What were used to calculate time in ancient times?
Tools used to calculate time in ancient times:
1. The "table" in Guibiao is a vertical vertical bar. A pole or stone pillar on the ground; "Gui" is a stone slab extending in a horizontal position from the heel of the watch to the north. Whenever the sun turns due south, its shadow falls on the surface. By measuring the length of the shadow, you can calculate the times of winter solstice, summer solstice and other solar terms. When the surface shadow is the longest, the winter solstice has arrived; when the surface shadow is the shortest, the summer solstice has arrived. It is the oldest and most familiar astronomical instrument created in our country.
2. Leaky kettle
Also known as clepsydra and clepsydra. There are two main types of clepsydras: leakage type and water-receiving type. Most of the early carvings were water leakage. Water leaks from the side of the bottom of the clepsydra, and the grid cross and tongue rise again, causing the leakage arrow floating on the water surface of the leakage kettle to descend with the water surface, and the scale on the leakage arrow indicates the time. Later, the water-receiving type was created. Water was poured from the clepsydra into the kettle at a constant flow rate. The leaky arrow floating on the water surface of the kettle indicated the time as the water surface rose, improving the timing accuracy. In order to obtain a constant flow rate, the water level in the clepsydra should first be kept constant. Secondly, the cross-sectional area of ??the water pipe that fills the kettle with water must be fixed. The water pipe adopts the "thirsty" (siphon) principle to facilitate adjustment and repair. There are two methods of keeping the water level constant or close to constant, both of which can be found in the "Qi Guofeng Cui Hushi Diagram" in the "Liu Jing Tu" (published in 1153) written by Yang Jia in the Song Dynasty. In the picture, the "Lü Cai Ding" made in the Tang Dynasty (about 600-650 AD) has several compensation pots added above the clepsydra. The "Yansu Ding" made today (1030 AD) uses the overflow method and is four inches deep. The excess water flows from the flat kettle (xiagui) through the bamboo injection tube into the water-reducing ounce. The leaky pot created by Yansu was called the Lotus leakage, which became popular in various places during the Northern Song Dynasty.
3. Hourglass
Historical records record that hourglasses are driven by quicksand because water tends to freeze in winter. "History of the Ming Dynasty Astronomical Records" records that Zhan Xiyuan created the "five-wheel hourglass" in the early Ming Dynasty. Later, Zhou Shuxue enlarged the quicksand holes to prevent clogging and used six wheels instead. Song Lian (1310-1381) recorded the structure of the hourglass in the "Collected Works of Scholars of the Song Dynasty", including the size of the parts and the number of teeth on each wheel of the reduction gear. He also said that the shaft tip of the fifth wheel has no teeth and is equipped with a viewfinder to indicate the time.
4. Armillary Sphere
Ancient literature on the armillary sphere contains the theory that Luo Xiahong and Xian Yuhuan created the armillary sphere during the reign of Emperor Wu of the Han Dynasty (140 BC to 87 BC), but there is no mention of its origin. structure. "Book of Jin Astronomical Records" records that Zhang Heng of the Eastern Han Dynasty (AD 78-139) made an armillary sphere and said that it was driven by water leakage in a secret room. The appearance and emergence times of stars indicated by the instrument were consistent with the results of astronomical observations. "New Book of Tang·Tianwen Zhi" has a more detailed description of the armillary sphere designed by Seng Yixing and Liang Lingzan in the 13th year of Kaiyuan of Tang Dynasty (725). The instrument is equipped with two rings of the sun and the moon respectively, and the water wheel drives the universe. The whole elephant rotates once a day, and the sun rotates 1/365 times. The instrument is also equipped with two puppets, who beat drums and mark the engravings respectively. It is a wooden building with a narrow top and a wide bottom.
