Anatomy.

A typical sea anemone is a sessile polyp attached at the base to the surface beneath it by an adhesive foot, called a basal or pedal disc, with a column-shaped body topped by an oral disc. Most are from in diameter and in length, but they are inflatable and vary greatly in dimensions. Some are very large; "Urticina columbiana" and "Stichodactyla mertensii" can both exceed a metre in diameter and "Metridium farcimen" a metre in length. Some species burrow in soft sediment and lack a basal disc, having instead a bulbous lower end, the physa, which anchors them in place.  The column or trunk is generally more or less cylindrical and may be plain and smooth or may bear specialist structures; these include solid papillae (fleshy protuberances), adhesive papillae, cinclides (slits) and small protruding vesicles. In some species the part immediately below the oral disc is constricted and is known as the capitulum. When the animal contracts, the oral disc, tentacles and capitulum fold inside the pharynx and are held in place by a strong sphincter muscle part way up the column. There may be a fold in the body wall, known as a parapet, at this point, and this parapet covers and protects the anemone when it is retracted.  The oral disc has a central mouth, usually slit-shaped, surrounded by one or more whorls of tentacles. The ends of the slit lead to grooves in the wall of the pharynx known as siphonoglyphs; there are usually two of these grooves, but some groups have a single one. The tentacles are generally tapered and often tipped by a pore, but in some species they are branched, club-tipped, or reduced to low knobs. The tentacles are armed with many cnidocytes, cells that are both defensive and used to capture prey. Cnidocytes contain stinging nematocysts, capsule-like organelles capable of everting suddenly, giving the phylum Cnidaria its name. Each nematocyst contains a small venom vesicle filled with actinotoxins, an inner filament, and an external sensory hair. A touch to the hair mechanically triggers a cell explosion, which launches a harpoon-like structure that attaches to the organism that triggered it, and injects a dose of venom in the flesh of the aggressor or prey. At the base of the tentacles in some species lie acrorhagi, elongated inflatable tentacle-like organs armed with cnidocytes, that can flail around and fend off other encroaching anemones; one or both anemones can be driven off or suffer injury in such battles. The venom is a mix of toxins, including neurotoxins, that paralyzes the prey so the anemone can move it to the mouth for digestion inside the gastrovascular cavity. Actinotoxins are highly toxic to prey species of fish and crustaceans. However, Amphiprioninae (clownfish), small banded fish in various colours, are not affected by their host anemone's sting and shelter themselves from predators among its tentacles. Several other species have similar adaptions and are also unaffected (see "Mutualistic relationships"). Most sea anemones are harmless to humans, but a few highly toxic species (notably "Actinodendron arboreum", "Phyllodiscus semoni" and "Stichodactyla" spp.) have caused severe injuries and are potentially lethal.

Digestive system.

Sea anemones have what can be described as an incomplete gut; the gastrovascular cavity functions as a stomach and possesses a single opening to the outside, which operates as both a mouth and anus. Waste and undigested matter is excreted through this opening. The mouth is typically slit-like in shape, and bears a groove at one or both ends. The groove, termed a "siphonoglyph", is ciliated, and helps to move food particles inwards and circulate water through the gastrovascular cavity.  The mouth opens into a flattened pharynx. This consists of an in-folding of the body wall, and is therefore lined by the animal's epidermis. The pharynx typically runs for about one third the length of the body before opening into the gastrovascular cavity that occupies the remainder of the body.  The gastrovascular cavity itself is divided into a number of chambers by mesenteries radiating inwards from the body wall. Some of the mesenteries form complete partitions with a free edge at the base of the pharynx, where they connect, but others reach only partway across. The mesenteries are usually found in multiples of twelve, and are symmetrically arranged around the central lumen. They have stomach lining on both sides, separated by a thin layer of mesoglea, and include filaments of tissue specialised for secreting digestive enzymes. In some species, these filaments extend below the lower margin of the mesentery, hanging free in the gastrovascular cavity as thread-like acontial filaments. These acontia are armed with nematocysts and can be extruded through cinclides, blister-like holes in the wall of the column, for use in defence.

Musculature and nervous system.

A primitive nervous system, without centralization, coordinates the processes involved in maintaining homeostasis, as well as biochemical and physical responses to various stimuli. There are two nerve nets, one in the epidermis and one in the gastrodermis; these unite at the pharynx, the junctions of the septa with the oral disc and the pedal disc, and across the mesogloea. No specialized sense organs are present but sensory cells include nematocytes and chemoreceptors.  The muscles and nerves are much simpler than those of most other animals, although more specialised than in other cnidarians, such as corals. Cells in the outer layer (epidermis) and the inner layer (gastrodermis) have microfilaments that group into contractile fibers. These fibers are not true muscles because they are not freely suspended in the body cavity as they are in more developed animals. Longitudinal fibres are found in the tentacles and oral disc, and also within the mesenteries, where they can contract the whole length of the body. Circular fibers are found in the body wall and, in some species, around the oral disc, allowing the animal to retract its tentacles into a protective sphincter.  Since the anemone lacks a rigid skeleton, the contractile cells pull against the fluid in the gastrovascular cavity, forming a hydrostatic skeleton. The anemone stabilizes itself by flattening its pharynx which acts as a valve, keeping the gastrovascular cavity at a constant volume and making it rigid. When the longitudinal muscles relax, the pharynx opens and the cilia lining the siphonoglyphs beat, wafting water inwards and refilling the gastrovascular cavity. In general, the sea anemone inflates its body to extend its tentacles and feed, and deflates it when resting or disturbed. The inflated body is also used to anchor the animal inside a crevice, burrow or tube.

Lifecycle.

Unlike other cnidarians, anemones (and other anthozoans) entirely lack the free-swimming medusal stage of their lifecycle; the polyp produces eggs and sperm, and the fertilized egg develops into a planula larva which develops directly into another polyp. Both sexual and asexual reproduction can occur.  The sexes in sea anemones are separate in some species, while other species are sequential hermaphrodites, changing sex at some stage in their life. The gonads are strips of tissue within the mesenteries. In sexual reproduction, males may release sperm to stimulate females to release eggs, and fertilization occurs, either internally in the gastrovascular cavity or in the water column. The eggs and sperm, or the larvae, are ejected through the mouth. In many species the eggs and sperm rise to the surface where fertilisation occurs. The fertilized egg develops into a planula larva, which drifts for a while before sinking to the seabed and undergoing metamorphosis into a juvenile sea anemone. Some larvae preferentially settle onto certain suitable substrates, The mottled anemone ("Urticina crassicornis") for example, settles onto green algae, perhaps attracted by a biofilm on the surface.  The brooding anemone ("Epiactis prolifera") is gynodioecious, starting life as a female and later becoming hermaphroditic, so that populations consist of females and hermaphrodites. As a female, the eggs can develop parthenogenetically into female offspring without fertilisation, and as a hermaphrodite, the eggs are routinely self-fertilised. The larvae emerge from the anemone's mouth and tumble down the column, lodging in a fold near the pedal disc. Here they develop and grow, remaining for about three months before crawling off to start independent lives.  Sea anemones have great powers of regeneration and can reproduce asexually, by budding, fragmentation, or by longitudinal or transverse binary fission. Some species such as certain "Anthopleura" divide longitudinally, pulling themselves apart, resulting in groups of individuals with identical colouring and markings. Transverse fission is less common, but occurs in "Anthopleura stellula" and "Gonactinia prolifera", with a rudimentary band of tentacles appearing halfway up the column before it splits horizontally. Some species can also reproduce by pedal laceration. In this process, a ring of material may break off from the pedal disc at the base of the column which then fragments, the pieces regenerating into new clonal individuals. Alternatively, fragments detach separately as the animal creeps across a surface. In "Metridium dianthus", fragmentation rates were higher in individuals living among live mussels than among dead shells, and all the new individuals had tentacles within three weeks.  The sea anemone "Aiptasia diaphana" displays sexual plasticity. Thus asexually produced clones derived form a single founder individual can contain both male and female individuals (ramets). When eggs and sperm (gametes) are formed, they can produce zygotes derived from “selfing” (within the founding clone) or out-crossing, that then develop into swimming planula larvae. Anemones tend to grow and reproduce relatively slowly, the magnificent sea anemone ("Heteractis magnifica") for example, may live for decades, with one individual surviving in captivity for eighty years.

Behaviour and ecology.

Movement.

A sea anemone is capable of changing its shape dramatically. The column and tentacles have longitudinal, transverse and diagonal sheets of muscle and can lengthen and contract, as well as bend and twist. The gullet and mesenteries can evert (turn inside out), or the oral disc and tentacles can retract inside the gullet, with the sphincter closing the aperture; during this process, the gullet folds transversely and water is discharged through the mouth.

Locomotion.

Although some species of sea anemone burrow in soft sediment, the majority are mainly sessile, attaching to a hard surface with their pedal disc, and tend to stay in the same spot for weeks or months at a time. They can move however, being able to creep around on their bases; this gliding can be seen with time-lapse photography but the motion is so slow as to be almost imperceptible to the naked eye. The process resembles the locomotion of a gastropod mollusc, a wave of contraction moving from the functionally posterior portion of the foot towards the front edge, which detaches and moves forwards. Sea anemones can also cast themselves loose from the substrate and drift to a new location. "Gonactinia prolifera" is unusual in that it can both walk and swim; walking is by making a series of short, looping steps, rather like a caterpillar, attaching its tentacles to the substrate and drawing its base closer; swimming is done by rapid movements of the tentacles beating synchronously like oar strokes. "Stomphia coccinea" can swim by flexing its column, and the sea onion anemone inflates and casts itself loose, adopting a spherical shape and allowing itself to be rolled about by the waves and currents. There are no truly pelagic sea anemones, but some stages in the life cycle post-metamorphosis are able, in response to certain environmental factors, to cast themselves off and have a free-living stage that aids in their dispersal.  The sea onion "Paranthus rapiformis" lives on subtidal mud flats and burrows into the sediment, holding itself in place by expanding its basal disc to form an anchor. If it gets washed out of its burrow by strong currents, it contracts into a pearly glistening ball which rolls about. Tube-dwelling anemones which live in parchment-like tubes, are in the anthozoan subclass Ceriantharia, and are only distantly related to sea anemones.

Feeding and diet.

Sea anemones are typically predators, ensnaring prey of suitable size that comes within reach of their tentacles and immobilizing it with the aid of their nematocysts. The prey is then transported to the mouth and thrust into the pharynx. The lips can stretch to aid in prey capture and can accommodate larger items such as crabs, dislodged molluscs and even small fish. "Stichodactyla helianthus" is reported to trap sea urchins by enfolding them in its carpet-like oral disc. A few species are parasitic on other marine organisms. One of these is "Peachia quinquecapitata", the larvae of which develop inside the medusae of jellyfish, feeding on their gonads and other tissues, before being liberated into the sea as free-living, juvenile anemones.

