World Architecture
World Architecture is a art or practice of designing and constructing buildings.
41. CN Canadian National Tower
Toronto, Canada
The CN Tower, next to the city hall on Front Street, Toronto, stands on the shore of Lake Ontario. It transmits television and FM radio for more than twenty broadcasters, as well as serving various other communications purposes. Including the masts, it is the tallest freestanding structure in the world the top of the transmission antenna is over 1,815 feet 553 meters high. But at the beginning of the twenty-first century, as technically demanding as it is, height alone does not constitute an architectural feat. The twin Petronas Towers in Kuala Lumpur, Malaysia, currently rank as the worlds tallest buildings, at 1,483 feet 454 meters. Others are proposed that will exceed that, including the 1,660-foot 508-meter Taipei Financial Center on Taiwan, to be completed in August 2002, and the 2,100-foot 642-meter Russia Tower in Moscow at 2,755 feet 843 meters, the Millennium Tower in Tokyo will dwarf them all. The CN Tower is remarkable architecture because of its construction technique. For about a year, concrete, mixed and tested on-site to ensure consistent quality, was poured around the clock into aslip form that gradually decreased in diameter, to create the elegantly tapered contour of the post tensioned hollow structure. Slip forming is a rapid construction technique based on extrusion. It employs a self-raising formwork that continually moves upward as the concrete is being placed, at a rate that gives the concrete time to set before being exposed as the formwork rises on a ring of hydraulic jacks, developing enough strength to support the work above. Continuous slip forming obviously speeds up the construction process while enabling excellent quality control, optimizing labor, and reducing the cost of building plant and scaffolding. It also results in monolithic, seamless structures. Developed in North America in the 1920sThe Granary at Logan Square in Philadelphia 1925 was one of the first examples in the United Statesit has been widely used to build grain silos, building service cores, and normally any tall structures with a consistent cross section. Early in the 1970s the number of multistory office blocks in downtown Toronto increased significantly, with a consequent interference with television and radio reception in large parts of the city. Toronto needed an antenna taller than any existing office block, indeed, of any that was anticipated, and the CN Tower was proposed to meet that need. The project was initiated in 1972 by the Canadian National Railway, which commissioned John Andrews Architects, working in collaboration with Webb Zerafa Menkes Housden Architects of Toronto. The structural engineering consultant was Roger R. Nicolet of Montreal the mechanical and electrical engineers were Ellard-Wilson Associates Ltd. of Toronto and the manager-contractor was Foundation Building Construction. The original design proposed three concrete towers linked by structural bridges, but that was developed into a single tower with three hollowlegs. As well as serving as electrical and mechanical service ducts, the hollow columns provided the necessary degree of flexibility for such a tall structure. Construction started in February 1973, and in four months a Y-shaped, 22-foot-thick 6.7-meter reinforced concrete base was founded on the bedrock 50 feet 15 meters beneath the city. The continuous slip-form process then began. When the tower reached 1,100 feet 336 meters, a seven-storySkyPod, fabricated on the ground, was raised into position and anchored by twelve steel-and-timber brackets that were slowly pushed up the tower by forty-five hydraulic jacks. The concrete-walled SkyPod, reached by four high-speed, glass-fronted elevators, houses a 400-seat revolving restaurant, a nightclub, and indoor and outdoor observation decks. Later, a 2.5-inch-thick 6.4-centimeter glass floor was installed. Beneath the SkyPod, delicate microwave dishes and other broadcasting equipment are protected by an annular radome. The concrete tower continues to the Space Deck at 1,465 feet 447 metersan observation gallery that on a clear day provides a view with 100-mile 160-kilometer visibility. A Sikorsky Skycrane helicopter lifted the towers 335-foot 100-meter communications mast in forty sections, each of about 7 tons 6.4 tonnes, and they were bolted together in place. The mast, erected in three weeks, was covered by fiberglass-reinforced sheathing. The maximum sway experienced at the very top in 120-mph 190-kph winds with 200-mph 320-kph gusts is 3.5 feet 1.07 meters. The CN Tower was completed in June 1975 and officially opened on 1 October. It cost Can$57 million and took about 1,550 workers forty months to construct. It is nearly twice the height of the Eiffel Tower and more than three times as tall as the Washington Monument. Soaring above Toronto, it is struck by lightning about seventy-five times every year. In 1995 Canada National passed ownership to a public company, the Canada Lands Company. In June 1998, the CN Tower officially opened a 75,000-square-foot 7,100-square-meter expansion including an entertainment center, shopping facilities, and restaurants.
The CN Tower, next to the city hall on Front Street, Toronto, stands on the shore of Lake Ontario. It transmits television and FM radio for more than twenty broadcasters, as well as serving various other communications purposes. Including the masts, it is the tallest freestanding structure in the world the top of the transmission antenna is over 1,815 feet 553 meters high. But at the beginning of the twenty-first century, as technically demanding as it is, height alone does not constitute an architectural feat. The twin Petronas Towers in Kuala Lumpur, Malaysia, currently rank as the worlds tallest buildings, at 1,483 feet 454 meters. Others are proposed that will exceed that, including the 1,660-foot 508-meter Taipei Financial Center on Taiwan, to be completed in August 2002, and the 2,100-foot 642-meter Russia Tower in Moscow at 2,755 feet 843 meters, the Millennium Tower in Tokyo will dwarf them all. The CN Tower is remarkable architecture because of its construction technique. For about a year, concrete, mixed and tested on-site to ensure consistent quality, was poured around the clock into aslip form that gradually decreased in diameter, to create the elegantly tapered contour of the post tensioned hollow structure. Slip forming is a rapid construction technique based on extrusion. It employs a self-raising formwork that continually moves upward as the concrete is being placed, at a rate that gives the concrete time to set before being exposed as the formwork rises on a ring of hydraulic jacks, developing enough strength to support the work above. Continuous slip forming obviously speeds up the construction process while enabling excellent quality control, optimizing labor, and reducing the cost of building plant and scaffolding. It also results in monolithic, seamless structures. Developed in North America in the 1920sThe Granary at Logan Square in Philadelphia 1925 was one of the first examples in the United Statesit has been widely used to build grain silos, building service cores, and normally any tall structures with a consistent cross section. Early in the 1970s the number of multistory office blocks in downtown Toronto increased significantly, with a consequent interference with television and radio reception in large parts of the city. Toronto needed an antenna taller than any existing office block, indeed, of any that was anticipated, and the CN Tower was proposed to meet that need. The project was initiated in 1972 by the Canadian National Railway, which commissioned John Andrews Architects, working in collaboration with Webb Zerafa Menkes Housden Architects of Toronto. The structural engineering consultant was Roger R. Nicolet of Montreal the mechanical and electrical engineers were Ellard-Wilson Associates Ltd. of Toronto and the manager-contractor was Foundation Building Construction. The original design proposed three concrete towers linked by structural bridges, but that was developed into a single tower with