5. Water transport ceremonial platform
It was made by Su Song, Han Gonglian and others in the third year of Yuanyou (1088) in the Northern Song Dynasty. They wrote "New Yixiang Fa Yao" in the early years of Shaosheng (1094-1097), which contains many general drawings and partial drawings. This water transport instrument platform is more than three feet and five feet high and two feet and one foot wide. It is a wooden building with a narrow top and a wide bottom. There is a water lifting device on the lower level of the platform. The river cart is pushed by manpower, driving the water lifting wheel and the lower wheel (tube cart) to lift the water up to the Tianhe River (receiving tank) and into the Tianchi (reservoir). The Taichung flat kettle keeps the water level constant, and releases a constant flow of water through a water pipe of a certain cross-section to the kettle on the pivot wheel (water wheel), pushing the pivot wheel. The pivot wheel drives the day and night wheel, the armillary image and the armillary sphere through the transmission gear. Water transport instrument and elephant platform The water transport instrument and elephant platform has a relatively complex gear transmission system. Above the pivot wheel and next to the circumference is a "balance" device - the escapement. This is a major creation in the history of timing machinery. It changes the continuous rotation of the pivot wheel into intermittent rotation. Above the pivot wheel and next to the circle there is
How long is half a moment, and how did the ancients calculate time
Noon: noon or around noon [midday; noon].
Half a ring: half a day; half a day: before ~ ??| after ~ | He thought about it before he remembered | before ~ ??I was at school, after ~ I was at home.
Relevant time period distinction
〖Half Noon〗 dialect. It means about nine or ten o'clock in the morning.
〖The first half of an hour, the first half of an hour, the first half of an hour〗〈方〉before noon; in the morning; in the first half of the day.
〖The second half of an hour, the second half of an hour, the second half of an hour〗〈方〉afternoon; afternoon; second half of the day.
A long time is called noon.
Today there are twenty-four hours in day and night, but in ancient times it was twelve hours. When Western mechanical clocks were introduced to China, people called the Chinese and Western time points "big time" and "hour" respectively. With the popularity of watches and clocks, people have forgotten "big time", but "hour" is still used today.
In ancient times, the hour (big hour) was not calculated by one, two, three, and four, but was marked by Zichou, Yinmao, and animals such as rats, cows, tigers, and rabbits, which were thought to be easy to remember.
The specific division is as follows: the time of Zi (rat) is from eleven to one o'clock, with twelve o'clock as the right time; the time of Chou (ox) is from one to three o'clock, with two o'clock as the right time; the time of Yin (tiger) is from three o'clock to five o'clock , with four o'clock as the on-time point; Mao (rabbit) time is from five to seven o'clock, with six o'clock as the on-time point; Chen (dragon) time is from seven to nine o'clock, with eight o'clock as the on-time point; Si (snake) time is nine o'clock From 11 o'clock to 11 o'clock, the time is 10 o'clock; at noon (horse) time, it is from 11 o'clock to 1 o'clock, and 12 o'clock is the time; The time of Monkey is from three o'clock to five o'clock, with four o'clock being the on-time point; the time of Unity (Rooster) is from five to seven o'clock, with six o'clock being the on-time point; the time of Xu (Dog) is from seven to nine o'clock, with eight o'clock being the time of day. Punctuality; Hai (pig) time is from nine to eleven o'clock, with ten o'clock being the punctuality.
The ancients said that time is different between day and night. During the day, it is called "clock", and at night, it is called "watch" or "drum". There is also the saying of "morning bells and evening drums". In ancient times, many bell and drum towers were set up in cities and towns. They would ring the bells in the morning (Chen Shi, today's seven o'clock) to tell the time, so "what time" was said during the day; The drums tell the time, so it is also said that there are several drums at night. It is also useful to "change" the time at night. This is because the night watchman beats the clapper while patrolling to tell the time by counting. There are five watches throughout the night, and the third watch is at midnight, so there is also a saying of "the third watch at midnight".
The unit of measurement below an hour is "a quarter". An hour is divided into eight quarters, and each quarter is equal to the current fifteen minutes. There is a saying in old novels of "Beheading at three quarters of an hour at noon", which means that if you perform a beheading at three quarters of an hour (fifteen minutes to noon), when Yang Qi is at its strongest and Yin Qi dissipates immediately, this is a heinous crime. It should be "not even allowed to be a ghost" as a sign of severe punishment.
The following is "zi". Regarding "zi", the Cantonese-speaking areas of Guangdong and Guangxi still use it today, such as "three o'clock in the afternoon", which means "fifteen fifty". According to the analysis of linguists, Cantonese retains a particularly large amount of "ancient Chinese". The reason is that the ancient Chinese people from the Central Plains lived in Lingnan and were separated from the people of the Central Plains for a long time. Their language did not "keep up with the time" with the people who stayed in the Central Plains. Advance together." The division method below "zi" is unknown. According to "Sui Shu Lv Li Zhi", seconds are ancient time units, and seconds below are "hu". The book does not explain how to convert it clearly. It only says: "'Second' is as thin as a awn." ; 'Suddenly' is like the thinnest spider silk."