Mutualistic relationships.

Although not plants and therefore incapable of photosynthesis themselves, many sea anemones form an important facultative mutualistic relationship with certain single-celled algae species that reside in the animals' gastrodermal cells, especially in the tentacles and oral disc. These algae may be either zooxanthellae, zoochlorellae or both. The sea anemone benefits from the products of the algae's photosynthesis, namely oxygen and food in the form of glycerol, glucose and alanine; the algae in turn are assured a reliable exposure to sunlight and protection from micro-feeders, which the sea anemones actively maintain. The algae also benefit by being protected by the sea anemone's stinging cells, reducing the likelihood of being eaten by herbivores. In the aggregating anemone ("Anthopleura elegantissima"), the colour of the anemone is largely dependent on the proportions and identities of the zooxanthellae and zoochlorellae present. The hidden anemone ("Lebrunia coralligens") has a whorl of seaweed-like pseudotentacles, rich in zooxanthellae, and an inner whorl of tentacles. A daily rhythm sees the pseudotentacles spread widely in the daytime for photosynthesis, but they are retracted at night, at which time the tentacles expand to search for prey. Several species of fish and invertebrates live in symbiotic or mutualistic relationships with sea anemones, most famously the clownfish. The symbiont receives the protection from predators provided by the anemone's stinging cells, and the anemone utilises the nutrients present in its faeces. Other animals that associate with sea anemones include cardinalfish (such as Banggai cardinalfish), juvenile threespot dascyllus, incognito (or anemone) goby, juvenile painted greenling, various crabs (such as "Inachus phalangium", "Mithraculus cinctimanus" and "Neopetrolisthes"), shrimp (such as certain "Alpheus", "Lebbeus", "Periclimenes" and "Thor"), opossum shrimp (such as "Heteromysis" and "Leptomysis"), and various marine snails.  Two of the more unusual relationships are those between certain anemones (such as "Adamsia", "Calliactis" and "Neoaiptasia") and hermit crabs or snails, and "Bundeopsis" or "Triactis" anemones and "Lybia" boxing crabs. In the former, the anemones live on the shell of the hermit crab or snail. In the latter, the small anemones are carried in the claws of the boxing crab.

Habitats.

Sea anemones are found in both deep oceans and shallow coastal waters worldwide. The greatest diversity is in the tropics although there are many species adapted to relatively cold waters. The majority of species cling on to rocks, shells or submerged timber, often hiding in cracks or under seaweed, but some burrow into sand and mud, and a few are pelagic.

Relationship with humans.

Sea anemones and their attendant anemone fish can make attractive aquarium exhibits and both are often harvested from the wild as adults or juveniles. These fishing activities significantly impact the populations of anemones and anemone fish by drastically reducing the densities of each in exploited areas. Besides their collection from the wild for use in reef aquaria, sea anemones are also threatened by alterations to their environment. Those living in shallow water coastal locations are affected directly by pollution and siltation, and indirectly by the effect these have on their photosynthetic symbionts and the prey on which they feed.  In southern Italy and southwestern Spain, the snakelocks anemone ("Anemonia viridis") is consumed as a delicacy. The whole animal is marinated in vinegar, then coated in a batter similar to that used to make calamari and deep-fried in olive oil.

Fossil record.

Most Actiniaria do not form hard parts that can be recognized as fossils, but a few fossils of sea anemones do exist; "Mackenzia", from the Middle Cambrian Burgess Shale of Canada, is the oldest fossil identified as a sea anemone.

Taxonomy.

Sea anemones, order Actiniaria, are classified in the phylum Cnidaria, class Anthozoa, subclass Hexacorallia. Rodriguez et al. proposed a new classification for the Actiniaria based on extensive DNA results.  Suborders and Superfamilies included in Actiniaria are:

Phylogeny.

External relationships.

Anthozoa contains three subclasses: Hexacorallia, which contains the Actiniaria; Octocorallia; and Ceriantharia. These are monophyletic, but the relationships within the subclasses remain unresolved.

Internal relationships.

The relationships of higher-level taxa in Carlgren's classification are re-interpreted as follows:

Sea anemones are a group of marine, predatory animals of the order Actiniaria. They are named after the anemone, a terrestrial flowering plant, because of the colourful appearance of many. Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Hexacorallia. As cnidarians, sea anemones are related to corals, jellyfish, tube-dwelling anemones, and "Hydra". Unlike jellyfish, sea anemones do not have a medusa stage in their life cycle.

Les anémones de mer, orties de mer ou actiniaires (Actiniaria) sont un groupe d'animaux marins vivant fixés à un support. Elles appartiennent à l'ordre des cnidaires (animaux à symétrie radiaire dont font partie les coraux et les méduses) anthozoaires. L'anémone est constituée d'un polype solitaire, sans squelette calcaire.


Family.

The family relations of the king are well known. Senusret I was the son of Amenemhat I. His mother was a certain queen with the name Neferitatenen. His main wife was Neferu III who was also his sister and mother of his successor Amenemhat II. The known children are Amenemhat II and the princesses Itakayt and Sebat. The latter was most likely a daughter of Neferu III as she appears with the latter together in one inscription.

Building program.

Senusret I dispatched several quarrying expeditions to the Sinai and Wadi Hammamat and built numerous shrines and temples throughout Egypt and Nubia during his long reign. He rebuilt the important temple of Re-Atum in Heliopolis which was the centre of the sun cult. He erected 2 red granite obelisks there to celebrate his Year 30 Heb Sed Jubilee. One of the obelisks still remains and is the oldest standing obelisk in Egypt. It is now in the Al-Masalla (Obelisk in Arabic) area of Al-Matariyyah district near the Ain Shams district (Heliopolis). It is 67 feet tall and weighs 120 tons or 240,000 pounds.  Senusret I is attested to be the builder of a number of major temples in Ancient Egypt, including the temple of Min at Koptos, the Temple of Satet on Elephantine, the Month-temple at Armant and the Month-temple at El-Tod, where a long inscription of the king is preserved.  A shrine (known as the White Chapel or Jubilee Chapel) with fine, high quality reliefs of Senusret I, was built at Karnak to commemorate his Year 30 jubilee. It has subsequently been successfully reconstructed from various stone blocks discovered by Henri Chevrier in 1926. Finally, Senusret remodelled the Temple of Khenti-Amentiu Osiris at Abydos, among his other major building projects.

The royal court.

Some of the key members of the court of Senusret I are known. The vizier at the beginning of his reign was Intefiqer, who is known from many inscriptions and from his tomb next to the pyramid of Amenemhat I. He seems to have held this office for a long period of time and was followed by a vizier named Senusret. Two treasurers are known from the reign of the king: Sobekhotep (year 22) and Mentuhotep. The latter had a huge tomb next to the pyramid of the king and he seems to have been the main architect of the Amun temple at Karnak. Several "high stewards" are attested. Hor is known from several stelae and from an inscription in the Wadi el-Hudi where he was evidently the leader of an expedition for amethyst. One of the stelae is dated to year nine of the king. A certain Nakhr followed in office attested around year 12 of the king. He had a tomb at Lisht. A certain Antef, son of a woman called Zatamun is known again from several stelae, one dates to year 24 another one to year 25 of Senusret I. Another Antef was the son a woman called Zatuser and was most likely also "high steward" in the king's reign.

Succession.

Senusret was crowned coregent with his father, Amenemhat I, in his father's 20th regnal year. Towards the end of his own life, he appointed his son Amenemhat II as his coregent. The stele of Wepwawetō is dated to the 44th year of Senusret and to the 2nd year of Amenemhet, thus he would have appointed him some time in his 43rd year. Senusret is thought to have died during his 46th year on the throne since the Turin Canon ascribes him a reign of 45 Years.

Senusret I (Middle Egyptian: z-n-wsrt; /siː ni ˈwas.riʔ/) also anglicized as Sesostris I and Senwosret I, was the second pharaoh of the Twelfth Dynasty of Egypt. He ruled from 1971 BC to 1926 BC (1920 BC to 1875 BC), and was one of the most powerful kings of this Dynasty. He was the son of Amenemhat I. Senusret I was known by his prenomen, Kheperkare, which means "the Ka of Re is created."

Sésostris (-1962 / -1928) est le fils aîné du fondateur de la, (-1991 / -1962). Pris comme co-régent de son père en l'an XX du règne de celui-ci, Sésostris se voit confier la conduite des opérations militaires contre les turbulents voisins de l'Égypte pendant que son père continue à administrer le pays. En l'an XXX, le pharaon est victime d'un attentat, qui lui coûte (ou non) la vie. Sésostris monte alors sur le trône.


Life.

Early years.

Born in Angers she was the eldest child of Count Fulk IV of Anjou but the only one born by his first wife, Hildegarde of Beaugency. Having lost her mother in 1070, at only two years of age, she received a good education and grew to be pious and concerned about religious reform, especially the struggle against the secular appropriation of church property. She was also noted for her beauty in her youth.

Duchess of Aquitaine.

It has long been presumed that, in 1089, her marriage was arranged to the young Duke and poet, William IX of Aquitaine. However, this union proved a dismal failure. Her husband was a voracious philanderer, whose affairs infuriated his wife. She suffered from severe mood swings, vacillating between vivacity and sullenness, and would nag her husband. She also had a habit of retiring in bad temper to a cloister after an argument, cutting off all contact with the outside world, before suddenly making a reappearance in the court as if her absence had never occurred. Such behavior, coupled with her failure to conceive a child, led William to send her back to her father and have the marriage dissolved in 1091.  Her behavior during her marriage to the Duke has been described by both Marion Meade and Alison Weir as schizophrenic, with Weir adding a suggestion of manic depression.  However, Ruth Harvey's 1993 critical investigation shows the assumption of William's marriage to Ermengarde to be based largely on an error in a nineteenth-century secondary source and it is highly likely that Philippa of Toulouse was William's only wife. Further research has found the claim that William was married to "Hermingerda", daughter of Fulk IV of Anjou is based on the very unreliable chronicle of William of Tyre, written between 1169 and 1187, more than 70 years after the events in question would have taken place. Tyre erroneously identifies Ermengarde's mother as Bertrand of Montfort, the sister of Amalricus de Montfort when her mother was in fact Audearde or Hildegarde of Beaugency. Tyre's chronicle lacks any contemporary corroboration, no primary text ever mentions a marriage between William and Ermengarde. It is therefore not only improbable that William married Ermengarde, it is likely that Ermengarde - at least as a wife of William - never existed.  But Stephen Philp, poet and mediaeval historian, has counter-argued that, on the basis of pure logic, even if we accept that Ermengarde never married Duke William IX, this has no bearing on whether she actually existed or not. Ermengarde's existence is indeed supported by the correction of the name of her mother. Moreover, several sources give colourful accounts of the marriage and its aftermath, and her later marriage, so there is no good reason to doubt it.

