What is a wall? Walls may be the physical barriers that have existed in various forms since pre-history, but can also be concepts, metaphors and metaphysical divides.

wall – noun

1. any of various permanent upright constructions having a length much greater than the thickness and presenting a continuous surface except where pierced by doors, windows, etc: used for shelter, protection, or privacy, or to subdivide interior space, to support floors, roofs, or the like, to retain earth, to fence in an area, etc.
2. Usually, walls. A rampart raised for defensive purposes.
3. An immaterial or intangible barrier, obstruction, etc, suggesting a wall: a wall of prejudice.
4. A wall-like, enclosing part, thing, mass, etc: a wall of fire; a wall of troops.
5. An embankment to prevent flooding, as a levee or sea wall.

– Selected definitions from Dictionary.com.

A wall is defined as a barrier, physical or nonphysical, that separates two things from each other. Walls are made for one of three main reasons:

• To keep things in.
• To keep things out.
• To do both of the above.

The etymology of the world 'Wall' comes from the Latin vallum, itself derived from vallus, 'a stake', and was originally used to refer to a defensive rampart or line of stakes.

History

As comedian Eddie Izzard once said, archaeologists always find a 'series of small walls'. Walls have been around as long as there have been people wishing to shelter from the elements. Later, people found them useful for keeping their animals in and other tribes out. These early walls may not be found during archaeological digs (having often been made of natural materials such as wood, animal dung and other degradable substances), but some of the techniques can be traced all the way through to walls that are still standing. A very good Entry on the ways that humans have built walls and structures out of their natural surroundings can be found at Earthbuilding - Building Using Natural Materials.

Often you may not be able to see the walls themselves, but you can see the earthworks that were built, to then be enhanced with fences and walls. Blewburton Hill, overlooking the village of Blewbury in the Vale of the White Horse, Oxfordshire, looks like it has rings around it. These earthworks, providing a series of ditches, were able to make walls effectively taller to provide better defence against invaders. All of the original walls have long gone, but the earthworks still remain.

Physical Walls

There are as many types of wall as there are materials to build with. There are undoubtedly thousands of ways to build a wall, from wood, to concrete, clay to cloth¹, grass and glass, straw and sticks. Some of the most common are:

Drystone Walls

Drystone walls (often written 'dry stone walls') are probably the first walls that were ever built from stones. The stones can either be used as they are found or shaped with tools. Stone walls around fields probably developed out of permanent settlements. Many early walls may have been built between fields to get the stones out of the soil, just by putting the stones that are in the way to the side. At the same time these walls protect the crops from being eaten by animals and can also keep the domestic animals under control. Basic and primitive shelters had been built before the development of agriculture, and it is possible that some of these may have utilised quickly-built stone walls.

They are used when mortar is easily washed away by harsh weather, or when there is no access to mortar. They allow wind to filter through the wall, making it more likely to stay standing when battered by the elements. It is also easier to fix, quicker to build and longer lasting than a mortar-constructed wall which is not load-bearing. Mariana Cook has published a book entitled Stone Walls: Personal Boundaries containing photographs of drystone walls.

Other Stone Walls

Most stone and brick walls use a form of mortar to hold the walls together. Mortar is a paste that, when dry, becomes rigid. Mortars are often made of wet mud, clay, sand, lime or cement. Advanced stone walls often have their stones brought to a rectangular shape with various techniques.

The outer walls of castles, known as curtain walls, were often made from two separate walls of cut stone facing each other with a gap in the middle. The gap was then filled with offcuts of the cut stones, pebbles, and the like, with mortar mixed in. This was pretty solid and much cheaper and faster than building a thick layer consisting entirely of ashlar, cut and shaped stone blocks². This technique was sometimes used on other buildings too - for example, it is still visible at the ruins of St Mary's Abbey in York.

The place with the most different kinds of historic stone walls in one place is probably Easter Island.

Bricks

House walls are often made of bricks. These are cuboid shapes, made of fired clay in colder climates but sun-dried mud or clay in warmer regions. Since Roman times, these have been built in standard sizes, as this makes building quicker and easier. Different brick sizes have been used throughout the world and throughout history, but they are commonly made a handspan long, to make them easier to build with. They have been made larger at times when the number of bricks used in houses has been taxed³. More recently, modern technology used in building sites has made it easier to make, transport, lift and build with larger brick sizes, increasing their use.

