The introduction of the Great Wall of China

The history of the Great Wall is said to start from the Spring and Autumn Periods when seven powerful states appeared at the same time. In order to protect themselves, they all built walls and mobilise troops on the borders. At that time, the total length of the wall had already reached 3,107 miles, belonging to different states.

The Ming Dynasty is the peak of wall building in Chinese history. The Ming suffered a lot by disturbances from minority tribes such as the Dadan, Tufan and Nuzhen. The Ming court from its first emperor to the last ceaselessly built and repaired walls in the north For example, out of Yanmenguan Pass were added three big stone walls and 23 small stone walls. Eleven Garrisons were distributed along the main line of the wall. The countless walls, fortresses, and watch towers made the country strongly fortified. In the early Qing Dynasty, some sections of the walls were repaired and several sections were extended. This great engineering work eventually stopped in the middle of the Qing Dynasty.

Just like a gigantic dragon, the Great Wall winds up and down across deserts, grasslands, mountains and plateaus stretching approximately 6,700 kilometers (4,163 miles ) from east to west of China. With a history of more than 2000 years, some of the section of the great wall are now in ruins or even entirely disappeared due to weathering or hit by artillery shells during World war two. However, it is still one of the most appealing attractions all around the world owing to its architectural grandeur, enigeering marvel and historical significance as one of the Seven Wonders of the world.

With an average height of 10 meters and a width of 5 meters, the wall runs up and down along the mountain ridges and valleys from east to west. The Great Wall runs from Shanhaiguan Pass near Bo Hai (Gulf of Bohai) to Jisayuguan Pass (in modern Gansu province) traversing Liaoning, Hebei, Tianjin, Beijing, Shanxi, Inner Mongolia, Shaanxi, Ningxia, Gansu.

The Great Wall is the world's longest human-made structure, stretching over approximately 6,400 km (4,000 miles) from Shanhaiguan in the east to Lop Nur in the west, along an arc that roughly delineates the southern edge of Inner Mongolia, but stretches to over 6,700 km (4,160 miles) in total. It is also the largest human-made structure ever built in terms of surface area and mass. At its peak the Ming Wall was guarded by more than one million men. It has been estimated that somewhere in the range of 2 to 3 million Chinese labourors died as part of the centuries-long project of building the wall.

The first major wall was built during the reign of the First Emperor, the main emperor of the short-lived Qin dynasty. This wall was not constructed as a single endeavor, but rather was created by the joining of several regional walls built by the Warring States. It was located much further north than the current Great Wall, and very little remains of it. A defensive wall on the northern border was built and maintained by several dynasties at different times in Chinese history. The Great Wall that can still be seen today was built during the Ming Dynasty, on a much larger scale and with longer lasting materials (solid stone used for the sides and the top of the Wall) than any wall that had been built before. The primary purpose of the wall was not to keep out people, who could scale the wall, but to insure that semi-nomadic people on the outside of the wall could not cross with their horses or return easily with stolen property.

There have been four major walls:

208 BC (the Qin Dynasty)

1st century BC (the Han Dynasty)

1138 - 1198 (the Five Dynasties and Ten Kingdoms Period)

1368-1620 (from Hongwu Emperor until Wanli Emperor of the Ming Dynasty)

Qin Shi Huang conquered all opposing states and unified in 221 BC, establishing the Qin Dynasty. Intending to impose centralized rule and prevent the rising of feudal lords again. To protect the empire against intrusions by the Xiongnu nomadic tribe from the north, he ordered the building of a new wall to connect the remaining fortifications along the empire's new northern frontier.

Built to withstand the attack of small arms such as swords and spears, these walls were made mostly by stamping earth and gravel between board frames.

Transporting the large quantity of materials required for construction was difficult, so builders always tried to use local resources. Stones from the mountains were used over mountain ranges, while rammed earth was used for construction in the plains. The peasants who died working were buried inside the wall, to be unearthed later by archaeologists.  Most of the ancient walls have eroded away over the centuries, and very few sections remain today. Possibly as many as one million people died building the Wall under the Qin Dynasty. (Inference:The Qin is Dynasty is short lived and Qin Shihuang problably paid little attention to the maintainence of the wall.)

Unlike the earlier Qin fortifications, the Ming construction was stronger and more elaborate due to the use of bricks and stone instead of rammed earth. As Mongol raids continued periodically over the years, the Ming devoted considerable resources to repair and reinforce the walls. Sections near the Ming capital of Beijing were especially strong as Beijing is important.

Great Wall from the Space
Great Wall is the only man-made object visible from the moon. This myth has persisted, assuming urban legend status, sometimes even entering school textbooks. The Great Wall simply cannot be seen by the unaided eye from the distance of the moon. Even its visibility from near-earth orbit is questionable.One astronaut reported, "We can see things as small as airport runways but the Great Wall is almost invisible from only 180 miles (290 km) up." Astronaut William Pogue thought he had seen it from Skylab but discovered he was actually looking at the Grand Canal near Beijing . He spotted the Great Wall with binoculars, but said that "it wasn't visible to the unaided eye." An Apollo astronaut said no human structures were visible at a distance of a few thousand miles. Chinese astronaut Yang Liwei said he couldn't see it at all.

