Dome

Dome (pronounced dohm)

(1) In architecture, a vault, having a circular plan and usually in the form of a portion of a sphere, so constructed as to exert an equal thrust in all directions.

(2) A domical roof or ceiling; a polygonal vault, ceiling, or roof.

(3) Any covering thought to resemble the hemispherical vault of a building or room; anything shaped like a hemisphere or inverted bowl.

(4) In water management, (usually in dam design), a semidome having its convex surface toward the impounded water.

(5) In crystallography, a form having planes that intersect the vertical axis and are parallel to one of the lateral axes.

(6) In geology, an upwarp (a broad anticline (a fold with strata sloping downwards on each side) caused by local uplift).

(7) In geology, a mountain peak having a rounded summit (a structure in which rock layers slope away in all directions from a central point).

(8) As vistadome, in passenger vehicles (usually railroad cars), a raised, glass-enclosed section of the roof of, placed over an elevated section of seats to afford passengers a full view of scenery (not usually truly in the hemispherical shape of a dome).

(9) In horology, the inner cover for the works of a watch which snaps into the rim of the case.

(10) A building; a house; an edifice (obsolete except as a literary device).

(11) As heat dome, a meteorological phenomenon in which the interplay of high & low pressure atmospheric systems interact to produce static, warm air over a large area.

(12) To cover with or as if with a dome; to shape like a dome.

(13) To rise or swell as a dome.

(14) In slang, a person's head (the form chrome dome used of the bald).

(15) In slang (both military and in some criminal classes), to shoot in the head (often in the form “got domed”).

(16) In African-American slang, to perform fellatio upon.

1505–1515: From the Middle French domme & dome (a town-house; a dome, a cupola) (which persists in modern French as dôme), from the Provençal doma, from the Italian duomo (cathedral), from the Medieval Latin domus (ecclesiae; literally “house (of the church)”), a calque of the Ancient Greek οἶκος τῆς ἐκκλησίας (oîkos tês ekklēsías).  Dome is a noun & verb, domed & doming are verbs and domelike, domical, domish & domesque are adjectives; the noun plural is domes.

By the 1650s, the formalized use in architecture ensured the meaning was (more or less) standardized as “a round, vaulted roof, a hemispherical covering of a building” and thus the ultimate specialized evolution from the Greek dōma (a house, housetop (used especially of those with a roof “in the eastern style”), from domos (house), from the primitive Indo-European root dem- (house, household).  The medieval use of the German dom and Italian duomo as verbal shorthand for “cathedral” (essentially a clipping from “house of God”) was picked up in the imperfect way so many words entered English to describe architectural features in the style of hemispherical cupolas, the domes at the intersection of the nave and the transept, or over the sanctuary, characteristic architectural feature of Italian cathedrals.  The sense in English of “a building, a house” had been borrowed in English as early as the 1510s and was used mostly of stately homes and it endures but only as a literary device and it’s rarely seen outside of poetry.

The shape occurs to one degree or another in nature and is common in man-made objects and the built environment so dome is an often seen modifier (cake dome, pleasure dome, lava dome; onion dome et al) and appears in the opening lines of one of the most cherished fragments of English verse: Kubla Khan (1797) by Samuel Taylor Coleridge (1772-1834).

In Xanadu did Kubla Khan
A stately pleasure-dome decree:
Where Alph, the sacred river, ran
Through caverns measureless to man
Down to a sunless sea.

Some of the use has also been opportunistic and not especially domical.  Vistadomes were raised, glass-enclosed sections built into the roofs of railway carriages, placed over an elevated section of seats to afford passengers a better view of the scenery.  The idea was picked up by General Motors, the Oldsmobile Vista Cruiser station wagon (1964-1977), the Buick Roadmaster Estate (1991-1996) and the Scenicruiser busses (1954-1956 and made famous in the Greyhound livery some wore until the 1970s) all used raised, partially-windowed sections although none were officially described as “domes”.

The Hagia Sophia, now the main mosque in Istanbul; the minarets were added after the fall of Constantinople to the Ottoman Turks in 1453 and there are many architectural critics who maintain visually they improve the balance of the structure.  The illustration on the right shows how the Byzantine engineers used pendentives to make the construction of domes possible.     