Bricks are not stacked on top of one another directly, but in order to make walls more stable different patterns of long 'stretcher' bricks and short 'header' bricks⁴ are used, overlapping the layer below. These patterns are known as 'bonds'. Common bonds include 'stretcher bond', stretcher bricks only commonly offset by half of their length for each level, 'Flemish bond', alternating stretcher and header bricks in each row and 'English bond', alternating row of stretchers and row of headers⁵. Sadly, patterns of brick other than stretcher bond are not used very often any more, due in part to the use of breeze blocks and larger brick sizes. They are 'glued' together, traditionally using mortar (made of sand, cement or lime, and water), but modern glue-based alternatives that make building faster are now available.

Wattle and Daub

Wattle and daub is the name given to a method of wall construction used worldwide. The wall (often the wall of a house or building) is begun using pieces of wood to form a frame. Between these, a sort of woven panel is made using smaller sticks. This is the wattle. A mixture of mud or manure and straw or similar - the straw was important to bind the mud together - is made and spread over the wattle on both sides. This is the daub. When the mud dries, it forms a solid surface.

Other Walls

• Paper walls are a part of traditional Japanese buildings. Thick rice paper is stretched over a wooden frame to provide privacy.

• Wooden walls are also common. Log cabins etc use round or rectangular logs piled on top of each other and mainly connected at the corners of the building. It is also possible to build a skeleton construction or frame from wood and cover it with a range of different materials, including wooden boards, plasterboard, grass or leaves – the possibilities are endless.

• Walls made of metal are often defensive in nature due to the tough nature of the material. A vault, cage, or rooms containing dangerous equipment are good examples. However, corrugated iron sheets are a quick and inexpensive way to construct walls of outbuildings like sheds, stables and barns.

• Climbing walls are artificial surfaces designed for climbers to practise their skills on. They feature a bewildering array of hand- and foot-holds and simulate as closely as possible conditions on real rock. They have proved popular especially in countries where weather conditions are variable.

• A ha-ha is a hidden ditch and wall. This is designed to usually keep animals out of the grounds nearby a grand country house while giving the impression of a continuous, uninterrupted landscape. A ha-ha is more aesthetically pleasing than a fence or hedge, which are visible interruptions on the landscape.

• Firewalls are walls in a building which will resist a fire and prevent it from spreading from one part to another. A 'firewall' can also mean a program designed to block unwanted intrusions into your computer, via the Internet, other network etc.

• Tents usually have walls made from textiles, although old/ancient forms of tents can also use tree bark or animal skins.

• A 'curtain wall' in the non-castle context is not a wall made from textiles but a facade that only carries its own weight and is hung from a building's ceiling/floor structure. The curtain wall facade was invented in the 19th Century and is the most common facade type for skyscrapers today.

• The Eye Wall of a Hurricane is a vertical line of clouds that separate the highest and most dangerous winds near the centre of the storm from the almost calm and dry centre itself. As the eye of the storm passes, the other side of the eye wall arrives and the wind and rain almost instantly return at full strength, often even stronger than before⁶.

Metaphysical Walls

An immaterial or intangible barrier, obstruction, etc, suggesting a wall: [for example] a wall of prejudice.

Again, these can come into many forms. These immaterial walls tend to lean towards the conceptual.

• Mental Walls. There is no set term for the mental barriers people place between themselves and the world, especially people. Some people place walls between people they don't know, and some people shut out others entirely. This may be due to a conscious decision, or due to episodes in their past tarnishing relationships with people.

• 'Chinese walls' is a business term denoting systems and procedures to isolate people making financial decisions from those with inside knowledge that may affect those decisions (ie, a means of preventing illegal 'insider trading'). For example, it is common for senior executives to sit on the boards of more than one company, so it is essential that they do not use inside information gained from one company to influence investment decisions by another company.

• A wall can also be used to describe a non-physical structure such as 'a wall of noise'. This is where noise is so overwhelming it feels like an invisible wall is there.

Metaphoric Walls

Walls appear in many metaphors. Here are a few, though this list is not intended to be exhaustive:

First Against the Wall

This indicates a person who is so disliked that they would be selected to be the first to face a firing squad. Douglas Adams gives an example of this usage in The Hitchhiker's Guide to the Galaxy:

The Hitchhiker's Guide to the Galaxy defines the marketing division of the Sirius Cybernetics Corporation as 'a bunch of mindless jerks who'll be the first against the wall when the revolution comes,' with a footnote to the effect that the editors would welcome applications from anyone interested in taking over the post of robotics correspondent.

