In architecture, a hall is a large space enclosed by a roof and walls. In the Iron Age and early Middle Ages in northern Europe, a mead hall was where a lord and his retainers ate and slept. In the Middle Ages, the great hall was the largest room in castles and large houses, where the servants slept; as more complex house plans developed, the hall remained a large room for dancing and large feasts still with servants sleeping there. It was immediately inside the main door. In modern British houses, an entrance hall next to the front door remains an indispensable feature if it is merely a corridor. Today, the hall of a house is the space next to the front door or vestibule leading to the rooms directly and/or indirectly. Where the hall inside the front door of a house is elongated, it may be called a passage, corridor or hallway. In warmer climates the houses of the wealthy were built around a courtyard, but in northern areas manors were built around a great hall; the hall was home to the hearth, was where all the residents of the house would eat and sleep.
One common example of this form is the longhouse. Only messy tasks would be done in separate rooms on the periphery of the hall. Still today the term hall is used to designate a country house such as a hall house, or a Wealden hall house, manor houses. In medieval Europe, the main room of a castle or manor house was the great hall. In a medieval building, the hall was; as heating technology improved and a desire for privacy grew, tasks moved from the hall to other rooms. First the master of the house withdrew to eating areas. Over time servants and children moved to their own areas, while work projects were given their own chambers leaving the hall for special functions. With time, its functions as dormitory, parlour and so on were divided off to separate rooms or, in the case of the kitchen, a separate building; until the early modern era that majority of the population lived in houses with a single room. In the 17th century lower classes began to have a second room, with the main chamber being the hall and the secondary room the parlor.
The hall and parlor house was found in England and was a fundamental, historical floor plan in parts of the United States from 1620 to 1860. In Europe as the wealthy embraced multiple rooms the common form was the enfilade, with rooms directly connecting to each other. In 1597 John Thorpe is the first recorded architect to replace multiple connected rooms with a rooms along a corridor each accessed by a separate door. Many buildings at colleges and universities are formally titled "_______ Hall" being named after the person who endowed it, for example, King's Hall, Cambridge. Others, such as Lady Margaret Hall, commemorate respected people. Between these in age, Nassau Hall at Princeton University began as the single building of the college. In medieval origin, these were the halls in which the members of the university lived together during term time. In many cases, some aspect of this community remains. At colleges in the universities of Oxford and Cambridge, Hall is the dining hall for students, with High Table at one end for fellows.
At "Formal Hall", gowns are worn for dinner during the evening, whereas for "informal Hall" they are not. The medieval collegiate dining hall, with a dais for the high table at the upper end and a screen passage at the lower end, is a modified or assimilated form of the Great hall. A hall is a building consisting of a principal room, rented out for meetings and social affairs, it may be or government-owned, such as a function hall owned by one company used for weddings and cotillions or a community hall available for rent to anyone, such as a British village hall. In religious architecture, as in Islamic architecture, the prayer hall is a large room dedicated to the practice of the worship.. A hall church is a church with nave and side aisles of equal height. Many churches have an associated church hall used for other events. Following a line of similar development, in office buildings and larger buildings, the entrance hall is known as the foyer; the atrium, a name sometimes used in public buildings for the entrance hall, was the central courtyard of a Roman house.
In architecture, the term "double-loaded" describes corridors. Conversely, a single-loaded corridor only has rooms on one side. A blind corridor doesn't lead anywhere. Billiard hall City hall, town hall or village hall Concert hall Concourse Convention center Dance hall Dining hall Firehall Great room or great hall Moot hall Prayer hall, such as the sanctuary of a synagogue Reading room Residence hall Waiting room Hall of fame The dictionary definition of hall at Wiktionary Media related to Halls at Wikimedia Commons
Louis Philippe I
Louis Philippe I was King of the French from 1830 to 1848. His father Louis Philippe II, Duke of Orléans had taken the name "Philippe Égalité" because he supported the French Revolution. However, following the deposition and execution of his cousin King Louis XVI, Louis Philippe fled the country, his father denounced his actions and voted for his death, but was imprisoned and executed that same year. Louis Philippe spent the next 21 years in exile before returning during the Bourbon Restoration, he was proclaimed king in 1830 after his cousin Charles X was forced to abdicate by the July Revolution. The reign of Louis Philippe is known as the July Monarchy and was dominated by wealthy industrialists and bankers, he followed conservative policies under the influence of French statesman François Guizot during the period 1840–48. He promoted friendship with Britain and sponsored colonial expansion, notably the French conquest of Algeria, his popularity faded as economic conditions in France deteriorated in 1847, he was forced to abdicate after the outbreak of the French Revolution of 1848.