Duchess and regent of Brittany.

In 1093, her father married her to Duke Alan IV of Brittany, probably to secure an alliance against Normandy, then controlled by William the Conqueror’s son, Robert Curthose. The union produced three children: the future Duke Conan III, Hawise (wife of Count Baldwin VII of Flanders, who repudiated her in 1110) and Geoffrey (who died young in Jerusalem in 1116).  Her husband left for Palestine in 1096 to take part in the First Crusade and she served as Regent of the Duchy from then until 1101. She spent little time in Rennes or the west of Brittany, preferring Nantes and the Saumur region. Influenced by Robert of Arbrissel, she approved the expansion of the abbey at Fontevraud, to which she withdrew on two occasions. An admirer of Saint Bernard of Clairvaux (to whose abbey she made donations), she favored the creation of Cistercian abbeys. She was also a benefactor of the monastery of Buzay, near Nantes.  Alan IV, an unpopular ruler, was forced to abdicated in favor of his son in 1112, and he and Ermengarde were separated after this.

Later years.

By 1116 Ermengarde was living in Fontevrault Abbey, where she reputedly became a friend of her first husband's second wife, Philippa of Toulouse.  In 1118 after the death of Philippa, Ermengarde decided to avenge her deceased friend. She went south from Fontevrault to the court of her former husband, Duke William of Aquitaine, where she demanded to be recognized as the rightful Duchess. William ignored this remarkable request. Accordingly, in October 1119, she suddenly appeared at the Council of Reims, being held by Pope Calixtus II, demanding that the Pope excommunicate William, oust his mistress from the ducal palace, and restore Ermengarde to her rightful place as the Duchess of Aquitaine. The Pope ""declined to accommodate her""; however, Ermengarde continued to trouble William for several years afterwards.

Death.

Ermengarde at one point went on Crusade to Palestine; she returned ten years later, and some historians believe her life ended in Jerusalem at the convent of Saint Anne. But obituary lists at Redon Abbey record a date of death in 1146 in Redon where her second husband, Alan IV was buried. It is believed that she died a nun. The contradictions about her death and the records of her burial maybe indicated that in fact she died in Jerusalem, and that her body was subsequently transferred to Redon.

Ermengarde of Anjou (ca. 1068 – 1 June 1146) was a member of the comital House of Anjou and by her two marriages was successively Duchess of Aquitaine and Brittany. Also, she was a patron of Fontevraud Abbey. Ermengarde was the regent of Brittany during the absence of her spouse from 1096 until 1101.

Ermengarde d'Anjou, née entre 1068 et 1072 au château d'Angers et morte le 1146 est la fille de Foulques IV d'Anjou le Réchin, comte d'Anjou.


Geography.

Rostov Oblast borders Ukraine and also Volgograd and Voronezh Oblasts in the north, Krasnodar and Stavropol Krais in the south, and the Republic of Kalmykia in the east. The Rostov oblast is located in the Pontic-Caspian steppe.  It is within the Russian Southern Federal District.

Rivers and lakes.

The Don River, one of Europe's largest rivers, flows through the oblast for part of its course. Lakes cover only 0.4% of the oblast's area.

Administrative divisions.

It was formed in 1937 out of the Azov-Black Sea Krai.

Demographics.

"Population":  2009 - 1.38 | 2010 - 1.38 | 2011 - 1.39 | 2012 - 1.51 | 2013 - 1.52 | 2014 - 1.61 | 2015 - 1.63 | 2016 - 1.60(e)  "Ethnic groups": Residents identified themselves as belonging to 157 different ethnic groups, including twenty-seven of more than two thousand persons each. The most important ethnicities are the 3,795,607 Russians (90.3%); the 77,802 Ukrainians (1.9%); the 110,727 Armenians (2.6%). Other important groups are the 35,902 Turks (0.9%); 16,493 Belarusians (0.4%)); 13,948 Tatars (0.3%); 17,961 Azerbaijanis (0.4%); 11,449 Chechens (0.3%); 16,657 Romani (0.4%); 11,597 Koreans (0.3%); 8,296 Georgians (0.2%), and 2,040 Assyrians (.05%). There were also 76,498 people (1.8%) belonging to other ethno-cultural groupings. 76,735 people were registered from administrative databases, and could not declare an ethnicity. It is estimated that the proportion of ethnicities in this group is the same as that of the declared group.

Religion.

According to a 2012 survey 49.5% of the population of Rostov Oblast adheres to the Russian Orthodox Church, 6% are unaffiliated generic Christians, 1% are either Orthodox Christian believers who don't belong to church or are members of other (non-Russian) Orthodox bodies, 1% are Muslims, and 1% are adherents of the Slavic native faith (Rodnovery) movement. In addition, 26% of the population declares to be "spiritual but not religious", 12% is atheist, and 3.5% follows other religions or did not give an answer to the question.  The Ascension Cathedral is the largest Russian Orthodox church in Novocherkassk, Rostov Oblast, Russia. It used to be one of the largest churches of the Russian Empire and the main church of the Don Host Province.  The five-domed building, which stands 75 meters tall, is a notable example of the Russian Neo-Byzantine architecture. It was erected between 1891 and 1904 on the site of an earlier church. The first church on the site was built to Luigi Rusca's designs. It collapsed in 1846. A replacement church collapsed 17 years later.  Church of the Intercession of the Holy Virgin ― one of the oldest churches in Rostov-on-Don. For a considerable period of time Intercession Church served as the principal church not only for the fortress of St. Dimitry of Rostov, but also for people of local settlements. Since the end of the 18th century Church of Intercession had been considered to be a cathedral. The status changed in 1822, when Church of the Nativity of the Blessed Virgin Mary on the decree of the Holy Synod was declared cathedral.

Attractions.

The region is 8057 of objects of archaeological heritage of Federal importance. These include lower-Gnilovskaya a settlement and a necropolis, fragments of the walls of the Genoese fortress of the 14th century, the archaeological Museum-reserve "Tanais", many burial Mounds and necropolises.  Since 2002, in the Rostov region are the country's only racing on tractors "bison-Track-Show". In a unique competition brings together machine operators of agricultural enterprises of Russia and abroad. In the past the race on tractors have become a real sports holiday of workers of agriculture.

Theatres.

The theater has two stages as well as a music and entertainment center, and hosts about 300 performances and concerts annually, as well as various forums and festivals. Its repertoire encompasses both musical traditions, as well as experiments in the field of contemporary art.

Economy.

Major industries of Rostov Oblast are agriculture, agricultural industry, food processing, heavy industry, coal and automobile manufacture.  The largest companies in the region include Novoshakhtinsk Petrochemical Plant, Gloria Jeans Corp., Rostvertol, Oil-extracting factory "Yug Rusi", North Caucasian Railway.

Rostov Oblast () is a federal subject of Russia (an oblast), located in the Southern Federal District. The oblast has an area of and a population of 4,277,976 (2010 Census), making it the sixth most populous federal subject in Russia. Its administrative center is the city of Rostov-on-Don, which also became the administrative center of the Southern Federal District in 2002.

L'oblast de Rostov (en, "") est une subdivision régionale (un oblast), du district fédéral du Sud de la Russie.


Demographics.

Yuyao has a local population of 400,000 in downtown, within the total 850,000 in the county. However, recently the migrated workers and their families have almost doubled the total population to about 1.6 million, but they do not show up in the official census and other related statistics data.

Geography and climate.

Yuyao lies in a subtropical monsoon zone, rich in sunshine and rain fall, warm and humid, distinct in the four seasons. The mean annual sunshine is 2,061 hours and the annual rate of sunshine is 47%. The mean annual temperature is 16 degree Celsius and the coldest months perennially are January and February, the hottest are July and August. The mean annual precipitation is around 1,300 millimeters and changes greatly from year to year. The hyetal distribution is also uneven during a year, and the rainfall centers on East Asian rainy season (梅雨) (aka bai-u rainy period) from April to June and typhoon period from July to December.  Yuyao offers a wide variety of landscape from wide open ocean in Hangzhou Bay, rice fields in fertile plains to high spires in Siming Mountains. Yaojiang River originates in Siming Mountains in the south where the Ninth Fantasy world of Taoism is located. Yaojiang River goes through the county and extends eastward into East China Sea as well as Pacific Ocean.

History.

Yuyao is well known for its rich heritage of civilization. The Neolithic Hemudu culture formed in Yuyao about 5,000 B.C. is one of the earliest sites of human civilization on earth. The material and ethical relics revealed large-scale rice plantation and other agricultural activities, hurdle style architecture, paddling and boating and respecting birds and sun.  Yuyao also produced many famous scholars in the history, for example, Yan Zi-Ling in Han Dynasty, Yu Fan in Three Kingdoms Period, Yu Xi in Jin Dynasty, Yu Shinan in Sui Dynasty and Tang Dynasty, Wang Yangming, Zhu Shunshui and Huang Zongxi in Ming Dynasty. Wang Yangming and Huang Zongxi were ranked among China’s top 10 ideologists. Yuyao was then named as “the Most Famous County”and “the Famous State on Literature”. During the Anti-Japanese War, Yuyao was one of China’s 19 bases against Japanese invaders, and was the center of anti-Japanese bases of eastern Zhejiang province.

Administrative divisions.

Subdistricts:  Towns:  The only township is Luting Township (鹿亭乡)

Economy.

Yuyao is known as a place for rice and fish. Its economy has been booming as private enterprises dominate after the economic reform began in late 1970s. In 2007, GDP will reach RMB 34 billions, with double digit annual growth rates over the past 20 years. It ranked as one of the top-20 counties in terms of comprehensive economic strength out of all the 2100 counties in China. The industry products are mainly electric appliances, plastic moulding, machinery and textiles. High-tech industries such as materials, optical, electro-mechanical integration and fine chemical industry are developing rapidly. The main agriculture, forestry and animal husbandry products of Yuyao are tea, fruits like waxberry and mandarin orange, bamboo, silkworm, fowl, livestock and fish. Fresh produce is available in all seasons.

Transport.

The Shanghai-Hangzhou-Ningbo Expressway and China National Highway 329 and Shanghai-Hangzhou-Ningbo Railway go through Yuyao. The world's longest trans-oceanic bridge - the Hangzhou Bay Bridge - was recently completed construction near the northern border of Yuyao. It reduced the cross bay traffic to only from the current section of Shanghai-Hangzhou-Ningbo Expressway around Hangzhou Bay.

Yuyao () is a county-level city in the northeast of Zhejiang province, China. It is under the jurisdiction of the sub-provincial city of Ningbo.

