Misplaced Pages

#416583

131-553: The design of the Berkeley City Hall was derived from the Town Hall at Tours , France, designed by Victor Laloux . The building design by architects John Bakewell Jr. , and Arthur Brown Jr. for the old city hall was selected as the winner of a 1907 competition to replace the original Town Hall which had burned to the ground in 1904 (designed by Samuel and Joseph Cather Newsom , 1884). The old city hall building has

262-491: A precipitate of aluminium hydroxide , Al(OH) 3 , forms. This is useful for clarification of water, as the precipitate nucleates on suspended particles in the water, hence removing them. Increasing the pH even further leads to the hydroxide dissolving again as aluminate , [Al(H 2 O) 2 (OH) 4 ] , is formed. Aluminium hydroxide forms both salts and aluminates and dissolves in acid and alkali, as well as on fusion with acidic and basic oxides. This behavior of Al(OH) 3

393-525: A "less classical sound". This name persisted: although the -um spelling was occasionally used in Britain, the American scientific language used -ium from the start. Most scientists throughout the world used -ium in the 19th century; and it was entrenched in several other European languages, such as French , German , and Dutch . In 1828, an American lexicographer, Noah Webster , entered only

524-499: A Swedish chemist, Jöns Jacob Berzelius , in which the name aluminium is given to the element that would be synthesized from alum. (Another article in the same journal issue also refers to the metal whose oxide is the basis of sapphire , i.e. the same metal, as to aluminium .) A January 1811 summary of one of Davy's lectures at the Royal Society mentioned the name aluminium as a possibility. The next year, Davy published

655-563: A central open space or park. In 1977, the city offices were moved to 2180 Milvia Street, which resulted in the name "old city hall". The fate of the old city hall building has been in limbo since 2002, when Berkeley voters rejected a bond to repair it. In 2007, the name of the building was changed to the Maudelle Shirek Building, after the former former Vice Mayor and eight-term City Council member Maudelle Shirek . Berkeley City Hall, also referred to as Old City Hall since

786-561: A chemistry textbook in which he used the spelling aluminum . Both spellings have coexisted since. Their usage is currently regional: aluminum dominates in the United States and Canada; aluminium is prevalent in the rest of the English-speaking world. In 1812, British scientist Thomas Young wrote an anonymous review of Davy's book, in which he proposed the name aluminium instead of aluminum , which he thought had

917-765: A garrison town with a resident general staff. The American presence is remembered today by the Woodrow Wilson Bridge over the Loire, which was officially opened in July 1918 and bears the name of the President of the United States from 1913 to 1921. Three American air force squadrons, including the 492nd, were based at the Parçay-Meslay airfield, their personnel playing an active part in the life of

1048-494: A grand marble entrance, a cupola, a spire and a curving staircase with wrought-iron banisters. A few years later in 1915, the same two architects designed San Francisco City Hall , which has similar features. The Old City Hall is also the keystone of the Berkeley Civic Center, which was inspired by the concepts of the " City Beautiful movement ", emphasizing broad vistas and important public buildings grouped around

1179-533: A half hours to get to Charles de Gaulle Airport . Tours has two main stations: Gare de Tours , the central station, and Gare de Saint-Pierre-des-Corps , used by trains that do not terminate in Tours. Tours Loire Valley Airport connects the Loire Valley to European cities. Historically, Tours was served by trams and trolleybuses , the trolleybus system lasting from 1949 to 1968. Tram service returned to

1310-441: A probable cause for it being soft with a low melting point and low electrical resistivity . Aluminium metal has an appearance ranging from silvery white to dull gray depending on its surface roughness . Aluminium mirrors are the most reflective of all metal mirrors for near ultraviolet and far infrared light. It is also one of the most reflective for light in the visible spectrum, nearly on par with silver in this respect, and

1441-683: A process termed passivation . Because of its general resistance to corrosion, aluminium is one of the few metals that retains silvery reflectance in finely powdered form, making it an important component of silver-colored paints. Aluminium is not attacked by oxidizing acids because of its passivation. This allows aluminium to be used to store reagents such as nitric acid , concentrated sulfuric acid , and some organic acids. In hot concentrated hydrochloric acid , aluminium reacts with water with evolution of hydrogen, and in aqueous sodium hydroxide or potassium hydroxide at room temperature to form aluminates —protective passivation under these conditions

SECTION 10

#1732791989417

1572-525: A refractory material, and in ceramics , as well as being the starting material for the electrolytic production of aluminium. Sapphire and ruby are impure corundum contaminated with trace amounts of other metals. The two main oxide-hydroxides, AlO(OH), are boehmite and diaspore . There are three main trihydroxides: bayerite , gibbsite , and nordstrandite , which differ in their crystalline structure ( polymorphs ). Many other intermediate and related structures are also known. Most are produced from ores by

1703-559: A square with busy pubs and restaurants, whose open-air tables fill the centre of the square. The Boulevard Beranger crosses the Rue Nationale at the Place Jean-Jaures and is the location of weekly markets and fairs. Tours is famous for its many bridges crossing the river Loire. One of them, Wilson Bridge, collapsed in 1978 but was rebuilt. In the garden of the ancient Palais des Archevêques (now Musée des Beaux-Arts )

1834-474: A stable noble gas configuration. Accordingly, the combined first three ionization energies of aluminium are far lower than the fourth ionization energy alone. Such an electron configuration is shared with the other well-characterized members of its group, boron , gallium , indium , and thallium ; it is also expected for nihonium . Aluminium can surrender its three outermost electrons in many chemical reactions (see below ). The electronegativity of aluminium

1965-561: A territory bitterly disputed between the counts of Blois and Anjou – the latter were victorious in the 11th century. It was the capital of France at the time of Louis XI, who had settled in the castle of Montils (today the castle of Plessis-les-Tours, at the junction of the Loire and the Indre rivers ). Tours and Touraine remained a permanent residence of the kings and court until the 16th century. The Renaissance gave Tours and Touraine many private mansions and castles, joined to some extent under

2096-820: A variety of wet processes using acid and base. Heating the hydroxides leads to formation of corundum. These materials are of central importance to the production of aluminium and are themselves extremely useful. Some mixed oxide phases are also very useful, such as spinel (MgAl 2 O 4 ), Na-β-alumina (NaAl 11 O 17 ), and tricalcium aluminate (Ca 3 Al 2 O 6 , an important mineral phase in Portland cement ). The only stable chalcogenides under normal conditions are aluminium sulfide (Al 2 S 3 ), selenide (Al 2 Se 3 ), and telluride (Al 2 Te 3 ). All three are prepared by direct reaction of their elements at about 1,000 °C (1,800 °F) and quickly hydrolyze completely in water to yield aluminium hydroxide and