Domes however are most associated with grand-scale, representational architecture (although quite a few builders of McMansions found them hard to resist).  One intriguing aspect of structural engineering upon which the integrity of a dome depends on what are called pendentives (the triangular segments of the lower part of a hemispherical dome left by the penetration of the dome by two semicircular vaults intersection at right angles).  Dating from 1727, pendentive was from the mid-sixteenth century French pendentif, from the Latin pendentem (nominative pendens) (hanging and the source of the English “pendulous”), the present participle of pendere (to hang) from the primitive Indo-European roots pen & spen- (to draw, stretch, spin).  What pendentives permit is the use of a circular dome over a square void square room or an elliptical one over something rectangular room.  Pendentives, (geometrically the triangular segments of a sphere), taper to points at the bottom and spread at the top to establish the continuous circular or elliptical base as required.  As structural supports, pendentives distribute the bulk of a dome’s weight to the four corners (the strongest points) and ultimately to the piers and the foundations below.  The classic example is the Hagia Sophia, the sixth century Byzantine cathedral at Constantinople (modern day Istanbul).  It was converted into a mosque when Constantinople fell to the Ottoman Turks in 1453 and, after a century-odd as a museum, is again a mosque.

Scale model of Germania.  Hitler would spend hours pondering the details but in 1945, he spent even longer looking at the model of what was planned for the Austrian city of Linz where he'd decided to have his tomb installed.

Domes have long been a favorite of emperors, dictators and those other megalomaniacs: architects.  A truly monumental one would have been the Volkshalle (People's Hall and known also as the Große Halle (Great Hall) & Ruhmeshalle (Hall of Glory), the centerpiece of Adolf Hitler’s (1889-1945; Führer (leader) and German head of government 1933-1945 & head of state 1934-1945) never realized plan to re-built Berlin as Germania, a worthy Welthauptstadt (world capital) of his “thousand year Reich”.  Although Albert Speer (1905–1981; Nazi court architect 1934-1942; Nazi minister of armaments and war production 1942-1945) was Germania’s chief architect, in some aspects he was really a glorified draftsman, correcting the technical errors in the drawings passed to him by the Führer who had be sketching parts of the design since the early 1920s.

Even by the standards of the super-dimensionality which was characteristic of the Third Reich, the domed hall would have been extraordinary.  The oculus would have been 46 m (151 feet) in diameter which would have accommodated the entire rotunda of Hadrian's Pantheon and the dome of St Peter's Basilica.  The  250 m (820 feet) diameter of the dome was (and this was a signature of Speer’s approach), bigger even than Hitler had requested and he was much displeased to learn of a rival architect’s plans for a dome 15 m (49 feet) greater in diameter to sit atop the city’s new railway station.  As things turned out, none of the grandiose structures were ever built and although a tinge of regret can be found in Speer’s post-war thoughts, even he admitted the designs were a failure because of “their lack of human scale”.

Berlin's rebuilt Reichstag with steel & glass dome.

Berlin did however eventually get a new dome, albeit it one rendered not in granite but the glass and steel the Führer thought was fine for factories and warehouses but which would have appalled him as a method of construction for public, representational architecture.  Plonked atop the rebuilt Reichstag, it was said to symbolize the reunification of Germany although quite how it managed that has never really been explained although the distinctive structure has become a city landmark and people seem to like it.  A clever design, it sits directly above the chamber of the Bundestag (the lower house of the bicameral federal parliament) and permits public observation, the clever design also reducing energy use by optimizing the input of natural light while moving shrouds minimize glare and heat-soak.

Cinerama Dome, Los Angeles in 1965, the year of its greatest commercial success.

The Cinerama Dome movie theatre sits on Hollywood’s Sunset Boulevard.  Opened in 1963, the Cinerama Dome introduced a new concept for film projection, a curved screen which sat inside a geodesic dome based on the design developed by US systems theorist & architect Richard Buckminster Fuller (1895–1983), one attraction of which was such things could be built at lower coast and in much less time than a conventional theatre building.  Intended to be the first of perhaps thousands around the planet, it was built in a still remarkable four months but it remains the only concrete geodesic on the planet and while it has operated intermittently since being closed during the COVID-19 pandemic, its future is uncertain and although it will probably be preserved as a historic building, it’s likely to be re-purposed as retail or restaurant space.

Lindsay Lohan at the Scary Movie V premiere, Cinerama Dome, April 2013.

The end of the line for Cinerama is another marker in the evolution of the technology which underpinned the evolution of the US economy from one based on agriculture, to one increasingly industrial to one geared around the military & entertainment.  In the 1950s, cinema’s greatest challenge came from television and the film studios fought back by creating differentiation in their products.  The venture into 3D proved a cul-de-sac for a number of reasons but one thing cinemas could do was make their big screens huge and during the 1950s the wide-screen Cinemascope enjoyed a boom.  However, there was a limit to how much screens could grow, hence the interest in Cinerama which projected onto a curved screen designed to take advantage of the way the human eye sees and processes images, the system at its best when provided by three synchronized projectors.  The idea lives on in the curved screens which have become popular among gaming freaks who enjoy the sense of “envelopment”.  It was also the era during which populations moved further from city centres into suburbs and thus, cinemas also needed to move, more of which (but often smaller) would be required.  Thus the attraction of the geodesic dome came which, largely pre-fabricated, was cheap to produce and quick to assemble.  However, Cinerama was expensive to film, to print, to produce and the sheer size and weight of the prints meant it was costly even to ship the material to venues and the conversion process to something which could be used with conventional projection.

