The terrain it traverses is complicated and varied. Long rivers,
steep mountains, lofty cliffs, boundless desert, and vast grasslands
all witness the imposing presence of the Great Wall.
Qin Wall
The
Qin Wall starts from Liaodong (today's east and south of Liaoning
Province) in the east and ends at Lintao (today's Lintao County
in Gansu Province) in the west. The wall was built according to
the local conditions and used local materials. Generally speaking,
the Qin Wall was made of large pieces of stones. Between the stones,
huge amounts of detritus was accumulated and filled in. It measures
about 4.4 to 5.5 yards. The steep cliffs were used as natural
walls after being chiseled a little. In Gobi area, the wall was
built by mixing grit with the local plants such as red willows,
reeds, and poplars. In flat plains, the wall was built from pounded
yellow earth, layer upon layer. Besides connecting the scattered
sections of previous states, Qin Wall was augmented with rather
complicated military structures such as blockhouses, barriers,
passes and beacon towers.
Related link: History
of the Qin Wall
Han Wall
Han
Wall followed the basic characteristic of Qin Wall, that is, to
build the wall according to the local conditions and used local
materials. The difference lies in the constructional types. The
Han Wall mainly wound through grasslands where big stones were
not available. The compressed earth construction was favored.
For example, in Dunhuang, where large amount of bulrush, poplar,
red willow and dogbane grew, these were used for wall construction.
The branches of these plants served as groundwork which was covered
by a layer of sun-dried mud bricks mixed with grit and above was
the rammed bulrush. On average, the thickness of the bulrush layer
measured 1.6 to 2.0 inches and the grit layer measured 7.9 inches.
Remnants of this work remain till this day. The willow branch
and bulrush could bear strong tension, and stones and grit were
not easy to be destroyed after being compacted in layers, so the
wall became rather solid.
Related link: History
of the Han Wall
The
military system of Han Wall included barriers, beacon towers,
strongholds, trenches, castles besides passes and blockhouses.
Tiantian, a newly created observation object, was built by placing
a layer of silver sand inside the trench. If the Huns dared to
set foot in, they would certainly leave footprint on the sand,
which would be noticed by sentries. Besides, the strict beacon
system was formed in Han Dynasty. The regulation prescribed that
a beacon be built at the interval of 1.6 miles, a block at the
interval of 3.1 miles, a fortress at the interval of 18.6 miles
and a pass at the interval of 62.1 miles. In the daytime, smoke
columns were used to warn the coming of attacks. One smoke column
indicated that less than one thousand enemies invaded, if more
than one thousand enemies attacked, two smoke columns would be
raised. Three smoke columns would be lifted in case more enemies
came. At night, soldiers would kindle firebrands to warn of coming
dangers.
Ming Wall
The
Ming Wall is the solidest and most complete one compared with
walls in other dynasties. The Ming Dynasty drew the experience
from the previous dynasties when they built the wall. More important
military fortifications were added on the wall. In flat areas,
outside the wall, big wide moats were dug to make approach difficult.
At the interval of 109.4 to 218.7 yards, there located a terrace
which protruded from the wall. It was especially designed for
close combat. Once enemies were camped outside the wall, soldiers
on guard could shoot from the terrace. They could take the advantage
of a commanding height to prevent enemies from putting ladders
against the wall to attack the city. At certain distances, there
was a fortress. It was used for storing up army supplies or stationing
troops who controlled a section of the wall nearby and carried
out the defense tasks along the wall.
Watch
towers were often square in shape and towered above the top of
the wall about 13.1 feet. While at places of strategical importance,
the watch towers were round and raised high above the wall. They
were built for soldiers to live in, to store food and weapons
for a long period of time. The Ming Dynasty still raised smoke
to warn of dangers. Besides, the boom of cannon was added to strengthen
the alarm effect. In ancient times when telephone and wireless
communication were not available, this method to transfer the
military message was obviously fast. Beacon towers in Ming Wall
were also used for ensuring the safety of ambassadors, supplying
them with room and board and offering forage for their horses.
Related link: History
of the Ming Wall