From BC 1300 to BC 1027, the use of standard meters was recorded in Oracle Bone Inscriptions during the Shang Dynasty in China. There is an article in the Book of Songs, National Style and Prescriptions, "Prescriptions were written in the Chu Palace. Slap in the sun and do it in the Chu room ... ". The exact record of using standard watches is 659 BC.
Sun clock, such as standard watches, will fail on cloudy days or at night. To this end, people have invented time-measuring instruments such as clepsydra, hourglass, oil lamp clock and candle clock.
In ancient China, there were mainly two kinds of timers designed by applying mechanical principles. One is timed by fluid mechanics, and there are notches and hourglasses later; One uses mechanical transmission structure to time, including armillary sphere and water transport instrument. In addition, there is a sundial that uses astronomical principles (mostly according to the direction of the sun's shadow to measure time), and it is also one of the oldest timepieces in China.
Sundial, water clock, hourglass
Standard watches, sundials, water clocks, sand clocks, fire clocks, candle clocks, thousand-copper leaky rolling bombs, Yanyou dripping, dragon boat fragrant leaking, dragon water, equatorial sundial, equatorial theodolite, armillary sphere, etc.
sundial
The "table" in the standard table is a pole or stone pillar standing vertically on the ground; "Gui" is a slate extending horizontally from the heel of the watch to the north. Whenever the sun turns due south, the shadow falls on the water of Guiyu. By measuring the length of the shadow, we can calculate the time of each solar term, such as winter solstice and summer solstice. When the shadow is the longest, the solstice of winter comes; In the shortest time, the summer solstice came. It is the oldest and most common astronomical instrument in China.
sundial
A sundial is also an instrument for measuring time by observing the shadow of the sun, which mainly determines the time or the number of minutes at that time according to the position of the shadow. Judging from the unearthed cultural relics, the sundial was used before the Han Dynasty, and it was always a common timer before the mechanical clock was introduced to China. The main part of a sundial consists of hands and facets. When the sun moves in the sky, the projection of the hand moves on the surface like the hands of a clock, which can indicate the time.
moment
Both the standard watch and the clepsydra use the shadow of the sun to calculate the time, but it will lose its function when it rains or it gets dark, so a kind of water clock that can time day and night is produced, which is the clepsydra. Leakage refers to the leakage of the pot; Carving means carving an arrow. The arrow is a ruler marked with a time scale. Missing carving is to calculate the time by observing the data displayed on the carved arrow in the pot by using the principle of balanced dripping. As a timer, cracks are more common than sundials. In ancient China, many literati and poets left many poetic chapters about missing prints. For example, Li He, a poet in the Tang Dynasty, said, "It's like adding seawater to a palace leak and dropping Nagato overnight." Su Shi in Song Dynasty: "When the moon is absent, people are quiet." Before the introduction of mechanical clocks into China, the missing engraving was the most widely used timepiece in China.
water clock
Also known as clepsydra and clepsydra. There are two main types of clepsydra: drainage type and water receiving type. Most of the early water leaks were drainage type. The bottom side of the leaky kettle leaks water, and the grid fork and the closing tongue rise again, so that the leaking arrow floating on the surface of the leaky kettle drops with the water surface, and the scale on the leaking arrow indicates the time. Later, the water-receiving type was created. Water is injected from the leaky kettle into the receiving kettle at a constant flow rate, and the leaking arrow floating on the water surface of the receiving kettle indicates the time with the rise of the water surface, thus improving the timing accuracy.
In order to obtain a constant flow, the water level of the clepsydra must be kept constant at first. Secondly, the cross-sectional area of the water pipe of the irrigation pot must be fixed, and the water pipe adopts the principle of "thirst for black" (siphon) to facilitate adjustment and maintenance. There are two ways to keep the water level unchanged or close to it, both of which can be found in "The Wind Map of Hu's Qi State" made by Yang Jia in Song Dynasty (published by 1 153). In the picture, there are several compensation pots carved above the leaky pot of Lv Caiding made in Tang Dynasty (about 600 ~ 650 AD), and Su Yanding made in modern times (1030) is carved by overflow method, which is four inches deep. Excess water flows from the flat kettle (lower cavity) into the water reduction angle through the bamboo injection tube. The leaky pot created by Yan Su is called Lotus Leak, which was popular all over the country in the Northern Song Dynasty.