Heat Domes

July 2023 Global heat map from the Climate Change Institute, University of Maine, USA.  For those unconvinced, Fox News continues to provide alternative facts.

The “heat dome” is a weather phenomenon, the physics of which has for decades been understood but of late the term has entered general use as much of the northern hemisphere has suffered from prolonged, unusually high temperatures, July 2023 measured as the hottest month ever recorded.  A heat dome occurs when a large, high-pressure system traps and concentrates hot air in a specific region, leading to prolonged and extremely high temperatures. Under a heat dome, the atmospheric pressure aloft prevents the hot air from rising and dissipating, effectively acting as a lid or cap over the area, thus the image of a dome sitting over the land.

The UK's Royal Meteorological Service's simple illustration of the physics of a heat dome.  Heat domes are also their own feedback loop.  A static areas of high pressure which already contains warm or hot air trapped under the high will become hotter and hotter, creating a heat dome.  Hot air will rise into the atmosphere, but high pressure acts as a lid and causes the air to subside or sink; as the air sinks, it warms by compression, and the heat builds. The ground also warms, losing moisture and making it easier to heat even more.

Cupola

Cupola (pronounced kyoo-puh-luh)

(1) In architecture, a light structure on a dome or roof, serving as a belfry, lantern, or belvedere (some functional, some merely ornamental).

(2) Any of various dome-like structures (especially in architecture or one covering a circular or polygonal area).

(3) In naval architecture, a protective dome for guns on a warship

(4) In armored vehicles, a raised structure with a narrow aperture for viewing, sometimes fitted with a gun or flame-thrower.

(5) In geology, an upward-projecting mass of plutonic rock extending from a larger batholith.

(6) In metallurgy, a vertical, air-blown coke-fired cylindrical furnace in which iron is re-melted for use in casting.

(7) In geometry, a solid formed by joining two polygons, one (the base) with twice as many edges as the other, by an alternating band of isosceles triangles and rectangles.

(8) In anatomy, a small cap over a structure, shaped like a dome or inverted cup.

(9) In railway carriage design, a small viewing window in the top of the caboose (guard’s van) for looking over the train, or the part of the caboose where one looks through this window (obsolete).

1540–1550: From the Italian cupola, from the Late Latin cūpula (a small cask; a little tub), from the Classical Latin cuppella, from cuppa & cūpa (tub), from the Ancient Greek κύπελλον (kúpellon) (small cup), the construct being cūp(a) + -ula, from the primitive Indo-European -dlom (the instrumental suffix) and used as a noun suffix denoting an instrument.  The origin in Latin was based on the resemblance to an upturned cup, hence the use to describe the rounded top of just about any structure where no specific descriptor existed.  Cupola is a noun and cupolated & cupolar are adjectives; the noun plural is cupolas or cupolae.

Cupola on the dome of St Peter's Basilica, Vatican City, Rome.

In architectural history, the cupola is considered a descendent of the oculus, which may seem strange given the evidence suggests domes came first but a cupola is something which can be added to a dome and the earliest may have been “bolted on” when the open nature of an oculus proved troublesome.  Fitted with one or more windows, they would still permit the entry of light but keep out the wind and rain.  From this functional origin, they became popular as features to crown turrets, roofs, and larger dome.  Confusingly, architects at one point decided a cupola was also the inner vault of a dome so historic plans and descriptions need to be read with care.  Although classically dome-like in shape, most modern cupolas are more angular.

Onion domes on the Kremlin, Red Square, Moscow, Russia.

Cupolas were a favorite in early Islamic architecture and began their proliferation the mid-late eighth century, presumably because they were a perfect decorative addition to a mosque’s minarets but such was the appeal they would appear also in the core of the building or at its corners.  Before long, they were a regular part of commercial and residential buildings, valued not only as decoration but as a light source and for the ease with which they could sit atop vertical ducts used for ventilation.  It was the Islamic influence which was responsible for the best known motif of Russian architecture, the onion dome which was well suited to the northern climate because, constructed with severe lines, effortlessly they resisted the gathering of snow.  The Moors brought the design to Spain and whatever religious conflicts may for centuries have disfigured the Middle East & Europe, Architectural taste proved ecumenical and onion domes can still be seen atop Christian churches in Austria and southern Germany.