Timing:
The sky is dark at midnight, the rooster crows on the first day, the sun rises and eclipse time, the sun is at noon, the sun is at dusk, and people are determined
The earthly branches are ugly, Yinmao and Chensi. Wuweishenyouxuhai
Modern 23-1 o'clock 1-3 o'clock 3-5 o'clock 5-7 o'clock 7-9 o'clock 9-11 o'clock 11-13 o'clock 13-15 o'clock 15-17 o'clock 17- 19:19-21:00, 21:00-23:00
Modern time for five nights, five drums and five nights
One watch and one drum at dusk, night 19-21 o'clock
People decide that the second watch, two drums, B night is 21-23 o'clock
The third watch, three drums, and night B are 23-1 o'clock in the middle of the night.
The cock crows, the fourth watch, and the four drums are Ding night, 1-3 o'clock.
Wing Dan Wu Gu Wu Ye 3-5 o'clock
If you are not asking about the meaning above, then as far as I know,
There are the following A method of measuring time:
The method of seeing the shadow of the pole, standing with a stick in the middle, with a dial around it, and measuring the time according to the shadow and deviation of the sun;
Update: Yes Use water, use sand...
How did ancient people calculate dates?
In the ancient Chinese calendar, A, B, B, D, Wu, Ji, Geng, Xin, Ren and Gui are called the "Ten Heavenly Stems", while Zi, Chou, Yin, Mao and Chen , Si, Wu, Wei, Shen, You, Xu and Hai are called the "Twelve Earthly Branches". The ancients used the heavenly stems and earthly branches to represent the year, month, day, and time. Year, month, day and hour are like four pillars supporting the building of "time", so they are called four pillars. The theory of heavenly stems and earthly branches formulated by the ancients should be based on observation and practice, rather than a concept created behind closed doors. For example, acupuncture acupuncture in traditional Chinese medicine pays attention to the Meridian flow. The acupoint selection is regular on different days and hours, which is consistent with the laws of the heavenly stems and earthly branches. As for later generations using the Heavenly Stems and Earthly Branches in fortune-telling and predicting a person's fate, it is up to everyone to judge its authenticity. Sixty Jiazi
The ten heavenly stems and the twelve earthly branches are combined in cycles: Jiazi, Yichou, Bingyin...all the way to Guihai, the final result is 60 combinations, called sixty Jiazi, so on and on, endlessly. The year, month, day and hour are all in a cycle of 60. 60 is a wonderful number in the field of time. Not only did the ancient Chinese use 60 as a cycle, but in the current timing method from the West, one minute is 60 seconds and one hour is 60 minutes. Is it just a coincidence? Similarly, the current 24 hours in a day corresponds to the traditional 12 hours in a day in China (hours are also big hours, two hours are one big hour). China uses 5 days as a big cycle of an hour. The so-called "five days and one hour" Hours", *** is 60 hours.
The sixty stem and branch combinations (called Sixty Jiazi) are listed below:
Jiazi, Yichou, Bingyin, Dingmao, Wuchen, Jisi, Gengwu, Xinwei, Renshen, Guiyou ,
Jiaxu, Yihai, Bingzi, Dingchou, Wuyin, Jimao, Gengchen, Xinsi, Renwu, Guiwei,
Jiashen, Yiyou, Bingxu, Dinghai, Wuzi, Jichou, Gengyin, Xinmao, Renchen, Guisi,
Jiawu, Yiwei, Bingshen, Dingyou, Wuxu, Jihai, Gengzi, Xinchou, Renyin, Guimao,
Jiachen, Yisi, Bingwu, Dingwei, Wushen, Jiyou, Gengxu, Xinhai, Renzi, Guichou,
Jiayin, Yimao , Bingchen, Dingsi, Wuwu, Jiwei, Gengshen, Xinyou, Renxu, and Guihai are divided into solar terms: Calendar
Use sixty Jiazi to commemorate the years in sequence, sixty years A reincarnation. For example, 1911 was the year of Xinhai, and the Xinhai Revolution broke out. According to the zodiac calendar, the new year begins after the Spring Festival. For example, the beginning of spring in 2006 was at 7:27 a.m. on February 4, so 7:26 was still the year of Yiyou, and starting from 7:27 was the year of Bingxu. Marking the months
In the same way, sixty months are used to mark the months in sequence. A new zodiac month also starts from a solar term. For example, if March 6, 2006, at 01:29 is Jingzhe, then it will be the month of Gengyin before that, and it will be the month of Xinmao after that. Years and months are divided according to solar terms. The intersection time of solar terms can only be determined after precise observation of astronomical phenomena. It reflects the position of the solar system and the earth in the universe. The days start with a starting day, and there is a cycle of 60 days: calendar day