three hollowlegs. As well as serving as electrical and mechanical service ducts, the hollow columns provided the necessary degree of flexibility for such a tall structure. Construction started in February 1973, and in four months a Y-shaped, 22-foot-thick 6.7-meter reinforced concrete base was founded on the bedrock 50 feet 15 meters beneath the city. The continuous slip-form process then began. When the tower reached 1,100 feet 336 meters, a seven-storySkyPod, fabricated on the ground, was raised into position and anchored by twelve steel-and-timber brackets that were slowly pushed up the tower by forty-five hydraulic jacks. The concrete-walled SkyPod, reached by four high-speed, glass-fronted elevators, houses a 400-seat revolving restaurant, a nightclub, and indoor and outdoor observation decks. Later, a 2.5-inch-thick 6.4-centimeter glass floor was installed. Beneath the SkyPod, delicate microwave dishes and other broadcasting equipment are protected by an annular radome. The concrete tower continues to the Space Deck at 1,465 feet 447 metersan observation gallery that on a clear day provides a view with 100-mile 160-kilometer visibility. A Sikorsky Skycrane helicopter lifted the towers 335-foot 100-meter communications mast in forty sections, each of about 7 tons 6.4 tonnes, and they were bolted together in place. The mast, erected in three weeks, was covered by fiberglass-reinforced sheathing. The maximum sway experienced at the very top in 120-mph 190-kph winds with 200-mph 320-kph gusts is 3.5 feet 1.07 meters. The CN Tower was completed in June 1975 and officially opened on 1 October. It cost Can$57 million and took about 1,550 workers forty months to construct. It is nearly twice the height of the Eiffel Tower and more than three times as tall as the Washington Monument. Soaring above Toronto, it is struck by lightning about seventy-five times every year. In 1995 Canada National passed ownership to a public company, the Canada Lands Company. In June 1998, the CN Tower officially opened a 75,000-square-foot 7,100-square-meter expansion including an entertainment center, shopping facilities, and restaurants.
42. Colosseum Flavian Amphitheater
Rome
The Flavian Amphitheater, now in ruins, towers over the southeast end of the Roman Forum, between the Esquiline and Palatine Hills. Its popular name, the Colosseum, was derived from the nearby colossal 120-foot-high, or 37.2-meter bronze statue of Nero, long since vanished. The most ambitious example of a new building type associated with urbanization, the Colosseum was an architectural feat, even by Roman standards. Its size is awesome, but the logistics of moving crowds to and from their seats was also a major achievement. The earliest amphitheater on the site was built in timber for the pontifex maximus Gaius Scribonius Curio in 59 b.c. that was replaced about thirty years later by a stone-and-timber version for Augustus Octavian Caesar, the first emperor. The Colosseum was commissioned in a.d. 69 by Vespasian, whose son Titus dedicated it in a.d. 80. The highest part of that structure was also timber, and not rebuilt in stone until after a.d. 223. It seems that the first three ranges of seats were completed in Vespasians reign, that Titus added two more ranges, and that Domitian completed the building around 300. Although early sources claim that the Colosseum seated 87,000 spectators, modern scholarship puts the figure closer to 50,000. Other Italian amphitheaters at Capua, Verona, and Tarragona are of similar size. The vast Colosseum, elliptical in plan, measured 620 by 510 feet 189 by 156 meters, covering nearly 6 acres about 2.4 hectares. Its general height was 160 feet 49 meters. The structural skeleton of the Colosseum was made of travertine limestone, quarried at Tivoli in the hills near Rome and transported to the site along a specially built road. Travertine blocks, some of them 5 feet high and 10 feet long 1.5 by 3 meters, were fixed together with metal cramps to form concentric elliptical walls. These were linked with radiating tufa walls carrying complex rising vaults of brick-faced concrete, in which volcanic stone such as pumice was used to reduce the weight. The vaults carried the tiers of seats. The Colosseum was built to house extravagant spectacles that took place in an arena measuring 280 by 175 feet 86 by 54 meters. Apart from a number of minor entrances to the arena, there were four principal gates at the ends of the axes, directly joined by passages to the exterior. A 15-foot-high 4.5-meter walls probably faced with marble, defined the arena and provided a measure of protection for the spectators. The floor of the arena was made of heavy planks, strewn with sand for the purpose of soaking up the blood of gladiators, prisoners of war, and wild animals that died in their thousands. Such emperors as Caligula and Nero even ordered cinnabar and borax to replace the sand. A labyrinth of chambers beneath the floor possibly housed the participants in the games, and there were complicated machines and hoists to lift men, beasts, and theatrical sets into the arena, adding to the spectacle. Sometimes the entire floor was removed and the arena flooded by a system of pipes so that galleys could be pitted against each other in mock naval battles. The terrace on top of the surrounding wall was wide enough to contain two or three rows of movable seats. Undoubtedly the best in the house, they were reserved for senators, magistrates, the vestal virgins, and other important people. The emperor and his immediate retinue occupied an elevated cubiculum. Upon entering the Colosseum through numbered arches corresponding to their ticket numbers, other visitors climbed sloping ramps to the gradus bleachers, which were divided into stories and allocated according to gender and social class. The first fourteen rows of marble seats were covered with cushions and set aside for the equestrian order. Above them a horizontal space defined the second range, where a third class of spectators, the populus, was seated. Still further up were the wooden benches for the common people. The open gallery at the very top was the only part of the amphitheaters from which women were permitted to watch. There were exceptions, of course. When the games were over, the crowd could quickly disperse through no fewer than sixty-four strategically placed exits, aptly known as vomitoria. The external wall of the Colosseum was divided into four stories, reflecting the circulation corridors within. Its eighty arches, most of which provided access to the interior, were framed by superimposed orders of pilasters nonstructural columns: Tuscan on the ground floor, Ionic above them, and Corinthian at the top. The fourth story, also embellished with Corinthian pilasters, had stone brackets for the wooden masts from which an awning velarium was suspended across the interior to shield spectators from the sun while they watched the slaughter below. Many of the visible parts of the building were enriched with moldings, ornament, facings of marble or polished stone, and statuary. Fountains of scented water were provided for refreshment. The Flavian Amphitheater was damaged several times by lightning strikes and repaired as often, so that games continued spasmodically until the sixth century, despite the opposition of the church and some Christian emperors. The last recorded slaughter of wild beasts was in the reign of Theodoric a.d. 454 526, since when it has been used sometimes as a fortress and to its detriment as a quarry. Renaissance palaces in Rome, such as the Cancellaria and the Farnese, and churches including Saint Peters Basilica, were built with columns plundered from the ancient monument. Various popes made efforts to preserve it, and in 1750 Pope Benedict XIV consecrated it to the martyrs who died there. Surprisingly, and despite popular belief, it was not the main venue for the execution of Christians. In 1996 a U.S.$25 million restoration of the Colosseum was launched. After the cellars were drained, fallen masonry replaced, bushes and weeds cleared from the arena, and the structure repaired and cleaned, the greatest amphitheater was reopened in July 2000 with a season of Greek plays.