US Marine Corps M17 flame-thrower in use, the M1919A4 Browning .30 caliber medium machine gun to the right is hard-mounted in the tank commander's cupola, South Vietnam, 1968.

In military use, a cupola is basically a helmet fixed in place and that may be on a building, a ship or an armored vehicle, the function being to protect the head while offering a field of view.  Sometimes, especially in tanks or armored cars, guns or flame-throwers were integrated into cupolas and in naval gunnery, there was the special use to describe the dome-like structures protecting a (usually single) gun mounting, something which distinguished them from the larger, flatter constructions which fulfilled the same purpose for multi-gun batteries.

Cupola on the International Space Station (ISS), outside & in.  Cupolas are used on space craft because they are a way of maximizing the window space for a certain amount of the hull’s surface area.

McMansion with turrets and cupola.

Although the moment seems to have passed, one recent trend in domestic architecture which really disturbed the arbiters of style was the proliferation in parts of the US of McMansions, huge houses of sometimes dubious build quality often in a confusion of architectural styles and adorned with balconies, turrets, columns and cupolas, the more the better.

Squinch

Squinch (pronounced skwinch)

(1) In architecture, a small arch, corbeling, or the like, built across the interior angle between two walls, as in a square tower for supporting the side of a superimposed octagonal spire or generally to support any superstructure such as a spire or dome.  Also called a squinch arch.

(2) To contort (the features) or squint (now rare).

(3) To squeeze together or crouch down, as to fit into a smaller space (now rare).

1490–1500: A variant of the obsolete scunch, short for scuncheon, from the Middle English sconch(e)on from the middle Middle French escoinson (The reveal of an aperture (such as a door or window) from the frame to the inner face of the wall) & esconchon.  Escoinson is drawn from its original formation es- & ex- (both from the Latin ex (out of, from)) + coin (corner).  The meaning in the sense of a squinting of the eyes emerged during the 1830s, the origin uncertain but likely an imperfect echoic.

The Hagia Sofia

Built by Byzantine Emperor Justinian I between 532 and 537 AD, the Hagia Sophia ((from the Greek `Αγία Σοφία (Holy Wisdom), Sancta Sophia or Sancta Sapientia in Latin)) sits at what has often been the strategically important point on the Bosporus between the Black Sea and the Mediterranean, long thought the boundary between Europe and Asia.

The four minarets were added at different times after 1453.  Thought aesthetically successful, they add also to structural integrity.

The Hagia Sophia was originally a Greek Orthodox Christian patriarchal cathedral in Constantinople (modern day Istanbul, Turkey), consecrated briefly as a Catholic church in the thirteenth century.  Noted for its vast dome, it was an extraordinary achievement of engineering, architecture and mathematics, for centuries the biggest building on Earth, remaining the largest cathedral for nearly a thousand years until the dedication in 1520 of the basilica in Seville.  In 1453, when Constantinople fell to the Ottomans, it became a mosque, remaining one until 1935, when, as part of the modernity project that was the Turkish Republic created by Mustafa Kemal Atatürk (1881–1938; (President of the Republic of Turkey 1923-1938)), it was made a museum, later becoming one of the country’s most popular tourist attractions.

Hagia Sofia dome with four (corner) squinch arches with supporting pendentives.

The pendentive is the construction element which permits a dome to be placed over a square or rectangular space.  Pendentives are triangular segments of a sphere that spread at the top, tapering to points at the bottom, thereby enabling the continuous circular or elliptical base needed to support the dome.  The horizontal curve of the dome’s base is connected directly to the vertical curves of the four supporting arches on each corner. Where the curve of the pendentive and dome is continuous, the vaulting form is known as a pendentive dome. 

Pendentives receive the outward force from the dome’s weight, concentrating it at the four corners from where it's transferred down the columns to the foundations below.  Before there were, pendentives, domes needed either the supporting structure to be round (The Pantheon) or were supported by corbelling or the use of squinches allowing the dome to sit on top of four arches.  Both methods imposed limitations of width and height whereas pendatives, which directed forces away from the walls, made possible bigger structures.  Invented in Ancient Rome, Byzantine architects perfected the technique and they came to be seen too in Islamic, Renaissance and Baroque architecture.

From the late twentieth century, religious sentiment in the secular state became more combative and by the early 2000s, demands were being heard from both the Christian Orthodox and Sunni Islam for the Hagia Sofia to again be a place of worship.  Political sentiments hardened and, in July 2020, on the very same day a court annulled the 1934 law which enabled the site to become a museum, Turkish president Recep Tayyip Erdoğan (b 1954; prime minister of Turkey 2003-2014 & president since 2014) signed a presidential decree under which the museum reverted to being the Great Mosque of Ayasofya.  Mr Erdoğan had flagged his intentions and the move was no surprise, this the fourth Byzantine church converted from museum to mosque during his time in office.  Architectural repurposing is hardly unknown west of the Bosporus either, thousands of mosques in Spain and Greece having over the centuries been converted to Christian churches.

