Economy of Devon (chewing gum) and HMNB Devonport (the largest naval base in western Europe) are in Plymouth. Torquay was home to Beverage Brands, the producers of WKD Original Vodka. Britannia Royal Naval College is at Dartmouth. Mining for tin and copper was carried on in Devon from ancient times until the 1930s: see Dartmoor tin-mining. Agriculture has been an important industry in South West England since the 19th century: approximately 80% of land in the South West of England is in agricultural use (19.6% of England's total). In the later 19th and early 20th centuries there were a number of potteries in
Royal Swedish Naval Staff College added. Only the coastal artillery course included physics. In higher education courses, special subjects were included, and in some of the general course subjects. In 1926 there were teachers in 18 subjects. As students, the Navy's subaltern officers were commanded in turn; an entry qualification was not needed. The Royal Swedish Naval Staff College was discontinued in 1961 and the Royal Swedish Armed Forces Staff College was formed by merging war colleges of the different military branches, namely the Royal Swedish Army Staff College (established 1878), the Royal Swedish Naval Staff College (established 1898) and the Royal Swedish Air Force