The Flavian Amphitheater, now in ruins, towers over the southeast end of the Roman Forum, between the Esquiline and Palatine Hills. Its popular name, the Colosseum, was derived from the nearby colossal 120-foot-high, or 37.2-meter bronze statue of Nero, long since vanished. The most ambitious example of a new building type associated with urbanization, the Colosseum was an architectural feat, even by Roman standards. Its size is awesome, but the logistics of moving crowds to and from their seats was also a major achievement. The earliest amphitheater on the site was built in timber for the pontifex maximus Gaius Scribonius Curio in 59 b.c. that was replaced about thirty years later by a stone-and-timber version for Augustus Octavian Caesar, the first emperor. The Colosseum was commissioned in a.d. 69 by Vespasian, whose son Titus dedicated it in a.d. 80. The highest part of that structure was also timber, and not rebuilt in stone until after a.d. 223. It seems that the first three ranges of seats were completed in Vespasians reign, that Titus added two more ranges, and that Domitian completed the building around 300. Although early sources claim that the Colosseum seated 87,000 spectators, modern scholarship puts the figure closer to 50,000. Other Italian amphitheaters at Capua, Verona, and Tarragona are of similar size. The vast Colosseum, elliptical in plan, measured 620 by 510 feet 189 by 156 meters, covering nearly 6 acres about 2.4 hectares. Its general height was 160 feet 49 meters. The structural skeleton of the Colosseum was made of travertine limestone, quarried at Tivoli in the hills near Rome and transported to the site along a specially built road. Travertine blocks, some of them 5 feet high and 10 feet long 1.5 by 3 meters, were fixed together with metal cramps to form concentric elliptical walls. These were linked with radiating tufa walls carrying complex rising vaults of brick-faced concrete, in which volcanic stone such as pumice was used to reduce the weight. The vaults carried the tiers of seats. The Colosseum was built to house extravagant spectacles that took place in an arena measuring 280 by 175 feet 86 by 54 meters. Apart from a number of minor entrances to the arena, there were four principal gates at the ends of the axes, directly joined by passages to the exterior. A 15-foot-high 4.5-meter walls probably faced with marble, defined the arena and provided a measure of protection for the spectators. The floor of the arena was made of heavy planks, strewn with sand for the purpose of soaking up the blood of gladiators, prisoners of war, and wild animals that died in their thousands. Such emperors as Caligula and Nero even ordered cinnabar and borax to replace the sand. A labyrinth of chambers beneath the floor possibly housed the participants in the games, and there were complicated machines and hoists to lift men, beasts, and theatrical sets into the arena, adding to the spectacle. Sometimes the entire floor was removed and the arena flooded by a system of pipes so that galleys could be pitted against each other in mock naval battles. The terrace on top of the surrounding wall was wide enough to contain two or three rows of movable seats. Undoubtedly the best in the house, they were reserved for senators, magistrates, the vestal virgins, and other important people. The emperor and his immediate retinue occupied an elevated cubiculum. Upon entering the Colosseum through numbered arches corresponding to their ticket numbers, other visitors climbed sloping ramps to the gradus bleachers, which were divided into stories and allocated according to gender and social class. The first fourteen rows of marble seats were covered with cushions and set aside for the equestrian order. Above them a horizontal space defined the second range, where a third class of spectators, the populus, was seated. Still further up were the wooden benches for the common people. The open gallery at the very top was the only part of the amphitheaters from which women were permitted to watch. There were exceptions, of course. When the games were over, the crowd could quickly disperse through no fewer than sixty-four strategically placed exits, aptly known as vomitoria. The external wall of the Colosseum was divided into four stories, reflecting the circulation corridors within. Its eighty arches, most of which provided access to the interior, were framed by superimposed orders of pilasters nonstructural columns: Tuscan on the ground floor, Ionic above them, and Corinthian at the top. The fourth story, also embellished with Corinthian pilasters, had stone brackets for the wooden masts from which an awning velarium was suspended across the interior to shield spectators from the sun while they watched the slaughter below. Many of the visible parts of the building were enriched with moldings, ornament, facings of marble or polished stone, and statuary. Fountains of scented water were provided for refreshment. The Flavian Amphitheater was damaged several times by lightning strikes and repaired as often, so that games continued spasmodically until the sixth century, despite the opposition of the church and some Christian emperors. The last recorded slaughter of wild beasts was in the reign of Theodoric a.d. 454 526, since when it has been used sometimes as a fortress and to its detriment as a quarry. Renaissance palaces in Rome, such as the Cancellaria and the Farnese, and churches including Saint Peters Basilica, were built with columns plundered from the ancient monument. Various popes made efforts to preserve it, and in 1750 Pope Benedict XIV consecrated it to the martyrs who died there. Surprisingly, and despite popular belief, it was not the main venue for the execution of Christians. In 1996 a U.S.$25 million restoration of the Colosseum was launched. After the cellars were drained, fallen masonry replaced, bushes and weeds cleared from the arena, and the structure repaired and cleaned, the greatest amphitheater was reopened in July 2000 with a season of Greek plays.