2227-755: A volleyball club named the Tours VB . Tours is a special place for Catholics who follow the devotion to the Holy Face of Jesus and the adoration of the Blessed Sacrament . In 1843, Sister Marie of St Peter of Tours reported a vision which started the devotion to the Holy Face of Jesus , in reparation for the many insults Christ suffered in His Passion. The Golden Arrow Prayer was first made public by her. The Venerable Leo Dupont also known as The Holy Man of Tours lived in Tours at about

2358-575: A way of purifying bauxite to yield alumina, now known as the Bayer process , in 1889. Modern production of aluminium is based on the Bayer and Hall–Héroult processes. As large-scale production caused aluminium prices to drop, the metal became widely used in jewelry, eyeglass frames, optical instruments, tableware, and foil , and other everyday items in the 1890s and early 20th century. Aluminium's ability to form hard yet light alloys with other metals provided

2489-434: Is Al. Al was present in the early Solar System with abundance of 0.005% relative to Al but its half-life of 728,000 years is too short for any original nuclei to survive; Al is therefore extinct . Unlike for Al, hydrogen burning is the primary source of Al, with the nuclide emerging after a nucleus of Mg catches a free proton. However, the trace quantities of Al that do exist are the most common gamma ray emitter in

2620-407: Is paramagnetic and thus essentially unaffected by static magnetic fields. The high electrical conductivity, however, means that it is strongly affected by alternating magnetic fields through the induction of eddy currents . Aluminium combines characteristics of pre- and post-transition metals. Since it has few available electrons for metallic bonding, like its heavier group 13 congeners, it has

2751-429: Is small and highly charged ; as such, it has more polarizing power , and bonds formed by aluminium have a more covalent character. The strong affinity of aluminium for oxygen leads to the common occurrence of its oxides in nature. Aluminium is found on Earth primarily in rocks in the crust , where it is the third-most abundant element , after oxygen and silicon , rather than in the mantle , and virtually never as

SECTION 20

#1732791989417

2882-483: Is 1.61 (Pauling scale). A free aluminium atom has a radius of 143  pm . With the three outermost electrons removed, the radius shrinks to 39 pm for a 4-coordinated atom or 53.5 pm for a 6-coordinated atom. At standard temperature and pressure , aluminium atoms (when not affected by atoms of other elements) form a face-centered cubic crystal system bound by metallic bonding provided by atoms' outermost electrons; hence aluminium (at these conditions)

3013-456: Is a huge cedar tree said to have been planted by Napoleon . The garden also has a stuffed elephant named Fritz. He escaped from the Barnum and Bailey circus during their stay in Tours in 1902. He went mad and had to be shot down, but the city paid to honor him, and he was taxidermied as a result. Tours is home to University of Tours (formerly known as University François Rabelais of Tours),

3144-548: Is a metal. This crystal system is shared by many other metals, such as lead and copper ; the size of a unit cell of aluminium is comparable to that of those other metals. The system, however, is not shared by the other members of its group: boron has ionization energies too high to allow metallization, thallium has a hexagonal close-packed structure, and gallium and indium have unusual structures that are not close-packed like those of aluminium and thallium. The few electrons that are available for metallic bonding in aluminium are

3275-449: Is a popular culinary city with specialties such as: rillettes , rillons, Touraine vineyards , AOC Sainte-Maure-de-Touraine cheeses and nougats . The city is also the end-point of the annual Paris–Tours cycle race . A popular folk etymology of the word "Tours" is that it comes from Turonus , the nephew of Brutus . Turonus died in a war between Corineus and the king of Aquitaine , Goffarius Pictus , provoked by Corineus hunting in

3406-522: Is almost never found in the elemental state; instead it is found in oxides or silicates. Feldspars , the most common group of minerals in the Earth's crust, are aluminosilicates. Aluminium also occurs in the minerals beryl , cryolite , garnet , spinel , and turquoise . Impurities in Al 2 O 3 , such as chromium and iron , yield the gemstones ruby and sapphire , respectively. Native aluminium metal

3537-405: Is also easily machined and cast . Aluminium is an excellent thermal and electrical conductor , having around 60% the conductivity of copper , both thermal and electrical, while having only 30% of copper's density. Aluminium is capable of superconductivity , with a superconducting critical temperature of 1.2 kelvin and a critical magnetic field of about 100 gauss (10 milliteslas ). It

3668-520: Is explained by the fact that the court of France lived in Touraine between 1430 and 1530. French, the language of the court, had become the official language of the entire kingdom. A Council of Tours in 813 decided that priests should preach sermons in different languages because the common people could no longer understand classical Latin . This was the first official recognition of an early French language distinct from Latin, and can be considered as

3799-553: Is extremely rare and can only be found as a minor phase in low oxygen fugacity environments, such as the interiors of certain volcanoes. Native aluminium has been reported in cold seeps in the northeastern continental slope of the South China Sea . It is possible that these deposits resulted from bacterial reduction of tetrahydroxoaluminate Al(OH) 4 . Although aluminium is a common and widespread element, not all aluminium minerals are economically viable sources of

3930-536: Is greatly reduced by aqueous salts, particularly in the presence of dissimilar metals. Aluminium reacts with most nonmetals upon heating, forming compounds such as aluminium nitride (AlN), aluminium sulfide (Al 2 S 3 ), and the aluminium halides (AlX 3 ). It also forms a wide range of intermetallic compounds involving metals from every group on the periodic table. The vast majority of compounds, including all aluminium-containing minerals and all commercially significant aluminium compounds, feature aluminium in

4061-492: Is in fact more basic than that of gallium. Aluminium also bears minor similarities to the metalloid boron in the same group: AlX 3 compounds are valence isoelectronic to BX 3 compounds (they have the same valence electronic structure), and both behave as Lewis acids and readily form adducts . Additionally, one of the main motifs of boron chemistry is regular icosahedral structures, and aluminium forms an important part of many icosahedral quasicrystal alloys, including

