This is a very often quoted statement but it is wrong. Without any spacial information the alert "enemy is attacking" is of no value at all. Either the signalling was only local (to get help by neibouring soldiers/troops/garrisons) or it _must_ have had any information about where (and not only how many) the enemy was attacking.
One very frequent misunderstanding is that the communication was between the (wall) beacon towers. This also is wrong. They used special signalling (beacon!) towers on the "inner" side of the GW. Those always were on prominent places and always in sight of the next one. They build something like a "second chain" behind the GW.
Inner side/second chain?Any photos of these inner side of the Great Wall?As far as I can see,there is only one side,except for the other walls built from another dynasty next to the previous one.
I thought the Great Wall was built on the ridges of the hills which are too narrow for another inner side to be built.That way,the inner side of the Great Wall will be too low to watch out for incoming enemies.
Here's something I picked out from the Great Wall Forum.
To provide a communication and early warning system – Relaying from one watchtower to another using fire signals at night and smoke signals during the day, messages could be sent over long distances in a short time.
To serve as lookout posts – The elevated locations of the Great Wall and its towers enabled distant observation for invaders to provide the earliest possible warning.
Either the signalling was only local (to get help by neibouring soldiers/troops/garrisons) or it _must_ have had any information about where (and not only how many) the enemy was attacking.
However,it does sound logical when the guards saw impending danger and light up the signal to warn others and get ready.
And yes,it doesn't matter where the location of the enemies attack.
Enemies may launch another surprise attack at some parts of the Great Wall.It's no use telling the soldiers where are the enemies are attacking.Getting help from neighboring soldiers won't help.The soldiers will leave the towers unattended,resulting the surprise attack of the enemy to be successful.In any case,the soldiers already knew where the enemies attacked when they saw the signal.On the Great Wall,anyone can get a bird's eye view on where the enemies are going to attack.
Their priority is just to alert everyone at the Great Wall to gear up and get ready,not getting back ups.There were back up soldiers waiting behind the Great Wall.Those at the top were just signaling those behind the Great Wall to come up and hack away at the enemies/to reinforce the defense system of the Great Wall and send a message to the capital,at the same time alerting the neighboring soldiers to look out for some more surprise attacks/getting ready with the weapons in the storage towers/shoot arrows at any enemy who intends to scale the Great Wall.
Even if the enemies manage to get pass the Great Wall,soldiers at the inland are already well prepared,thanks to the signal.
Many sources have stated the soldiers used a "chain-system" of signaling at the Great Wall.You can't trust those too?
Edited by WuXiaHer0, 17 December 2009 - 09:42 AM.