43. Colossus Bridge Schuylkill River
Pennsylvania
The Upper Ferry bridge built at Fairmount near Philadelphia in 1812 and tragically destroyed by fire in 1838 was the longest single-trussed wooden arch in the United States, spanning over 340 feet 102 meters. It caused a sensation in its day and was inevitably labeled a newwonder of the world,the Colossus at Philadelphia, andthe Colossus at Fairmount. This covered bridge, responding to new constraints, took timber engineering to its limits. At the beginning of the nineteenth century, driven by the need for agricultural growth, the population of the narrow coastal plain of the northeastern United States was spreading beyond thetidewater region. Before then, many short streams and estuaries had adequately met communication needs, but the inland farmers demanded roads, fords, and bridges. Water mills, increasing in number as farming increased, were of necessity sited where rivers could not be forded, and they also needed transportation routes. There were good supplies of building lumber in the region and the harsh climate was better suited to wooden construction than to masonry. The earliest bridges were merely logs carried on timber stringers their spans were limited to the available lengths. As bridge technology developed, longer spans were achieved by joining stringers and employing trusses and arches. Climate was an important factor and the covered bridge soon became not only popular but also necessary. The roof protected the structural timber from alternate wetting and drying, discouraging rot and extending the life of the bridge. There is a story, perhaps apocryphal, of a Virginia builder who observed that bridges were coveredfor the same reason that our belles [wear] hoop skirts and crinolines: to protect the structural beauty that is seldom seen, but nevertheless appreciateda delightful analogy. The first covered bridge in the United States replaced a pontoon across the Schuylkill River in Philadelphia and was therefore optimistically called the Permanent Bridge. A stone bridge was originally intended, but when the abutments and piers were completed in 1804, the decision was made to span the river with timber. The New England bridge architect Thomas Palmer designed a structure braced with three arches and multiple king posts, and it was constructed by Owen Biddle, a Philadelphia architect and builder. When it was opened to traffic in 1805 it had no cover, but on Palmers advice and the prompting of Permanent Bridge Company shareholders, a roof and clapboard siding were soon added. Palmer believed the covering would extend the life of the structure from twelve years to perhaps forty it was still sound when replaced forty-five years later. Within five years there was a demand for another bridge across the Schuylkill, to be built at Upper Ferry and connecting the area then known as Fairmont with the western bank. The design was put in the hands of Lewis Wernwag, an immigrant carpenter from W
The Upper Ferry bridge built at Fairmount near Philadelphia in 1812 and tragically destroyed by fire in 1838 was the longest single-trussed wooden arch in the United States, spanning over 340 feet 102 meters. It caused a sensation in its day and was inevitably labeled a newwonder of the world,the Colossus at Philadelphia, andthe Colossus at Fairmount. This covered bridge, responding to new constraints, took timber engineering to its limits. At the beginning of the nineteenth century, driven by the need for agricultural growth, the population of the narrow coastal plain of the northeastern United States was spreading beyond thetidewater region. Before then, many short streams and estuaries had adequately met communication needs, but the inland farmers demanded roads, fords, and bridges. Water mills, increasing in number as farming increased, were of necessity sited where rivers could not be forded, and they also needed transportation routes. There were good supplies of building lumber in the region and the harsh climate was better suited to wooden construction than to masonry. The earliest bridges were merely logs carried on timber stringers their spans were limited to the available lengths. As bridge technology developed, longer spans were achieved by joining stringers and employing trusses and arches. Climate was an important factor and the covered bridge soon became not only popular but also necessary. The roof protected the structural timber from alternate wetting and drying, discouraging rot and extending the life of the bridge. There is a story, perhaps apocryphal, of a Virginia builder who observed that bridges were coveredfor the same reason that our belles [wear] hoop skirts and crinolines: to protect the structural beauty that is seldom seen, but nevertheless appreciateda delightful analogy. The first covered bridge in the United States replaced a pontoon across the Schuylkill River in Philadelphia and was therefore optimistically called the Permanent Bridge. A stone bridge was originally intended, but when the abutments and piers were completed in 1804, the decision was made to span the river with timber. The New England bridge architect Thomas Palmer designed a structure braced with three arches and multiple king posts, and it was constructed by Owen Biddle, a Philadelphia architect and builder. When it was opened to traffic in 1805 it had no cover, but on Palmers advice and the prompting of Permanent Bridge Company shareholders, a roof and clapboard siding were soon added. Palmer believed the covering would extend the life of the structure from twelve years to perhaps forty it was still sound when replaced forty-five years later. Within five years there was a demand for another bridge across the Schuylkill, to be built at Upper Ferry and connecting the area then known as Fairmont with the western bank. The design was put in the hands of Lewis Wernwag, an immigrant carpenter from W
44. Colossus of Rhodes
Greece
One of the seven wonders of the ancient world, the huge statue of the pre-Olympian sun god Helios stood at the entrance to the harbor of Rhodes on the Aegean island of the same name. The work of the celebrated sculptor Chares of Lindos, the giant figure, shown in some representations to be shielding his eyes as he looked out across the sea, towered 110 feet 33 meters above the entrance to the Mandraki harbor. According to Greek mythology, Helios was the son of the Titans Hyperion and Thea, and brother of Selene, goddess of the moon, and Eos, goddess of the dawn. He was worshiped throughout the Peloponnese, and the people of Rhodes held annual gymnastic games in his honor. The cast-bronze shell of the Colossus, reinforced and stabilized with an iron-and-stone framework, stood on a white marble base. It has been suggested that, in order to attach the upper parts of the monument, earth ramps and mounds were built. Work commenced around 294 b.c.although some sources put the date at ten years earlierand the statue took twelve years to complete. Its size is hard to comprehend, but some idea can be gained from Pliny the Elder, who wrote,Few people can make their arms meet round the thumb. From medieval times, artists romanticized impressions have shown the Colossus straddling the entrance to Mandraki harbor, towering over the ships that sailed between his feet. Given its height, the width of the harbor mouth, and the technology available to the builders, that construct is most improbable. The fact is that no one knows exactly what the statue looked like, nor where it stood. Recent scholarship suggests that it stood on the eastern promontory of the Mandraki, or perhaps a little inland. Rhodes was an important island in the ancient civilization of the Aegean. The Dorians inhabited it in the second millennium b.c., and their city-states of Lindos, Camiros, and Ialysos were vigorous commercial centers with colonies throughout the region. In the fifth century b.c., it belonged to the Delian League, a confederacy of city-states led by Athens, ties they severed in 412 b.c. Just four years later their own confederation was celebrated in the completion of the new city of Rhodes, said to have been designed by Hippodamos of Miletus it seems more likely that it was laid out according to Hippodamean principles. In 332 b.c. Rhodes came under the control of Alexander the Great, but following his death nine years later its citizens revolted and expelled the Macedonians. Rhodess power and wealth reached a zenith in the second and third centuries b.c., and it became a famous cultural center. One badge of that political unity and artistic eminence was the Colossus, built to commemorate the raising of the Antigonid Macedonian Demetrios Poliorcetes long siege 305 304 b.c.. The metal for the statue was taken from the siege machines abandoned by the invaders when they withdrew. It is said that the dedicatory inscription read,To you, O Sun, the people of Dorian Rhodes set up this bronze statue reaching to Olympus when they had pacified the waves of war and crowned their city with the spoils taken from the enemy. Not only over the seas but also on land did they kindle the lovely torch of freedom. A violent earthquake struck Rhodes about 225 b.c. The city was extensively damaged, and the Colossus, broken at the knee, crashed down. Ptolemy III of Egypt offered to meet the restoration costs, but when an oracle warned them against rebuilding, the Rhodians declined. It is ironic that the Colossus was actually lying in ruins when it was accorded a place among the wonders of the world. In a.d. 654 the Arabs invaded Rhodes, and two years later a Muslim dealersome sources say a Syrian Jewbought the fragments of the statue as scrap metal and carried them away to be melted down. Tradition has it that they were transported to Syria by a caravan of 900 camels. In December 1999 the Municipal Council of Rhodes announced an international design competition for a new Colossus. As the islands millennium project, the monument will encompassmodern artistic expression and technical construction that will surpass conventional standards [while borrowing] all the ancient symbolic values of the original. Expected to cost U.S.$2.8 million, it is, intended to be finished in time for the Athens Olympic Games in 2004.