Yuyao (余姚 ; pinyin : Yúyáo) est une ville de la province du Zhejiang en Chine. C'est une ville-district placée sous la juridiction administrative de la ville-préfecture de Ningbo. On y parle le wu.


Geography and climate.

Yichun spans 27°33′−29°06′ N latitude and 113°54′−116°27′ E longitude, bordering Nanchang, the provincial capital, and Fuzhou to the east, Ji'an and Xinyu to the south, Pingxiang to the southwest, Changsha and Yueyang (both in Hunan) to the northwest, and Jiujiang to the north.  Yichun has a humid subtropical climate (Köppen "Cfa") affected by the East Asian monsoon, with long, humid, very hot summers (albeit slightly cooler than much of the rest of the province) and cool and drier winters with occasional cold snaps. The monthly 24-hour average temperature ranges from in January to in July, with an annual mean of. The average annual precipitation is. Winter begins somewhat sunny and dry but becomes progressively wetter and cloudier; spring begins especially gloomy, and from April to June each of the months averages more than of rainfall. After the heavy rains subside in June, summer is especially sunny. Autumn is warm and relatively dry.

Administration.

Yichun has 1 district, 3 county-level cities, and 6 counties under its direct jurisdiction.

Economy and infrastructure.

The State Highway 320, State Highway 105, the Shanghai-Ruijin Highway and the Ganyue Highway (the Jiangxi-Guangdong Highway) form a convenient traffic network in the city.  Yichun is a stop along the major railway running between Beijing and Nanchang. Since 2014, it also has a station on the Shanghai-Changsha CRH high speed train line between Changsha and Nanchang station. Direct flights to Yichun airport are also available from Shanghai.  A large sports complex with two stadiums was built in the 1990s and draws teams for sports competitions from all across China. Agriculture is the main industry but other natural resource industries such as timber and mining are extremely important for the economy. Major mineral deposits include aluminum, tungsten, gold, zinc, and copper.

Culture and tourism.

Yichun has abundant historical, cultural and natural tourism resources. Hongzhou Kiln, a famous kiln of the Tang Dynasty, was first built during the Southern Dynasties (AD 420-589). Wucheng Site of the Shang Dynasty was discovered in Yichun in 1973. Gezhao Mountain, situated in Zhangshu, is a famous Taoist mountain in China. It is home to a number of ancient buildings. Tourists also visit the Guan Mountain Scenic Area, which is located at the juncture of Yifeng and Tonggu counties. The famous Mingyue (moon) Mountain gained its name from its shape like a bright crescent moon. Mingyue Shan can be accessed using the cable car taking to the top of the mountain. The area consists of over ten peaks which are all more than a thousand meters (about 3,281 feet) above sea level. It is also a national forest park comprising six tourist zones. Among them, the Yangshan Scenic Spot is an important birthplace of Buddhism in South China, and the Wentang Town, at the foot of the Mingyue Mountain, is known for hot springs teeming with selenium.

Yichun (; postal: Ichun) is a mountainous prefecture-level city in western/northwestern Jiangxi Province, China, bordering Hunan to the west. Yichun literally means "pleasant spring". It is located in the northwest of the province along a river surrounded by mountains. Yichun has a profound Buddhist culture. "Can Lin Qing Gui", the monastic rules for Buddhists at the Buddhist temple, originated from Yichun. Yichun is also the birthplace of a number of literary figures, such as Tao Yuanming and Deng Gu, both of whom are poets from ancient times.

Yichun () est une ville du nord-ouest de la province du Jiangxi en Chine. On y parle le dialecte de Yichun du gan. Il y aurait existé (ou existerait encore) un camp de concentration.


History.

San Juan Capistrano is the site of a Catholic mission for which it is named, Mission San Juan Capistrano. When the Mission was founded in 1776, the region was populated by the Acjachemen band of Native Americans, called Juaneños by the Spanish. The mission was named after Giovanni da Capistrano (1386–1456), the Franciscan saint from Capestrano, in the Italian region of Abruzzo.  Giovanni da Capistrano, although raised to the sainthood by the Roman Catholic Church is documented by historical research by the Oxford University historian Norman Davies to have burnt to death more than 50 Jews in May 1453 in the Polish city of Wroclaw.  The city is the site of California's oldest residential neighborhood, Los Rios. It is also the home of the oldest in use building in California, the Serra Chapel in the Mission. The area was the site of both the first vineyard and first winery in California.

Demographics.

2010.

At the 2010 census San Juan Capistrano had a population of 34,593. The population density was 2,419.9 people per square mile (934.3/km). The racial makeup of San Juan Capistrano was 26,664 (77.1%) White (55.8% Non-Hispanic White), 193 (0.6%) African American, 286 (0.8%) Native American, 975 (2.8%) Asian, 33 (0.1%) Pacific Islander, 5,234 (15.1%) from other races, and 1,208 (3.5%) from two or more races. Hispanic or Latino of any race were 13,388 persons (38.7%).  The census reported that 34,506 people (99.7% of the population) lived in households, and 87 (0.3%) lived in non-institutionalized group quarters.  There were 11,394 households, 4,030 (35.4%) had children under the age of 18 living in them, 6,706 (58.9%) were opposite-sex married couples living together, 1,089 (9.6%) had a female householder with no husband present, 526 (4.6%) had a male householder with no wife present. There were 456 (4.0%) unmarried opposite-sex partnerships, and 87 (0.8%) same-sex married couples or partnerships. 2,381 households (20.9%) were one person and 1,407 (12.3%) had someone living alone who was 65 or older. The average household size was 3.03. There were 8,321 families (73.0% of households); the average family size was 3.44.  The age distribution was 8,518 people (24.6%) under the age of 18, 3,066 people (8.9%) aged 18 to 24, 7,804 people (22.6%) aged 25 to 44, 9,792 people (28.3%) aged 45 to 64, and 5,413 people (15.6%) who were 65 or older. The median age was 40.2 years. For every 100 females, there were 98.3 males. For every 100 females age 18 and over, there were 96.7 males.  There were 11,940 housing units at an average density of 835.2 per square mile, of the occupied units 8,462 (74.3%) were owner-occupied and 2,932 (25.7%) were rented.The homeowner vacancy rate was 1.3%; the rental vacancy rate was 4.7%. 24,052 people (69.5% of the population) lived in owner-occupied housing units and 10,454 people (30.2%) lived in rental housing units.  According to the 2010 United States Census, San Juan Capistrano had a median household income of $75,356, with 12.7% of the population living below the federal poverty line.

2000.

As of the census of 2000, there were 33,826 people in 10,930 households, including 8,196 families, in the city. The population density was 2,381.2 inhabitants per square mile (919.1/km). There were 11,320 housing units at an average density of 307.6 persons/km (796.9 persons/mi). The racial makeup of the city was 78.47% White, 0.78% African American, 1.07% Native American, 1.92% Asian, 0.11% Pacific Islander, 14.21% from other races, and 3.43% from two or more races. 33.13% of the population were Hispanic or Latino of any race.  Of the 10,930 households, 39.9% had children under the age of 18 living with them, 62.7% were married couples living together, 8.5% had a female householder with no husband present, and 25.0% were non-families. 19.7% of households were one person and 10.3% were one person aged 65 or older. The average household size was 3.06 and the average family size was 3.45.  The age distribution was 28.1% under the age of 18, 7.8% from 18 to 24, 27.3% from 25 to 44, 23.7% from 45 to 64, and 13.1% 65 or older. The median age was 36 years. For every 100 females, there were 96.9 males. For every 100 females age 18 and over, there were 94.0 males.  The median household income was $62,392 and the median family income was $69,481. Males had a median income of $47,574 versus $34,821 for females. The per capita income for the city was $29,926. About 10.7% of the population and 6.6% of families were below the poverty line, including 14.8% of those under age 18 and 4.2% of those age 65 or over.

Government.

As of 2019, the City Council members are: Troy A. Bourne, (Mayor), John Taylor, (Mayor Pro Tem), Sergio Farias, Brian L. Maryott, and Derek Reeve. The current city manager is Benjamin Siegel.  In the California State Legislature, San Juan Capistrano is in, and in.  In the United States House of Representatives, San Juan Capistrano is in.

Geography.

San Juan Capistrano is located in south Orange County and is bisected by Interstate 5. (33.499493, -117.661614).  According to the United States Census Bureau, the city has a total area of. of it is land and of it (1.26%) is water.

Economy.

For detailed information on San Juan Capistrano's economy, see the City's 2018 Comprehensive Annual Financial Report.  San Juan Capistrano is home to over 1,700 businesses. The City's unemployment rate was at 3.7% as of December 2017.

Top employers.

The Capistrano Unified School District (CUSD) Office is located within the city limits, and employs approximately 4,400 people. However, as most of these employees are located at individual school sites, only the employees within city limits are included in this list.  The city of San Juan Capistrano employs approximately 93 people.

The Cliff Swallows of Capistrano.

San Juan Capistrano is also known for its cliff swallows. The protected birds return during migration, which originates in the town of Goya, Argentina, around St. Joseph's Day (March 19) each year. The day is celebrated by the city's annual Swallows' Day Parade and other festive events. The swallows leave around October 23, the former feast day of St. John of Capistrano. The 1940 hit song "When the Swallows Come Back to Capistrano", written by Leon René, is a love song inspired by this annual event.  From 2009 to 2017, the famous swallows did not return to San Juan Capistrano. They instead began migrating to and nesting in the Chino Hills of Southern California, north of San Juan Capistrano. They built their mud nests in the eaves of the Vellano Country Club, situated around a golf course in the Chino Hills just north of the Chino Hills State Park. Mission San Juan Capistrano officials stated that the swallows changed their route because the mission is no longer the tallest building in the area due to urban sprawl, and thus stopped attracting the swallows for nesting.  Realizing the city's famous birds were no longer returning home, members of the Mission San Juan Capistrano enlisted the help of Dr. Charles R. Brown, a cliff swallows specialist from the University of Tulsa. In 2012, the first phase of a two-step process began, where the sounds and calls of the cliff swallows were played throughout the mission to lure the birds back home. In 2015, the project continued with the second phase where a replica wall of man-made colonies was built to give the birds a nest to return to. The nests were built to be very similar to the original nests made in the mission, prior to the early 1900s re-stabilization. As of summer of 2017, the cliff swallows have returned home to Mission San Juan Capistrano and are still celebrated each year at the town's annual Swallows Day Parade and Mercado Street Fair.  In 2018, the town celebrated its 80th annual Swallows Day Parade and Mercado Street Fair put on by the San Juan Capistrano Fiesta Association. The parade is the end celebration of a three-month Fiesta de las Golondrinas where the town puts on events to commemorate the migration home of the songbirds. The parade shuts down a portion of the downtown area to make way for floats, horses, and people walking in the parade. The event holds the title of being the longest-running and largest non-motorized parade west of the Mississippi.  In 2020, the Mission canceled its annual celebration due to the outbreak of COVID-19.