The court’s rationale for annulling the 1934 decree was interesting, the judges finding it unconstitutional, under not only the contemporary Turkish constitution but also Ottoman law.  The court held that Mehmed II (1432-1481, محمد ثانى‎ in Ottoman Turkish, romanized as Meḥmed-i sānī), who conquered Constantinople in 1453, gained the Hagia Sofia as his personal property and, by the creation of a waqf (In the Arabic وَقْف‎ (ˈwɑqf), also known as a hubous (حُبوس); an inalienable charitable endowment of property under the Hanafi (Sunni law)), had lawfully made the structure permanently a mosque and thus unable to be used for any other purpose.  Under the Hanafi, Mehmed’s waqf was held to be valid, as was his gaining personal ownership in 1453 by virtue of the war code of the time.

Oculus

Oculus (pronounced ok-yuh-luhs)

(1) In anatomy, an eye.

(2) In architecture, a window or other circular (or oval) opening, especially one at the apex of a dome.

(3) In archaeology, a design representing an eye, as on funerary pottery found in megalithic tombs of Europe.

(4) In the mechanical engineering (associated with fluid dynamics), the central boss of a volute.

(5) In poetic and literary use, luminary of the sun and stars; eye of the soul, mind's eye; a spot resembling an eye, such as on a peacock feather; a principle ornament or the main feature of something.

(6) In botany, a bud, bulb or knob on many roots, on the reed etc.

(7) As oculist (plural oculists), one who practices the discipline of oculism (an archaic name for an ophthalmologist or optometrist).

1857: From the Latin oculus (an eye), from the Proto-Italic okwelos, from the primitive Indo-European hsokw (eye; to see).  It was cognate with the Sanskrit अक्षि (ákṣi), the Ancient Greek ὄσσε (ósse), the Gothic augō, the Old English ēaġe (from which Modern English would gain eye) & the Proto-Slavic oko.  Originating in antiquity, it was a widely used feature of Byzantine and Neoclassical architecture, known in French as the œil de boeuf (bull's-eye).  The noun plural is oculi.  An impressively long word with the same root is ocularpneumoplethysmography, a non-invasive technique for detecting carotid stenosis by measurement of ophthalmic artery pressure.  Oculus & oculist are nouns; the noun plural is oculi (under the standard rules of English plural formations, the result would be oculuses by that seems to have been too awful to contemplate). 

The Pantheon

The Pantheon in Rome (from the Latin Pantheum, from the Ancient Greek Πάνθειον (Pantheion) ([temple] of all the gods) was built as a Roman temple and since the 609 has been a Roman Catholic church (Basilica di Santa Maria ad Martyres or Basilica of Saint Mary and the Martyrs).  It was built on the site of an earlier temple constructed during the time of Christ and rebuilt by the Emperor Hadrian circa 126 AD, the actual date uncertain because Hadrian retained the old inscriptions.

Cylindrical with a portico of sixteen staggered Corinthian columns, the dome has a diameter of 43.2m (142 feet) and was for over 1300 years the largest in the world and remains, after some two-thousand years, the largest unreinforced concrete dome, a feat achieved by a gradual reduction in the thickness and weight of the materials used for the upper layers.  Each of the granite columns weigh sixty tons.  Quarried in Egypt, they were dragged 100 km (60 miles), placed on barges and shipped up the Nile to Alexandria where they were transferred to boats to cross the Mediterranean to the port of Ostia.  From there, they were sent by barges, up the Tiber to Rome where they were dragged to the construction site for erection.

The dome was originally covered in bronze and there are reports from travelers of it sparkling in the sunlight, the glint playing on the surrounding skyline.  However during the middle ages most was pilfered, sometimes with official sanction, sometimes not, the shortage of building materials often acute.  The last of it, Pope Urban VIII (Maffeo Barberini, 1568–1644, pope 1623-1644) in 1631, needing ordinance for his military campaigns to expand the borders of the Papal States, stripped what bronze remained as well as that from the portico to melt down for cannons.  Romans, as cynical about their rulers then as now, were soon sharing the saying “quod non fecerunt barbari, fecerunt Barberini” (what was not done by the barbarians, was done by the Barberini).

The ass's ears, circa 1860.

