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.
Downham Market, sometimes simply referred to as Downham, is a market town and civil parish in Norfolk, England. It lies on the edge of the Fens, on the River Great Ouse, approximately 11 miles south of King's Lynn, 39 miles west of Norwich and 30 miles north of Cambridge.
The civil parish has an area of 5.2 km² and in the 2011 census had a population of 9,994 in 4,637 households.
Fire Station in 2006, now a heritage centre
It was an agricultural centre, developing as a market for the produce of the Fens with a bridge across the Ouse. During the Middle Ages, it was famed for its butter market and also hosted a notable horse fair. The market is now held Fridays and Saturdays.
Notable buildings in the town include its mediaeval parish church, dedicated to St Edmund, and the Victorian clock tower, constructed in 1878. The town is also known as the place where Charles I hid after the Battle of Naseby. In 2004 the town completed a regeneration project on the Market Place, moving the market to the town hall car park. The decorative town sign depicts the crown and arrows of St Edmund with horses to show the importance of the horse fairs in the town's history.
A heritage centre, Discover Downham, opened in a former fire station in 2016. The town is twinned with Civray, Vienne, France.