One of the seven wonders of the ancient world, the huge statue of the pre-Olympian sun god Helios stood at the entrance to the harbor of Rhodes on the Aegean island of the same name. The work of the celebrated sculptor Chares of Lindos, the giant figure, shown in some representations to be shielding his eyes as he looked out across the sea, towered 110 feet 33 meters above the entrance to the Mandraki harbor. According to Greek mythology, Helios was the son of the Titans Hyperion and Thea, and brother of Selene, goddess of the moon, and Eos, goddess of the dawn. He was worshiped throughout the Peloponnese, and the people of Rhodes held annual gymnastic games in his honor. The cast-bronze shell of the Colossus, reinforced and stabilized with an iron-and-stone framework, stood on a white marble base. It has been suggested that, in order to attach the upper parts of the monument, earth ramps and mounds were built. Work commenced around 294 b.c.although some sources put the date at ten years earlierand the statue took twelve years to complete. Its size is hard to comprehend, but some idea can be gained from Pliny the Elder, who wrote,Few people can make their arms meet round the thumb. From medieval times, artists romanticized impressions have shown the Colossus straddling the entrance to Mandraki harbor, towering over the ships that sailed between his feet. Given its height, the width of the harbor mouth, and the technology available to the builders, that construct is most improbable. The fact is that no one knows exactly what the statue looked like, nor where it stood. Recent scholarship suggests that it stood on the eastern promontory of the Mandraki, or perhaps a little inland. Rhodes was an important island in the ancient civilization of the Aegean. The Dorians inhabited it in the second millennium b.c., and their city-states of Lindos, Camiros, and Ialysos were vigorous commercial centers with colonies throughout the region. In the fifth century b.c., it belonged to the Delian League, a confederacy of city-states led by Athens, ties they severed in 412 b.c. Just four years later their own confederation was celebrated in the completion of the new city of Rhodes, said to have been designed by Hippodamos of Miletus it seems more likely that it was laid out according to Hippodamean principles. In 332 b.c. Rhodes came under the control of Alexander the Great, but following his death nine years later its citizens revolted and expelled the Macedonians. Rhodess power and wealth reached a zenith in the second and third centuries b.c., and it became a famous cultural center. One badge of that political unity and artistic eminence was the Colossus, built to commemorate the raising of the Antigonid Macedonian Demetrios Poliorcetes long siege 305 304 b.c.. The metal for the statue was taken from the siege machines abandoned by the invaders when they withdrew. It is said that the dedicatory inscription read,To you, O Sun, the people of Dorian Rhodes set up this bronze statue reaching to Olympus when they had pacified the waves of war and crowned their city with the spoils taken from the enemy. Not only over the seas but also on land did they kindle the lovely torch of freedom. A violent earthquake struck Rhodes about 225 b.c. The city was extensively damaged, and the Colossus, broken at the knee, crashed down. Ptolemy III of Egypt offered to meet the restoration costs, but when an oracle warned them against rebuilding, the Rhodians declined. It is ironic that the Colossus was actually lying in ruins when it was accorded a place among the wonders of the world. In a.d. 654 the Arabs invaded Rhodes, and two years later a Muslim dealersome sources say a Syrian Jewbought the fragments of the statue as scrap metal and carried them away to be melted down. Tradition has it that they were transported to Syria by a caravan of 900 camels. In December 1999 the Municipal Council of Rhodes announced an international design competition for a new Colossus. As the islands millennium project, the monument will encompassmodern artistic expression and technical construction that will surpass conventional standards [while borrowing] all the ancient symbolic values of the original. Expected to cost U.S.$2.8 million, it is, intended to be finished in time for the Athens Olympic Games in 2004.
45. Confederation Bridge Prince Edward Island
Canada
The 8-mile-long 12.9-kilometer Confederation Bridge, which crosses the Northumberland Strait between Jourimain Island, New Brunswick, and Borden-Carleton on Prince Edward Island, is the longest bridge over ice-covered water in the world. Its daring conception, the quality of its engineering, and the logistics of its realization are among the factors that make it one of the great constructional feats of the twentieth century. The project is also environmentally, politically, and culturally significant. Prince Edward Island, on Canadas Atlantic coast, is the nations smallest province, with a population of around 130,000. It lies in the Gulf of St. Lawrence at an average of 15 miles 24 kilometers across the strait from mainland New Brunswick and Nova Scotia. The strait freezes for up to three months every year, and links with the island historically were expensive, freight and passengers having to be moved by ferry. In 1912 the Canadian government decided to build a railcar ferry to run between Borden-Carleton and Cape Tormentine, New Brunswick, and the Prince Edward Irland was commissioned in 1917. In the first year she made only 506 round-trips. In 1938, as a response to wider automobile ownership, a car deck was added, and the vessel continued to operate until 1969. The subsequent decades saw improvements to the service, and new ferries now make the seventy-five-minute crossing at hour-and-a-half intervals. Prince Edward Island has become a vacation resort and by the beginning of the 1990s tourism had joined commercial fishing and agriculture as a mainstay of its economy. Between 1982 and 1986 several consortia approached Public Works Canada PWC with proposals for a privately financed permanent link between the island and the mainland. Three were for bridges the first estimated at Can$640 million, one for a tunnel, and another for a combined causeway-tunnel-bridge link. In December 1986, the central government instructed PWC to commission feasibility studies of fixed-link alternatives. By June 1987 twelve expressions of interest were in hand, and the acceptance of Strait Crossings proposal was announced in December 1992. Strait Crossing Development SCD, a consortium of Janin Atlas, Ballast Nedam Canada, and Strait Crossing, was established to develop, finance, build, and operate the Confederation Bridge. The proposal, put before the island population in a plebiscite the following January, was generally supported, but lobster fishermen and conservationists raised concerns that led to protracted delays. Their conservation measures won for the contractors the Canadian Construction Associations 1994 Environmental Achievement Award. Working with the Canadian Wildlife Service, SCD provided nesting platforms for endangered osprey in Cape Jourimain National Wildlife Area. The consortium also initiated a Lobster Habitat Enhancement Program, using dredged material to establish new lobster grounds in three formerly nonproductive locations. Construction work commenced in mid-July 1995. The shore-to-shore Confederation Bridge consists of three parts. The 1,980-foot 0.6-kilometer east approach from Borden-Carleton and the 4,290-foot 1.3-kilometer west approach from Jourimain Island, New Brunswick, join the 6.9-mile 11-kilometer main bridge across the narrowest part of the Northumberland Strait. Its two-lane carriageway rises from 120 feet 40 meters to 180 feet 60 meters above the water at the central navigation span. The bridge takes about ten minutes to cross at the design speed of 50 mph 80 kph. Engineers designed for a 100-year life, taking into account the combined severe effects of wind, waves, and ice. In part, this was achieved by using concrete up to 60 percent stronger than normal in construction. The concrete employed in the 60-foot-diameter 20-meter ice shields, designed to break up the ice flow at the pier bases, was more than twice normal strength. Because climatic conditions limited on-site construction to six months of the year, the bridge was designed to be assembled in the summers from posttensioned concrete components precast during the winters. The parts of the approach bridges were cast at a staging facility in Bayfield, New Brunswick, transported by land or water to the site, and assembled by a twin launching truss with a traveling gantry crane. Another staging facility was set up in Borden-Carleton to precast the 175 main bridge components. Some weigh as much as 8,000 tons 8,128 tonnes the main box girders are 570 feet 190 meters long, yet designed to be joined with tolerances of less than 1 inch 2.54 centimeters. In August 1995 a purpose-built floating crane, the Svanen, began placing the components of the east approach bridge, completing it in November the west approach was built the following spring. The main bridge followed, and by August 1996 the navigation span was the last to be placed. On 19 November the structure was complete: sixty-five reinforced concrete piers, founded on bedrock, supported the 8-mile 12.9-kilometer superstructure which curves gracefully across Northumberland Strait. During the next six months, the finishing workthe polymer-modified asphalt cement road surface, traffic signals, emergency call boxes, weather monitoring equipment, closed-circuit television cameras, and toll boothswas carried out, and the bridge was opened on 31 May 1997. The estimated direct construction cost was Can$730 million.