Curiously enough, an edition of the Encyclopaedia Galactica that had the good fortune to fall through a time warp from a thousand years in the future defined the marketing division of the Sirius Cybernetics Corporation as 'a bunch of mindless jerks who were the first against the wall when the revolution came.'

The Writing is on the Wall⁷

This doesn't mean that someone has sprayed graffiti on your wall, though this is a popular use of walls in the Modern Age. It is used to mean that the end of something is inevitable, such as 'from the moment the big supermarket moved in, the writing was on the wall for the village shop'. Its origins are Biblical in nature: the story of Belshazzar in the book of Daniel chapter 5.

Belshazzar the king made a great feast... In the same hour came forth fingers of a man’s hand, and wrote ...upon the plaster of the wall of the king’s palace: and the king saw the part of the hand that wrote...

Then was Daniel brought in before the king. ...Daniel answered and said before the king, '...This is the writing that was written, MENE, MENE, TEKEL, UPHARSIN. ...MENE; God hath numbered thy kingdom, and finished it. TEKEL; Thou art weighed in the balances, and art found wanting. PERES; Thy kingdom is divided, and given to the Medes and Persians. ...In that night was Belshazzar the king of the Chaldeans slain. And Darius the Median took the kingdom.

The pop group Destiny's Child clearly had their own interpretation in mind on their 1999 track Intro (The Writing's On The Wall), when they wrote:

It's obvious, the writing's on the wall, thou shalt not hate.

Wall of Silence

This term is more commonly used in certain types of police investigation where a neighbourhood or group of people maintain a silence so deep that it is described as being a wall. This barrier often makes the difference between solving the crime, and not doing so. For example, after the murder of schoolboy Jessie James in Manchester, BBC News noted that:

Jessie James was shot dead in a community that has had to get used to gun culture and the so-called wall of silence that comes with it.

The Wall; Hitting the Wall

Athletes, particularly long-distance runners, talk of the dreaded Wall. This is the point at which a runner feels utterly unable to go further and is physically and mentally spent. Experts from the English Institute of Sport explained on BBC Athletics:

Setting out at too high a pace will result in you running out of carbohydrate stores and 'hitting the wall' prematurely.

Going To the Wall

This phrase originally comes from mediæval times, when attending church was obligatory and before pews were common. The saying went 'the weak go to the wall', because the elderly and infirm were allowed to rest against the walls for support. The term is now used most frequently in business to describe a business that is on the verge of bankruptcy. In The Times, the chief executive of Dixons said of a crisis in the high street:

Downturns in markets make life tough and a bit difficult, but the strong get stronger and the weak get weaker or go to the wall.

Off the Wall

The phrase 'off the wall' is used to describe anything extremely unusual or bizarre. The origins of the phrase are unclear, although some speculate that it hails from ball games such as squash, where the direction of the ball after it bounces off the wall is often extremely unpredictable.

Another Brick in the Wall

The Ancient Spartans have a reputation of being the world's most warlike society, so much so that it was forbidden for a Spartan to retreat in battle. According to legend, in around 820 BC Lycurgus, the ruler of Sparta, was asked Why, o king, do you have no walls around Sparta? to which Lycurgus replied: A wall of men, instead of bricks, is best. The last vestige of this greatness was Leonidas at the Battle of Thermopylae in 480 BC, where 300 Spartans and their allies held off 150,000 Persians. On day three, all but Demophilus and the Thespians left the Spartans to their hopeless last stand against the Persians.

The saying 'every man is a brick in the wall', has been corrupted to 'another brick in the wall', meaning one of the crowd.

Naval Walls

In 480 BC, according to Herodotus, when the Athenians learned that the vast Persian Empire under Xerxes was invading Greece, they went to the Oracle at Delphi who told them to put their faith in the 'wooden wall'. No one could agree on how to interpret this, with a debate over whether the 'wooden wall' referred to the defensive 'long walls' between Athens and the port of Piraeus. This debate continued until Themistocles, an Athenian general, argued that it referred to Athens' navy. Athens then went on the offensive rather than preparing for a siege, and the Athenian navy went on to win a hugely important victory over the Persian fleet at the Battle of Salamis.

