A symbol of China’s historical detachment and sense of vulnerability, the Great Wall snakes through the Chinese panorama, over deserts, hills, and plains, for greater than 2, 500 miles (4,000 km). However, despite its seemingly impregnable battlements, the wall was ultimately an ineffective barricade. Within the thirteenth century it was breached by the ferocious onslaught of the Mongols and then within the seventeenth century by the Manchu, helped by the decline of the Ming dynasty. In the present day, its dilapidated remains crumble throughout the rugged terrain of northern China and only chosen sections have been restored.
THE GREAT WALL
Sections of the bastion known as the Great Wall have been first constructed throughout the Warring States interval (475-221 BC) by individual states to thwart incursions by northern tribes and to defend towards aggressive neighbors. Easy and unconnected earthen ramparts, they weren’t joined together till the Qin dynasty (221-207 BC) first unified China underneath Shi Huangd, the First Emperor. The maintenance and growth of the wall mirrored every succeeding dynasty’s feelings of insecurity. Enlarged underneath the expansionist Han dynasty (206 BC-AD 220), the wall was uncared for by the cosmopolitan Tang dynasty (AD 618-907), only to be closely fortified by the more inwardlooking Ming dynasty.
The Qin wall was an easy tamped earth affair, however the later Han dynasty adopted an extra advanced expertise that enabled them to construct partitions even in the bleak expanses of the Gobi Desert. They’d line wood frames with a layer of willow reeds and twigs and then fill the frame with a combination of mud, high quality gravel, and water. This could then be pressed firmly into place. When the combination dried, the frame could possibly be eliminated, leaving behind a big slab of hard, bricklike mud that may very well be constructed upon again in the identical method. That is very similar to modern building, when steel rods are use to strengthen concrete.