Huan Tan (who died in 56 AD) wrote in The History of the Three Dynasties, the Three Kingdoms, the Six Dynasties, the Qin and Han Dynasties, and the Later Dynasties that the degree of engraving leakage varies with the humidity, temperature and humidity, and should be checked with reference to sundials and stars day and night. At that time, the influence of water temperature and air humidity on the timing accuracy of engraving leakage was realized.
The earliest missing records can be found in Zhou Li. Among the unearthed cultural relics, the oldest engraved leak is the relic of the Western Han Dynasty, with 3 pieces, all of which are drainage-type. Among them, the bronze clepsydra unearthed in Hangjinqi, Yikezhaomeng, Inner Mongolia Autonomous Region in 1976 is the most complete and engraved with a clear age. There are two relatively complete engravings handed down from ancient times, both of which were influenced by water: one was built by the Beijing Museum of Chinese History in the third year of Yuan Dynasty (13 16); One is from the Palace Museum in Beijing, from the Qing Dynasty.
hourglass
Because water freezes easily in winter, it is driven by quicksand. Tian Wenzhi of Shi Ming records that Zhan Xiyuan created the "five-wheel hourglass" in the early days. Later, in order to prevent congestion, Zhou Shuxue enlarged the quicksand cave and replaced it with six wheels. Song Lian (1310 ~1381) wrote "songji", which recorded the hourglass structure, with the size of parts and the number of teeth of each wheel of the reduction gear, and said that the shaft tip of the fifth wheel had no teeth, but it was equipped with a landscape disk indicating time.
armillary sphere
In ancient literature, Luo was said to be an armillary sphere of Emperor Wu of the Han Dynasty (140 ~ 87 BC), but its structure was not mentioned. Jin Zhi records that Zhang Heng (AD 78 ~ 139) made the armillary sphere, saying that it was driven by water leakage in the secret room, and the time of the stars indicated by the instrument was consistent with the astronomical observation results. The Book of the New Tang Dynasty, Tian Wen Zhi, records in detail the armillary sphere designed by the monks and their party by Liang Lingzan in the 13th year of Tang Kaiyuan (725). The instrument is equipped with two wheels, namely the sun and the moon, and the waterwheel drives the elephant. The elephant turns once a day and the sun turns 1/365 times. The instrument is also equipped with two puppets, which drum and carve respectively. This is a wooden building with a narrow bottom and a large width.
Water transport image table
Yuan You three years in the Northern Song Dynasty (1088) was written by Su Song, Han Gonglian and others. In the early years of Shao Sheng's life (1094 ~ 1097), they wrote "An Outline of New Devices", which contained several general plans and component drawings. This watercraft is more than three feet high and two feet wide. This is a narrow and wide wooden building. There is a water lifting device on the lower floor of the platform, and the upper wheel and the lower wheel (pipe truck) are driven by manpower to lift the water to Tianhe (receiving pool) and inject it into Tianchi (reservoir). The water level of the flat kettle in the platform is kept constant, and a constant flow of water is discharged to the kettle on the pivot wheel (waterwheel) through a water pipe with a certain section to push the pivot wheel. The pivot wheel drives the day and night wheel, the elephant and the armillary sphere through the transmission gear.
There is a complex gear transmission system in the image platform of water transport instrument. There is a "celestial balance" device-escapement mechanism above and around the pivot wheel, which is a great creation in the history of timing machinery, and it changes the continuous rotating motion of the pivot wheel into intermittent rotating motion.
A large number of lamps leak
1276, Guo Shoujing of the Yuan Dynasty in China made a big leaky lamp. It is driven by water power, and the puppet is driven by a gear train and a rather complicated cam mechanism to automatically tell the time "ring the bell for a while, carve the drum for two minutes, ring the cymbals three times, and ring the cymbals four times".