What are the armillary sphere and meteorological instrument used for?

The armillary sphere studies earthquakes.

Hou Fengyi studies wind direction, wind speed and meteorology.

It was all invented by Zhang Heng.

Here I begin to get down to business:

Zhang Heng not only completed the theory of "Huntian", but also developed a new instrument for observing celestial phenomena in Luoyang in 1 17. This is the world's first large astronomical instrument driven by water. ?

The place where Zhang Heng observed the celestial phenomena was called Lingtai, which was located in the south of Pingchang Gate in Luoyang. Lingtai was the observatory at that time. The manager here is Lingtai Cheng, who belongs to Taishiling. There are more than 40 people waiting for the weather, the weather, the sun and the stars. The organization is huge and the division of labor is fine. Zhang Heng took advantage of this advantage and conducted a lot of observation, research and experiments. In A.D. 1 16 (the third year of the Eastern Han and Yuan Dynasties), he first made a model of an armillary sphere, which was called Little Armature.

As can be seen from the notes of the armillary sphere, the small armillary sphere is a wooden ball smaller than the armillary sphere. First draw a great circle on the sphere as the equator, then draw a great circle with an angle of 24 degrees with it as the ecliptic, and divide it into 365 on the yellow equator. Scale, all started from the winter solstice. At the equatorial north pole and its collision point (that is, the south pole), each needle is used? One hole is used as both ends of the rotation axis of the sphere. Take a long bamboo stick and make a hole in the center of both ends, so that the distance between the two holes is equal to the length of half a big arc of the ball. Overlap the two holes of the bamboo stick with the north and south poles, and the bamboo stick runs through the ball. At this time, the connecting line between the two holes of the bamboo stick must be consistent with the ball, because the distance from the north pole to the south pole pinhole center is exactly equal to 182 5. Cut off half a bamboo stick along the middle line, so that the middle line is just the connecting line of the holes at both ends of the bamboo stick. Starting from the winter solstice, move the center line of the bamboo pole every other degree along the equator, and read the degree of its intersection with the ecliptic every time, so that every time the equator increases by one degree, the degree of the ecliptic is more or less. This number is the number of times the yellow equator advances and retreats. When the increase rate of equatorial degree is greater than that of ecliptic degree, it is multiple and progressive; ; On the contrary, less is counting backwards. This is the earliest and most detailed record of the specific method for measuring the advance and retreat of the Yellow Equator in ancient China. ?

After the small armillary sphere model is made, it is accurate as an experiment, and then it is cast into a formal instrument with copper. Under the careful operation of Zhang Heng, it took a lot of effort. After more than a year's efforts, this instrument was finally made successfully. Because this musical instrument is made according to the theory of Huntian, Zhang Heng named the model made of bamboo "Xiaohun" and the model made of copper "Huntian Instrument". Zhang Heng's astrolabe is similar to the modern fake astrolabe in many places, but the modern fake astrolabe is certainly much more accurate than it.

Zhang Heng's armillary sphere is made according to the principle of armillary sphere. Its shape is a spherical thing, equivalent to the current celestial globe. The armillary sphere is divided into inner and outer layers, each layer can rotate, and an iron shaft runs through the center of the sphere in the middle. The direction of the axis is the direction of the earth's rotation, and the contact between the axis and the sphere has two intersections, namely the North Pole and the South Pole on the celestial sphere. Half of the ball is hidden below the horizon and the other half is exposed above the horizon. There are 28 constellations and other stars on the sphere, and there are ecliptic circle and equatorial circle on the sphere, which form an included angle of 24 degrees and have 24 solar terms respectively. From the winter solstice (winter solstice is the beginning of a year in ancient times), divide this circle into 365? Degree, each degree is subdivided into four small squares. There are two circles outside the sphere, one is the horizon and the other is the meridian circle. The circumference of the outer circle is one foot, four feet and six inches. The celestial axis is supported on the meridian ring at an oblique angle of 36 degrees from the horizon, which means that the North Pole is 36 degrees higher than the horizon. This is the elevation angle of the North Pole of Luoyang and the geographical latitude of Luoyang. The structure of this instrument contains almost all the advanced astronomical knowledge at that time. ?

