History of The Great Wall of China Page 5

The Changes of The Great Wall

The wall now extended across the principle trading routes and if you wished to trade with the Chinese you needed to enter through the gates in the wall. Around these gates towns were established and became the trade centers of the area. At most gates foreigners were not allowed to go past the gates so these became the portals of trade into China.

One perfect example is the beautifully preserved Jade Gate. Built in 101 BC, it is 28 feet high and 66 feet square. Close by they built a fort for the Han soldiers guarding the wall. This section of the wall is 453 feet long, 115 feet wide and 23 feet high.

The wall became more than a trade route and a barrier to keep out the enemy, it became vital for communications. Along its ramparts messages could be sent at amazing speeds from one end of the empire to the other. All along the northern border beacon towers were built every 15 to 30 miles. They formed a communication network, which ran from outposts deep into enemy territory to the ancient capital in the east.

From these towers the Han troops used smoke by day and torches by night to send messages along the length of the wall. They burnt wood, and straw mixed with wolf dung, which produced rich black columns of smoke. Statutes strictly governed the code of these signals. One column of smoke indicated an impending attack by a force of less than 500. Two columns indicated an attack by a force less than 3,000 and four columns indicated an attack by a force of up to 10,000.