Old Berkeley City Hall - Misplaced Pages Continue

4192-476: Is low in comparison with many other metals. All other isotopes of aluminium are radioactive . The most stable of these is Al : while it was present along with stable Al in the interstellar medium from which the Solar System formed, having been produced by stellar nucleosynthesis as well, its half-life is only 717,000 years and therefore a detectable amount has not survived since the formation of

4323-500: Is negligible. Aqua regia also dissolves aluminium. Aluminium is corroded by dissolved chlorides , such as common sodium chloride , which is why household plumbing is never made from aluminium. The oxide layer on aluminium is also destroyed by contact with mercury due to amalgamation or with salts of some electropositive metals. As such, the strongest aluminium alloys are less corrosion-resistant due to galvanic reactions with alloyed copper , and aluminium's corrosion resistance

4454-521: Is not as important. It is a polymer with the formula (AlH 3 ) n , in contrast to the corresponding boron hydride that is a dimer with the formula (BH 3 ) 2 . Aluminium's per-particle abundance in the Solar System is 3.15 ppm (parts per million). It is the twelfth most abundant of all elements and third most abundant among the elements that have odd atomic numbers, after hydrogen and nitrogen. The only stable isotope of aluminium, Al,

4585-426: Is painted light brown, while the lantern, spire, and sash are dark brown. Since its completion in 1909, the building has undergone minimal alterations. The main facade's wooden sash windows were replaced with aluminum , preserving the original design. In 1950, the building's rear was extended to create additional office space, enclosing windows on either side of the stair -bay and darkening the main staircase. Inside,

4716-416: Is quite soft and lacking in strength. In most applications various aluminium alloys are used instead because of their higher strength and hardness. The yield strength of pure aluminium is 7–11 MPa , while aluminium alloys have yield strengths ranging from 200 MPa to 600 MPa. Aluminium is ductile , with a percent elongation of 50-70%, and malleable allowing it to be easily drawn and extruded . It

4847-435: Is soft, nonmagnetic , and ductile . It has one stable isotope, Al, which is highly abundant, making aluminium the twelfth-most common element in the universe. The radioactivity of Al leads to it being used in radiometric dating . Chemically, aluminium is a post-transition metal in the boron group ; as is common for the group, aluminium forms compounds primarily in the +3 oxidation state . The aluminium cation Al

4978-422: Is surrounded by six fluorine atoms in a distorted octahedral arrangement, with each fluorine atom being shared between the corners of two octahedra. Such {AlF 6 } units also exist in complex fluorides such as cryolite , Na 3 AlF 6 . AlF 3 melts at 1,290 °C (2,354 °F) and is made by reaction of aluminium oxide with hydrogen fluoride gas at 700 °C (1,300 °F). With heavier halides,

5109-547: Is termed amphoterism and is characteristic of weakly basic cations that form insoluble hydroxides and whose hydrated species can also donate their protons. One effect of this is that aluminium salts with weak acids are hydrolyzed in water to the aquated hydroxide and the corresponding nonmetal hydride: for example, aluminium sulfide yields hydrogen sulfide . However, some salts like aluminium carbonate exist in aqueous solution but are unstable as such; and only incomplete hydrolysis takes place for salts with strong acids, such as

5240-416: Is that of the preceding noble gas , whereas those of its heavier congeners gallium , indium , thallium , and nihonium also include a filled d-subshell and in some cases a filled f-subshell. Hence, the inner electrons of aluminium shield the valence electrons almost completely, unlike those of aluminium's heavier congeners. As such, aluminium is the most electropositive metal in its group, and its hydroxide

5371-433: Is the eighteenth most abundant nucleus in the universe. It is created almost entirely after fusion of carbon in massive stars that will later become Type II supernovas : this fusion creates Mg, which upon capturing free protons and neutrons, becomes aluminium. Some smaller quantities of Al are created in hydrogen burning shells of evolved stars, where Mg can capture free protons. Essentially all aluminium now in existence

Old Berkeley City Hall - Misplaced Pages Continue

5502-420: Is topped with a raised, hipped roof adorned with ornamental flames. The highlight of the building is a 60-foot lantern and spire . The lantern rises from the roof, featuring a paneled base with a high metal balustrade around an open colonnade . This colonnade supports a classic entablature crowned by a narrow dome with engaged piers and finials , topped by a beveled spire. The two identical wings of

5633-571: Is twinned with: Aluminium Aluminium (or aluminum in North American English ) is a chemical element ; it has symbol   Al and atomic number  13. Aluminium has a density lower than that of other common metals , about one-third that of steel . It has a great affinity towards oxygen , forming a protective layer of oxide on the surface when exposed to air. Aluminium visually resembles silver , both in its color and in its great ability to reflect light. It

5764-473: Is very mild for such a northern latitude. Summers are influenced by its inland position, resulting in frequent days of 25 °C (77 °F) or warmer, whereas winters are kept mild by Atlantic air masses. The entire valley between Orlans and Angers is famous for the luminosity of its air and for its fabulous châteaux, most of them Renaissance (over 600 between Orlans and Angers). The Cathedral of Tours, dedicated to Saint Gatien , its canonized first bishop ,

5895-715: The Battle of Tours . The Muslim army was defeated, preventing an Islamic conquest of France. In 845, Tours repelled the first attack of the Viking chief Haesten . In 850, the Vikings settled at the mouths of the Seine and the Loire. Still led by Haesten, they went up the Loire again in 852 and sacked Angers , Tours and Marmoutier Abbey. During the Middle Ages, Tours consisted of two juxtaposed and competing centres. The "City" in

6026-455: The Friedel–Crafts reactions . Aluminium trichloride has major industrial uses involving this reaction, such as in the manufacture of anthraquinones and styrene ; it is also often used as the precursor for many other aluminium compounds and as a reagent for converting nonmetal fluorides into the corresponding chlorides (a transhalogenation reaction ). Aluminium forms one stable oxide with

6157-475: The London Metal Exchange , the oldest industrial metal exchange in the world, in 1978. The output continued to grow: the annual production of aluminium exceeded 50,000,000 metric tons in 2013. The real price for aluminium declined from $ 14,000 per metric ton in 1900 to $ 2,340 in 1948 (in 1998 United States dollars). Extraction and processing costs were lowered over technological progress and

6288-543: The UNESCO , and is home to the Vieux-Tours, a patrimonial site. The garden city has a green heritage and an urban landscape strongly influenced by its natural space. The historic city that is nicknamed " Le Petit Paris " and its region by its history and culture has always been a land of birth or host to many personalities, international sporting events, and is a university city with more than 30,000 students in 2019. Tours