Education.

San Juan Capistrano is served by Capistrano Unified School District. In the 2007–08 academic year, San Juan Hills High School opened with about 600 freshman students. It is the city's only public high school. Ultimately, nearly all San Juan Capistrano's high school students will move to this campus as well as some students from Capistrano Beach, San Clemente High School, and southern Ladera Ranch. Residents from these other communities did not want to attend a school in San Juan on the basis that it was farther than the current schools they were attending and that the communities had too many differences. Many residents wanted to stay at the established high schools their communities had been attending for years. While there was initially tension caused by the boundary changes implemented with the construction of the new high school, it has since died down. The main relief for the tension was the construction of a connecting road from Avenida La Pata to Avenue Vista Hermosa, allowing for students from San Clemente to take a more direct route to the school. The $127 million infrastructure project completed on August 13, 2016.  San Juan has four public elementary schools (grades K–5): Del Obispo Elementary School, Harold Ambuehl Elementary School, Kinoshita Elementary School, and San Juan Elementary School. The local public middle school (grades 6–8) is Marco Forster Middle School. Capistrano Valley High School (grades 9–12) lies just outside of the city's borders, but serves many of the city's students.  A public continuation high school, Junipero Serra High School, also serves the area. Not to be confused with the Catholic school to the north, the Serra High School is a campus dedicated to helping adults finish their pre-collegiate educational goals.  San Juan also has six private, non-secular schools. Capistrano Valley Christian Schools (grades pre-K – 12), Saddleback Valley Christian School (grades pre-K – 12), St. Margaret's Episcopal School (grades pre-K – 12), and JSerra Catholic High School (grades 9–12). Mission Basilica School (grades K–8) is located on the historic Mission grounds, utilizes some of the historic buildings as classrooms, and is part of Mission Basilica San Juan Capistrano. The other is Rancho Capistrano Christian School (grades K–8), located off Interstate 5 on Saddleback Church's south campus.

Transportation.

Buses.

The Orange County Transportation Authority operates bus routes within the city, connecting it to other parts of Orange County.

Rail.

The San Juan Capistrano station is served by Amtrak and Metrolink. The station is located one block away from the historic San Juan Capistrano Mission next to Los Rios Street in downtown San Juan Capistrano. Its location to the city's tourist attractions makes it a popular stop during the summer months.

Highways.

Interstate 5 has 7 exits within San Juan Capistrano city limits and 8 entrances. Of those 7 exits, 6 leads to roads within San Juan Capistrano and of the 8 entrances, 1 is isolated meaning there is only one interstate entrance or exit for a specific road within the city (Stonehill Drive / Camino Capistrano I-5 northbound entrance as entrance number 80). From south to north, the exits within the city are (with exit numbers in parentheses): Camino Las Ramblas / Pacific Coast Highway (CA-1) (79), Camino Capistrano (81), Ortega Highway (CA-74) (82), Junipero Serra Road (83), California State Route 73 (85A), and Avery Parkway (85).  Avery Parkway's northbound exit and entrance is within the nearby city of Mission Viejo while the southbound exit and entrance is within San Juan Capistrano.

Media.

San Juan Capistrano is served by two newspapers, the Capistrano Valley News (owned by the Orange County Register) and The Capistrano Dispatch. The Capistrano Valley News runs once weekly on Thursdays and The Dispatch runs on the second and fourth Fridays of each month.  "The San Juan Capistrano Patch", an online-only news website, also serves the city.

San Juan Capistrano (; ; ) is a city in Orange County, California, United States. The current OMB metropolitan designation for San Juan Capistrano and the Orange County area is "Santa Ana–Anaheim–Irvine, CA". The population was 34,593 at the 2010 census, up from 33,826 at the 2000 census.

San Juan Capistrano est une municipalité située dans le comté d'Orange, en Californie, à environ au sud-est de Santa Ana. Selon le recensement de 2010, sa population était de, sa superficie de.


History.

Early years – Hendee and Hedstrom.

The "Indian Co." was founded as the Hendee Manufacturing Company by George M. Hendee in 1897 to manufacture bicycles. These were initially badged as "Silver King" and "Silver Queen" brands but the name "American Indian", quickly shortened to just "Indian", was adopted by Hendee from 1898 onwards because it gave better product recognition in export markets. Oscar Hedstrom joined in 1900. Both Hendee and Hedstrom were former bicycle racers and manufacturers, and after building three prototypes in Middletown, Connecticut, they teamed up to produce a motorcycle with a 1.75 bhp, single-cylinder engine in Hendee's home town of Springfield. The motorcycle was successful and sales increased dramatically during the next decade.  In 1901, a prototype and two production units of the diamond framed Indian Single were successfully designed, built and tested. The first Indian motorcycles, having chain drives and streamlined styling, were sold to the public in 1902. In 1903, Indian's co-founder and chief engineer Oscar Hedstrom set the world motorcycle speed record of 56 mph. In 1904 the company introduced the deep red color that would become Indian's trademark. Annual production of Indian motorcycles then exceeded 500, rising to a peak of 32,000 in 1913. The engines of the Indian Single were built by the Aurora Firm in Illinois under license from the Hendee Mfg. Co. until 1906.  Aurora produced engines under license for Indian from about 1901 to 1907. Aurora was also allowed to sell Indian design engines to third parties and pay Indian a fee. After 1907, Aurora could make its own complete motorcycles, which it did as Thor, and Indian began manufacturing its own engines.

Competitive successes.

In 1905, Indian built its first V-twin factory racer and in following years made a strong showing in racing and record-breaking. In 1907, the company introduced the first street version V-twin and a roadster styled after the factory racer. The roadster can be distinguished from the racers by the presence of twist grip linkages. One of the firm's most famous riders was Erwin "Cannonball" Baker, who set many long-distance records. In 1914, he rode an Indian across America, from San Diego to New York, in a record 11 days, 12 hours and ten minutes. Baker's mount in subsequent years was the Powerplus, a side-valve V-twin, which was introduced in 1916. Its 61ci (1000 cc), 42 degree V-twin engine was more powerful and quieter than previous designs, giving a top speed of 60 mph (96 km/h). The Powerplus was highly successful, both as a roadster and as the basis for racing bikes. It remained in production with few changes until 1924. Competition success played a big part in Indian's rapid growth and spurred technical innovation as well. One of the American firm's best early results came in the Isle of Man TT in 1911, when Indian riders Oliver Cyril Godfrey, Franklin and Moorehouse finished first, second and third. Indian star Jake DeRosier set several speed records, both in America and at Brooklands in Britain, and won an estimated 900 races on dirt and board tracks. He left Indian for Excelsior and died in 1913, aged 33, of injuries sustained in a board track race crash with Charles "Fearless" Balke, who later became Indian's top rider. Work at the Indian factory was stopped while DeRosier's funeral procession passed by.  Oscar Hedstrom left Indian in 1913 after disagreements with the board of directors regarding dubious practices to inflate the company's stock value. George Hendee resigned in 1916.

Lightweights 1916-1919.

Indian introduced the 221 cc single cylinder two-stroke Model K "Featherweight" in 1916. The Model K had an open cradle frame with the engine as a stressed member and a pivoting front fork that had been used earlier on single-cylinder motorcycles but had mostly been replaced on other Indian motorcycles by a leaf-sprung trailing link fork.  The Model K was manufactured for one year and was replaced in 1917 by the Model O. The Model O had a four-stroke flat-twin engine and a new frame, but retained the pivoting fork at the front. The Model O was manufactured until 1919.

World War I.

As the US entered World War I, Indian sold most of its Powerplus line in 1917 and 1918 to the United States government, starving its network of dealers. This blow to domestic availability of the motorcycles led to a loss of dealers from which Indian never quite recovered. While the motorcycles were popular in the military, post-war demand was then taken up by other manufacturers to whom many of the previously loyal Indian dealers turned. While Indian shared in the business boom of the 1920s, it had lost its Number One position in the US market to Harley-Davidson.

Inter-war era.

The Scout and Chief V-twins, introduced in the early 1920s, became the Springfield firm's most successful models. Designed by Charles Franklin, the middleweight Scout and larger Chief shared a 42-degree V-twin engine layout. Both models gained a reputation for strength and reliability.  In 1930, Indian merged with Du Pont Motors. DuPont Motors founder E. Paul DuPont ceased production of duPont automobiles and concentrated the company's resources on Indian. DuPont's paint industry connections resulted in no fewer than 24 color options in 1934. Models of that era had Indian's famous war bonnet logo on the gas tank. Indian's huge Springfield factory was known as the Wigwam, and native American imagery was much used in advertising.  In 1940, Indian sold nearly as many motorcycles as its major rival, Harley-Davidson. During this time, Indian also manufactured other products such as aircraft engines, bicycles, boat motors and air conditioners.

Scout.

The Indian Scout was built from 1920 through 1949. It rivaled the Chief as Indian's most important model.  The Scout was introduced for 1920. Designed by Charles B. Franklin, the Scout had its gearbox bolted to the engine and was driven by gears instead of by belt or chain. The engine originally displaced ; the Scout 45, with a displacement of, became available in 1927 to compete with the Excelsior Super X. A front brake became standard on the original Scout early in 1928.  Later in 1928, the Scout and Scout 45 were replaced by the Model 101 Scout. Another Franklin design, the 101 Scout had a longer wheelbase and lower seat height than the original. The 101 Scout was well known for its handling.  The 101 Scout was replaced by the Standard Scout for 1932. The Standard Scout shared its frame with the Chief and the Four; as a result, the Standard Scout was heavier and less nimble than the 101.  A second line of Scouts was introduced for 1933. Based on the frame of the discontinued Indian Prince single-cylinder motorcycle, the Motoplane used the 45 cubic inch engine from the Standard Scout while the Pony Scout had a reduced displacement of. In 1934 the Motoplane was replaced by the Sport Scout with a heavier but stiffer frame better able to withstand the power of the 45 cubic inch engine, while the Pony Scout, later renamed the Junior Scout, was continued with the Prince/Motoplane frame. Between the introduction of the Sport Scout in 1934 and the discontinuation of the Standard Scout in 1937 there were three Scout models (Pony/Junior, Standard, and Sport) with three different frames. The Sport Scout and the Junior Scout were continued until civilian production was interrupted in early 1942.

Chief.

Introduced in 1922, the Indian Chief had a engine based on the Powerplus engine; a year later the engine was enlarged to. Numerous improvements were made to the Chief over the years, including the provision of a front brake in 1928.  In 1940, all models were fitted with the large skirted fenders that became an Indian trademark, and the Chief gained a new sprung frame that was superior to rival Harley's unsprung rear end. The 1940s Chiefs were handsome and comfortable machines, capable of in standard form and over when tuned, although their increased weight hampered acceleration.  The 1948 Chief had a 74 cubic inch engine, hand shift and foot clutch. While one handlebar grip controlled the throttle the other was a manual spark advance.  In 1950, the V-twin engine was enlarged to and telescopic forks were adopted. But Indian's financial problems meant that few bikes were built. Production of the Chief ended in 1953.

