Eight hundred miles of urgency is a very fast way of information transmission in ancient times, China established an official information transmission network throughout the country 3,000 years ago, these information networks throughout the country bear the heavy responsibility of transmitting government documents, so it has always been valued by the rulers, after the construction of successive dynasties, this network is increasingly developed and perfect, this is the station system.
By the time of the Tang Dynasty, Chinese caravanserais were spread all over the country, and these stations were nodes of the national information network that needed to be laid out, and the state stipulated that the distance between the two adjacent stations was 20 miles.
During the Tang Xuanzong period, there were as many as 1639 post stations in the country, and the postal stations were divided into three types: land stations, water stations, and water roads, of which 260 were water stations, 1297 were land stations, and 86 were water and land phase stations.
In the Tang Dynasty, the various provinces were divided into six grades: 20 first-class stagecoaches, 15 second-class stagecoaches, decreasing below the third class, and the last sixth-class stagecoaches with two to three stagecoaches.
According to the busy work of the stagecoach, the water station is also divided into three classes: 12 people with a stagecoach, nine stagecoaches for idle things, and six stagecoaches for the idle water stations. There are more than 20,000 workers specializing in stagecoach services, including 17,000 stagecoach soldiers. Each station has a post house, equipped with stagecoaches, donkeys, stagecoaches and stagecoaches, which shows that the construction of the post stations at that time was relatively perfect.
How fast is the eight-hundred-mile rush?
We take the Tang Dynasty as an example to calculate, the Tang government officially stipulates that ordinary stagecoaches require about 180 miles a day, and the fastest requires 600 miles a day. An Lushan rebelled in Fanyang, when Tang Xuanzong was in Huaqing Palace, the two places were separated by three thousand miles, and within 6 days Tang Xuanzong knew about this news, and the transmission speed at that time reached 500 miles per day.
The Tang Dynasty took Tang Taizong Li Shimin's two steps- one step on each left and right feet as the size standard, called "steps", stipulating that three hundred steps are one mile, and one-fifth of a "step" is one foot. In the Tang Dynasty, one foot was 0.303 meters in modern times, and one mile was 454.2 meters. Then a trip of 500 miles a day is equivalent to 226.1 kilometers in modern times, which was very fast in that era.
This is the highest information transmission speed of the Tang Dynasty, as for the eight hundred mile rush, basically can only reach this speed, this is already the rhythm of running dead horses, often after the message is sent to the destination, the sender itself if the physique is not strong enough, it will die with the horse due to overwork.
The information conveyed by the eight hundred lijia is generally a hundred thousand urgent military and national events, such as the invasion of the country by the enemy army, the occurrence of serious military rebellions in the country such as the Anshi Rebellion, and the occurrence of extremely serious natural disasters in the country, otherwise the eight hundred lijia will not be used to send letters urgently.
But there are exceptions, "Red Dust rides a concubine and laughs, no one knows that it is a lychee coming." Yang Guifei loved to eat lychees, but lychees grew in the south, and the distance from the south to Chang'an was far away, so Tang Xuanzong ordered that the lychees be transported with the fastest stagecoach, and even if the lychees were sent to Chang'an in three days, the taste of the lychees was not good.
For this reason, Tang Xuanzong was so brainbroken that there was nothing he could do, but Li Longji, who loved beauty and did not love Jiangshan, ushered in the chaos of An Shi. Although there were post stations to report letters, although it took eight years to suppress the Anshi Rebellion, the Tang Dynasty could no longer restore its former glory.