6419-475: The aluminum spelling in his American Dictionary of the English Language . In the 1830s, the -um spelling gained usage in the United States; by the 1860s, it had become the more common spelling there outside science. In 1892, Hall used the -um spelling in his advertising handbill for his new electrolytic method of producing the metal, despite his constant use of the -ium spelling in all

6550-423: The chemical formula Al 2 O 3 , commonly called alumina . It can be found in nature in the mineral corundum , α-alumina; there is also a γ-alumina phase. Its crystalline form, corundum, is very hard ( Mohs hardness 9), has a high melting point of 2,045 °C (3,713 °F), has very low volatility, is chemically inert, and a good electrical insulator, it is often used in abrasives (such as toothpaste), as

6681-638: The free metal . It is obtained industrially by mining bauxite , a sedimentary rock rich in aluminium minerals. The discovery of aluminium was announced in 1825 by Danish physicist Hans Christian Ørsted . The first industrial production of aluminium was initiated by French chemist Henri Étienne Sainte-Claire Deville in 1856. Aluminium became much more available to the public with the Hall–Héroult process developed independently by French engineer Paul Héroult and American engineer Charles Martin Hall in 1886, and

SECTION 50

#1732791989417

6812-551: The interstellar gas ; if the original Al were still present, gamma ray maps of the Milky Way would be brighter. Overall, the Earth is about 1.59% aluminium by mass (seventh in abundance by mass). Aluminium occurs in greater proportion in the Earth's crust than in the universe at large. This is because aluminium easily forms the oxide and becomes bound into rocks and stays in the Earth's crust , while less reactive metals sink to

6943-417: The 18th-century architecture. Pierre Patout succeeded Lefèvre as the architect in charge of rebuilding in 1945. At one time, there was talk of demolishing the southern side of the rue Nationale to make it in keeping with the new development. The recent history of Tours is marked by the personality of Jean Royer , who was mayor for 36 years and helped save the old town from demolition by establishing one of

7074-503: The 20th century progressed, Tours became a dynamic conurbation, economically oriented towards the service sector. The city was greatly affected by the First World War . A force of 25,000 American soldiers arrived in 1917, setting up textile factories for the manufacture of uniforms, repair shops for military equipment, munitions dumps, an army post office and an American military hospital at Augustins. Because of this, Tours became

7205-526: The 5th century BCE. The ancients are known to have used alum as a dyeing mordant and for city defense. After the Crusades , alum, an indispensable good in the European fabric industry, was a subject of international commerce; it was imported to Europe from the eastern Mediterranean until the mid-15th century. The nature of alum remained unknown. Around 1530, Swiss physician Paracelsus suggested alum

7336-472: The Al–Zn–Mg class. Aluminium has a high chemical affinity to oxygen, which renders it suitable for use as a reducing agent in the thermite reaction. A fine powder of aluminium reacts explosively on contact with liquid oxygen ; under normal conditions, however, aluminium forms a thin oxide layer (~5 nm at room temperature) that protects the metal from further corrosion by oxygen, water, or dilute acid,

7467-651: The Catholics returned to power in Angers: the attendant assumed the right to nominate the aldermen. The Massacre of Saint-Barthelemy was not repeated at Tours. The Protestants were imprisoned by the aldermen – a measure which prevented their extermination. The permanent return of the Court to Paris and then Versailles marked the beginning of a slow but permanent decline. Guillaume the Metayer (1763–1798), known as Rochambeau ,

7598-551: The Holy Face on Rue St. Etienne in Tours receives many pilgrims every year. Tours was the site of the episcopal activity of St. Martin of Tours and has further Christian connotations in that the pivotal Battle of Tours in 732 is often considered the first decisive victory over the invading Islamic forces, turning the tide against them. The battle also helped lay the foundations of the Carolingian Empire . Tours

7729-519: The Loire to the north and the Cher to the south. The buildings of Tours are white with blue slate (called Ardoise ) roofs; this style is common in the north of France, while most buildings in the south of France have terracotta roofs. Tours is famous for its original medieval district, called le Vieux Tours . Unique to the Old City are its preserved half-timbered buildings and la Place Plumereau ,

7860-418: The United States dollar, and alumina prices. The BRIC countries' combined share in primary production and primary consumption grew substantially in the first decade of the 21st century. China is accumulating an especially large share of the world's production thanks to an abundance of resources, cheap energy, and governmental stimuli; it also increased its consumption share from 2% in 1972 to 40% in 2010. In

7991-514: The United States, Western Europe, and Japan, most aluminium was consumed in transportation, engineering, construction, and packaging. In 2021, prices for industrial metals such as aluminium have soared to near-record levels as energy shortages in China drive up costs for electricity. The names aluminium and aluminum are derived from the word alumine , an obsolete term for alumina , the primary naturally occurring oxide of aluminium . Alumine

SECTION 60

#1732791989417

8122-578: The aluminium atoms have tetrahedral four-coordination and the other half have trigonal bipyramidal five-coordination. Four pnictides – aluminium nitride (AlN), aluminium phosphide (AlP), aluminium arsenide (AlAs), and aluminium antimonide (AlSb) – are known. They are all III-V semiconductors isoelectronic to silicon and germanium , all of which but AlN have the zinc blende structure. All four can be made by high-temperature (and possibly high-pressure) direct reaction of their component elements. Aluminium alloys well with most other metals (with

8253-408: The area around the railway station in 1944, causing several hundred deaths. A plan for the rebuilding of the central area drawn up by the local architect Camille Lefèvre had been adopted even before the end of the war. The plan was for 20 small quadrangular blocks of housing to be arranged around the main road (la rue Nationale ), which was widened. This regular layout attempted to echo but simplify

8384-629: The birth of French. The Ordinance of Montils-lès-Tours , promulgated by Charles VII in 1454, made it mandatory to write laws and oral customs in the native language of the area. An ordinance of Charles VIII (born in Amboise , near Tours) in 1490 and one of Louis XII (born in Blois , near Tours) in 1510 broaden the scope of the ordinance of Charles VII. Finally, the Ordinance of Villers-Cotterêts , signed into law by Francis I in 1539, called for

8515-425: The building (each 31' by 77') are perpendicular to the central portion and share similar architectural details. The ground floors of these wings have round arch openings framed by cartouches with lion masques and supporting brackets. The second-floor balconies span three smaller rectangular windows and are faced with metal balustrades. Each wing has a hipped roof capped with ornamental flames. The building's stucco