Four.

Indian purchased the Ace Motor Corporation in 1927 and moved production of the 4-cylinder Ace motorcycle to Springfield. It was marketed as the Indian Ace in 1927.  In 1928, the Indian Ace was replaced by the Indian 401, a development of the Ace designed by Arthur O. Lemon, former Chief Engineer at Ace, who was employed by Indian when they bought Ace. The Ace's leading-link forks and central coil spring were replaced by Indian's trailing-link forks and quarter-elliptic leaf spring.  In 1929, the Indian 401 was replaced by the Indian 402 which received a stronger twin-downtube frame based on the 101 Scout frame and a sturdier five-bearing crankshaft than the Ace, which only had a three-bearing crankshaft.  Despite the low demand for luxury motorcycles during the Great Depression, Indian not only continued production of the Four, but continued to develop the motorcycle. One of the less popular versions of the Four was the "upside down" engine on the 1936-37 models. While earlier (and later) Fours had inlet-over-exhaust (IOE) cylinder heads with overhead inlet valves and side exhaust valves, the 1936-1937 Indian Four had a unique EOI cylinder head, with the positions reversed. In theory, this would improve fuel vaporization, and the new engine was more powerful. However, the new system made the cylinder head, and the rider's inseam, very hot. This, along with an exhaust valvetrain that required frequent adjustment, caused sales to drop. The addition of dual carburetors in 1937 did not revive interest. The design was returned to the original configuration in 1938.  Like the Chief, the Four was given large, skirted fenders and plunger rear suspension in 1940. In 1941, the 18-inch wheels of previous models were replaced with 16-inch wheels with balloon tires.  The Indian Four was discontinued in 1942. Recognition of the historical significance of the 1940 four-cylinder model was made with an August 2006 United States Postal Service 39-cent stamp issue, part of a four panel set entitled "American Motorcycles". A 1941 model is part of the Smithsonian Motorcycle Collection on display at the National Museum of American History. Single examples of both the 1931 and 1935 Indian Fours are in the ground vehicle collection of the Old Rhinebeck Aerodrome.

World War II.

During World War II, Chiefs, Scouts, and Junior Scouts were used in small numbers for various purposes by the United States Army and were also used extensively by British and other Commonwealth military services, under Lend Lease programs. However, none of these Indian models could unseat the Harley-Davidson WLA as the motorcycle mainly used by the US military.  An early war military design by Indian was based on the Scout 640 (and was often compared to Harley-Davidson's WLA), but was either too expensive or heavy, or a combination of both. Indian's later offering, the 741B was not selected to gain a US Military contract. Indian also made a version based on the Chief, the 344. Approximately 1,000 experimental versions mounting the 750 cc motor sideways and using shaft drive, as on a modern Moto Guzzi, the 841, were also tried.

841.

During World War II, the US Army requested experimental motorcycle designs suitable for desert fighting. In response Indian designed and built the 841. Approximately 1,056 models were built.  The Indian 841 was heavily inspired by the BMW R71 motorcycle (which, though not used by the German Army later was the basis for the Soviet M72, which is the basis for the Ural and Chiang Jiang motorcycle) as was its competitor, the Harley-Davidson XA. However, unlike the XA, the 841 was not a copy of the R71. Although its tubular frame, plunger rear suspension, and shaft drive were similar to the BMW's, the 841 was different from the BMW in several aspects, most noticeably so with its 90-degree longitudinal-crankshaft V-twin engine and girder fork.  The Indian 841 and the Harley-Davidson XA were both tested by the Army, but neither motorcycle was adopted for wider military use. It was determined that the Jeep was more suitable for the roles and missions for which these motorcycles had been intended.

Post-war decline and demise.

In 1945, a group headed by Ralph B. Rogers purchased a controlling interest of the company. On November 1, 1945, duPont formally turned the operations of Indian over to Rogers. Under Rogers' control, Indian resumed production with only one model, the Chief, for 1946 and ‘47. 1947 was also the year the Indian-head fender light, also known as the "war bonnet", was introduced. In 1948, they added two rebadged import models, the Czech built CZ125b, and the Brockhouse Engineering produced Corgi Scooter. The Scooter, a novel 100cc vehicle developed for paratroopers during World War II, was rebadged the Papoose. Indian also produced a limited amount (appx. 50) 648 model Scouts for racing.  In 1949, they discontinued the Chief, as they began domestic manufacture of two lightweight motorcycles, the single-cylinder 220 cc 149 Arrow and the twin-cylinder 440 cc 249 Scout. The Scout was offered in various trim levels. The initial shipment of lightweights developed a reputation for unreliability, often associated with a rush to market. Later shipments were reported by publications of the time to have resolved most reliability issues by the following year.  The 1950 lineup brought back the Chief, with telescopic forks. It also saw the introduction of the twin-cylinder 500 cc Warrior model, which received both a standard and high pipe sporting TT trim. On the Corporate side, Rogers would step down as CEO of Indian to take employment at Texas Instruments. Replacing Rogers was hand-picked successor John Brockhouse, President and owner of Brockhouse engineering. Unfortunately new management did not bring new fortune, and production of all models wound down in 1952, with most 1953 Chiefs built from remaining parts. All product manufacturing ended in 1953.

Corporate successors.

Brockhouse Engineering (1953-1960).

As Rogers liquidated Indian in 1953, Brockhouse Engineering acquired the rights to the Indian name. The Indian Sales Corp continued to support the rebranded Papoose Scooter (which would cease production in 1954) and the Brave, a European-styled 125 cc lightweight bike. All other models were abandoned after reducing inventory. The Brave had been designed prior to the acquisition, and produced by an English subsidiary owned by Brockhouse. Indian had imported these outsourced models since 1951, when Brockhouse was then-President of Indian under Rogers Ownership. Outside these two models that directly benefitted Brockhouses umbrella industries, ISC also sold a variety of rebadged imports, including Vincent’s, AJS, and Matchless from various dates until solidifying their import models line-up to a single manufacturer.  From 1955 through 1960, they imported English Royal Enfield motorcycles, mildly customized them in the United States, and sold them under Indian branding. Almost all Royal Enfield models had a corresponding Indian model in the US. The models were Indian Chief, Trailblazer, Apache (all three were 700 cc twins), Tomahawk (500 cc twin), Woodsman (500 cc single), Westerner (500 cc single), Hounds Arrow (250 cc single), Fire Arrow (250 cc single), Lance (150 cc 2-stroke single) and a 3-wheeled Patrol Car (350 cc single).

Associated Motor Cycles (1960-1963).

In 1960, the Indian name was bought by AMC of the UK. Royal Enfield being their competition, they abruptly stopped all Enfield-based Indian models except the 700 cc Chief. In 1962 AMC, facing financial issue, withdrew from all marketing of the Indian Brand name, as the company choose to focus exclusively on their Norton and Matchless Brands.

Floyd Clymer (1963-1970).

From the 1960s, entrepreneur Floyd Clymer began using the Indian name. He attached it to imported motorcycles, commissioned to Italian ex-pilot and engineer Leopoldo Tartarini, owner of Italjet Moto, to manufacture Minarelli-engined 50 cc minibikes under the Indian Papoose name. These were successful so Clymer commissioned Tartarini to build full-size Indian motorcycles based on the "Italjet Griffon" design, fitted with Royal Enfield Interceptor 750 cc parallel-twin engines.  A further development was the "Indian Velo 500", a limited-production run using a Velocette single-cylinder engine with various Norton, and Royal Enfield drivetrain components, and Italian Chassis parts. This included a lightweight frame from the Italjet company, Marzocchi front forks with Grimeca front hub having a twin-leading shoe brake, Borrani aluminium rims and quickly-detachable tank and seat, resulting in a weight-saving of compared to the traditional Velocette Venom.  The project ended abruptly due to Clymer's death and the failure of Velocette, with 200 machines shipped to US and a further 50 remaining in Italy, which were bought by London Velocette dealer Geoff Dodkin. When roadtesting, UK monthly magazine "Motorcycle Sport" described it as ""British engineering and Italian styling in a package originally intended for the American market"", reporting that Dodkin would supply his bikes with either a standard Venom engine specification, or, at higher cost, a Thruxton version.

Alan Newman Ownership (1970-1977).

After Clymer's death in 1970 his widow sold the alleged Indian trademark to Los Angeles attorney Alan Newman, who continued to import minicycles made by ItalJet, and later manufactured in a wholly owned assembly plant located in Taipei (Taiwan). Several models with engine displacement between 50 cc and 175 cc were produced, mostly fitted with Italian two-stroke engines made either by Italjet or Franco Morini.  In 1974, Newman planned to revive large-capacity machines as the "Indian 900", using a Ducati 860 cc engine and commissioned Leo Tartarini of Italjet to produce a prototype. The project failed, leaving the prototype as the only survivor.  Sales of Newman's Indians were dwindling by 1975. The company was declared bankrupt in January 1977.

American Moped Associates & DMCA (1977-1984).

The Indian Trademark was purchased from bankruptcy court for $10,000 in late 1977 by American Moped Associates, who would employ the Taiwanese manufacturing plant to make a new moped using licensed patents from Hondas discontinued PC50-K1. The result was the "Indian AMI-50 Chief". This moped was offered from 1978 until late 1983, as the trademark was purchased by Carmen DeLeone’s DMCA (Derbi) group in 1982, who discounted the remaining moped stock, and discontinued manufacture. Derbi-Manco would offer Badge engineered go-carts utilizing the ‘4-stroke Indian’ moniker, before the Indian name disappeared from all motorized vehicles in 1984. The right to the brand name then passed through a succession of owners and became a subject of competing claims in the late 1980s.

Other attempts (1984-1999).

By 1992, the Clymer claim to the trademark had been transferred to Indian Motocycle Manufacturing Co. Inc. of Berlin, a corporation headed by Philip S. Zanghi.  In June 1994, in Albuquerque, New Mexico, Wayne Baughman, president of Indian Motorcycle Manufacturing Incorporated, presented, started, and rode a prototype Indian Century V-Twin Chief. Baughman had made previous statements about building new motorcycles under the Indian brand but this was his first appearance with a working motorcycle.  Neither Zanghi nor Baughman began production of motorcycles. In August 1997, Zanghi was convicted of securities fraud, tax evasion, and money laundering.  In January 1998, Eller Industries was given permission to purchase the Indian copyright from the receivers of the previous owner. Eller Industries hired Roush Industries to design the engine for the motorcycle, and was negotiating with the Cow Creek Band of Umpqua Tribe of Indians to build a motorcycle factory on their tribal land. Three renderings, one each of a cruiser, a sport cruiser, and a sport bike, on frames specified by suspension designer James Parker, were shown to the motorcycling press in February 1998.  Eller Industries arranged a public unveiling of the cruiser prototype for November 1998, but was prevented from showing the prototype by a restraining order from the receiver, who said that Eller had failed to meet the terms of its obligations. The contract was withdrawn after the company missed its deadline to close the deal and could not agree with the receiver to an extension on the deadline. Other conditions, including payment of administrative costs and presenting a working prototype, were also not met by Eller Industries. Based on this, a Federal bankruptcy court in Denver, Colorado, allowed the sale of the trademark to IMCOA Licensing America Inc. in December 1998.