The 8-mile-long 12.9-kilometer Confederation Bridge, which crosses the Northumberland Strait between Jourimain Island, New Brunswick, and Borden-Carleton on Prince Edward Island, is the longest bridge over ice-covered water in the world. Its daring conception, the quality of its engineering, and the logistics of its realization are among the factors that make it one of the great constructional feats of the twentieth century. The project is also environmentally, politically, and culturally significant. Prince Edward Island, on Canadas Atlantic coast, is the nations smallest province, with a population of around 130,000. It lies in the Gulf of St. Lawrence at an average of 15 miles 24 kilometers across the strait from mainland New Brunswick and Nova Scotia. The strait freezes for up to three months every year, and links with the island historically were expensive, freight and passengers having to be moved by ferry. In 1912 the Canadian government decided to build a railcar ferry to run between Borden-Carleton and Cape Tormentine, New Brunswick, and the Prince Edward Irland was commissioned in 1917. In the first year she made only 506 round-trips. In 1938, as a response to wider automobile ownership, a car deck was added, and the vessel continued to operate until 1969. The subsequent decades saw improvements to the service, and new ferries now make the seventy-five-minute crossing at hour-and-a-half intervals. Prince Edward Island has become a vacation resort and by the beginning of the 1990s tourism had joined commercial fishing and agriculture as a mainstay of its economy. Between 1982 and 1986 several consortia approached Public Works Canada PWC with proposals for a privately financed permanent link between the island and the mainland. Three were for bridges the first estimated at Can$640 million, one for a tunnel, and another for a combined causeway-tunnel-bridge link. In December 1986, the central government instructed PWC to commission feasibility studies of fixed-link alternatives. By June 1987 twelve expressions of interest were in hand, and the acceptance of Strait Crossings proposal was announced in December 1992. Strait Crossing Development SCD, a consortium of Janin Atlas, Ballast Nedam Canada, and Strait Crossing, was established to develop, finance, build, and operate the Confederation Bridge. The proposal, put before the island population in a plebiscite the following January, was generally supported, but lobster fishermen and conservationists raised concerns that led to protracted delays. Their conservation measures won for the contractors the Canadian Construction Associations 1994 Environmental Achievement Award. Working with the Canadian Wildlife Service, SCD provided nesting platforms for endangered osprey in Cape Jourimain National Wildlife Area. The consortium also initiated a Lobster Habitat Enhancement Program, using dredged material to establish new lobster grounds in three formerly nonproductive locations. Construction work commenced in mid-July 1995. The shore-to-shore Confederation Bridge consists of three parts. The 1,980-foot 0.6-kilometer east approach from Borden-Carleton and the 4,290-foot 1.3-kilometer west approach from Jourimain Island, New Brunswick, join the 6.9-mile 11-kilometer main bridge across the narrowest part of the Northumberland Strait. Its two-lane carriageway rises from 120 feet 40 meters to 180 feet 60 meters above the water at the central navigation span. The bridge takes about ten minutes to cross at the design speed of 50 mph 80 kph. Engineers designed for a 100-year life, taking into account the combined severe effects of wind, waves, and ice. In part, this was achieved by using concrete up to 60 percent stronger than normal in construction. The concrete employed in the 60-foot-diameter 20-meter ice shields, designed to break up the ice flow at the pier bases, was more than twice normal strength. Because climatic conditions limited on-site construction to six months of the year, the bridge was designed to be assembled in the summers from posttensioned concrete components precast during the winters. The parts of the approach bridges were cast at a staging facility in Bayfield, New Brunswick, transported by land or water to the site, and assembled by a twin launching truss with a traveling gantry crane. Another staging facility was set up in Borden-Carleton to precast the 175 main bridge components. Some weigh as much as 8,000 tons 8,128 tonnes the main box girders are 570 feet 190 meters long, yet designed to be joined with tolerances of less than 1 inch 2.54 centimeters. In August 1995 a purpose-built floating crane, the Svanen, began placing the components of the east approach bridge, completing it in November the west approach was built the following spring. The main bridge followed, and by August 1996 the navigation span was the last to be placed. On 19 November the structure was complete: sixty-five reinforced concrete piers, founded on bedrock, supported the 8-mile 12.9-kilometer superstructure which curves gracefully across Northumberland Strait. During the next six months, the finishing workthe polymer-modified asphalt cement road surface, traffic signals, emergency call boxes, weather monitoring equipment, closed-circuit television cameras, and toll boothswas carried out, and the bridge was opened on 31 May 1997. The estimated direct construction cost was Can$730 million.
