History : Mar-Apr 2016
CONSTRUCTING THE GREAT WALL 4 The Great Wall was not the result of a single project. It was built in stretches over a period of more than two centuries. The first parts were built in the west and the wall was extended eastward as the nomads sought out unprotected areas for their incursions. The first walls built by the Ming were made in the traditional way, with earth and adobe to create a mud wall. Later in the 16th century, a more expensive and durable system was developed. Two brick walls were built on a stone base. The space inside was filled with compacted dirt, gravel, and sand. The illustration to the left shows how this model may have been carried out. 1Hard at Work Civilians as well as soldiers worked on building the wall. The civilians were rewarded with tax breaks. The builders sometimes mutinied, as they did in Datong in 1524 when the garrison killed the superviser. 2Baked to Last Cooked in kilns at 2102˚F (1150˚C) for seven days, the bricks were of the highest quality. Modern experiments have calculated that this manufacturing process made them as strong as reinforced concrete. 1 3Strong as Rice Stronger even than the bricks was the mortar. In some stretches the bricks have worn away and only the mortar is left. Recent analyses show that the mixture contained a secret ingredient: rice flour. 4Thousands of Miles The Ming Great Wall extends for nearly 5,000 miles. In some sections there are double or even triple stretches, so the wall’s total length is estimated at just under 5,500 miles.