Roman architect and Engineer Marcus Vitruvius Pollio (circa 75-10 BC) wrote the influential De architectura which defined the building and aesthesis standards of Classical architecture and the design of the Pantheon follows his rules, height and width exactly match, meaning a perfect sphere would precisely fit inside the dome.  Vitruvius would not have been best pleased at the additions made in the 1600s by Urban VIII.  Sometimes wrongly blamed on Bernini, pontiff turned amateur architect added two bell towers to the sides of the façade which, although disliked by Romans who nicknamed them le orecchie del culo (the ass’s ears), it wasn’t until late in the nineteen century they were finally demolished.

The Pantheon, Rome.

The oculus in the Pantheon is the most famous of the many built by the Romans.  Open to the weather, it allows rain to enter and fall to the floor, where it is carried away through drains. A masterpiece of Roman architectural scale, though it looks small, the oculus’ diameter is 27 feet (8.2m) allowing it to light the building as the sun lights the earth and rain also keeps the building cool during the hot summer months.  A clever trick of lighting (and mathematics) was played out on every 21 April, the founding date of Rome.  At midday, the sunlight hits the metal grille above the door, filling the entrance way with light, timed to coincide with a ceremony at which the emperor appears in the space, reflecting his status as either an earthly god on one on whom the blessings of the gods shone.  Which of these applied depended on the Emperor.  In style, if not scale, the Pantheon was the inspiration for the Große Halle (Great Hall (and referred to in contemporary documents also as the Volkshalle (People's Hall or Ruhmeshalle (Hall of Glory)) which was to be the centrepiece of Germania as Berlin was to be re-named upon becoming the capital of the Third Reich.

Albert Speer's (1905–1981; Nazi court architect 1934-1942; Nazi minister of armaments and war production 1942-1945) post-war memoirs (1969) are not wholly truthful but on matters of architecture they are thought reliable and provide an insight not only into the grandiose plans but also the political and psychological aspects of representational buildings to which Adolf Hitler (1889-1945; Führer (leader) and German head of government 1933-1945 & head of state 1934-1945) attached such importance.  The monumental size alone was significant and despite Hitler being scornful of the mystical notions of some of his paladins, Speer was convinced that inherent in the awe-inspiring scale of the designs was the idea of them becoming places of worship, something which would be reinforced as they aged, unchanged, over the centuries.  Able to accommodate 150-180,000 people, the dome would have had a diameter of 250 metres (825 feet). rising in a slightly parabolic curve to a height of 221 metres (726 feet) while the oculus would be 46 metres (152 feet) in diameter, larger than the entire dome of either the Pantheon (43 metres (142 feet)) or that of St Peter's Basilica (44 metres (145 feet)).  The interior would be 16 times the volume of St Peter's.

Model of the Great Hall intended for Germania.

Speer also noted that even in the late 1930s when first he showed the architectural drawings to Hitler, the Führer suspended belief in facts when it suited him.  Because it was technically possible, Speer originally envisaged building the dome without the use of any structural steel but Hitler objected that were it to be struck by a bomb, the vaulting might be so damaged that without a supporting framework, repairs would be impossible.  Speer conceded the point but when he had questioned whether it was wise to have so tall a structure build in the very heart of the Reich's capital where it would act as a navigational aid for attacking bombers, Hitler breezily replied that Hermann Göring (1893–1946; leading Nazi 1922-1945, Hitler's designated successor & Reichsmarschall 1940-1945) had assured him his Luftwaffe would ensure "no enemy plane will ever enter Germany's skies".  Infamously, the Reichsmarschall would boast to the German people: "If as much as a single enemy aircraft flies over German soil, my name is Meier!"; the Royal Air Force's (RAF) bombing raids on Berlin soon began.

Lindsay Lohan with peacock feathers. during blonde phase.

The eye-like feature on a peacock's tail-feathers are called an oculus and because the collective noun for a group of peacocks (peafowl) is "an ostentation" so these several could be styled "an ostentation of oculi".  This photograph is available as a 2024 calendar.                   

Xanadau

Xanadu (pronounced zan-a-du)

Also known as Shangdu, Xanadu was the capital of Kublai Khan's (1215-1294) Yuan dynasty (1271-1368) in China, before he decided to move his throne to the Jin dynasty (1115-1234) capital of Zhōngdū (middle capital), which he renamed Khanbaliq, later known in the West as Peking and of late, Beijing.  Xanadu then became his summer capital.  Xanadu was visited by the Venetian merchant Marco Polo (circa 1254–1324) in about 1275, and was destroyed in 1369 by the Ming army under Zhu Yuanzhang (1328-1398).

Relic site of Xanadu.  Xanadu was located in what is now called Inner Mongolia, 220 miles (350 km) north of what is no the city of Beijing (Peking).  Today, only ruins remain, surrounded by a grassy mound that was once the city walls. Since 2002, restoration work has been undertaken and in June 2012, Shangdu was made a World Heritage Site.