46. Coop Himmelblau
Themaverick Viennese partnership Co
47. Crystal Palace
London, England
The Crystal Palace, a vast demountable building designed by Joseph Paxton for the Great Exhibition of 1851 in Hyde Park, London, was in many ways crucial in the development of architecture: it was the pinnacle of innovative metal structure, it revealed the exciting potential of efficient prefabrication, and it was an early demonstration of the modern doctrine that beauty can exist in the clear expression of materials and function. Altogether, it was one of the most noteworthy buildings of the nineteenth century. The idea for a Great Exhibition came from the Society for the Encouragement of Arts, Manufactures, and Commerce, and was given impetus by Henry Cole, then an assistant keeper in the Public Records Office. His wide interests extended to the publication of The Journal of Design that encouraged artists to design for industrialized mass production and urged manufacturers to employ them. That, he believed, would raise the quality of everyday articles. Cole was elected to the societys council in 1846, and the following year, with others, he successfully solicited Queen Victorias consort, Prince Albert of Saxe-Coburg-Gotha, to accept the role of its president. Under Royal Charter, and spurred by the success of French industrial expositions since 1844, the society held Exhibitions of Art Manufactures from 1847 through 1849 After visiting the exclusively French exhibition in Paris in 1849, Cole realized that an international show would inform British industry of progress and commercial competition elsewhere in the world. Prince Albert, convinced thatthat great end to which all history pointsthe realization of the unity of mankind was imminent, caught the vision. The Royal Commission for the Exhibition of 1851 was established to expedite a self-financinglarge [exhibition] embracing foreign productions. It was envisioned asa new starting-point from which all nations will be able to direct their further exertions, but it was at the same time an expression of British nationalism. Britain had led the world into the Industrial Revolution, and her outlook was smug, to say the least. The Great Exhibition would provide a vehicle to flaunt her industrial, military, and economic superiority and justify her colonialism. The show was to have a display area of 700,000 square feet 66,000 square meters, much bigger than anything the French had managed. That was too large even for the intended venue in the courtyard of Somerset House, so it was decided to locate it in Hyde Park. An open competition for the design of a building for theGreat Exhibition of the Works of All Nations attracted 245 entries from 233 architects, including 38 from abroad. The Commissioners Building Committee liked none of them besides, it was unlikely that any could have been completed on time. Having prepared its own plan for a large dome standing on a brick drum, the committee called for bids. The result was alarming: building materials alone would have devoured at least half of the available funds of
The Crystal Palace, a vast demountable building designed by Joseph Paxton for the Great Exhibition of 1851 in Hyde Park, London, was in many ways crucial in the development of architecture: it was the pinnacle of innovative metal structure, it revealed the exciting potential of efficient prefabrication, and it was an early demonstration of the modern doctrine that beauty can exist in the clear expression of materials and function. Altogether, it was one of the most noteworthy buildings of the nineteenth century. The idea for a Great Exhibition came from the Society for the Encouragement of Arts, Manufactures, and Commerce, and was given impetus by Henry Cole, then an assistant keeper in the Public Records Office. His wide interests extended to the publication of The Journal of Design that encouraged artists to design for industrialized mass production and urged manufacturers to employ them. That, he believed, would raise the quality of everyday articles. Cole was elected to the societys council in 1846, and the following year, with others, he successfully solicited Queen Victorias consort, Prince Albert of Saxe-Coburg-Gotha, to accept the role of its president. Under Royal Charter, and spurred by the success of French industrial expositions since 1844, the society held Exhibitions of Art Manufactures from 1847 through 1849 After visiting the exclusively French exhibition in Paris in 1849, Cole realized that an international show would inform British industry of progress and commercial competition elsewhere in the world. Prince Albert, convinced thatthat great end to which all history pointsthe realization of the unity of mankind was imminent, caught the vision. The Royal Commission for the Exhibition of 1851 was established to expedite a self-financinglarge [exhibition] embracing foreign productions. It was envisioned asa new starting-point from which all nations will be able to direct their further exertions, but it was at the same time an expression of British nationalism. Britain had led the world into the Industrial Revolution, and her outlook was smug, to say the least. The Great Exhibition would provide a vehicle to flaunt her industrial, military, and economic superiority and justify her colonialism. The show was to have a display area of 700,000 square feet 66,000 square meters, much bigger than anything the French had managed. That was too large even for the intended venue in the courtyard of Somerset House, so it was decided to locate it in Hyde Park. An open competition for the design of a building for theGreat Exhibition of the Works of All Nations attracted 245 entries from 233 architects, including 38 from abroad. The Commissioners Building Committee liked none of them besides, it was unlikely that any could have been completed on time. Having prepared its own plan for a large dome standing on a brick drum, the committee called for bids. The result was alarming: building materials alone would have devoured at least half of the available funds of
48. Curtain walls
Traditionally, the wall of a building served both structural and environmental purposes. That is, it carried to the ground the weight of the building and its contents and, while admitting air and light through openings, protected the interior from extremes of weather, noise, and other undesirable intrusions. The introduction of structures in which the loads are carried by beams and columns liberated the wall from load bearing, allowing it to function solely as an environmental filtera relatively thin, light curtain, so to speak. This was first seen in the later medieval cathedrals with their vast stained-glass windows, but it would not be widely developed until the nineteenth century, with the advent of metal-framed architecture and, subsequently, reinforced concrete. The metal-and-glass membrane supported by the building frame, known as the curtain wall, is principally associated with multistory office buildings after about 1880.
Although the first skyscrapers, such as the Rookery 1885 1886 and Monadnock Building 1889 1891, both in Chicago and both designed by architects Burnham and Root, had thick conventional load-bearing walls, the twin economic necessities of getting buildings up quickly and optimizing the quantity and quality of interior space soon led to buildings whose outer walls consisted almost entirely of windows supported by perimeter columns and beams. This was a first step toward the development of a true curtain wall, that is, a continuous wall in front of the structural frame. The earliest example was Albert Kahns Packard Motor Car Forge Shop in Detroit 1905. A curtain of glass in steel frames allowed more space
and light in the factory, just as it would in an office tower, and Kahn again employed it for the Brown-Lipe-Chapin gear factory 1908 and the T-model Ford assembly plant in Highland Park, Michigan 1908 1909. This rational industrial architecture drew the admiration of Europe and was emulated in Peter Behrenss A. E. G. Turbine Factory 1909 1910 in Berlin and Gropius and Meyers Fagus Works in Alfeld-an-der-Leine, Germany, of 1911.
