A fire alarm system warns people when smoke, fire, carbon monoxide or other fire-related emergencies are detected. These alarms may be activated automatically from smoke detectors and heat detectors or may also be activated via manual fire alarm activation devices such as manual call points or pull stations. Alarms can be either motorized bells or wall mountable sounders or horns. They can also be speaker strobes which sound an alarm, followed by a voice evacuation message which warns people inside the building not to use the elevators. Fire alarm sounders can be set to certain frequencies and different tones including low, medium, and high, depending on the country and manufacturer of the device. Most fire alarm systems in Europe sound like a siren with alternating frequencies. Fire alarm electronic devices are known as horns in the United States and Canada and can be either continuous or set to different codes. Fire alarm warning devices can also be set to different volume levels.
Kent is a county in South East England and one of the home counties. It borders Greater London to the north-west, Surrey to the west and East Sussex to the south-west, and Essex to the north across the estuary of the River Thames; it faces the French department of Pas-de-Calais across the Strait of Dover. The county town is Maidstone. It is the fifth most populous county in England, the most populous non-Metropolitan county and the most populous of the home counties.
Kent was one of the first British territories to be settled by Germanic tribes, most notably the Jutes, following the withdrawal of the Romans. Canterbury Cathedral in Kent, the oldest cathedral in England, has been the seat of the Archbishops of Canterbury since the conversion of England to Christianity that began in the 6th century with Saint Augustine. Rochester Cathedral in Medway is England's second-oldest cathedral. Located between London and the Strait of Dover, which separates England from mainland Europe, Kent has been the setting for both conflict and diplomacy, including the Battle of Britain in World War II and the Leeds Castle peace talks of 1978 and 2004.
England relied on the county's ports to provide warships through much of its history; the Cinque Ports in the 10th–14th centuries and Chatham Dockyard in the 16th–20th centuries were of particular importance. France can be seen clearly in fine weather from Folkestone and the White Cliffs of Dover. Hills in the form of the North Downs and the Greensand Ridge span the length of the county and in the Vale of Holmesdale in between and to the south are most of the county's 26 castles.
Kent's economy is greatly diversified: agriculture, haulage, logistics and tourism are major industries. Because of its relative abundance of fruit-growing and hop gardens, Kent is known as "The Garden of England". In northwest Kent, industries include extraction of aggregate building materials, printing and scientific research. Coal mining has also played its part in Kent's industrial heritage. Large parts of Kent are within the London commuter belt and its strong transport connections to the capital and the nearby continent make Kent a high-income county. Twenty-eight per cent of the county forms part of two Areas of Outstanding Natural Beauty: the North Downs and The High Weald.