He lived out his life in exile in the United Kingdom. His supporters were known as Orléanists, as opposed to Legitimists who supported the main line of the House of Bourbon. Louis Philippe was born in the Palais Royal, the residence of the Orléans family in Paris, to Louis Philippe, Duke of Chartres, Louise Marie Adélaïde de Bourbon; as a member of the reigning House of Bourbon, he was a Prince of the Blood, which entitled him the use of the style "Serene Highness". His mother was an wealthy heiress, descended from Louis XIV of France through a legitimized line. Louis Philippe was the eldest of three sons and a daughter, a family, to have erratic fortunes from the beginning of the French Revolution to the Bourbon Restoration; the elder branch of the House of Bourbon, to which the kings of France belonged distrusted the intentions of the cadet branch, which would succeed to the throne of France should the senior branch die out. Louis Philippe's father was exiled from the royal court, the Orléans confined themselves to studies of the literature and sciences emerging from the Enlightenment.
Louis Philippe was tutored by the Countess of Genlis, beginning in 1782. She instilled in him a fondness for liberal thought; when Louis Philippe's grandfather died in 1785, his father succeeded him as Duke of Orléans and Louis Philippe succeeded his father as Duke of Chartres. In 1788, with the Revolution looming, the young Louis Philippe showed his liberal sympathies when he helped break down the door of a prison cell in Mont Saint-Michel, during a visit there with the Countess of Genlis. From October 1788 to October 1789, the Palais Royal was a meeting-place for the revolutionaries. Louis Philippe grew up in a period that changed Europe as a whole and, following his father's strong support for the Revolution, he involved himself in those changes. In his diary, he reports that he himself took the initiative to join the Jacobin Club, a move that his father supported. In June 1791, Louis Philippe got his first opportunity to become involved in the affairs of France. In 1785, he had been given the hereditary appointment of Colonel of the Chartres Dragoons.
With war imminent in 1791, all proprietary colonels were ordered to join their regiments. Louis Philippe showed himself to be a model officer, he demonstrated his personal bravery in two famous instances. First, three days after Louis XVI's flight to Varennes, a quarrel between two local priests and one of the new constitutional vicars became heated, a crowd surrounded the inn where the priests were staying, demanding blood; the young colonel broke through the crowd and extricated the two priests, who fled. At a river crossing on the same day, another crowd threatened to harm the priests. Louis Philippe put himself between a peasant armed with a carbine and the priests, saving their lives; the next day, Louis Philippe dove into a river to save a drowning local engineer. For this action, he received a civic crown from the local municipality, his regiment was moved north to Flanders at the end of 1791 after the August 27, 1791 Declaration of Pillnitz. Louis Philippe served under his father's crony, Armand Louis de Gontaut the Duke of Biron, along with several officers who gained distinction in Napoleon's empire and afterwards.
These included Lieutenant Colonel Alexandre de Beauharnais. After war was declared by the Kingdom of France on the Habsburg Monarchy on April 20, 1792, Louis Philippe saw his first exchanges of fire of the French Revolutionary Wars within the invaded by France Austrian Netherlands at Boussu, Walloon, on about April 28, 1792, at Quaregnon, Walloon, on about April 29, 1792, at Quiévrain, near Jemappes, Walloon, on about April 30, 1792, where he was instrumental in rallying a unit of retreating soldiers after the victorious Battle of Quiévrain only two days earlier on April 28th of 1792. Biron wrote to War Minister de Grave, praising the young colonel, promoted to brigadier, commanding a brigade of cavalry in Lückner's Army of the North. In the Army of the North, Louis Philippe served with four future Marshals of France: Macdonald, Mortier and Oudinot. Dumouriez was appointed to command the Army of the North in August 1792. Louis Philippe commanded a division under him in the Valmy campaign. At the September 20, 1792 Battle of Va
Daylighting is the practice of placing windows, other openings, reflective surfaces so that sunlight can provide effective internal lighting. Particular attention is given to daylighting while designing a building when the aim is to maximize visual comfort or to reduce energy use. Energy savings can be achieved from the reduced use of artificial lighting or from passive solar heating. Artificial lighting energy use can be reduced by installing fewer electric lights where daylight is present or by automatically dimming/switching off electric lights in response to the presence of daylight – a process known as daylight harvesting; the amount of daylight received in an internal space can be analyzed by measuring illuminance on a grid or undertaking a daylight factor calculation. Computer programs such as Radiance allow an architect or engineer to calculate benefits of a particular design; the human eye's response to light is non-linear, so a more distribution of the same amount of light makes a room appear brighter.