It is widely accepted that the first office block with a curtain wall was Willis Jefferson Polks eight-story Hallidie Building 1917 1918 in San Francisco. Although it was cluttered in places with florid cast-iron ornament, the street facade, suspended 3 feet 3 inches 1 meter in front of the structure by brackets fixed to cantilevered floor slabs, presented an unbroken skin of glass. Elsewhere, others dreamed of crystal prisms in which the buildings whole external membrane was glass: the serried towers of H. Th. Wijdevelds Amsterdam 2000 1919 1920 and Le Corbusiers Ville Contemporaine 1922 andprobably best knownthe skyscrapers Ludwig Mies van der Rohe projected between 1919 and 1923. But dreams and visions they remained, because the technology was not yet available to turn them to reality. One exception was the A. O. Smith Research Building in Milwaukee 1928 1930 by Holabird and Root, the first multistory structure with a full curtain wall rather than a single facade of large sheets of plate glass supported on aluminum frames.
Spin-offs from defense technologies after World War II paved the way for tall curtain wall buildings. Important among them was cost reduction in the production of aluminum, whose corrosion resistance could be improved by a process known as anodizing. This lightweight metal could be extruded into the complicated profiles needed to frame the glass and strengthen the wall against wind loads. Reliable cold-setting synthetic rubber sealants had also become more widely available. These advances were combined with more efficient sheet glass manufacture, especially polished cast glass and, after 1952, the much flatter float glass. Wall elements could be fabricated off-site to exacting tolerances and then transported, assembled, fixed, and glazed with none of thewet processes that impede building contracts. Relevant engineering developments included reverse-cycle air-conditioningavailable since 1928and fluorescent lighting, first demonstrated at the 1938 Chicago Worlds Fair. All these technologies were exploited in Pietro Belluschis twelve-story Equitable Building in Portland, Oregon 1944 1948, described by one historian asan ethereal tower of sea green glass and aluminum. Another writer asserts that itset styles for hundreds that came after.
The thirty-nine-story United Nations Secretariat Building in New York City followed in 1947 1952. The final design was developed from a proposal by Le Corbusier, and Wallace Harrison acted as executive architect in consultation with him. The curtain walls of the Secretariat Buildings east and west facades are all glass, cantilevered 27 inches 80 centimeters from the line of the perimeter columns black-painted glass spandrels hide the between-floor spaces. The blue-green tinted windows are ofThermopane, a special glass that absorbs radiant heat, preventing it from reaching the interior, thus reducing the load on the air-conditioning system. The only breaks in the sheer curtain wall are full-width air-conditioning intake grilles at four levels. Because of its innovation, and no doubt because of its associations, the U.N. Secretariat, together with Mies van der Rohes Lake Shore Drive Apartments 1951 in Chicago and Skidmore, Owings, and Merrills Lever House 1952 on Park Avenue, New York, contributed to the universal standard for high-rise buildings.
The latter building, a twenty-four-story, green-tinted glass and stainless steel tower, designed by Gordon Bunshaft, marked a change of direction in American corporate architecture and in the way New Yorkers built. In keeping with the wishes of a client who made household cleaning products, Bunshaft produced an immaculate, clean-lined tower. The architectural critic Lewis Mumford called itan impeccable achievement. The top three floors are reserved for mechanical services. A mobile gantry carries a window cleaners platform that serves all faces of the building such devices became standard for the curtain wall office buildings that followed. Lever House was the first skyscraper to exploit the allowable plot ratios in city planning regulations. By
occupying only a quarter of the site, it allowed much more natural light to enter the offices than conventional stepped-back skyscrapers that covered the whole allotment. Lever House is a New York historic landmark, and in November 1999 a $10.7 million contract was let to renovate its curtain walls, designed by Skidmore, Owings, and Merrill under the supervision of the New York City Historical Society.
That leads us to the inherent problems in curtain wall construction, for all of its advantages. In forty-five years, the pristine facades failed in a number of wayswater penetration and consequent damage, corrosion, and broken glass panels. Since their inception, curtain wall systems have been continually revised, most changes geared toward reducing weight while retaining strength. Stiffened sheet aluminum, enameled steel laminated with insulation, and later even thin sheets of stone were used for spandrel panels. The design of jointsproblem spots for leakswas improved and more durable sealants were invented. More recently, the availability of reliable adhesives has allowed architects to indulge in so-calledfish tank joints between glass panels, doing away with framing bars. Glass technology has also been refined. Double glazing, first manufactured in the 1940s, improves both the sound and thermal insulation of curtain walls. Heat-absorbing glass, already available in the 1950s, evolved in the following decade into reflective glass with thin metallic coatings, also used to reduce heat gain within buildings. In 1984 heat mirror glass was developed when combined with double glazing, its insulating value approaches that of masonry, but the esthetic effect seems to be a denial of the form of the building: all it does is reflect whats around it.
Given that the two significant advantages of curtain wall construction are the reduction of weight and speed of erection, it might be concluded that it costs less than conventional work. That is not necessarily true, because its behavior as an environmental filter, especially in relation to heat flow, may result in higher air-conditioning costs. Often, the preciousness of the architects detailing increases costs, as evidenced by Mies van der Rohes bronze-and-brown-glass Seagram Building 1954 1958 in New York City. It cost $36 million, approximately twice as much as office towers normally did.
The tall glass prism was the major contribution of the United States to the so-called International Style of modern architecture. But its glorious day passed with the rise of postmodernism, and the crystal towers that Frank Lloyd Wright dismissed asglass boxes on stilts were replaced with less anonymous designs. Even Philip Johnson, Mies van der Rohes most ardent disciple, forsook the minimalist forms of curtain-wall architecture in favor of a more congenial architecture.
49. De Re Aedificatora
Leon Battista Albertis theoretical treatise on architecture, titled De Re Aedificatoria About Buildings, was dedicated in 1452 but not published until 1485. What qualifies it as an architectural feat? It changed the understanding and practice of architecture in much of Europe and continued to influence developments there and in the New World for about 400 years. Although he was gathering the ideas for the book, Alberti 1404 1472 was not an architect but a Catholic priest.
Alberti was born in Genoa, the illegitimate child of Lorenzo, an exiled Florentine from a family of bankers. When he was about ten years old, Battista he addedLeon later entered a boarding school in Padua to receive a basic classical education. Several years of legal studies at the University of Bologna led to a doctorate in church law in 1428, after which he went to Florence. He soon began writing. His first published anthology of poems, Il cavallo The Horse of 1431, was quickly followed by Della famiglia About the Familythe first of many philosophical dialoguesand La tranquillit
50. De Stijl
Founded in Leiden, the Netherlands, in 1916, the group known as De Stijl was Europes most important theoretical movement in art and architecture until the mid-1920s, when leadership passed to Germany.
In 1916 the architect J. J. P. Oud met the critic and painter Theo van Doesburg and soon introduced him to another young architect, Jan Wils. First forming De Sphinx artists club in Leiden, the three founded, with the railwayman-philosopher Anthony Kok and the painters Piet Mondrian, Bart van der Leck, and expatriate Hungarian Vilmos Husz
