months of 30 days each. However, their astronomers soon realized that this year was short by about five days. In six years, this difference would add up to 30 days or a full month! They solved the problem by adding on a thirteenth month after every six years. The calendar which we, along with the rest of the world, use today came from the early Romans. They also gave us the names of the months of the year. It may surprise you to know that this calendar was not as simple as it seems, but was arrived at after a long process of trial and error. This took many many centuries, involved several famous personalities, and led to fierce arguments, even riots! Ultimately, the present day Gregorian calendar as it is called, was designed, accurate to a day in every 3,323 years! The Romans were a powerful force that ruled over much of the known world at the height of their might. Wherever they went, the influence of their rich culture\u2014the Roman alphabet, numerals and even their calendar\u2014 was adopted by different people, far and wide. When the Romans first took their calendar 79","Janus from the Greeks, it had a year of only 304 days, divided into ten months beginning with March. The last month of December was followed by an uncounted winter gap. In fact, right till the reign of Julius Caesar, the calendar was flexible and followed no hard and fast rules. Rulers lengthened or shortened months at will. If somebody important wanted more time to complete a project, he merely made the month longer! Students must have dreamt of lengthening the vacation months! Ultimately, the calendar was changed so often that it became hopelessly confusing and meaningless, for business or administration. A king of Rome called Numa Pompilus is believed to have added the months of January and February around 700 B.C., since the ten- month year was much too short. They were attached to the end of the year in the uncounted winter gap, and were the new eleventh and twelfth months. January took its name from Janus, a two-headed Roman god who was believed to guard doors and gates. One of his heads was said to turn back to the past, the other towards the future. February derived its name from the Latin 'Februarius' which means 'to purify'. The ancient Romans traditionally held a festival of purification in February, the twelfth month, to prepare for the next year. The name stuck even after the month was shifted from twelfth to second place in the calendar. 80","This new calendar was more accurate, but still not good enough for it was only 355 days long. By Julius Caesar's reign, the dates were three months ahead of the seasons. It is like having Christmas fall in the spring, or Holi in middle of the rains! Julius Caesar took a major step to rearrange the old calendar into something better. He acted on the advice of a Greek astronomer called Sosigenes, and the 'Julian calendar' was drawn up in his honour. This was a immense improvement on anything that had been used before, and was used for 1,500 years. This calendar was based on the time taken by the earth to complete one revolution round the sun, that is, the solar year of 3651\/4 days. Sosigenes realized that the ordinary year must have an exact number of days to be practical. Any leftover hours would become most awkward. He decided on a year of 365 days with an extra day added at the end of every four years to correct the error. The extra long years became known as leap years. The number of months remained at twelve, but since 365 is not exactly divisible by twelve, they could not all be of the same length. Various changes were made in the calendar to make the months longer, so as to make the calendar just right. We saw how January was originally the eleventh month, with only 29 days. Caesar 81","A page from a Medieval pushed it to become the first month of the year Christian calendar with 31 days. March, May, July, October and December were also given 31 days each, while the others had 30 days. However, when the New Year was shifted to January 1, the names of the other months were not shifted. So we see a difference in the meanings of certain months and their order of appearance in the year. For instance, September comes from 'septem' meaning the number seven, but its position in the year is ninth. October means 'octo' or eight but it is really the tenth month. Similarly, November is from 'novem' or nine, but it comes in at number eleven. December's old name has stuck as well, for it is named after 'deka' or ten, but is really the twelfth month of the year. The Romans never bothered to alter these names. Julius Caesar is remembered for something else as well. He renamed the fifth month of the earlier calendar, Quintilis, after himself. It is called July since then and was given 31 days in his honour. Caesar 'borrowed' one day from February to do this, so February was left with only 29 days. In a leap year, it was reasonable to attach the extra day to February to give it 30 days. It was brought forward too, to become the year's second month instead of the twelfth. The Romans named many of the other months after gods and goddesses. March, with its squalls and gusty winds, was named after Mars, the Roman God of War. He was also the 82","God of Farming, and was worshipped in Roman Emperor Augustus March when the fields were made ready for (63 b.C.