The source of all daylight is the Sun. The proportion of direct to diffuse light impacts the quality of daylight. "Direct sunlight" reaches a site without being scattered within Earth's atmosphere. Light, scattered in the atmosphere is diffused daylight. Ground reflected light contributes to the daylight; each climate has different composition of these daylights and different cloud coverage, so daylighting strategies vary with site locations and climates. There is no direct sunlight on the polar-side wall of a building from the autumnal equinox to the spring equinox at latitudes north of the Tropic of Cancer and south of the Tropic of Capricorn. Traditionally, houses were designed with minimal windows on the polar side, but more and larger windows on the equatorial-side. Equatorial-side windows receive at least some direct sunlight on any sunny day of the year, so they are effective at daylighting areas of the house adjacent to the windows. In higher latitudes during midwinter, light incidence is directional and casts long shadows.
This may be ameliorated through light diffusion, light pipes or tubes, through somewhat reflective internal surfaces. In low latitudes in summertime, windows that face east and west and sometimes those that face toward the pole receive more sunlight than windows facing toward the equator. Windows are the most common way to admit daylight into a space, their vertical orientation means that they selectively admit sunlight and diffuse daylight at different times of the day and year. Therefore, windows on multiple orientations must be combined to produce the right mix of light for the building, depending on the climate and latitude. There are three ways to improve the amount of light available from a window: placing the window close to a light colored wall, slanting the sides of window openings so the inner opening is larger than the outer opening, or using a large light colored window-sill to project light into the room. Different types and grades of glass and different window treatments can affect the amount of light transmission through the windows.
The type of glazing is an important issue, expressed by its VT coefficient known as visual light transmittance. As the name suggests, this coefficient measures. A low VT can reduce by half or more the light coming into a room, but be aware of high VT glass: high VT numbers can be a cause of glare. On the other hand, you should take into account the undesirable effects of large windows. Windows grade into translucent walls. Another important element in creating daylighting is the use of clerestory windows; these are high, vertically placed windows. They can be used to increase direct solar gain; when facing toward the sun and other windows may admit unacceptable glare. In the case of a passive solar house, clerestories may provide a direct light path to polar-side rooms that otherwise would not be illuminated. Alternatively, clerestories can be used to admit diffuse daylight that evenly illuminates a space such as a classroom or office. Clerestory windows shine onto interior wall surfaces painted white or another light color.
These walls are placed so as to reflect indirect light to interior areas. This method has the advantage of reducing the directionality of light to make it softer and more diffuse, reducing shadows. Another roof-angled glass alternative is a sawtooth roof. Sawtooth roofs have vertical roof glass facing away from the equator side of the building to capture diffused light; the angled portion of the glass-support structure is opaque and well insulated with a cool roof and radiant barrier. The sawtooth roof's lighting concept reduces the summer "solar furnace" skylight problem, but still allows warm interior air to rise and touch the exterior roof glass in the cold winter, with significant undesirable heat transfer. Skylights are light transmitting fenestration forming all, or a portion of, the roof of a building space. Skylights are used in daylighting design in residential and commercial buildings because they are the mos
Glass production involves two main methods – the float glass process that produces sheet glass, glassblowing that produces bottles and other containers. Broadly, modern glass container factories are three-part operations: the batch house, the hot end, the cold end; the batch house handles the raw materials. The following table lists common viscosity fixpoints, applicable to large-scale glass production and experimental glass melting in the laboratory: Batch processing is one of the initial steps of the glass-making process; the batch house houses the raw materials in large silos and holds anywhere from 1–5 days of material. Some batch systems include material processing such as raw material screening/sieve, drying, or pre-heating. Whether automated or manual, the batch house measures, assembles and delivers the glass raw material recipe via an array of chutes and scales to the furnace; the batch enters the furnace at the'dog house' or'batch charger'. Different glass types, desired quality, raw material purity / availability, furnace design will affect the batch recipe.