8646-584: The cathedral itself. Before the French Revolution , the inhabitants of Tours ( Les Tourangeaux ) were known for speaking the "purest" form of French in the entire country. The pronunciation of Touraine was traditionally regarded as the most standard pronunciation of the French language, until the 19th century when the standard pronunciation of French shifted to that of the Parisian bourgeoisie. That

8777-487: The cathedral. Another bone of contention was the original Vinci Congress Centre by Jean Nouvel . The project incurred debts although it at least made Tours one of France's principal conference centres. Jean Germain , a member of the Socialist Party, became mayor in 1995 and made debt reduction his priority. Ten years later, his economic management was regarded as much wiser than that of his predecessor because of

8908-436: The characteristic physical properties of a post-transition metal, with longer-than-expected interatomic distances. Furthermore, as Al is a small and highly charged cation, it is strongly polarizing and bonding in aluminium compounds tends towards covalency ; this behavior is similar to that of beryllium (Be ), and the two display an example of a diagonal relationship . The underlying core under aluminium's valence shell

9039-487: The city centre. Some architectural masterpieces of the 16th and 17th centuries were lost, as was the monumental entry to the city. The Wilson Bridge, which carried a water main that supplied the city, was dynamited to slow the progress of the German advance. With the water main severed, nobody could extinguish the inferno. That made inhabitants have no option but to flee to safety. More heavy air raids by Allied forces devastated

9170-600: The city in 2013, when a new tram system began operation. Twenty-one Alstom Citadis trams were ordered. There is also a bus service, the main central stop being Jean Jaurès , next to the Hôtel de Ville , and rue Nationale , the high street of Tours. The tram and bus networks are operated by Fil Bleu and they share a ticketing system. A second tram line is scheduled for 2025. The city's football team, Tours FC , currently play in Championnat National 3 ,

9301-671: The city. Americans paraded at funerals and award ceremonies for the Croix de Guerre. They also took part in festivals and their YMCA organised shows for the troops. Some men married women from Tours. In 1920, the city hosted the Congress of Tours, which saw the creation of the French Communist Party . One future consequence of that congress was the presence of Ho Chi Minh , the Vietnamese nationalist, who became one of

9432-419: The coordination numbers are lower. The other trihalides are dimeric or polymeric with tetrahedral four-coordinate aluminium centers. Aluminium trichloride (AlCl 3 ) has a layered polymeric structure below its melting point of 192.4 °C (378 °F) but transforms on melting to Al 2 Cl 6 dimers. At higher temperatures those increasingly dissociate into trigonal planar AlCl 3 monomers similar to

9563-428: The core. In the Earth's crust, aluminium is the most abundant metallic element (8.23% by mass ) and the third most abundant of all elements (after oxygen and silicon). A large number of silicates in the Earth's crust contain aluminium. In contrast, the Earth's mantle is only 2.38% aluminium by mass. Aluminium also occurs in seawater at a concentration of 2 μg/kg. Because of its strong affinity for oxygen, aluminium

9694-474: The decay of Al was responsible for the melting and differentiation of some asteroids after their formation 4.55 billion years ago. The remaining isotopes of aluminium, with mass numbers ranging from 21 to 43, all have half-lives well under an hour. Three metastable states are known, all with half-lives under a minute. An aluminium atom has 13 electrons, arranged in an electron configuration of [ Ne ] 3s 3p , with three electrons beyond

9825-571: The east, successor of the late Roman ' castrum ', was composed of the cathedral and palace of the archbishops as well as the castle of Tours. The castle of Tours acted as a seat of the authority of the Counts of Tours (later Counts of Anjou) and the King of France. In the west, the "new city" structured around the Abbey of Saint Martin was freed from the control of the city during the 10th century (an enclosure

9956-399: The environment, no living organism is known to metabolize aluminium salts , but this aluminium is well tolerated by plants and animals. Because of the abundance of these salts, the potential for a biological role for them is of interest, and studies are ongoing. Of aluminium isotopes, only Al is stable. This situation is common for elements with an odd atomic number. It is

10087-478: The exception of most alkali metals and group 13 metals) and over 150 intermetallics with other metals are known. Preparation involves heating fixed metals together in certain proportion, followed by gradual cooling and annealing . Bonding in them is predominantly metallic and the crystal structure primarily depends on efficiency of packing. There are few compounds with lower oxidation states. A few aluminium(I) compounds exist: AlF, AlCl, AlBr, and AlI exist in

10218-520: The fact that its nuclei are much lighter, while difference in the unit cell size does not compensate for this difference. The only lighter metals are the metals of groups 1 and 2 , which apart from beryllium and magnesium are too reactive for structural use (and beryllium is very toxic). Aluminium is not as strong or stiff as steel, but the low density makes up for this in the aerospace industry and for many other applications where light weight and relatively high strength are crucial. Pure aluminium

10349-565: The fifth level of French football . They also have a second team, CCSP Tours . CCSP's home stadium is the Stade des Tourettes and they play in the Division d'Honneur Regionale de Centre , the seventh tier of the French football league system . Tours has served as the finish location for Paris–Tours , a one-day road cycling classic race held almost every October since 1896. Tours also has

10480-454: The financial stability of the city returning. However, his achievements were criticised by the municipal opposition for a lack of ambition. There were no large building projects instituted under his two terms. That position is disputed by those in power, who affirm their policy of concentrating on the quality of life, as evidenced by urban restoration, the development of public transport and cultural activities. Tours has an oceanic climate that

10611-680: The first Conservation Areas . This example of conservation policy would later inspire the Malraux Law for the safeguarding of historic city centres. In the 1970s, Jean Royer also extended the city to the south by diverting the course of the Cher River to create the districts of Rives du Cher and des Fontaines. At the time, it was one of the largest urban developments in Europe. In 1970, the François Rabelais University

10742-492: The first members of the party. Tours was also marked by the Second World War , as the city suffered massive destruction in 1940. For four years it was a city of military camps and fortifications. From 10 to 13 June 1940, Tours was the temporary seat of the French government before its move to Bordeaux . German incendiary bombs caused a huge fire, which blazed out of control from 20 to 22 June and destroyed part of