The misconception is wrapped up in broader myths about what is and what is not visible from space. For the record: No manmade structures on Earth can be seen with the unaided astronaut's eye from the Moon. However many things such as thin highways, dams and even large vehicles -- are easily spotted from Earth-orbit with no optical aids. like telescopes, cameras or binoculars.

However low-earth orbit, about a thousand times nearer than the moon, it may be visible under favorable conditions. The Great Wall is only a few meters wide - sized similar to highways and airport runways - and is about the same color as the soil surrounding it.Veteran U.S. astronaut Gene Cernan has stated: "At Earth orbit of 160 km to 320 km high, the Great Wall of China is, indeed, visible to the naked eye." Ed Lu, Expedition 7 Science Officer aboard the International Space Station, adds that, "...it's less visible than a lot of other objects. And you have to know where to look." A recent photograph taken from the International Space Station appears to confirm that 's Great Wall can be seen with the naked eye after all. Leroy Chiao, a Chinese-American astronaut, took what the state-run China Daily newspaper says is the first photographic evidence that the Great Wall could be seen from space with the naked eye, under certain favorable viewing conditions and if one knows exactly where to look.

The beginning of the Great Wall

Qin Shihuang later found that the walls of the Yan, Zhao and ex-Qin States were not linked from each other and could hardly stop enemies from breaking in again. So in the year 215 B.C., he ordered to link up these three walls. The weather-beaten parts were also rebuilt and new parts were added in some places. The whole construction lasted for 10 years.The finished wall extended further at the north end as the territory of the Qin Dynasty in the north had expanded. The wall started at Lintao, i.e. Minxian County now, went eastward to now Guyuan of Ningxia Hui Autonomous Region, met the Wall of the Zhao State that ran eastward from Gaoque of the Great Bend of the Yellow River, went on and crossed the Yellow River, entered now north Shanxi and Hebei Province, ran the rest part of the Wall of the Zhao State and headed on along the north branch of Yanshan Mountain, passed by way of the five counties of Shangu, Yuyang, Right Beiping, West Liao and East Liao, and finally arrived at Jieshishan Mountain near the Datongjiang River of Pyongyang, Korea. This wall was longer than and lay slightly north to the Great Wall we see today, which was built by the Ming Dynasty about 1,500 years after.

The relics of the wall can still be seen scattered along the route. Some parts relatively well preserved are about five or six meters high, made of blocks of mud or stone of the local resources.(Inference:Qin Dynasty wall building technology is very weak,other civilisation develop bricks but China is still using stamped earth.)

The long contruction of the Great Wall
The Great Wall during the Han dynasty built walls mainly for three times.

Lying in the border area, the wall of Earlier Han was also mentioned as "border wall". It was usually three to four meters high and about two meters wide. Though stacked or stamped with earth and stone, it was considerably solid; in present Min'qin, Dunhuang and Yumen of Gansu Province, relics of the Wall and beacons can still be found. Along the wall were set up garrisons equipped with beacons.

In the Han Dynasty, firing the beacon when enemies pushed in abided by a formula. At an exigent event, if in the daytime, hay and dried reed were burned, giving off heavy smoke signifying an alarm; while at night, blazing fire lighted the dark sky.(Inference:They have a another form of comunication other than using their own languages.)

On winning the war, Liu Xiu added more soldiers to the border and built more than one lower and thinner border walls to the south of the Earlier-Han Wall, and near their lines set up beacons and fortresses. These border walls thickened the defense area in the frontier. It is mentioned in the Book of Later Han, a complied historical literature, that "in the year Jianwu 12 (A.D. 36), General Du Mao ordered garrisons build beacons and fortresses" and that "in the 14th year of Guangwu (A.D. 39), General Ma Cheng took over Du Mao, continuing to build the four border walls separately from the Hexi Region to Weiji, from Heshang to Anyi, from Taiyuan to Jingxing and from Zhongshan to Ye. The four barriers well guarded Later Han's capital – Luoyang. The present positions of the walls are as follows:
* The wall from Hexi Region to Weiji: from Lishi County of Shanxi Province to southeast Xianyang of Shannxi Province
* The Wall from Heshang to Anyi: from east Gaoling County of Shannxi Province to Anyi County of Shanxi Province
* The wall from Taiyuan to Jingxing: from Taiyuan of Shanxi Province to Jingxing County of Hebei Province
* The wall from Zhongshan to Ye: from south Dingxian County of Hebei Province to Linzhang County of He'nan Province

In April 581, Sui ordered Jihu, one descendant of South Hun, to build walls. This construction was limited to 20 days.
** In December 581, Sui repaired the eastern parts of the Northern Wei and Northern Qi Dynasty.
** In 585, Sui requisitioned 30,000 labors to fix the wall running from eastern bank of the Yellow River in Linwu of Ningxia Hui Autonomous Region to present Suide of Shannxi Province. This part of wall extended from east to west about 350 kilometers.
** In 586, Sui repaired its walls thoroughly within 20 days. Meanwhile, to protect its borderline, Sui built more than ten fortresses along the east part of wall in present Henshan County of Shannxi.
** It is recorded in one literature that "in 587, Sui requisitioned more than 100,000 labors to fix up the wall within 20 days." 
** In July 607, Sui ordered more than 1,000,000 labors to build the wall running east from present Yulin of Shannxi Province to the bank of Hunhe River. The whole construction was limited to 10 days.
** In July 608, Sui ordered 200,000 labors to build the wall starting at present Xining of Qinhai Province. The wall went east, but the destination is not recorded in historical materials.

