Friday, 13 December 2013

D is for Domes









































































The Dome

 Whether, blue on the islands, tiled on the mainland, squat and low, elegant and high, single, or in clusters, domes are instantly recognizable and have become emblematic of Orthodoxy  in the same way that Gothic spires came to represent Catholicism in Europe.

 Because its shape so easily resembled the heavens in the interior of a church, it rapidly became the preferred style after the first great domed church became reality in 537 AD. The Emperor Justinian himself presided at the inauguration of Hagia Sophia, the Church of the Holy Wisdom in Constantinople.  He knew the enormity of the achievement and celebrated it by riding from his palace to the new church in a four horse chariot, sacrificing  a thousand of oxen, thousands of  sheep,600 stags, innumerable birds, etc for the celebratory feast (shades of Homer) and, on first entering the new church, announcing:  “Solomon, I have surpassed you”.(1)


From Wikipedia.com 

 Justinian may not have been Greek in the sense that we now understand the term. His language was Latin and he was born in present day Yugoslavia but his boast was pure Greek –every great achievement, the result of a contest, and the winner enjoying, not just the victory, but the defeat of the person bested! Some say  Justinian had a statue of Solomon placed outside of Hagia Sophia so it could watch and wonder in perpetuity!
( You can too. Try natgeotv.com/ca/ancient-megastructures/videos/hagia-sophia-dome-secrets)

A Little Background

Ancient Greeks did not do curves . Neither did the Romans at first. Their architecture was massive and  linear. Two horrendous fires would change all that. The first occurred in Rome In 67 AD when most of city burned. Whether or not Nero actually fiddled at the time is a moot point, but that he issued a series of strict building regulations to prevent future fires is not. One of the regulations stated that a roof could no longer be constructed with wooden beams.  The flammability of these roofs had contributed greatly to the devastation.  All of the great buildings of antiquity, even the mighty Parthenon in Athens, had wood-beamed roofs.

The necessity of finding new non-flammable ways to cover an interior space led to the invention of the vault which could be constructed of stone or brick (A vault is any curved ceiling). The simplest was the barrel vault; others like the cross vault demanded a little more math, but once that was mastered, wood could be phased out. 

 If the length of wooden beams had determined the width of a building before, now it was how big a space it  was possible to cover  before the walls could not support the weight of the curved ceiling. The rotunda was born when the first hemispherical roof was set on round (or hexagonal)  walls so that the entire circumference of the wall could bear the tremendous weight of the dome.

 Its drawback was that the dome could only be same diameter as the walls supporting it, no problem for a mausoleum but a bit cramped for a temple.  The grandest effort in the rotunda category was Hadrian’s Pantheon in Rome and only light weight cement made of local  volcanic deposits made it possible, - that and the means and manpower to cut down an entire forest to build the wooden scaffolding that held the form of the great dome while the concrete was being poured.

                               
Pinterest.com

 It was (and is) a tremendous feat, a building of  90 percent concrete with a dome 43.30 meters across following classical proportions: The distance from the floor to the top of the dome was equal to its diameter; that is what makes its interior space so visually appealing.
The ocular or ‘eye’ at the top was open to the heavens and called the eye of Zeus. The Pantheon was dedicated to all of the Roman gods and popularly called the temple of the world.

Other rotundas were built in the Roman and Greek world; there is still one in Thessaloniki (2) but none ever equaled the Pantheon’s  vast  “canopied void”,  the largest dome in the world right into the 20th century.  One problem was that the cement, when it came to be used elsewhere in the empire, was simply too heavy. In fact, elsewhere, bricks came to be used instead of concrete for vaults and domes but that alone could not solve the size of the dome to the strength of the walls problem

                          The Rotunda in Thessaloniki

That took a second fire, this time long after the Roman capital had moved east to Constantinople.  The Emperor Justinian in 532 had held on to his throne by the skin of his teeth and the expedient of massacring thousands of his enemies in the Hippodrome. During the riots great fires raged. So Justinian had two reasons to bring the greatest architects and mathematicians together – to build more fireproof churches and to build a great church that would reflect his greatness and the glory of God – one suspects in that order. 

The breakthrough Justinian demanded and got was this: a large dome suspended over a space that was larger than its circumference; a church that could hold a huge congregation.  Put simply, the problem was solved by the use of four massive piers rising in a rectangle from the floor; the square at the top of the piers was joined by arches. The trick then was the use of concave pendentives to slowly make the square on top of the pillars into a circle that would then become the base of the dome. It required fancy math and even better builders (10,000 workers and 100 foremen working in competing teams.  (Greeks!)









In the drawing you see two of the piers (black) and two of the concave purple pendentives leading up to the circle holding the dome. Of course you should use Google images and type in Ag Sophia Constantinople but this drawing shows the structure that made the church possible. Less easy to see from the above drawing is that this four pier construction allowed a cross to be inscribed on the floor plan, icing on the cake for a church that loves symbols and for whom the cross is the greatest icon of all. A bird’s eye view shows this:












The result was a church with a dome 31 meters in diameter, 48.5 meters above the floor over a church that with the help of half domes and pillars had a floor space 77 meters long and 71 meters wide.

 This was a defining moment in the history of architecture. Peter Brown put it best when he commented that,frozen in stone,  Hagia Sophia managed to combine Roman Imperial grandeur  with the Greek tradition of abstract thought”. (3)

The grandeur bit is obvious but that the church itself was transformed into a complex symbol of the transformed world after the resurrection, an entire cosmos under the “dome” of heaven, is pure Greek.  Hagia Sophia quickly became the beau ideal of Orthodox churches throughout the empire including present day Greece although in Greece its copies were mostly miniatures.

I confess that when I first entered Ag Sophia, in spite of dutifully reading about it, my first impression was that was huge and rather barn-like; at the time I did not grasp what a wonderful creative step in architecture it really was. In our age of reinforced concrete and steel trusses, it just looked like something I had already seen before. In fact I was looking at a brilliant and imaginative prototype. 

In 1900, when Greece had to come up with a pavilion that would represent the country to the world for the Paris Exposition, it chose a pavilion in the shape of a domed church. Of course! (4)

Footnotes
1     1)A great many of my facts about domes I have unashamedly taken from Daniel Boorstin’s The Creators: A History of Heroes of the Imagination (Phoenix press, c 1992). His fascinating text got me looking at domes and hemispheres in a whole new way.
2)See Oddball Churches: Agios Georgios in Thessaloniki
3.    3) Peter Brown, The World of Late Antiquity, Thames and Hudson, 1971.
4.    4) Ag Sostis  on Syngrou  Avenue is the pavilion, brought to Athens in 1902 and turned into a church.


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