Indian Motorcycle Company of America (1999–2003).

The Indian Motorcycle Company of America was formed from the merger of nine companies, including manufacturer California Motorcycle Company (CMC) and IMCOA Licensing America Inc., which was awarded the Indian trademark by the Federal District Court of Colorado in 1998. The new company began manufacturing motorcycles in 1999 at the former CMC's facilities in Gilroy, California. The first "Gilroy Indian" model was a new design called the Chief. Scout and Spirit models were also manufactured from 2001. These bikes were initially made with off-the-shelf 88 cubic inch S&S engines, but later used the Powerplus (bottlecap) engine design from 2002 to 2003. The Indian Motorcycle Corporation went into bankruptcy and ceased all production operations in Gilroy on September 19, 2003.

Indian Motorcycle Company (2006-2011).

On July 20, 2006, the newly formed Indian Motorcycle Company, owned largely by Stellican Limited, a London-based private equity firm, announced its new home in Kings Mountain, North Carolina, where it restarted the Indian motorcycle brand, manufacturing Indian Chief motorcycles in limited numbers, with a focus on exclusivity rather than performance. Starting out where the defunct Gilroy IMC operation left off in 2003, the "Kings Mountain" models were continuation models based on the new series of motorcycles developed in 1999. The 2009 Indian Chief incorporated a redesigned Powerplus V-twin powertrain with electronic closed-loop sequential-port fuel injection, and a charging system providing increased capacity for the electronic fuel injection.

Polaris Acquisition (since 2011).

In April 2011, Polaris Industries, the off-road and leisure vehicle maker and parent company of Victory Motorcycles, announced its intention to acquire Indian Motorcycle. Indian's production facilities were moved to Spirit Lake, Iowa, where production began on August 5, 2011. In March 2013, Indian unveiled their new "Thunder Stroke" engine, and began to sell their newly designed motorcycles based on it in August 2013.

Current production.

On August 3, 2013, Polaris announced three all-new Indian-branded motorcycles based on the traditional styling of the Indian marque, along with the Thunder Stroke 111 V-twin engine. The motor has a triple-cam design with a chain-driven center cam turning front and rear cams via gears, permitting parallel placement of the pushrods to give a similar appearance to older Indian designs. It is air cooled, with large traditional fins and an airbox in the cast aluminum frame. All Indians using the Thunder Stroke 111 engine share this aluminum frame design, though the wheelbase and front end rake vary depending on model. The integrated transmission is also gear-driven.  Since 2013, Indian has expanded its line up to five models, currently offered in 23 trim levels. Of these, twelve have the Thunderstroke 111 engine. Five offerings use the smaller engine displacement, liquid cooled Scout engines. The Scout has four trims in its line featuring the engine, while the Scout 60 has its eponymous variant. Indian offers 3 distinctions of their FTR 1200, a sportier cycle introduced in 2019. And as of 2020, the Challenger Bagger featuring the all-new Indian PowerPlus liquid-cooled 60-degree V-twin has been introduced, with three variations.

Chief Classic (2014–2018 ).

The standard Chief Classic has the valanced fenders and the lighted "war bonnet" on the front fender. Cruise control, antilock braking system, keyless starting, and electronic fuel injection are standard on this and all other models. It has a six-speed transmission and manually-adjustable single-shock swingarm.

Chief Vintage (2014– ).

The Indian Chief Vintage shares the chassis, drivetrain, and styling of the Chief Classic, and adds tan leather quick-release saddlebags, matching tan leather two-up seat, additional chrome trim, quick-release windshield, and a six-speed transmission.

Springfield (2016– ).

The Springfield was introduced in March 2016 during Daytona Bike week. It is named after the birthplace of Indian Motorcycles, Springfield, Massachusetts. The Springfield is a bit of a hybrid bike, sharing steering geometry and hardbags with the Chieftain and RoadMaster models but is equipped with a quick detach windshield like the Vintage. It also boasts an adjustable rear air shock like the other touring models.

Chieftain (2014– ).

The Indian Chieftain touring motorcycle is the first Indian model with front fairing and hard saddlebags. It has a stereo with speakers in the fairing, Bluetooth media players, tire pressure sensors, air-adjustable rear shock, and motorized windshield adjustment. Initial reports from the press were favorable for styling, performance, and handling. The Chieftain was named 2013 Motorcycle of the Year by RoadRunner Motorcycle Touring & Travel magazine.

Scout (2015– ).

The Indian Scout was introduced at the 2014 Sturgis Motorcycle Rally as a 2015 model. The 2015 Scout is a cruiser with a liquid-cooled, double overhead camshaft V-twin engine and a frame formed by multiple aluminum alloy castings bolted to each other and to the engine. The Indian Scout was named 2015 Motorcycle of the year by Motorcycle.com.

Scout Sixty (2016– ).

The Indian Scout Sixty was introduced in November 2015 as a 2016 model. The Scout Sixty is a cruiser with a liquid-cooled, double overhead camshaft V-twin engine. The new Scout Sixty has many of the same features as the 2014 Scout, but with a smaller 999 cc engine.

Roadmaster (2015– ).

The Indian Roadmaster was introduced at the 2014 Sturgis Motorcycle Rally shortly before the Scout. The Roadmaster is a Chieftain with an added trunk, front fairing lowers, heated seats, heated grips, LED headlights, passenger floorboards, and a rear crash bar. The Roadmaster had been developed before the Chieftain. Cycle World recorded @ 4,440 rpm and @ 2,480 rpm at the rear tire. They also recorded a tested 1/4 mile time of 13.91 seconds at and a acceleration at 5.2 seconds, a braking distance of, and fuel economy of.

Chief Dark Horse (2016– ).

The 2016 Indian Dark Horse was introduced on Valentine's Day 2015. It is based on a Chief Classic painted in flat black, with the driving lights, oil cooler, analog fuel gauge, passenger pillion seat and passenger pegs removed.

Chieftain Dark Horse (2016– ).

The 2016 Indian Chieftain Dark Horse was introduced in May 2016. It has a full fairing and hard saddlebags, but lacks other accessories in the Chieftain line. It has a claimed @ 3000 rpm and a dry weight of.

Chieftain Limited (2017- ).

The 2017 Indian Chieftain Limited adds more of a bagger style to the Chieftain. The front fender was opened up to show off 19" custom wheels, and a limited coloring scheme. This model also boasts the full ride command touch screen display that the Roadmaster also uses. It has the upper fairing with power windscreen and optional passenger seat.

RoadMaster Classic (2017- ).

The 2017 Indian Roadmaster Classic was introduced in February 2017. It has the traditional styling tan leather bags and trunk along with heated seats, heated grips, LED headlights, passenger floorboards, and rear crash bars. It does not have the hard front lowers found on the original Roadmaster.

Springfield Dark Horse (2018- ).

For 2018 Indian offers the Springfield in Dark Horse flavor. Open front fender with 19" cast front wheel.

Scout Bobber (2018- ).

The Scout Bobber is a factory modified version of the Scout that features style components taken from the “bobber” community of motorcycles, hence the name. These modifications include chopped front and rear mud guards, bar end mirrors, low seat, low handlebars, and a side-mounted license plate holder.

FTR1200 (2019- ).

The FTR1200 takes its inspiration from the flat track racing heritage of Indian. It is considered a “street tracker”, a street legal motorcycle with flat track bike styling.

Challenger (2020- ).

The Challenger is the first bagger crafted by Indian Motorcycle. It embeds the new Indian PowerPlus liquid-cooled 60-degree V-twin engine that produces 122 horsepower and 128 foot pounds of torque. The front suspension uses an inverted 43mm fork, which provides 5.1 inches of travel and rear suspension is provided by a hydraulically adjustable rear shock.

Challenger Dark Horse (2020- ).

The Indian Challenger with the Dark Horse flavor is powered by the PowerPlus liquid-cooled 60-degree V-twin engine that produces 122 horsepower and 128 foot pounds of torque. The front suspension uses an inverted 43mm fork, which provides 5.1 inches of travel and rear suspension is provided by a hydraulically adjustable rear shock.

Land speed records.

Between 1962 and 1967, Burt Munro from New Zealand used a modified 1920s Indian Scout to set a number of land speed records, as dramatised in the 2005 film "The World's Fastest Indian". In 2014 Indian had a similar custom streamliner built, the "Spirit of Munro", to promote their new 111 cubic-inch engine and challenge speed records.

Bicycles.

Both Hendee and Hedstrom had built bicycles before they met, and Hendee had marketed his under the Silver King and Silver Queen names. They continued to manufacture bicycles after their motorcycles became successful and even made bicycles designed to resemble their motorcycles.

Indian Motorcycle is an American brand of motorcycles originally produced from 1901 to 1953 in Springfield, Massachusetts, United States. Hendee Manufacturing Company initially produced the motorcycles, but the name was changed to the Indian Manufacturing Company in 1923.

Indian est une marque américaine de motos fabriquées de 1901 à 1953 à Springfield dans le Massachusetts. La firme est d'abord connue sous le nom d'Hendee Manufacturing Company, puis est rebaptisée Indian Motorcycle Manufacturing Company en 1901. Elle disparait en 1953, mais la production est relancée en 2004. Depuis avril 2011, la société est devenue une filiale de Polaris Industries, aux côtés de Victory Motorcycles.


History.

Early dimmers were directly controlled through the manual manipulation of large dimmer panels. This required all power to come through the lighting control location, which could be inconvenient, inefficient and potentially dangerous for large or high-powered systems, such as those used for stage lighting.  In 1896, Granville Woods patented his "Safety Dimmer", which greatly reduced wasted energy by reducing the amount of energy generated to match desired demand rather than burning off unwanted energy.  In 1959, Joel S. Spira, who would found the Lutron Electronics Company in 1961, invented a dimmer based on a diode and a tapped autotransformer, saving energy and allowing the dimmer to be installed in a standard electrical wallbox.  In 1966, Eugene Alessio patented a light bulb socket adapter for adjusting a light level on a single light bulb using a triac. To house this device, he decided on a 2-inch round device with one end capable of being screwed into a light bulb socket and the other end able to receive a light bulb.  When solid-state dimmers came into use, analog remote control systems (such as 0-10 V lighting control systems) became feasible. The wire for the control systems was much smaller (with low current and lower danger) than the heavy power cables of previous lighting systems. Each dimmer had its own control wires, resulting in many wires leaving the lighting control location.  More recent digital control protocols such as DMX512, DALI, or one of the many Ethernet-based protocols like Art-Net, ETCnet, sACN, Pathport, ShowNet or KiNET enable the control of a large number of dimmers (and other stage equipment) through a single cable.