A day and night constitute a day. Sixty years are used to mark the dates in sequence. For example, today is Jiazi day, and tomorrow is Yichou day, a cycle of 60 days. A new day starts at midnight. Timekeeping
Each day is divided into 12 equal parts, which are 12 hours. 5 days = 60 hours, represented by sixty years. For example, the current hour is Bingyin, and the next hour is Dingmao. The establishment of time needs to be calculated using true solar time. The dates and times record the movement and rotation of the earth around the sun. The four pillars
The values ??of the heavenly stems and earthly branches of the year, month, day, and hour are called the year pillar, month pillar, day pillar, and hour pillar respectively. BaZi
We often say that a person's horoscope is the four-pillar record of the time when he was born. It records some information about the relative positions of the earth, sun, and universe when a person was born. So from the meaning of the Bazi itself, it is a record of time. As for how to interpret the Bazi, it is a matter of opinion and wisdom. If you rely too much on it, you are superstitious. Because after all, it only records a very small part of a person's information. The universe is so vast and life is so complicated. People's lives mainly rely on their own efforts and struggles.
How did ancient people calculate time?
Tools used to calculate time in ancient times:
1. The "watch" in Guibiao is a rod. A pole or stone pillar standing vertically on the ground; "Gui" is a stone slab extending horizontally from the heel to the north. Whenever the sun turns due south, its shadow falls on the surface. By measuring the length of the shadow, you can calculate the times of winter solstice, summer solstice and other solar terms. When the surface shadow is the longest, the winter solstice has arrived; when the surface shadow is the shortest, the summer solstice has arrived. It is the oldest and most familiar astronomical instrument created in our country.
2. Leaky kettle
Also known as clepsydra and clepsydra. There are two main types of clepsydras: leakage type and water-receiving type. Most of the early carvings were water leakage. Water leaks from the side of the bottom of the clepsydra, and the grid fork and tongue rise again, causing the leakage arrow floating on the water of the leakage kettle to descend with the water surface, and the scale on the leakage arrow indicates the time. Later, the water-receiving type was created. Water was poured from the clepsydra into the kettle at a constant flow rate. The leaky arrow floating on the water surface of the kettle indicated the time as the water surface rose, improving the timing accuracy. In order to obtain a constant flow rate, the water level in the clepsydra should first be kept constant. Secondly, the cross-sectional area of ??the water pipe that fills the kettle with water must be fixed. The water pipe adopts the "thirsty" (siphon) principle to facilitate adjustment and repair. There are two methods of keeping the water level constant or close to constant, both of which can be found in the "Qi Guofeng Cui Hushi Diagram" in the "Liu Jing Tu" (published in 1153) written by Yang Jia in the Song Dynasty. In the picture, the "Lü Cai Ding" made in the Tang Dynasty (about 600-650 AD) has several compensation pots added above the clepsydra. The "Yansu Ding" made today (1030 AD) uses the overflow method and is four inches deep. The excess water flows from the flat kettle (xiagui) through the bamboo injection tube into the water-reducing ounce. The leaky pot created by Yansu was called the Lotus leakage, which became popular in various places during the Northern Song Dynasty.
3. Hourglass
Historical records record that hourglasses are driven by quicksand because water tends to freeze in winter. "History of the Ming Dynasty Astronomical Records" records that Zhan Xiyuan created the "five-wheel hourglass" in the early Ming Dynasty. Later, Zhou Shuxue enlarged the quicksand holes to prevent clogging and used six wheels instead. Song Lian (1310-1381) recorded the structure of the hourglass in the "Collected Works of Scholars of the Song Dynasty", including the size of the parts and the number of teeth on each wheel of the reduction gear. He also said that the shaft tip of the fifth wheel has no teeth and is equipped with a viewfinder to indicate the time.