Kubla Khan (1797) by Samuel Taylor Coleridge (1772-1834)

By his own account, Samuel Taylor Coleridge was reading about Shangdu while taking laudanum, an opium based medicine.  It led to an opium-induced dream, during which he composed some three-hundred lines of verse.  As soon as he awoke, he wrote down the first fifty but unfortunately, was then interrupted by “a man on business from (the local Somerset village of) Porlock.”   Once the business was concluded, Coleridge found the distraction had driven from his mind the rest of the poem.  All find Coleridge’s story charming but scholars doubt it’s true, the poet having used a similar excuse years before.  Most think it a case of writer’s block.

In Xanadu did Kubla Khan
A stately pleasure-dome decree:
Where Alph, the sacred river, ran
Through caverns measureless to man
Down to a sunless sea.
So twice five miles of fertile ground
With walls and towers were girdled round:
And here were gardens bright with sinuous rills
Where blossomed many an incense-bearing tree;
And here were forests ancient as the hills,
Enfolding sunny spots of greenery.
But oh! that deep romantic chasm which slanted
Down the green hill athwart a cedarn cover!
A savage place! as holy and enchanted
As e'er beneath a waning moon was haunted
By woman wailing for her demon-lover!
And from this chasm, with ceaseless turmoil seething,
As if this earth in fast thick pants were breathing,
A mighty fountain momently was forced;
Amid whose swift half-intermitted burst
Huge fragments vaulted like rebounding hail,
Or chaffy grain beneath the thresher's flail:
And 'mid these dancing rocks at once and ever
It flung up momently the sacred river.
Five miles meandering with a mazy motion
Through wood and dale the sacred river ran,
Then reached the caverns measureless to man,
And sank in tumult to a lifeless ocean:
And 'mid this tumult Kubla heard from far
Ancestral voices prophesying war!
The shadow of the dome of pleasure
Floated midway on the waves:
Where was heard the mingled measure
From the fountain and the caves.
It was a miracle of rare device,
A sunny pleasure-dome with caves of ice!
A damsel with a dulcimer
In a vision once I saw:
It was an Abyssinian maid,
And on her dulcimer she played,
Singing of Mount Abora.
Could I revive within me
Her symphony and song,
To such a deep delight 't would win me
That with music loud and long,
I would build that dome in air,
That sunny dome! those caves of ice!
And all who heard should see them there,
And all should cry, Beware! Beware!
His flashing eyes, his floating hair!
Weave a circle round him thrice,
And close your eyes with holy dread,
For he on honey-dew hath fed,
And drunk the milk of Paradise.

Radome

Radome (pronounced rey-dohm)

A dome-shaped device used as a protective housing for a radar antenna (although the word is loosely used and applied to structures of varied shapes in which radar equipment is installed).

1940–1945: A portmanteau word, a blend of ra(dar) + dome.  In electronics, radar is a device for determining the presence and location of an object by measuring the time for the echo of a radio wave to return from it and the direction from which it returns and in figurative use refers to a means or sense of awareness or perception.  Dating from 1940-1945, radar was originally the acronym RADAR which was creation of US scientific English: RA(dio)D(etecting)A(nd)R(anging).  In the way English does things, the acronym RADAR came to be used with such frequency that it became a legitimate common noun, the all lower-case “radar” now the default form.  Dating from 1505–1515, dome was from the Middle French domme & dome (a town-house; a dome, a cupola) (which persists in modern French as dôme), from the Provençal doma, from the Italian duomo (cathedral), from the Medieval Latin domus (ecclesiae; literally “house (of the church)”), a calque of the Ancient Greek οἶκος τῆς ἐκκλησίας (oîkos tês ekklēsías).  Radome is a noun & verb; the noun plural is radomes.

Spherical radomes at the Pine Gap satellite surveillance base, some 11 miles (18 km) south-west of Alice Springs in Australia's Northern Territory.  Officially, it's jointly operated by the defence departments of the US and Australia and was once known as the Joint Defence Space Research Facility (JDSRF) but, presumably aware nobody was fooled, it was in 1988 renamed the Joint Defence Facility Pine Gap (JDFPG).  The Pine Gap facility is a restricted zone so it's not a tourist attraction which is unfortunate because it's hard to think of any other reason to visit Alice Springs.

Lindsay Lohan on the cover or Radar magazine, June-July 2007.  The last print-edition of Radar was in 2008; since 2009 it's been released on-line.