Types of dimmer.

Rheostat dimmer.

Dimmers based on rheostats were inefficient since they would dissipate a significant portion of the power rating of the load as heat. They were large and required plenty of cooling air. Because their dimming effect depended a great deal on the total load applied to each rheostat, the load needed to be matched fairly carefully to the power rating of the rheostat. Finally, as they relied on mechanical control they were slow and it was difficult to change many channels at a time.

Saltwater dimmer.

Early examples of a rheostat dimmer include a salt water dimmer or liquid rheostat; the liquid between a movable and fixed contact provided a variable resistance. The closer the contacts to each other, the more voltage was available for the light. Salt water dimmers required regular addition of water and maintenance due to corrosion; exposed parts were energized during operation, presenting a shock hazard.

Coil-rotation transformer.

The coil-rotation transformer used a fixed-position electromagnet coil in conjunction with a variable-position coil to vary the voltage in the line by varying the alignment of the two coils. Rotated 90 degrees apart, the secondary coil is affected by two equal but opposite fields from the primary, which effectively cancel each other out and produce no voltage in the secondary.  These coils resembled the standard rotor and stator as used in an electric motor, except that the rotor was held against rotation using brakes and was moved to specific positions using high-torque gearing. Because the rotor did not ever turn a complete revolution, a commutator was not required and long flexible cables could be used on the rotor instead.

Autotransformer dimmer.

Variable autotransformers (trade name "Variac") were then introduced. While they are still nearly as large as rheostat dimmers, which they closely resemble, they are relatively efficient devices. Their voltage output, and so their dimming effect, is largely independent of the load applied so it was far easier to design the lighting that would be attached to each autotransformer channel. Remote control of the dimmers was still impractical, although some dimmers were equipped with motor drives that could slowly and steadily reduce or increase the brightness of the attached lamps. Autotransformers have fallen out of use for lighting but are used for other applications.

Solid-state dimmer.

Solid-state or semiconductor dimmers were introduced to solve some of these problems. Semiconductor dimmers switch on at an adjustable time (phase angle) after the start of each alternating current half-cycle, thereby altering the voltage waveform applied to lamps and so changing its RMS effective value. Because they switch instead of absorbing part of the voltage supplied, there is very little wasted power. Dimming can be almost instantaneous and is easily controlled by remote electronics. This development also made it possible to make dimmers small enough to be used in place (within the pattress) of normal domestic light switches.  The switches generate some heat during switching and can also cause radio-frequency interference. Inductors or chokes are used as part of the circuitry to suppress this interference. When the dimmer is at 50% power the switches are switching their highest voltage in Europe) and the sudden surge of power causes the coils on the inductor to move, creating a buzzing sound associated with some types of dimmer; this same effect can be heard in the filaments of the incandescent lamps as "singing". The suppression circuitry might be insufficient to prevent buzzing to be heard on sensitive audio and radio equipment that shares the mains supply with the lighting loads. In this case, special steps must be taken to prevent this interference. European dimmers must comply with relevant EMC legislation requirements; this involves suppressing the emissions described above to limits described in EN55104. In the electrical schematic shown, a typical silicon-controlled rectifier (SCR) based light dimmer dims the light through phase-angle control. This unit is wired in series with the load. Diodes (D2, D3, D4 and D5) form a bridge, which generates pulsed DC. R1 and C1 form a circuit with a time constant. As the voltage increases from zero (at the start of every halfwave) C1 will charge up. When C1 is able to make Zener diode D6 conduct and inject current into the SCR, the SCR will fire. When the SCR conducts, D1 will discharge C1 via the SCR. The SCR will shut off when the current falls to zero and the supply voltage drops at the end of the half cycle, ready for the circuit to start work on the next half cycle. This circuit is called a Leading-Edge Dimmer or Forward Phase Dimming. Leading edge dimmers work well with incandescent lamps, but not with all types of LED lamps.  Dimmers based on Insulated-gate bipolar transistors (IGBTs) do away with most of the noise present in TRIACs by chopping off the falling side of the sine wave. These circuits are called Trailing-Edge Dimmers or Reverse Phase Dimming, and work well with LED lamps. An even newer, but still expensive technology is sine-wave dimming, which is implemented as high power switched-mode power supplies followed by a filter.

Control.

Non domestic dimmers are usually controlled remotely by means of various protocols. Analogue dimmers usually require a separate wire for each channel of dimming carrying a voltage between 0 and 10 V. Some analogue circuitry then derives a control signal from this and the mains supply for the switches. As more channels are added to the system more wires are needed between the lighting controller and the dimmers.  In the late 70s, serial analogue protocols were developed. These multiplexed a series of analogue levels onto a single wire, with embedded clocking signal similar to a composite video signal (in the case of Strand Lighting's European D54 standard, handling 384 dimmers) or separate clocking signal (in the case of the US standard AMX192).  Digital protocols, such as DMX512 have proved to be the answer since the late 80s. In early implementations a digital signal was sent from the controller to a demultiplexer, which sat next to the dimmers. This converted the digital signal into a collection of 0 to +10 V or 0 to −10 V signals which could be connected to the individual analogue control circuits.  Modern dimmer designs use microprocessors to convert the digital signal directly into a control signal for the switches. This has many advantages, giving closer control over the dimming, and giving the opportunity for diagnostic feedback to be sent digitally back to the lighting controller.  Some dimmers in residential applications are also equipped with a radio receiver to be used as wireless light switches which can be remotely controlled by a radio transmitter.

Patching.

Patching is the physical ("hard patch") or virtual ("soft patch") assignment to a circuit or channel for the purpose of control.

Hard patch.

Dimmers are usually arranged together in racks, where they can be accessed easily, and then power is run to the instruments being controlled. In architectural installations electricity is run straight from the dimmers to the lights via permanent wiring (this is called a circuit). They are hard run and cannot be changed.  However venues such as theatres demand more flexibility. To allow for changes for each show, and occasionally during shows, theatres sometimes install circuits run permanently to sockets around the theatre. Instead of these circuits going directly to the dimmer they are connected to a "patch bay". A patch bay usually sits next to the dimmers enabling the dimmers to be connected to specific circuits via a patch cable. The patch bay may also enable many circuits to be connected to one dimmer and even series connection for low-voltage lamps. Also in some theatres individual cables are run directly from the light to dimmer. The assigned connections between the circuits (either at the patch bay or in the form of individual cables) and the dimmers is known as the mains or hard patch. This is most common in older theatres, and on a tour where dimmers will be brought in by the touring company.

Soft patch.

Most modern fixed installations do not have patch bays, instead they have a dimmer-per-circuit and patch dimmers into channels using a computerised control consoles Soft Patch.

Dimming curves.

The design of most analogue dimmers meant that the output of the dimmer was not directly proportional to the input. Instead, as the operator brought up a fader, the dimmer would dim slowly at first, then quickly in the middle, then slowly at the top. The shape of the curve resembled that of the third quarter of a sine wave. Different dimmers produced different dimmer curves, and different applications typically demanded different responses.  Television often uses a "square law" curve, providing finer control in top part of the curve, essential to allow accurate trimming of the colour temperature of lighting. Theatrical dimmers tend to use a softer "S" or linear curve. Digital dimmers can be made to have whatever curve the manufacturer desires; they may have a choice between a linear relationship and selection of different curves, so that they can be matched with older analogue dimmers. Sophisticated systems provide user-programmable or nonstandard curves, and a common use of a nonstandard curve is to turn a dimmer into a "non-dim", switching on at a user defined control level.

Preheat.

Switching high-intensity incandescent (filament) lamps to full power from cold can shorten their life dramatically, owing to the large inrush current that occurs. To reduce stress on the lamp filaments, dimmers may have a preheat function. This sets a minimum level, usually between 5% and 10%, which appears turned-off, but stops the lamp from cooling down too much. This also speeds up the lamp's reaction to sudden bursts of power that operators of rock'n'roll-style shows appreciate. The opposite of this function is sometimes called top-set. This limits the maximum power supplied to a lamp, which can also extend its life.  In less advanced systems, this same effect is achieved by literally pre-heating (warming) the globes before an event or performance. This is usually achieved by slowly bringing the lights up to full (or usually 90-95%) power over a period of between 1/2 to 1 hour. This is as effective as a built-in preheat function.

The digital revolution.

Modern digital desks can emulate preheat and dimmer curves and allow a soft patch to be done in memory. This is often preferred as it means that the dimmer rack can be exchanged for another one without having to transfer complicated settings. Many different curves, or "profiles" can be programmed and used on different channels.

Rise time.

One measure of the quality of a leading edge dimmer is the "rise time". The rise time in this context is the amount of time it takes for the cut part of the waveform to get from zero to the instantaneous output voltage. In the waveform above it is a measure of the slope of the almost vertical edge of the red trace. Typically it is measured in tens to hundreds of microseconds. A longer rise time reduces the noise of the dimmer and the lamp as well as extending the life of the lamp. A longer rise time also reduces the electromagnetic interference produced by the dimmer. Unsurprisingly, a longer rise time is more expensive to implement than a short one, this is because the size of choke has to be increased. Newer dimming methods can help minimize such problems.

A dimmers is a device connected to a light fixture and used to lower the brightness of light. By changing the voltage waveform applied to the lamp, it is possible to lower the intensity of the light output. Although variable-voltage devices are used for various purposes, the term "dimmer" is generally reserved for those intended to control light output from resistive incandescent, halogen, and (more recently) compact fluorescent lights (CFLs) and light-emitting diodes (LEDs). More specialized equipment is needed to dim fluorescent, mercury vapor, solid-state, and other arc lighting.

Un gradateur est un appareil électrique destiné à faire varier la puissance délivrée à un autre appareil utile, souvent un éclairage (projecteurs de scène, par exemple). C'est donc un dispositif de l'électronique de puissance, qui fonctionne en faisant varier la tension et l'intensité de sortie, ce qui modifie ainsi la puissance dans l'appareil utile, nommé "la charge". Le gradateur diminue la puissance délivrée à la charge, en comparaison d'un circuit sans gradateur. Ce dispositif est utilisé sur des tensions alternatives (souvent sinusoïdales) : c'est un convertisseur direct alternatif-alternatif.