The hot end of a glassworks is where the molten glass is formed into glass products, beginning when the batch is fed into the furnace at a slow, controlled rate by the batch processing system. The furnaces are natural gas- or fuel oil-fired, operate at temperatures up to 1,575 °C; the temperature is limited only by the quality of the furnace’s superstructure material and by the glass composition. Types of furnaces used in container glass making include'end-port','side-port', and'oxy-fuel'. Furnace "size" is classified by metric tons per day production capability. There are two primary methods of making glass containers: the blow & blow method for narrow-neck containers only, the press & blow method used for jars and tapered narrow-neck containers. Figure 1: Steps during Blow&Blow container forming process In both methods, a stream of molten glass, at its plastic temperature, is cut with a shearing blade to form a solid cylinder of glass, called a gob; the gob is of predetermined weight just sufficient to make a bottle.
Both processes start with the gob falling, by gravity, guided, through troughs and chutes, into the blank moulds, two halves of which are clamped shut and sealed by the "baffle" from above. In the blow and blow process, the glass is first blown through a valve in the baffle, forcing it down into the three-piece "ring mould", held in the "neckring arm" below the blanks, to form the "finish", The compressed air is blown through the glass, which results in hollow and formed container. Compressed air is blown again at the second stage to give final shape. Containers are made in two major stages; the first stage moulds all the details around the opening, but the body of the container is made much smaller than its final size. These manufactured containers are called parisons, quite they are blow-molded into final shape. Referring to the mechanism, the "rings" are sealed from below by a short plunger. After the "settleblow" finishes, the plunger retracts to allow the skin that's formed to soften. "Counterblow" air comes up through the plunger, to create the parison.
The baffle rises and the blanks open. The parison is inverted in an arc to the "mould side" by the "neckring arm", which holds the parison by the "finish"; as the neckring arm reaches the end of its arc, two mould halves close around the parison. The neckring arm opens to release its grip on the "finish" reverts to the blank side. Final blow, applied through the "blowhead", blows the glass out, expanding into the mould, to make the final container shape. In the press and blow process, the parison is formed by a long metal plunger which rises up and presses the glass out, in order to fill the ring and blank moulds; the process continues as before, with the parison being transferred to the final-shape mould, the glass being blown out into the mould. The container is picked up from the mould by the "take-out" mechanism, held over the "deadplate", where air cooling helps cool down the still-soft glass; the bottles are swept onto a conveyor by the "push out paddles" that have air pockets to keep the bottles standing after landing on the "deadplate".
The forming machines move the parts that form the container. The machine consist of basic 19 mechanisms in operation to form a bottle and powered by compressed air, the mechanisms are electronically timed to coordinate all movements of the mechanisms; the most used forming machine arrangement is the individual section machine. This machine has a bank of 5–20 identical sections, each of which contains one complete set of mechanisms to make containers; the sections are in a row, the gobs feed into each section via a moving chute, called the gob distributor. Sections make either one, three or four containers simultaneously.. In the case of multiple gobs, the shears cut the gobs and they fall into the blank moulds in parallel. After the forming process, some containers—particularly those intended for alcoholic spirits—undergo a treatment t
Pavement lights, vault lights, floor lights, or sidewalk prisms are flat-topped walk-on skylights set into pavement or floors to let sunlight into the space below. They use anidolic lighting prisms to throw the light sideways under the building, they declined in popularity with the advent of cheap electric lighting. Some cities are systematically removing historic sidewalk lights. Pavement lights have been used in a few new architectural designs. Sidewalk prisms are a method of daylighting basements, are able to serve as a sole source of illumination during the day. At night, lighting in the basements beneath produces a glowing sidewalk. Vault lights may be used to make subterranean space useful, they are more common in city centers, high-rent areas where space is valuable. Landlords took an interest in improving not only the floor area ratio, but the amount of space, lit, on the grounds that this was profitable. Occupiers valued daylight not only as a way of saving on artificial lighting costs, but as a way to let premises remain cooler in summer, a way to save on ventilation costs.