-A.D. 14) sowing. It was in March too that the Romans could prepare themselves for battle again after their long, cold winter. The Goddess Maia, daughter of mighty Atlas who was believed to carry the world on his shoulders, gave her name to the month of May. It is likely that June got its name from the Goddess Juno, wife of Jupiter and queen of the heavens, who rode a chariot drawn by peacocks. Ancient Rome celebrated a festival in her honour at the beginning of this month. When a new emperor came to the throne, he liked to change many things to assert his importance. So it was with Emperor Augustus, grand nephew of Caesar, who came to the throne when the latter was murdered. It was important to him to have a month named after himself, so he renamed the old month Sextilis as 'August' after himself. Now August had only 30 days\u2014a day less than July. Augustus objected strongly, and so another day was taken from February and added to August to make it equal to July\u2014Caesar's month! February was thus left with only 28 days, except in leap years when it had 29, while August had 31. All this juggling really did muddle up the entire arrangement! It made three 31-day months (July, August and September) appear in succession. So Augustus thought hard and 83","made more changes. He reduced September to 30 days, added a day to October to increase it to 31 days, reduced November by one day to 30 days and finally increased December from 30 to 31 days. The important thing was to have an accurate calendar of 365 days. It does seem extremely strange to us today that a calendar which was used all over Europe could be changed just to flatter an Emperor of Rome. However, we still follow the same 365-day calendar, and its sequence of months with their lengths remain unchanged even today. Has it ever happened to you that a small mistake grew bigger and bigger till it became quite serious? This is what happened with the Julian calendar, which seemed accurate enough to begin with. However, even after leap years had been added, things were not quite right, for the calendar year now became long by 11 minutes and 14 seconds. This was because the earth actually takes 365.2422 days to complete one revolution of the sun. The correction of a full day every four years was, therefore, a little too much, and this error added up to a full day in 128 years. The earth's year is 365 days 5 hours 48 minutes and 46 seconds.","By the sixteenth century, the Julian year was Astronomical Gregorian ten days behind the solar year. Catholics grew years years terribly concerned about the calendar's inaccuracy. It meant that Easter would A year of 365 days is a quarter-day gradually shift from being a springtime short of the astronomical year. festival into a winter one! For a long time, people clamoured for some kind of reform. Adding an extra day every fourth year brings the calendar into step. Ultimately in 1582, Pope Gregory XIII decided to correct matters. On the advice of astronomer Clavius, he issued a decree which stated that instead of having 100 leap years in every 400 years (one every four years), there would be only 97. How would this be done, since every year exactly divisible by four should be a leap year? Pope Gregory declared that the century years (1600, 1700, 1800 and so on) would be regarded as leap years only if they were divisible by 400. As you can calculate, 1600 and 2000 are leap years, but 1700, 1800 and 1900 are not, and February has only 28 days in all these years. This settled matters very well, for the error in the Gregorian calendar was reduced to merely 26 seconds per year, or one day in the next 3,323 years! But the problem of the extra days still remained. Pope Gregory's solution was to drop ten days from the calendar, so that October 4, 1582, was followed straightaway by October 15,1582, to bring everything back to its correct timing. 85","All Catholic countries agreed to adopt the new calendar\u2014after all, the Pope was the Head of the Roman Church and nobody dared disobey him. Britain was Protestant, and kept using the Julian calendar for almost another century. By then, the error had increased to eleven days. Their Parliament finally passed an Act recommending that the use of the Gregorian calendar. September 2 was to be followed by September 14. The dates in between would really vanish into thin air! Strangely enough, many people reacted very strongly to this change. They felt angry and cheated out of eleven days. Maybe some of them would miss birthdays or other important events! There was rioting in London and supporters of the Gregorian system were attacked by enraged mobs. However, the anger finally died out. Today, all countries use the Gregorian calendar. Russia was the last country in Europe to adopt it after 1917 when the erstwhile U.S.S.R. was created. It is wiser to keep time with the rest of the world, is it not? 86","Calendars The World Over A Muslim calendar of 1787 It is difficult to discard old ways altogether, especially if they hold some special meaning. Although everybody uses the Gregorian calendar, some countries still have other kinds of calendars, which they have been traditionally following from ancient times. The Muslim calendar, has been retained by most Arab countries, while the old Hindu and Jewish calendars continue to be used for religious purposes. So certain countries or religions really follow two different calendars, which can be confusing at times. Some newspapers in these countries print their dates according to both the calendars in use. The Gregorian calendar, as we saw, is a solar calendar (based on the earth's journey round the sun, which takes a little over 365 days). Another calendar people consult is the lunar calendar (based on the movement of the 87","Ancient Egyptian temple calendar","moon). This was popularly used in the ancient world, and the traditional Hindu, Muslim and Chinese calendars are still based on it. Since the moon takes 29.5 days to complete one revolution of the earth, it takes 354 days for 12 such revolutions. The lunar year of 354 is 11 days shorter than the solar year. In three years this difference grows to a whopping 33 days! To keep the lunar year in step with the solar year, this difficulty is solved by making every third lunar year consist of 13 months. We call this additional month malmas in Hindi. Every calendar welcomes the first day of the year as the New Year. This is one of the oldest and gayest customs of mankind, and is celebrated the world over. New Year's day is a great time for parties and reunions that ring out the old