4. Armillary Sphere
Ancient literature on the armillary sphere contains the theory that Luo Xiahong and Xianyu Wang created the armillary sphere during the reign of Emperor Wu of the Han Dynasty (140 BC to 87 BC), but there is no mention of its origin. structure.
"Book of Jin Astronomical Records" records that Zhang Heng of the Eastern Han Dynasty (AD 78-139) made an armillary sphere and said that it was driven by water leakage in a secret room. The appearance and emergence times of stars indicated by the instrument were consistent with the results of astronomical observations. "New Book of Tang·Tianwen Zhi" has a more detailed description of the armillary sphere designed by Seng Yixing and Liang Lingzan in the 13th year of Kaiyuan of Tang Dynasty (725). The instrument is equipped with two rings of the sun and the moon respectively, and the water wheels drive the universe. The whole elephant rotates once a day, and the sun rotates 1/365 times. The instrument is also equipped with two puppets, who beat drums and mark the engravings respectively. It is a wooden building with a narrow top and a wide bottom.
5. Water transport ceremonial platform
It was made by Su Song, Han Gonglian and others in the third year of Yuanyou (1088) in the Northern Song Dynasty. They wrote "New Yixiang Fa Yao" in the early years of Shaosheng (1094-1097), which contains many general drawings and partial drawings. This water-moving instrument platform is more than three and a half feet high and two feet and one foot wide. It is a wooden building with a narrow top and a wide bottom. There is a water lifting device on the lower level of the platform. The river cart is pushed by manpower, driving the water lifting wheel and the lower wheel (tube cart) to lift the water up to the Tianhe River (receiving tank) and into the Tianchi (reservoir). The Taichung flat kettle keeps the water level constant, and releases a constant flow of water through a water pipe of a certain cross-section to the kettle on the pivot wheel (water wheel), pushing the pivot wheel. The pivot wheel drives the day and night wheel, the armillary image and the armillary sphere through the transmission gear. Water transport instrument and elephant platform The water transport instrument and elephant platform has a relatively complex gear transmission system. Above the pivot wheel and next to the circumference is a "balance" device - the escapement. This is a major creation in the history of timing machinery. It changes the continuous rotation of the pivot wheel into intermittent rotation. Above the pivot wheel and next to the circle are
How did ancient people calculate days
Jiazi is one of the stems and branches, and the order is the first. The former one is Guihai, and the latter one is Yichou. In terms of yin and yang and the five elements, the armor of the heavenly stem belongs to the wood of yang, and the son of the earthly branch belongs to the water of yang. Water is the source of wood.
A cycle of stems and branches (sixty Jiazi)
Jiazi, Yi, Chou, Bingyin, Ding, Mao, Wuchen, Jisi, Gengwu, Xinwei, Renshen, Guiyou, Jiaxu, Yihai
Bingzi, Ding Chouwuyinjimaogengchenxinsirenwuguiweijiashenyiyoubingxudinghai
Guimao Jiachen Yisi Bingwu Dingweiwu Shenjiyou Gengxu Xinhai
Renzi Guichou Jiayin Yimao Bingchen Dingsi Wuwu Jiwei Gengshen Xinyou Renxuguihai
This The cycle is called "One Year", which is 60 years.
How did ancient people view time?
In ancient times, in order to adapt to the needs of life and production, various forms were gradually formed based on the alternation of day and night. A method of timing.
Ancient timekeeping system China’s timekeeping system is not unequal: in ancient times, people "worked at sunrise and rested at sundown", and also abided by the laws of nature, with the sunrise and sunset Entering the standard time for work and rest is equivalent to dividing the day into two parts. This is a natural unequal time. It can be seen in the oracle bone inscriptions unearthed in the Yin Ruins that there are special names for different times of the day, such as Dan, Dacai, Dajian, Zhongri, Zang, Xiaocai, Xiaocai, Mo (twilight), Xi, etc. Later, at night, there were five watches and five o'clock, that is, the night was divided into five watches, and each watch was divided into five o'clock, and the habit of striking the bang to tell the time was formed. Isochrone method: In the Western Zhou Dynasty, in order to measure time, a day was divided into twelve equal-length periods based on the diurnal motion of the sun, using the words Zi, Chou, Yin, Mao, Chen, Si, Wu, Wei, Shen, It is represented by the twelve branches of You, Xu and Hai. Another isochronous system is to divide the day into one hundred equal parts, that is, the hundred-quarter system. This is a unique timing method in ancient China. The age of its creation is still uncertain, but there are written records about the hundred-quarter timing. , there are also unearthed cultural relics to prove it. Xu Shen of the Eastern Han Dynasty pointed out in "Shuowen Jiezi" that "day and night are one hundred quarters". When Ma Rong of the Eastern Han Dynasty annotated "Yao Dian", he said: "In ancient times, the day is sixty quarters long and the night is short. The day is four short. At ten quarters, the night is sixty quarters long; at fifty quarters during the day, the night is also fifty quarters long." The ancient system mentioned here should refer to the Spring and Autumn Period and the Warring States Period or earlier. In all dynasties after the Han Dynasty, Twelve Chen and Baike were used together. But one hundred and twelve are incommensurable, so the coordination plans of each dynasty often changed.