Radomes don’t actually fulfill any electronic function as such.  They are weatherproof structures which are purely protective (and on ships where space is at a premium they also protect personnel from the moving machinery) and are thus constructed from materials transparent to radio waves.  The original radomes were recognizably domish but they quickly came to be built in whatever shape was most suitable to their location and application: pure spheres, planars and geodesic spheres are common.  When used on aircraft, the structures need to be sufficiently aerodynamic not to compromise performance, thus the early use of nose-cones as radomes and on larger airframes, dish-like devices have been fashioned.

North American Sabre:  F-86A (left) and F-86D with black radome (right).

Introduced in 1947, the North American F-86 Sabre was the US Air Force’s (USAF) first swept-wing fighter and the last trans-sonic platform used as a front-line interceptor.  Although as early as 1950 elements within the USAF were concerned it would soon be obsolete, it proved a solid, versatile platform and close to 10,000 were produced, equipping not on US & other NATO forces but also those of a remarkable number of other nations and some remained in front-line service until the 1990s.  In 1952, the F-86D was introduced which historians of military aviation regard as the definitive version.  As well as the large number of improvements typical of the era, an AN/APG-36 all-weather radar system was enclosed in a radome which resembled an enlarged version of the central bosses previously often used on propellers.

What lies beneath a radome: Heinkel He 219 Uhu with radar antennae array.

The size of the F-86D’s radome is indicative also that the now familiar tendency for electronic components to become smaller is nothing new.  Only a half decade before the F86-D first flew, Germany’s Heinkel He 219 Uhu had entered combat as a night-fighter, its most distinctive feature the array of radar antennae protruding from the nose.  The arrangement was highly effective but, needing to be as large as they were, a radome would have been impossible.  The He 219 was one of the outstanding airframes World War II (1969-1945) and of its type, at least the equal of anything produced by the Allies but it was the victim of the internal politics which bedevilled industrial and military developments in the Third Reich, something which wasn’t fully understood until some years after the end of hostilities.  Remarkably, although its dynamic qualities should have made volume production compelling, fewer than 300 were ever built, mainly because Adolf Hitler (1889-1945; Führer (leader) and German head of government 1933-1945 & head of state 1934-1945): (1) was less inclined to allocate priorities to defensive equipment (attack always his preferred strategy) and (2) the debacle of the earlier Heinkel He 177 Gref heavy bomber (which he described as “the worst junk ever manufactured) had made him distrustful of whatever the company did.

Peak dagmar: 1955 Cadillac Series 62 Coupe de Ville.

As early as 1941, the US car industry had with enthusiasm taken to adorning the front of their vehicles with decorative conical devices they intended to summon in the minds of buyers the imagery of speeding artillery shells, then something often seen in popular publications.  However, in the 1950s, the hardware of the jet-age became the motif of choice but the protuberances remained, some lasting even into the next decade.  They came to be known as “dagmars” because of the vague anatomical similarity to one of the early stars of television but the original inspiration really had been military field ordnance.  Cadillac actually abandoned the use of dagmars in their 1959 models (a rare example of restraint that year) but concurrent with that, they also toured the show circuit with the Cadillac Cyclone (XP-74) concept car.

1959 Cadillac Cyclone (XP-74) concept car.

Although it was powered by the corporation’s standard 390 cubic inch (6.5 litre) V8, there was some adventurous engineering including a rear-mounted automatic transaxle and independent rear suspension (using swing axles, something not as bad as it sounds given the grip of tyres at the time) but few dwelt long on such things, their attention grabbed by features such as the bubble top canopy (silver coated for UV protection) which opened automatically in conjunction with the electrically operated sliding doors.

1958 Edsel Citation Convertible (left) and 1964 GM-X Stiletto, a General Motors (GM) "dream car" built for the 1964 New York World's Fair.

Most innovative however was a feature which wouldn’t reach volume production until well into the twenty-first century: Borrowing from the North American F86-D Sabre, two radomes were fitted at the front, housing antennae for a radar-operated collision avoidance system (ROCAS) which fed to the driver information on object which lay in the vehicle’s path including distance and the length it would take to brake, audible signals and a warning lights part of the package.  Unfortunately, as was often the case with the concept cars, the crash avoidance system didn't function, essentially because the electronics required for it to be useful would not for decades become available.  As the dagmars had, the Cyclone’s twin radomes attracted the inevitable comparisons but given the sensor and antennae technology of the time, two were apparently demanded although, had Cadillac more slavishly followed the F-86D and installed a single central unit, the response might have been even more ribald, the frontal styling of the doomed Edsel then still being derisively compared to female genitalia; cartoonists would have had fun with a Cyclone so equipped seducing an Edsel.  In 1964, there's never been anything to suggest GM's designers were thinking of the anatomical possibilities offered by an Edsel meeting a Stiletto.