Royal copper-plated tablet

[Imperial copper-plated flat instrument]

The imperial copper-plated flat instrument was made in the 20th year of the reign of Emperor Kangxi of the Qing Dynasty (1681) at the Palace of the Qing Dynasty, with a diameter of 32.1 cm. The old collection of the Qing Palace
The simple leveling instrument is divided into three parts: the upper heavy plate is the northern flat plate, the outer circle is carved with December, 30 ° per month, the second is carved with 12 hours, the center of the plate is the North Pole, and the upper is attached with a time plate. The medium and heavy disk is the celestial disk, and one side is the polar star disk. It is engraved with the lunar calendar day, the twelfth house of the equator, 360 ° of the circumference, the twenty-four solar terms, the right ascension line, the ecliptic, and the Milky Way system. The twenty-eight constellations are arranged along the equator and marked by the first to sixth order stars. The other side of the celestial disk is the equatorial Antarctic star disk, which is roughly the same as the Arctic star disk except for changes in the astrogram. The lower heavy plate is a flat plate in the south. The center of the plate symbolizes the South Pole. The center is equipped with a time dial and a large vernier. The surface of the plate is engraved with a change line, a solar term line, and a sunrise line. There is a lifting ring on the top of the tablet, the upper end is engraved with “tablet”, and the lower end is engraved with the inscription “Kangxi made it in the middle of Xinyou at the age of 20”, which is made for the office of the Qing Palace
Therefore, the level gauge is not equipped with a camera and cannot be measured, but through the demonstration, the time of sunrise and sunset, the time of sunrise and sunrise, the time of sunrise and sunrise, the time of mid-sky star, the time of moon, and so on can be calculated. If you want to find a star in the middle of the sky at a certain time (the star in the middle of the sky refers to the phenomenon that a star passes through the meridian circle), that is to say, the north star disk rotates to the left, so that the equatorial longitude of the sun on that day is aligned with that time, and the star that stays at the meridian position of the sky disk is the star in the middle of the sky at the desired time.