Ancient Egyptian and Babylonian timekeeping systems: Unequal time: As early as 3000 BC, the ancient Egyptians divided day and night into 12 hours. They use sunrise as the beginning of the day, noon as the day at 6 o'clock; sundown as the night, and midnight as the night at 6 o'clock. Because the length of day and night varies throughout the year, the actual length of each hour in different seasons is also unequal. This timekeeping method spread to Europe and was used until the fourteenth century AD (see Ancient Egyptian Astronomy). Isochrone method: In the eighth century BC, in order to meet the needs of astronomy, the ancient Babylonians formulated the isochrone method. They divided the day into 24 equal-length periods, the 24-hour clock. The isochronous system was later inherited by Hipparchus and Ptolemy, and prescribed noon as the beginning of the day. This method of timing is often used in astronomy and is also called "astronomical time". Since it was inconvenient for daily life, midnight was used as the beginning of the day from 1925 onwards.
The development of ancient timekeeping tools has roughly gone through three stages:
Flow timekeeping The oldest timekeeping tool is undoubtedly the leaking clepsydra.
Later, there were hourglasses that used sand instead of water, lamp clocks that measured time based on the amount of oil consumed by oil lamps, and incense and seal clocks that burned incense (the incense snaked along the grooves of the seal characters in the metal box) and so on. The oldest existing clepsydra in China dates from the Western Han Dynasty. The oldest existing hourglass in the world is an Egyptian water clock from the 14th century BC.
Mechanical Clock Zhang Heng, an astronomer in the Han Dynasty of China, made a water-transported armillary sphere (see the leaking water-turned armillary sphere), which can display celestial phenomena such as the appearance and appearance of stars and the zenith, which is completely consistent with the outdoor celestial phenomena. This is the world's earliest water-driven mechanical clock. Liang Lingzhan, an astronomical instrument manufacturer in the Tang Dynasty, made the Water Movement Universal Image. In addition to matching the astronomical phenomena, there are two wooden figures that automatically beat drums every quarter and bells every hour. This is an improved mechanical clock of Zhang Heng Water Transport Hunxiang. During the Yuanyou period of the Song Dynasty, Su Song, Han Gonglian and other officials jointly created the water transport ceremonial platform. In the Yuan Dynasty, there was a lamp leaking from the Daming Palace made by Guo Shoujing. In the Ming Dynasty, Zhan Xiyuan made a five-wheel hourglass. These mechanical clocks have complete gear trains, cams and escapements. Mechanical clocks in Europe began in the fourteenth century and became popular for about four hundred years.
Pendulum Clock In 1582, Galileo Galilei discovered the isochronism of the pendulum. From 1656 to 1657, Huygens of the Netherlands introduced the pendulum into a mechanical clock, thus creating the pendulum clock. In 1673, Huygens used a balance wheel-oil wire system to create an easy-to-carry clock. In 1735, Harrison of England produced the first navigational bell, which solved the navigation positioning problem that was urgently needed in the development of capitalism at that time. In 1896, France's Guillaume developed alloy steel with a low expansion coefficient and built an astronomical pendulum clock with extremely high precision. If the clock is placed in a vacuum chamber and stored in the basement at a constant temperature, it will become an astronomical pendulum clock, with an error of no more than a few thousandths of a second per day (see astronomical timepiece).
Ancient Time Measuring Tools Pole Shadow Time Measurement The ancients have known for a long time that the length of the shadow of an upright pole constantly changes with the position of the sun in the sky. Looking at the pole shadow is more convenient than directly observing the sun, but the timing results are not unequal.
"Historical Records: Biography of Sima Ranju" contains the Spring and Autumn Period...