Pavement lights and related products were marketed as a way of saving on artificial lighting costs and making space more usable and pleasant. Modern studies of similar daylighting technology provide evidence for those claims. Vault lights are used in floors under glass roofs, for example in Budapest's historic Párizsi udvar and New York's mostly-demolished old Pennsylvania Station. Vault lights could be set into the basement floor, underneath other vault lights, creating a double-deck arrangement, which would light the subbasement. Manhole covers and coalhole covers with lighting elements were made; some steps have vault lights set into the vertical stair risers. Older cities and smaller centers around the world have had pavement lights. Most such lights are a century old, although lights are being installed in some new construction. A basement that extends below a sidewalk or pavement is called an areaway, a sidewalk vault, or a hollow sidewalk. In some cities, these areaways were created by the raising of the street level to combat floods, in some cases they form an underground tunnel network.
To light these spaces, sidewalks incorporated gratings, which were a trip hazard and let water and street dirt as well as light into the basement. Replacing the open gratings with glass was an obvious improvement. Sidewalk prisms developed from deck prisms; the earliest pavement light used a single large round glass lens set in an iron frame. The large lens was directly exposed to traffic, if the lens broke, a large hole was left in the pavement, unsafe for pedestrians. Thaddeus Hyatt corrected these faults with his "Hyatt light" of 1854. Many small lenses were set in a wrought-iron frame, the frame included raised nubs around each lens to improve traction in wet weather and to protect them from damage and wear. If all the lenses were broken out, the panel would still be safe to walk on. In the 1930s, London authorities ruled that glass sections could not be larger than 100 mm by 100 mm. Modern glass floors are made of laminated and toughened glass pavers, which can be larger, they have an upper protective layer that can be replaced if it becomes cracked.
The top surface of the pavers may be chosen and treated to improve traction. Wrought iron, cast iron, stainless steel frames have all been used. Reinforced concrete slabs began to replace iron frames in the 1890s in New York. Benefits claimed included a less slippery surface when wet. Concrete panels may be cast in-situ. Late concrete panels were made with metal-framed "armored prisms", which were intended to prevent breakage and make replacing individual prisms easier; the glass is not caulked into the frame. Rather than chiselling out the old glass, the glass can be popped out of the frame. Translucent concrete has been proposed as a floor material; this would make it a vault light with small lighting elements. It innately redirects the light from the angle of incidence to an angle ~parallel to the optical fibers; the transparent elements may be referred to as lenses, or as jewels. The glass in many old pavement lights is now either straw-colored; this is a side-effect of the manufacturing process.
Pure silica glass is transparent, but older glass manufacture used silica from sand, which contains iron and other impurities. Iron produces a greenish tint in the finished glass. To remove this effect, a "decolorizer" such as manganese dioxide was added during the manufacture of the glass; when exposed to ultraviolet light, the manganese "solarizes", turning purple, why many existing sidewalk prisms are now purple. WWI increased demand for manganese in the US and cut off the supply of high-grade ore from Germany, so selenium dioxide was used as a decolorizer instead. Selenium solarizes, but to a straw color. Replacement glass, tinted purple deliberately, in order to match the current colour, has been used in some historic restoration projects. In 1871 London, Hayward Brothers patented th
A roof lantern is a daylighting architectural element. Architectural lanterns are atop a larger roof and provide natural light into the space or room below. In contemporary use it is an architectural skylight structure; the term'roof top lantern' is used to describe the lighted decorative lanterns atop taxi cabs in Japan, designed to reflect the cultural heritage of Japanese paper lanterns. The glazed lantern was developed during the Middle Ages. Roof lanterns of masonry and glass were used in Renaissance architecture, such as in principal cathedrals. In 16th-century France and Italy, they began usage in orangeries, an early form of a conservatory structure with tall windows and a glazed roof section for wintering citrus trees and other plants in non-temperate climates. Post-Renaissance roof lanterns were made of timber and glass and were prone to leaking. Wood-framed in the 18th and 19th centuries, skylights became more popular in metal construction with the advent of sheet-metal shops during the Victorian era.
Every urban row house of the late-19th and early-20th centuries relied upon a metal-framed skylight to illuminate its enclosed stairwell. More elaborate dwellings of the era showed a fondness for the Roof Lantern, in which the humble ceiling-window design of the skylight is elaborated into a miniature glass-paneled conservatory-style roof cupola or tower. Modern lanterns benefit from advances in glazing and sealing techniques, plus the development of high performance insulated glass and sealants, which reduce energy loss and provide water-tightness in the same manner as conventional skylights. Roof lanterns are constructed using wood, UPVC or aluminium, or a combination of those materials, they serve as an architectural feature, distinguished from commercial manufactured skylights by their custom design, providing unique views to the outdoors. Traditional architectural styles characterise most roof lanterns in the UK. In the U. S. where the term'custom' skylight is used, modern styles of roof lanterns are common in the building vernacular.