Similarly, over two thousand years later the Royal Navy was called 'England's wooden wall' until the introduction of iron warships such as HMS Warrior.

Wallflower

A wallflower, as well as being a type of flower, was a shy, retiring but attractive woman who remained close to a ballroom's wall during dances, rather than engaging in the dance itself. The phrase has more recently come to refer to any shy people not engaging in a sociable activity and singletons unable or unwilling to find a partner.

Famous Walls

There are many world-famous walls that deserve a mention.

The Berlin Wall

The Berlin Wall was erected in August 1961 to prevent people from leaving East Berlin. The wall bisected the city without regard to streets or train lines, even utility lines were cut off. The Wall was heavily guarded to prevent attempts to scale it, and more than 200 people died in the attempt over the course of the Wall's history.

In late 1989 the Berlin Wall began to come down, paving the way for the reunification of Germany. By 1991 only a few sections of the Wall remained, and the path where it stood is now marked by paving stones for remembrance. The Berlin Wall was the most visible part of the Iron Curtain, the barrier between Capitalism and Communism both ideologically and physically in Europe.

Céide Fields

Some of the oldest extant walls known are those surrounding the Céide Fields⁸ in the west of Ireland. This field system constitutes the most extensive Stone Age site in the world, dating back almost 6,000 years.

The Great Wall of China

The Great Wall of China is the longest wall ever built, so much so that there is a persistent urban legend that it can be viewed from outer space. It was built to stop Mongols from invading the south part of the Chinese Empire.

Hadrian's Wall

A Roman defensive wall built in 122 AD, Hadrian's Wall is located in northern Britain and stretches a distance of 74 miles. The wall is now a UNESCO World Heritage Site and a National Trail.

There is a village halfway along Hadrian's Wall called Wall. Walkers are allowed to camp for one night on Wall Village Green free of charge. Facilities there include toilets, which are open all night, and swings. This proves that a Wall can be welcoming, and not just a barrier.

When Emperor Antoninus Pius succeeded Hadrian, he ordered a new wall built 98 miles north of Hadrian's wall. The Antonine Wall was started in 142 AD and ran from the Firth of Clyde to Bo'ness, Falkirk, on the Firth of Forth. It was not as well built as Hadrian's Wall, built of earth reinforced with timber and stone, protected by a ditch to the north. While in use it was still an effective fortification, with a fort approximately every two miles.

Irishman's Wall

In the bleak north of Dartmoor is a kilometre-long wall known as Irishman's Wall. According to local folklore, the wall was erected back in the days when you could claim land in the wilds by simply enclosing it with a wall. An ambitious local landowner decided to claim some land close to the village of Okehampton, and paid a team of strong Irish workers to get the job done quickly. The villagers, unhappy at losing common land but not bold enough to take the Irishmen on face-to-face, decided sabotage was the safest solution. Night after night, they went out and knocked over sections of the wall until eventually the Irishmen and their master grew tired of the charade and called the project off. The wall remains incomplete to this day.

Jericho

Jericho is possibly the first recorded walled city ever. The first mention made of it is found in the Bible:

By faith the walls of Jericho fell, after the people had marched around them for seven days.
- Hebrews, 11:30

Wailing Wall

The Wailing Wall is the Western Wall of the ancient Jewish temple in Jerusalem. It is considered to be one of Judaism's most sacred sites: the sole surviving part of the Temple destroyed by Emperor Titus in 70 AD following the Great Jewish Revolt. The whole Temple site is also an important Muslim religious site and in modern history has been the focus of bitter dispute.

A Few Other Walls

Pink Floyd's The Wall

The Pink Floyd album The Wall was a semi-autobiographical concept album about a man who constructs a wall around himself in response to his experiences, and the walls that society has imposed on him. The music inspired a film. This, directed by Sir Alan Parker, contained no dialogue and instead used the images of the music, along with artwork by Gerald Scarfe, to convey the storyline.

Wall of Death

A popular fairground and circus attraction, a Wall of Death is a circular vertical wall which a stunt driver on a motorbike or even, in larger walls, a car drives around at high speed while performing various stunts. More recently Walls of Death have developed into spherical cages called Globes or Spheres of Death where the rider, having reached a high enough speed, achieves a loop-the-loop.

