An automatic door, also known as an auto door, is a door that opens automatically, usually on sensing the approach of a person.
In the 1st century AD, mathematician Heron of Alexandria in Roman Egypt invented the first known automatic door. He described two different automatic door applications. The first application used heat from a fire lit by the city's temple priest. After a few hours atmospheric pressure built up in a brass vessel causing it to pump water into adjacent containers. These containers acted as weights that – through a series of ropes and pulleys – would open the temple's doors at about the time people were to arrive for prayer. Heron used a similar application to open the gates to the city.
In 1931, engineers Horace H. Raymond and Sheldon S. Roby of the tool and hardware manufacturer Stanley Works designed the first model of an optical device triggering the opening of an automatic door. The invention was patented and installed in Wilcox's Pier Restaurant in West Haven, Connecticut for the benefit of waiters carrying plates of food and drink. The entire system plus installation was sold for $100.
In 1954, Dee Horton and Lew Hewitt invented the first sliding automatic door. The automatic door used a mat actuator. In 1960, they co-founded Horton Automatics Inc and placed the first commercial automatic sliding door on the market.
Colchester (/ˈkoʊltʃɛstər/ (audio speaker iconlisten)) is a historic market town and the largest settlement within the borough of Colchester in the county of Essex, in the East of England. Colchester occupies the site of what was Camulodunum, the first major Roman city in, and sometime capital of, Roman Britain. Colchester lays claim to be Britain's oldest recorded town. Colchester has been a military garrison since the Roman era and is currently home to the 16th Air Assault Brigade. In 2019 it had an estimated population of 138,131.
Situated on the River Colne, Colchester is 50 miles (80 kilometres) northeast of London and is connected to the capital by the A12 road and its railway station which is on the Great Eastern Main Line. It is seen as a popular town for commuters, and is less than 30 miles (50 km) from London Stansted Airport and 20 miles (30 km) from the passenger ferry port of Harwich.
Colchester is home to Colchester Castle and Colchester United Football Club. The demonym is Colcestrian.