Conservatory Cupola Daylighting Passive daylighting Britannica Online Encyclopedia: Lantern
A retractable roof is a roof system designed to roll back the roof on tracks so that the interior of the facility is open to the outdoors. Retractable roofs are sometimes referred to as operable roofs or retractable skylights; the term operable skylight, while quite similar, refers to a skylight that opens on a hinge, rather than on a track. Retractable roofs are used in residences and bars, swim centres, other facilities wishing to provide an open-air experience at the push of a button; the United States Patent and Trademark Office records show that David S. Miller, founder of Rollamatic Retractable Roofs, filed U. S. Patent 3,277,619 in August 1963 for a movable and remotely controllable roof section for houses and other types of buildings; as Rollamatic was founded five years earlier, the first installation of a motorized retractable roof must be between 1958 and 1963. While any shape is possible, common shapes are flat, hip-ridge and dome. A residence might incorporate one or more 3' by 5' retractables.
Stadium retractable roofs are used in locales where inclement weather, extreme heat, or extreme cold are prevalent during the respective sports seasons, in order to allow for playing of traditionally outdoor sports in more favorable conditions, as well as the comfort of spectators watching games played in such weather. Unlike their predecessors, the domes built during the 1960s, 1970s, early 1980s, retractable roofs allow for playing of the same traditionally outdoor sports in outdoor conditions when the weather is more favorable. Another purpose of retractable roofs is to allow for growth of natural grass playing fields in environments where extreme hot and/or cold temperatures would otherwise make installation and maintenance of such a field cost prohibitive. Installations throughout the world employ a variety of different styles; the first retractable roof sports venue was the now-demolished Civic Arena in Pittsburgh, United States. Constructed in 1961 for the Pittsburgh Civic Light Opera, the arena was home to minor-league and NCAA D-1 basketball and ice hockey teams before becoming the home of the NHL's Pittsburgh Penguins in 1967, as well as hosting over a dozen regular season NBA games in the 1960s and 1970s.
The arena's dome-shaped roof covered 170,000 square feet and was made up of eight equal segments constructed from close to 3,000 tons of steel, in which six segments could retract underneath the remaining two, supported by a 260-foot long exterior cantilevered arm. Olympic Stadium in Montreal, Quebec was slated to be the first outdoor retractable roof stadium at its debut for the 1976 Summer Olympics. However, plagued by construction problems, the roof was not installed until 1987, was not retractable until 1988. Movement of the roof was impossible in high wind conditions, technical problems plagued the facility. A permanent, fixed roof was installed in 1998. By contrast, the Rogers Centre in Toronto, Ontario had a functional retractable roof at its debut in 1989. Architecturally speaking, retractable roofs vary from stadium to stadium in shape and movement. For example, Miller Park has a fan style roof, while Toyota Stadium in Japan has an accordion-like roof. Most retractable roofs are made of metal, while some, such as the roof of State Farm Stadium, are made of water-resistant fabric.
Although each retractable roof differs in these aspects, Safeco Field's roof is unique in that it is the only one in North America that does not form a climate-controlled enclosure when in the extended position. In North American major sports leagues, specific rules exist governing the movement of retractable roofs before and during gameplay; these rules vary between the MLB, as well as from stadium to stadium. In general, if a game begins with the roof open and weather conditions become less favorable, the home team may, with the approval of the field officials and visiting team, request the roof be closed. Depending on the stadium, weather or gameplay conditions, the judgment of the officials, play may or may not continue until the roof is closed. If the game begins with the roof closed, it may be opened under some circumstances depending on the venue. If it is closed after the game begins it must remain closed for the duration of the game; some modern athletic facilities are using less-complex roof systems referred to as open roofs.
These are constructed with similar materials as retractable roofs, such as polycarbonate or tempered glass roofs. Hinged at the structure's gutters, open roofs close and open by the mechanics of a rack and pinion system or a push/pull drive system. Open roofs are seen at smaller athletic venues such as country clubs and universities, in the construction of commercial greenhouses and garden centres for climate control purposes. CBC archives. CBC Archives A clip from 1975 where the stadium architect talks about his design for the Montreal Olympic Stadium. CBC Archives A look back on the history of the Montreal Olympic Stadium. Guidelines for movement of a retractable roof