year and ring in the new one. It is a time to make New Year 'resolutions' as well, though these are soon forgotten! In the bigger cities of the world, many people collect in a big square to welcome the New Year. They greet each other and embrace each other. In London, Trafalgar Square is the traditional gathering place, while Times Square is popular in New York. In fact, no festival has been celebrated in such a variety of ways and on so many different dates according to the calendars used by different countries or religions. We do not really know how New Year 89","celebrations first began. Some believe that the Chinese were the first people to start them, others claim that it was the ancient Germans, while still others say that it was the Romans. The Chinese celebrate two New Year days. One is on January 1, which is New Year's day according to the Gregorian calendar. Their other day is reckoned by the Chinese lunar calendar, and can fall any time between January 21 and February 19. During this time, there is a gay festival which lasts several days. It is a time too for family get-togethers over lavish meals. Children look forward eagerly to this happy festival, for they are given 'good luck' money in red packets. Indonesia also has two celebrations\u2014on January 1, and on the Islamic New Year, a date that varies from year to year. The Russian Orthodox Church observes the New Year according to the Julian calendar which places the day on January 1. 'Rosh Hashananah' is the Jewish New Year, celebrated about the time of the autumnal equinox at the end of September or beginning of October. In Vietnam, the New Year usually begins in February. The Koreans celebrate their New Year during the first three days of January, while Iran celebrates it on March 21. The people of Morocco observe the beginning of the year on the tenth day of Muharram which is the first month of the Islamic year. 90","The ancient Greeks began their New Year Charles X with the new moon after June 21. The Roman (1759-1836) New Year was celebrated on March 1, till Caesar changed it to January 1, according to the new Julian calendar. It is said that the ancient Germans established a New Year festival because of the changing seasons. The German winter set in around mid-November, when they gathered the harvest. It was a happy occasion when everybody got together at the end of a time of hard work in the fields. They looked forward to a period of rest from work in the cold, long winter ahead, and so made merry. Even though it was only November, they considered it the beginning of a new year! In most Christian countries, the new year now begins on January 1. In the Middle Ages however, one calendar was used throughout much of Europe in which each new year began on April 1. So it was celebrated as New Year's day. People exchanged gifts and visited friends. Being the beginning of springtime as well, celebration was in the air. In the sixteenth century, it is said that Charles X, King of France, ordered people to adopt the new reformed calendar where the year began with January 1. Although most people agreed to do this, there were some stubborn ones who refused to change. They continued to celebrate April 1 as New Year's day, and so became the butt of jokes and tricks 91","Lunar calendar\u201412 lunar months by their friends and neighbours! They sent are 11 days short of a year. them on fools' errands, made them gifts, invited them to parties that were not held and generally played lots of tricks on them on the day. These people became known as April Fools, and April 1 became April Fool's Day. This became a day for practical jokes all over the world. April Fool's Day is probably one of the most enjoyable days in school, for you have a good excuse to play the fool without fear of punishment! In India, each religious group has its own date for beginning the year. In fact, around thirty different calendars exist! Some are lunar, some solar, while others are based on religion or even astrology. You can imagine what a great muddle our dates would be in, if all these calendars were to be used! In 1957, the Indian Government found a way out. It introduced the Saka calendar as the official calendar, and stated that only this would be used along with the Gregorian calendar. The Saka or Indian national calen- dar is based on the lunar system, but the days of this calendar correspond permanently with the Gregorian calendar. Chaitra, which is the first month of the year, falls on March 21 every year, and on March 22 in a leap year. This is the Hindu New Year. The Sakas, incidentally, were the first invaders from Central Asia who established two dynasties in north-west India. Chastana 92","was the founder of the second dynasty in 78 A.D. which marked the beginning of the Saka era. This lasted for almost three centuries till they fought the powerful emperor, Chandragupta Vikramaditya, who defeated and killed the Saka king in 388 A.D. Since then the Saka calendar began its count from 78 A.D. The Indian national calendar lags 78 years behind the Christian era. So if you are born in 1982, according to the Indian calendar your date of birth falls in 1904! How do you celebrate the New Year? Is it with a big bang, or do you sleep through the end of the old year, to wake up right into the new? It is a time for sending New Year cards to all those near and dear to you, with wishes for a happy year ahead. You even send cards to casual friends, and to most people you know. You probably receive piles of colourful New Year cards, to put on shelves or hang from ribbons and streamers. The custom of sending New Year cards is very old. Did you know that the Chinese have been doing it for more than 1,000 years? These cards carried the name of the visitor who came to call (for there was no postal system then!), but there were no greetings or messages on them. For people the world over, the coming of the New Year is a symbol of starting a new life with renewed