Five mysteries of Nanjing ancient city wall

What was the original length of Nanjing City Wall? In the past 600 years, the data released by the government alone exceeded 10.

2 1,1June 373, the length of Nanjing city wall recorded by the Royal Archives was "per week 1734 feet", which is equivalent to 34.349 kilometers in today's system. This is the earliest record about the length of Nanjing city wall. However, 1386 and 1386, on February 22nd, 2006, Zhu Yuanzhang ordered the rebuilding of Houhu Town, the length of which was changed, but there was no further detailed record in the archives. 15 16 years, Chen Yi called it "96 Li Zhou" in "A Textual Research on Jinling's Ancient and Modern Pictures", which was also used in the Wanli Book of the Ming Dynasty. Matteo Ricci, who had been to Nanjing three times, was the first person to doubt the length of the city wall. He thought, "It is difficult to determine the full length of this thick wall." So, he used a story told by Nanjing people at that time to express its length: "Two people rode in opposite directions of the city, and it took a whole day to meet."

Until the early Qing Dynasty, Gu quoted the statistics of the magistrate and called its length "57 miles and 5 minutes". This length was used by local officials for a long time in Qing dynasty, but in other documents, there are different versions of this length. During the Republic of China, with the popularization and application of modern surveying and mapping technology, the length of Nanjing city wall was different in different documents. 1945, the map of Nanjing corrected by aerial photography by the US Military Map Supply Office, provides the data of "39.500 yards, that is, about 23.2 miles (about 70 miles)". The China Economic Daily in the Republic of China called the Nanjing City Wall "about 34.23 kilometers long". Mr. Zhu Qiqi, a famous cultural expert in Nanjing, called it "the old saying is 96 Li, and the actual measurement is 66.8 Li". In a word, the length of Nanjing City Wall is always a "muddled account".

1954 The data measured before the demolition in Nanjing is: the circumference is 34.36 kilometers, and if the Chengmen and Taicheng sections are added, the total length is 37. 14 kilometers. However, after four years of large-scale demolition, the circumference of the city wall counted by the Municipal Construction Committee is 33.676 kilometers. This data has been used to this day. However, for many years, because this data was obtained after urban demolition, its scientific nature has been questioned by academic circles. Some of the city walls demolished now have changed a lot, and it will be difficult to get a more scientific length.

How many bricks are there?

A recent book said that the Nanjing City Wall "consumed 400 million bricks in total". In order to count the "exact" quantity of Nanjing city wall bricks, several basic concepts must be considered. First of all, we should know the total length of bricks for city walls. Nanjing city wall, even if calculated, is "33.676 km" to be verified, including Miyagi, Imperial City and Waiguo. Some sections of the city wall are made of stones instead of bricks, and many sections of Waiguo do not use bricks at all, commonly known as "Tuchengtou" or "Tuchengtou", so the total length of bricks is difficult to determine. Secondly, we should know the height and thickness of the wall in different sections. The existing Nanjing city walls are not uniform in height and thickness. Sometimes, in the same position, the thickness difference is as much as twice, and the height difference is as much as several meters. In particular, the so-called "gable wall" is only one brick thick, which is the part of the mountain, so it is impossible to determine the height and thickness by unified standards. Third, we should distinguish different fillers in the wall. Some sections of the city wall are city bricks from the inside out, some sections are gravel or broken bricks, some sections are rammed earth, and so on.

Zhu Yuanzhang did not leave an exact figure for future generations on the consumption of city bricks. At present, there is no record in the local county annals of the number of city bricks collected by the imperial court from the local government. Based on the size (approximate number) of a single city brick in the early Ming Dynasty (40×20× 10 (cm)), the city wall masonry is about 88 city bricks per cubic meter. However, only relying on this material, under the uncertain factors of the length, height and thickness of the city wall and the inside of the city wall, it is impossible to calculate the number of all bricks used in the Nanjing city wall. It may be more scientific to express it with an approximate number of "hundreds of millions" or "hundreds of millions".

Where did the bricks come from?

Almost all foreign tourists will be deeply impressed by the inscriptions on the city bricks after visiting the Nanjing City Wall. For a long time, the academic circles have two views on the source of city bricks: first, after the imperial court apportioned the task of burning bricks to various governments and counties in the early Ming Dynasty, it organized local migrant workers to carry grain and grass to Nanjing to burn city bricks; Secondly, it was burned locally in the counties and counties recorded in the city brick inscription, and then transported to Nanjing. In fact, the complexity of the source of Nanjing city bricks is beyond people's imagination.

600 years ago, the origin of Nanjing city bricks, like design drawings, labor and cost, was not recorded in royal archives. This kind of "negligence" is almost incomprehensible in some western countries. Fortunately, in the Ming Dynasty, when building the Nanjing city wall, in order to ensure the quality of city bricks, the court ordered officials, local organizations, craftsmen and civilian workers in charge of brick areas to leave their names on the city bricks. In recent years, according to the county-level standards of local bricks, it is found that there are at least 200 kinds of city bricks, which correspond to brick houses, towns and imperial courts. This data is still not the scientific basis for all the sources of Nanjing city wall bricks, because many bricks without exact place names have been found, such as bricks with only years and bricks with only one word. In addition, the bricks lost in the demolition of the city and the bricks that have not been found inside the existing city walls are still missing.