10873-730: The gas phase after explosion and in stellar absorption spectra. More thoroughly investigated are compounds of the formula R 4 Al 2 which contain an Al–Al bond and where R is a large organic ligand . A variety of compounds of empirical formula AlR 3 and AlR 1.5 Cl 1.5 exist. The aluminium trialkyls and triaryls are reactive, volatile, and colorless liquids or low-melting solids. They catch fire spontaneously in air and react with water, thus necessitating precautions when handling them. They often form dimers, unlike their boron analogues, but this tendency diminishes for branched-chain alkyls (e.g. Pr , Bu , Me 3 CCH 2 ); for example, triisobutylaluminium exists as an equilibrium mixture of

11004-453: The gaseous phase when the respective trihalide is heated with aluminium, and at cryogenic temperatures. A stable derivative of aluminium monoiodide is the cyclic adduct formed with triethylamine , Al 4 I 4 (NEt 3 ) 4 . Al 2 O and Al 2 S also exist but are very unstable. Very simple aluminium(II) compounds are invoked or observed in the reactions of Al metal with oxidants. For example, aluminium monoxide , AlO, has been detected in

11135-545: The generic name of the Châteaux of the Loire. It is also at the time of Louis XI that the silk industry was introduced – despite difficulties, the industry still survives to this day. Charles IX passed through the city at the time of his royal tour of France between 1564 and 1566, accompanied by the Court and various noblemen: his brother the Duke of Anjou , Henri de Navarre , the cardinals of Bourbon and Lorraine . At this time,

11266-646: The halides, nitrate , and sulfate . For similar reasons, anhydrous aluminium salts cannot be made by heating their "hydrates": hydrated aluminium chloride is in fact not AlCl 3 ·6H 2 O but [Al(H 2 O) 6 ]Cl 3 , and the Al–O bonds are so strong that heating is not sufficient to break them and form Al–Cl bonds instead: All four trihalides are well known. Unlike the structures of the three heavier trihalides, aluminium fluoride (AlF 3 ) features six-coordinate aluminium, which explains its involatility and insolubility as well as high heat of formation . Each aluminium atom

11397-718: The influence of the saint, the abbey and the city in Gaul. In the 9th century, Tours was at the heart of the Carolingian Renaissance , in particular because of Alcuin , of York in Northumbria, a renowned book collector and an abbot of Marmoutier Abbey . In 732, Abdul Rahman Al Ghafiqi and an army of Muslim horsemen from Al-Andalus advanced 500 kilometres (300 miles) deep into France, and were stopped at Moussais-la-Bataille (between Châtellerault and Poitiers ) by Charles Martel and his infantry. This ignited

11528-566: The king's forests without permission. It is said that Turonus was buried in Tours and the city is founded around his grave. In Gallic times, Tours was an important crossing point over the Loire . It became part of the Roman Empire during the 1st century AD, and the city was named Caesarodunum ("hill of Caesar"). The name evolved in the 4th century when the original Gallic name, Turones , became Civitas Turonum and then Tours . It

11659-759: The largest amphitheaters of the Roman Empire, the Tours Amphitheatre . Known for the Battle of Tours in 732 AD, it is a National Sanctuary with connections to the Merovingians and the Carolingians , with the Capetians making the kingdom's currency the Livre tournois . Saint Martin and Gregory of Tours were from Tours. Tours was once part of Touraine , a former province of France. Tours

11790-493: The largest city in the region of Centre-Val de Loire , France. It is the prefecture of the department of Indre-et-Loire . The commune of Tours had 136,463 inhabitants as of 2018 while the population of the whole metropolitan area was 516,973. Tours sits on the lower reaches of the Loire , between Orléans and the Atlantic coast. Formerly named Caesarodunum by its founder, Roman Emperor Augustus , it possesses one of

11921-433: The low-pressure polymerization of ethene and propene . There are also some heterocyclic and cluster organoaluminium compounds involving Al–N bonds. The industrially most important aluminium hydride is lithium aluminium hydride (LiAlH 4 ), which is used as a reducing agent in organic chemistry . It can be produced from lithium hydride and aluminium trichloride . The simplest hydride, aluminium hydride or alane,

12052-471: The main floor hallway is genuine, but the two columns at the stairway's base are scagliola , imitating marble . This original decorative work remains unaltered. [REDACTED]  This article incorporates public domain material from websites or documents of the National Park Service . Tours Tours ( / t ʊər / TOOR , French: [tuʁ] ) is

12183-512: The mass production of aluminium led to its extensive use in industry and everyday life. In the First and Second World Wars, aluminium was a crucial strategic resource for aviation . In 1954, aluminium became the most produced non-ferrous metal , surpassing copper . In the 21st century, most aluminium was consumed in transportation, engineering, construction, and packaging in the United States, Western Europe, and Japan. Despite its prevalence in

12314-529: The metal remained rare; its cost exceeded that of gold. The first industrial production of aluminium was established in 1856 by French chemist Henri Etienne Sainte-Claire Deville and companions. Deville had discovered that aluminium trichloride could be reduced by sodium, which was more convenient and less expensive than potassium, which Wöhler had used. Even then, aluminium was still not of great purity and produced aluminium differed in properties by sample. Because of its electricity-conducting capacity, aluminium

12445-655: The metal to be isolated from alum was alumium , which Davy suggested in an 1808 article on his electrochemical research, published in Philosophical Transactions of the Royal Society . It appeared that the name was created from the English word alum and the Latin suffix -ium ; but it was customary then to give elements names originating in Latin, so this name was not adopted universally. This name

12576-465: The metal with many uses at the time. During World War I , major governments demanded large shipments of aluminium for light strong airframes; during World War II , demand by major governments for aviation was even higher. By the mid-20th century, aluminium had become a part of everyday life and an essential component of housewares. In 1954, production of aluminium surpassed that of copper , historically second in production only to iron, making it

12707-491: The metal. Almost all metallic aluminium is produced from the ore bauxite (AlO x (OH) 3–2 x ). Bauxite occurs as a weathering product of low iron and silica bedrock in tropical climatic conditions. In 2017, most bauxite was mined in Australia, China, Guinea, and India. The history of aluminium has been shaped by usage of alum . The first written record of alum, made by Greek historian Herodotus , dates back to

12838-485: The monomer and dimer. These dimers, such as trimethylaluminium (Al 2 Me 6 ), usually feature tetrahedral Al centers formed by dimerization with some alkyl group bridging between both aluminium atoms. They are hard acids and react readily with ligands, forming adducts. In industry, they are mostly used in alkene insertion reactions, as discovered by Karl Ziegler , most importantly in "growth reactions" that form long-chain unbranched primary alkenes and alcohols, and in