hope for the future, and putting old troubles behind. That is why the New Year 93","Charlemagne of France has been greeted with joy everywhere down (742-814) the ages, in the hope that it will bring in a good, new life. You maybe wondering when these different calendars actually count time from\u2014for they certainly did not, start together. The time system we use in everyday life, the Gregorian calendar, begins its count with the birth of Christ. Everything before his time is marked B.C. (Before Christ). Your history book is full of dates with B.C. after them, which you probably know by heart. Everything after the birth of Christ is marked A.D. (Anno Domino or In the Year of our Lore). This practice of dating events from the birth of Christ came into general use only in the time of Emperor Charlemagne in the ninth century. A mistake was made then, which dated the birth of Christ five years later than it actually was. The Greeks dated their calendar from the Olympic Games which started in 776 B.C. The Romans counted time from the founding of their city in 753 B.C. by Romulus. The Muslims use a different calendar that begins its count from the flight of Prophet Mohammed from Mecca to Medina, the Hejira, in 622 A.D. Jewish reckoning goes back to the supposed year of creation which they calculated as having taken place 3,760 years and three months before the birth of Christ. As mentioned, the Indian national calendar based 94","on the Saka era begins in 78 A.D. All these A wood calendar used in Tyrol from dates are according to the Gregorian calendar. the late 17th century until the mid-19th century. Each plate Once man had a calendar to organize his represents one month. life, he felt the necessity of grouping days together into periods shorter than months, for his different activities. It was convenient to fix different days for marketing, trade, feasts and other activities. In the beginning, every tenth day was allotted to a certain task. At other places, one day after every five or seven days was fixed for such an activity. In Babylonia, every seventh day was treated as a special day. This was because of their belief in the sacredness of the number seven which was probably related to the seven planets. In ancient astronomy, the name 'planet' referred to the seven celestial bodies that were seen to move noticeably against the background of apparently 'fixed' stars. These included the Sun, the Moon as well as the five planets, Mercury, Venus, Mars, Jupiter and Saturn. In fact, a fixed day in the week was devoted to the worship of one of these planets, which were looked upon as gods. The Egyptians also adopted the seven-day system. They named the seven days after the five planets, and the sun and the moon which gave us the names of the first two days of the week\u2014Sunday and Monday. Their other names were Mars day, Mercury day, Jupiter day, Venus day and Saturn day. 95","By the first century B.C., the seven-day week had been adopted throughout the Roman world. The present names of the weekdays are taken from the Anglo-Saxon names of gods. The day named after the sun is Sunnandaeg or Sunday. The moon's day is Monandaeg or Monday. Similarly, the day named after the planet Mars is called Tiwesdaeg or Tuesday. It was the Norse god of War. The day named after Mercury is Wodendaeg or Wednesday. Jupiter's day is Thordaeg or Thursday, the day of Thor, the Thunder God. The day of Venus is Friggdaeg or Friday. It comes from Freya, wife of God Woden and mother of Thor. It is said that she was given a day so that she would not be jealous! Saturn's day is Saeterndaeg or Saturday, named after the Roman God, Saturn. One day of the week was kept for rest and prayer. This was traditionally Sunday for all Christians, while Jews rested on Saturday. This was the 'Sabbath\/day. Incidentally, a day used to be counted as an interval between sunrise and sunset. The Romans counted it from midnight to midnight. This method is used almost everywhere. The calendar we use today is very accurate. However, it is not very symmetrical with its months of varying lengths. There have been suggestions to make a new 'World calendar' where the present months will remain the same but the days will be rearranged. This has been designed by 96","dividing the year into four quarters of 91 days each, with an additional day at the end of the year. The first month of each quarter has 31 days and the rest of the months, 30 days each. The additional day follows December 30 and does not belong to any month or week. Similarly, in the leap year, the extra day follows June 30 without being part of any month or week. In the World calendar, January 1, April 1, July 1 and October 1 all fall on Sundays. There are many advantages of such an arrangement. In the first place, it would save on printing new calendars every year, for dates would always fall on the same day of the week. If your birthday is on a Friday this year, it would always fall on a Friday. It would also be easier to work out school holidays, festivals and other occasions on definite dates for all time. In spite of these advantages, however, the idea of the World calendar has not become very popular. Perhaps this is because old habits die hard, and we are quite habituated to the existing one. 97","Crossing Time Zones Irina jumped up and down in excitement. She was going to meet Grandma who lived in faraway Vladivostock, by the Trans-Siberian Railway from Moscow. It would be a long, long journey of almost 10,000 km across the vast stretches of Siberia. And it would take seven whole days to reach! Grandma was a wonderful cook. She had promised to make plenty of delicious goodies for Irina when she came. No wonder she could hardly contain her excitement! The 'Russia Express', as the long train was called, travelled fast across the treeless plains of Siberia. Yet the journey seemed endless. It was very early in the morning\u2014 5 o'clock according to Irina's watch, when 98"]