and at Kirkby Thore, where it is used in the Plaster industry Slate is found at various locations throughout Cumbria, with the Honister slate mine at Borrowdale now a major tourist attraction Lead was mined extensively in Nenthead from the 18th century until the early part of the 20th century Industrial processes Nuclear reprocessing – at Sellafield Thorp nuclear fuel reprocessing plant – part of Sellafield Blast furnace – e.g. the Duddon Furnace near Broughton-in-Furness Bessemer process – invented by Henry Bessemer and used at the Workington Steel Works Wind power and Wind generators surrounding much of the Lake District Very Low Frequency transmitters – at Anthorn and Skelton for submarine communications Phosphoric acid and Sulphuric acid – once made in vast quantities at the Marchon Chemical Company plant at Whitehaven. Phosphoric acid was made by adding the manufactured sulphuric acid to Calcium phosphate rock, brought by ship from Morocco to Whitehaven harbour. Major employers Cumbria County Council BAE Systems Submarine Solutions, once Vickers Shipbuilding and Engineering Ltd, and Vickers – in Barrow-in-Furness BNFL – British Nuclear Fuels – owners and operators of the Nuclear reprocessing site – at Sellafield, and the world's first nuclear power station, Calder Hall, now closed. McVitie's part of United Biscuits – the UK's second largest biscuit factory in Carlisle Corus Group, previously British Steel plc – makers of railway lines in Workington – closed down Summer 2006. History Cumbria is a county where you can find many Stone circles – including the impressive Castlerigg stone circle near Keswick Cumbria is on the border between England and Scotland, and defensive Peel towers were built to protect the English from invaders, the Border Reivers. The Roman empire built Hadrian's Wall dividing England and Scotland, and various forts throughout Cumbria, including Hardknott Roman Fort in Eskdale The Dovenby Hall estate in Dovenby, near Cockermouth, dates from 1154 and has been used, amongst other things, as a private residence, a mental institution, and, most recently, as home of the Ford Rally Team. Clifton Moor Skirmish – the last battle on English soil between the Jacobite forces of Prince Charles Stuart and the English army commanded by the Duke of Cumberland at Clifton near Penrith. Other pages of interest The year 2001 proved to be a terrible year for Cumbria because of the foot and mouth crisis, suffering 893 confirmed cases of the disease out of a total of