12969-485: The most notable feature is a broad U-shaped stairway leading to the second floor, with a wrought iron banister decorated with gold-colored medallions . The interior walls, ceiling , and columns create an illusion of more expensive materials through expert craftsmanship. What appears to be dressed stone walls and a tooled leather and brocade tapestry ceiling are actually plaster painted in red, olive, green, cream, and gilt to mimic these materials. The marble wainscoting in

13100-506: The most produced non-ferrous metal . During the mid-20th century, aluminium emerged as a civil engineering material, with building applications in both basic construction and interior finish work, and increasingly being used in military engineering, for both airplanes and land armor vehicle engines. Earth's first artificial satellite , launched in 1957, consisted of two separate aluminium semi-spheres joined and all subsequent space vehicles have used aluminium to some extent. The aluminium can

13231-614: The next decade, the -um spelling dominated American usage. In 1925, the American Chemical Society adopted this spelling. The International Union of Pure and Applied Chemistry (IUPAC) adopted aluminium as the standard international name for the element in 1990. In 1993, they recognized aluminum as an acceptable variant; the most recent 2005 edition of the IUPAC nomenclature of inorganic chemistry also acknowledges this spelling. IUPAC official publications use

13362-625: The north and south. The main facade , facing east, is particularly impressive. Set back about 30 feet from the street, it is surrounded by landscaped gardens featuring lawns , shrubs , trees, and curving flower beds. A broad central stairway leads to a balustraded terrace spanning the front of the central section. The central portion of the building (86' by 66') comprises five bays. The ground floor features round arch openings with molded architraves , containing wood-framed sash windows with triple horizontal and vertical divisions. These windows have shallow balconies with classical balustrades. Above,

13493-429: The only primordial aluminium isotope, i.e. the only one that has existed on Earth in its current form since the formation of the planet. It is therefore a mononuclidic element and its standard atomic weight is virtually the same as that of the isotope. This makes aluminium very useful in nuclear magnetic resonance (NMR), as its single stable isotope has a high NMR sensitivity. The standard atomic weight of aluminium

13624-407: The oxidation state 3+. The coordination number of such compounds varies, but generally Al is either six- or four-coordinate. Almost all compounds of aluminium(III) are colorless. In aqueous solution, Al exists as the hexaaqua cation [Al(H 2 O) 6 ] , which has an approximate K a of 10 . Such solutions are acidic as this cation can act as a proton donor and progressively hydrolyze until

13755-460: The patents he filed between 1886 and 1903. It is unknown whether this spelling was introduced by mistake or intentionally, but Hall preferred aluminum since its introduction because it resembled platinum , the name of a prestigious metal. By 1890, both spellings had been common in the United States, the -ium spelling being slightly more common; by 1895, the situation had reversed; by 1900, aluminum had become twice as common as aluminium ; in

13886-404: The planet. However, minute traces of Al are produced from argon in the atmosphere by spallation caused by cosmic ray protons. The ratio of Al to Be has been used for radiodating of geological processes over 10 to 10  year time scales, in particular transport, deposition, sediment storage, burial times, and erosion. Most meteorite scientists believe that the energy released by

14017-496: The relocation of city offices to 2180 Milvia Street in 1977, is a two-story Beaux-Arts building in the French Renaissance style . Constructed with steel-reinforced concrete and finished with stucco , it features an attic and a basement . The building's U-shaped structure includes a semi-circular stair-bay at the rear. Its symmetrical design is divided into a central section flanked by two smaller wings, projecting to

14148-423: The respective hydrogen chalcogenide . As aluminium is a small atom relative to these chalcogens, these have four-coordinate tetrahedral aluminium with various polymorphs having structures related to wurtzite , with two-thirds of the possible metal sites occupied either in an orderly (α) or random (β) fashion; the sulfide also has a γ form related to γ-alumina, and an unusual high-temperature hexagonal form where half

14279-667: The rest of the country, Tours is a jumping-off point for tourist visits to the Loire Valley and the royal châteaux . Tours is on one of the main lines of the TGV. It is possible to travel to the west coast of Bordeaux in two and a half hours. From there, the line follows the Mediterranean coast via Avignon , and then to Spain and Barcelona . There are also lines to Lyon , Strasbourg and Lille . It takes less than one hour by train to get from Tours to Paris by TGV and one and

14410-516: The route of pilgrimage to Santiago de Compostela , a major centre during the Middle Ages. In the 6th century, Gregory of Tours , author of the Ten Books of History , restored a cathedral destroyed by a fire in 561. Saint Martin's monastery benefited from its inception, at the very start of the 6th century from patronage and support from the Frankish king, Clovis I , which increased considerably

14541-606: The same time as, for example, the Château de Chenonceau . When the 15th-century illuminator Jean Fouquet was set the task of illuminating Josephus 's Jewish Antiquities , his depiction of Solomon's Temple was modelled on the nearly complete cathedral of Tours. The atmosphere of the Gothic cathedral close permeates Honoré de Balzac 's dark short novel of jealousy and provincial intrigues, Le Curé de Tours ( The Curate of Tours ) and his medieval story Maître Cornélius opens in

14672-598: The same time. In 1849 he started the nightly adoration of the Blessed Sacrament , which spread throughout France. Upon hearing of Sister Marie of St Peter 's reported visions, he started to burn a vigil lamp continuously before a picture of the Holy Face of Jesus . The devotion was eventually approved by Pope Pius XII in 1958 and he formally declared the Feast of the Holy Face of Jesus as Shrove Tuesday (the Tuesday before Ash Wednesday) for all Roman Catholics. The Oratory of

14803-485: The scale of the economies. However, the need to exploit lower-grade poorer quality deposits and the use of fast increasing input costs (above all, energy) increased the net cost of aluminium; the real price began to grow in the 1970s with the rise of energy cost. Production moved from the industrialized countries to countries where production was cheaper. Production costs in the late 20th century changed because of advances in technology, lower energy prices, exchange rates of

14934-405: The second-floor windows, now fitted with aluminum sash that retain the original divisions, also feature projecting balconies with balustrades. The central facade is adorned with six giant order-length ionic columns supporting a cornice with ornamental dentils and monumental urns . Behind the urns is a blank frieze ending in a secondary cornice molding with a central cartouche . The central portion