Towards the end of the contruction and maintence of the Great Wall
 

Sui expensed large numbers of labors and set severe time limits for building walls. At such great cost, the constructions were finished. But it broke countless families so as to the extreme of tyranny, and eventually incurred uprisings. The Sui Dynasty breathed its last in 618 after its 37-year rule, and was finally replaced by the Tang Dynasty (618 ~ 907).The strength of Tang Dynasty reached the peak of all times. Tang Dynasty didn't build any wall.For the following period from Five Dynasties and Ten Kingdoms to the Song Dynasty, the walls fell into the territories of the two states of Liao and Jin and were not renovated. In 1279, Mongol founded the Yuan Dynasty. With the north and south of China unified, it occupied a large territory, the largest ever in Chinese history. Without harassment form beyond the Wall, no wall was built. In 1368, through a series of battles against Yuan, the Ming Dynasty established. In its first years, to consolidate its rule and stabilize the society, Ming The state-run industries, such as iron and bronze, weapon and ammunition industries and civil engineering, also developed and came to the highest level of all times.(Inference:During this time when the economy is good,the Ming Dynasty research and gain advance technology for architecture or metallurgy.)

From 1399 to 1402, King Ming Huidi built the wall starting in present Xuanhua and ending in now Datong of Shanxi.In 1413, to strengthen the defense on the north, King Ming Chengzu dug a deep and wide trench along the inner side of the above wall and piled the diggings into a stone fence. (Trench and fence heaped of the diggings was one form of wall for defense purpose. It was adopted in places where walls couldn't be easily built or materials lacked.) The trench started at Xi'ma'lin of Wanquan County of Hebei Province and ran about 100 kilometers eastward to the Chang'an'ling Fortress of Xuanhua of Hebei Province.In 1436, King Ming Yingzong set up 22 watchtowers along the line running about 250 kilometers from Longwu County of Hebei Province to Dushikou to North Jixian County. The same year, Ming built beacons along the route from present Yanchi of Ningxia Hui Autonomous Region. In 1466, King Ming Xianzong built two groups of 34 platforms along the two lines separately going from Dingbian County to Huanxian County and from Anbian County to Qingyang County. The both lines went northward from present east Gansu Province to north Shannxi Province.

In the time of Ming Yingzong, Mongolia lying in the north was dominated by Tuohuan, head of Wala, one major branch of Mongolia, and gradually thrived.

On the whole, the Wall of the Ming Dynasty was built along the lines of the walls of the Northern Qi and the Northern Wei Dynasties. During the reigns of King Ming Taizu, Ming Yingzong and Ming Xianzong, the Ming Dynasty enhanced the north-border defense mainly by constructing passes and beacons. It's not until the time of King Ming Xiaozong that walls and over 1000 fortresses were built massively. The Great Wall we see today was mostly built that time.

 
Answers to the questions
1) Qin Shihung ordered the connection of the other kingdoms walls but did not repaired it.During the Han dynasty,Liu Xiu built more thin border walls, this thicken the defences and later,he contructed 4 fortress to defend Luoyang.Later, Sui dynasty emperor ordered Jihu to built the wall under a condition he must finish in a mumber of days,this cause unhappiness in familys and Sui dynasty collapse.During the Ming dynasty,King Han Huidi rebuilt ths wall using bricks, which strengthen it and King Ming Chengzu dig trenches and pile up dirt to prevent nomadic tribes from Mongolia intruding on their territory.

2)It started in 225BCE and end in 16th Century

3)At first,the Qin built it by stamping earth between board frames,as they cannot transport materials across the country,they sue materials around them,During the Ming dynasty,technology became more advance, they use bricks to built the wall thus, the wall is what we see today.

4a)The technology involed is very primitive, as u can make a rock by squashing sand together, they used earth and stamped them to make walls,Later when the technology improve tremendously and enigeering became more advance, they used brick to contruct it.
4b)The materials had to be gather first,then make boards to make stamped earth
Acknowledgement
 
http://www.travelchinaguide.com/china_great_wall/history/

http://placestovisitinchina.com/great-wall-of-china-facts.php
http://www.mapsofworld.com/travel-destinations/great-wall-of-china.html

http://www.greatwall-of-china.com/51-90/the-great-wall-of-china.html

12:51 AM,Thursday, September 9, 2010