Wall Street

Wall Street in New York is the financial district of the United States, but originally there really was a wall. It was built by settlers in 1644 to protect the New Amsterdam settlement from attack. The street ran alongside the wall and, when the wall was taken down in 1699, the street remained.

On 17 May, 1792, the Buttonwood Agreement was signed under a buttonwood tree on Wall Street creating an organisation of stock brokers that would, on 8 March, 1817, rename themselves the New York Stock and Exchange Board, headquartered at 40 Wall Street. Today the New York Stock Exchange is one of the largest in the world and is one of several stock exchanges located on Wall Street.

Wall of Sound

Record producer Phil Spector developed the Wall of Sound technique for his music recordings. Rather than having one or two musicians per instrument, often, but not always guitars, this technique has a large orchestra of electric and acoustic guitarists perform the same parts in unison with the sound recorded in an echo chamber. Instead of hearing the music come from one instrument and source, the listener almost hears the sound as something solid.

Although many bands, including the Beach Boys, Queen and ABBA used this technique to great effect, not every musician appreciated it. After years of campaigning, in 2003 Paul McCartney released Let It Be... Naked, a version of the Beatles' Let It Be album with the wall of sound removed.

Edible Walls

In Britain, 'Wall's' is a brand name associated with both ice cream and sausages. Wall’s was founded by butcher Richard Wall, when he opened a stall in St James’s Market, London in 1786. Success followed swiftly, and in 1812 Richard Wall received a royal appointment, as a purveyor of pork to the Prince Regent. His son, Thomas Wall, continued the family business, renaming it Thomas Wall & Sons in 1834.

Traditionally demand for Wall's meat products, including sausages and pies, would fall in summer, and so in the early 20th Century Wall's began manufacturing ice cream in the summer to maintain profits all year round.

Since 1994 the two branches of Wall's, the meat and the frozen confectionery sections, have been owned by two different multi-national companies, yet both still continue to use the historic trade name 'Wall's'.

Fictional Walls

Stardust is a novel by Neil Gaiman that was later adapted into a film. It begins in the town of Wall, which marks the border between England and Faerie, particularly the kingdom of Stormhold. It is described with the words,

The town of Wall stands today as it has stood for six hundred years... Immediately to the east of Wall is a high grey rock wall, from which the town takes its name. This wall is old, built of rough, square lumps of hewn granite... There is only one break in the wall... For every nine years, the folk from Beyond the Wall and over the hill set up their stalls, and for a day and a night the meadow played host to the Faerie Market.

In Game of Thrones there is a giant wall patrolled by the men of the Night Watch, which marks the boundary between the Seven Kingdoms and the largely unknown land beyond.

Terry Pratchett's novel The Carpet People is about microscopic people whose entire world is a carpet. The Woodwall is described as a day's march long, and a good hour's walk wide. Half of it had been burned – unimaginably burned.... The Woodwall is a matchstick on the carpet.

And Finally

One last wall from the realm of mythology: in a Roman romance popularised by Ovid, a young man named Pyramus falls in love with the girl next door, whose name is Thisbe. Sadly, the parents of Pyramus and Thisbe are not the best of friends, and forbid them from seeing one another. The couple are thus only able to signal their love from afar, until they discover a small hole in the wall which separates their houses, whereupon their love blossoms further, and a plan is made to run away and live happily ever after. Unfortunately, the plan falls through, and everyone (apart from the wall) dies.

This tragic story has been retold in many different guises. Some readers may recognise elements of the tragedy of Romeo and Juliet, in which Romeo o'erleaps an orchard wall. Additionally Shakespeare includes the original story of Pyramus and Thisbe as a play-within-a-play in A Midsummer Night's Dream. In this, a troupe of amateur actors, known as the Rude Mechanicals, rehearse and perform this romance for the entertainment of the lead characters⁹. So far, so inconsequential. However, during their rehearsal, the Mechanicals stumble upon a stage management problem, as expressed by Snout, and a solution is found, given by Bottom. Let their words stand as words of wisdom, or even practical advice, to anyone wishing to erect any form of barrier, be it metaphysical or physical, between people or places; if more heed were taken, perhaps the world would be a more peaceful place.

Snout:
You can never bring in a wall. What say you, Bottom?

Bottom:
Some man or other must present Wall: and let him have some plaster, or some loam, or some rough-cast about him, to signify wall; and let him hold his fingers thus, and through that cranny shall Pyramus and Thisby whisper.