15065-617: The site of one of the most important choral competitions, called Florilège Vocal de Tours International Choir Competition, and is a member city of the European Grand Prix for Choral Singing . The population data in the table and graph below refer to the commune of Tours proper, in its geography at the given years. The commune of Tours absorbed the former commune of Saint-Étienne in 1845 and Sainte-Radegonde-en-Touraine and Saint-Symphorien in 1964. Today, with extensive rail (including TGV ) and autoroute connections linking to

15196-408: The structure of BCl 3 . Aluminium tribromide and aluminium triiodide form Al 2 X 6 dimers in all three phases and hence do not show such significant changes of properties upon phase change. These materials are prepared by treating aluminium with the halogen. The aluminium trihalides form many addition compounds or complexes; their Lewis acidic nature makes them useful as catalysts for

15327-536: The two therefore look similar. Aluminium is also good at reflecting solar radiation , although prolonged exposure to sunlight in air adds wear to the surface of the metal; this may be prevented if aluminium is anodized , which adds a protective layer of oxide on the surface. The density of aluminium is 2.70 g/cm , about 1/3 that of steel, much lower than other commonly encountered metals, making aluminium parts easily identifiable through their lightness. Aluminium's low density compared to most other metals arises from

15458-410: The use of French in all legal acts, notarized contracts and official legislation to avoid any linguistic confusion. Gregory of Tours wrote in the 6th century that some people in the area could still speak Gaulish . The city has a population of 140,000 and is called "Le Jardin de la France" ("The Garden of France"). There are several parks located within the city. Tours is located between two rivers,

15589-484: The well-known counter-revolutionary chief of Mayenne, was shot in Tours. The arrival of the railway in the 19th century saved the city by making it an important nodal point. The main railway station is known as Tours-Saint-Pierre-des-Corps. At that time, Tours was expanding towards the south into a district known as the Prébendes. The importance of the city as a centre of communications contributed to its revival and, as

15720-461: Was a salt of an earth of alum. In 1595, German doctor and chemist Andreas Libavius experimentally confirmed this. In 1722, German chemist Friedrich Hoffmann announced his belief that the base of alum was a distinct earth. In 1754, German chemist Andreas Sigismund Marggraf synthesized alumina by boiling clay in sulfuric acid and subsequently adding potash . Attempts to produce aluminium date back to 1760. The first successful attempt, however,

15851-511: Was at this time that the Tours Amphitheatre was built. Tours became a metropolis in the Roman province of Lugdunum towards 380–388 AD, dominating Maine , Brittany, and the Loire Valley . One important figure in the city was Saint Martin of Tours , a bishop who shared his coat with a naked beggar in Amiens . The importance of Martin in the medieval Christian West made Tours, and its position on

15982-521: Was begun about 1170 to replace the cathedral that was burnt out in 1166 during the dispute between Louis VII of France and Henry II of England . The lowermost stages of the western towers belong to the 12th century, but the rest of the west end is in the profusely detailed 15th-century Flamboyant Gothic , which were completed just as the Renaissance was affecting the patrons who planned the châteaux of Touraine. The towers were being constructed at

16113-494: Was borrowed from French, which in turn derived it from alumen , the classical Latin name for alum , the mineral from which it was collected. The Latin word alumen stems from the Proto-Indo-European root *alu- meaning "bitter" or "beer". British chemist Humphry Davy , who performed a number of experiments aimed to isolate the metal, is credited as the person who named the element. The first name proposed for

16244-485: Was built towards 918) and became "Châteauneuf". This space, organized between Saint Martin and the Loire, became the economic centre of Tours. Between these two centres were Varennes, vineyards and fields, little occupied except for the Abbaye Saint-Julien established on the banks of the Loire. The two centres were linked during the 14th century. Tours became the capital of the county of Tours or Touraine ,

16375-422: Was completed in 1824 by Danish physicist and chemist Hans Christian Ørsted . He reacted anhydrous aluminium chloride with potassium amalgam , yielding a lump of metal looking similar to tin. He presented his results and demonstrated a sample of the new metal in 1825. In 1827, German chemist Friedrich Wöhler repeated Ørsted's experiments but did not identify any aluminium. (The reason for this inconsistency

16506-443: Was criticized by contemporary chemists from France, Germany, and Sweden, who insisted the metal should be named for the oxide, alumina, from which it would be isolated. The English name alum does not come directly from Latin, whereas alumine / alumina obviously comes from the Latin word alumen (upon declension , alumen changes to alumin- ). One example was Essai sur la Nomenclature chimique (July 1811), written in French by

16637-444: Was founded and centred on the bank of the Loire in the downtown area, not, as was the current practice, in a campus in the suburbs. The latter solution was also chosen by the twin university of Orleans. Royer's long term as mayor was, however, not without controversy, as is exemplified by the construction of the practical but aesthetically unattractive motorway, which runs along the bed of a former canal just 1,500 metres (4,900 feet) from

16768-418: Was invented in 1956 and employed as a storage for drinks in 1958. Throughout the 20th century, the production of aluminium rose rapidly: while the world production of aluminium in 1900 was 6,800 metric tons, the annual production first exceeded 100,000 metric tons in 1916; 1,000,000 tons in 1941; 10,000,000 tons in 1971. In the 1970s, the increased demand for aluminium made it an exchange commodity; it entered

16899-433: Was only discovered in 1921.) He conducted a similar experiment in the same year by mixing anhydrous aluminium chloride with potassium and produced a powder of aluminium. In 1845, he was able to produce small pieces of the metal and described some physical properties of this metal. For many years thereafter, Wöhler was credited as the discoverer of aluminium. As Wöhler's method could not yield great quantities of aluminium,

17030-690: Was the first city of the silk industry. It was taken by Louis XI , as the royal capital under the Valois Kings with its Loire castles and city of art with the School of Tours. The prefecture was partially destroyed during the French Wars of Religion in the late 16th century and again during the Second World War in June 1940. The White and Blue city keeps a historical center registered in

17161-580: Was used as the cap of the Washington Monument , completed in 1885. The tallest building in the world at the time, the non-corroding metal cap was intended to serve as a lightning rod peak. The first industrial large-scale production method was independently developed in 1886 by French engineer Paul Héroult and American engineer Charles Martin Hall ; it is now known as the Hall–Héroult process . The Hall–Héroult process converts alumina into metal. Austrian chemist Carl Joseph Bayer discovered

#416583