In order to make the armillary sphere rotate by itself according to time, Zhang Heng designed a set of leaky cans. The leaky drip pot is an ancient timekeeping tool. It uses a special water container with a small hole at the bottom, and the water drops into the pot engraved with time marks. People can know what time it is just by looking at the water depth in the pot. The clock was not invented at that time, so our ancestors used it to time. Zhang Heng used this principle to design a set of drippers, skillfully used two pots to cooperate with the armillary sphere, and used the power of dripping water in the pots to drive the gears, thus driving the armillary sphere to run. By properly selecting the number of gears, the armillary sphere skillfully rotates day and night, vividly demonstrating the changes of the astronomical phenomena, and people can observe the phenomenon that the sun, the moon and the stars run from the armillary sphere. ?

After Zhang Heng made the bronze armillary sphere, he installed it in a secret room and turned it with the power of running water. Then, let a manager close the room and report loudly to the observer standing on the observation platform: which star on the armillary sphere is rising, which star is reaching the zenith and which star is falling. Everything is in perfect harmony with the sky.

In addition to armillary sphere and broken kettle wine, Zhang Heng also created a mechanical calendar called "Ruilun Ghost Pod". The Book of Jin Tian Wenzhi records: "When Shun Di arrived, Zhang Heng made another elephant ... and turned it into a room in a temple through water leakage. The existence of stars corresponds to the sky. Because of his embarrassment, he turned to the auspicious wheel and ghost pod under the steps, and the moon was full and started to fall according to the calendar. " Ghost pod is a legendary tree. It lays a pod every day. After pod 15, one pod is dropped every day and then grows again. Inspired by this, Zhang Heng created Ruilun Ghost Pod, which is equipped with a mechanism. Fifteen dials with cam function are installed on a vertical shaft, so that they can act on the fifteen ghost pods in turn, each rising and falling at an appropriate time. Then put the Ruilun ghost pod next to the terrace outside the armillary sphere hall. Connected to the drip pot, it is also connected to the armillary sphere by leakage. From the beginning of each month, one piece of konoha leaves will be transferred out every day, and 15 will be transferred out on the day of 15 * *, and then another piece will be transferred every day, which will be reduced in turn until the moon sets. Because the lunar calendar is in harmony with the movement of the moon, this instrument can not only display the date, but also show the increase and decrease of the moon round by round, that is, it rotates and opens again and again according to the order of the new moon, winding, looking at the sun, winding and dark day in the lunar calendar, so that people can get the effect similar to the activity calendar from the Swiss wheel.

In a word, Zhang Heng's Lingxian and Huntianyi are extremely important scientific achievements in ancient astronomy in China. On the one hand, it summarizes the valuable achievements and rich experience of ancient astronomy, on the other hand, it deliberately innovates, representing an excellent example of using scientific instruments. In particular, the armillary sphere, a precise scientific instrument, provides an excellent method for observing astronomical phenomena, which has great inspiration and reference for future astronomical research. ?

In the fourth year of Andi (1 17), Zhang Heng invented the "water-borne armillary sphere", wrote "Notes on the Huntian and Lingxian" and advocated the theory of Huntian. In the first year of Yangjia, Shun Di (132), the seismograph he invented could detect earthquakes in Luoyang and thousands of miles away. This seismograph ranks first in the world, 1700 years earlier than Europe. Zhang Heng is also a meteorologist. He invented it, also known as the Bird Hou. Install a bronze bird with flowers at the top of a 5-foot-high wooden pole. If there is wind, the bronze bird will turn, and the bird's head will face the direction of the wind to determine the wind direction. This instrument is 1000 years earlier than Hou Feng chicken in Europe, and it is also the highest in the world.