he employed later in his private veneer mill at Battersea, and the Royal Navy saw mills at Woolwich Dockyard and Chatham Dockyard, as well as mills he designed for private concerns, such as Borthwick's at Leith in Scotland. Later history The Block Mills have remained in constant Navy occupation ever since and in consequence are not open to the public. Manufacture of blocks using these machines naturally declined over the years, production finally stopping in the 1960s, but some of the original machines, part of the transmission drives and the engine-house shells still survive in the buildings. The National Museum of Science and Industry, London, has a selection of machines, donated by the Admiralty between 1933 and 1951, and others are on display in the Dockyard Apprentice Museum at Portsmouth. Several websites claim that the Smithsonian Institution in Washington, D.C. also has machines from Portsmouth: this is a myth, according to the Institution. The Block Mills have not been in use for many years, although a lot of the original pulley systems remain in situ, albeit in a poor state of repair. The building is also in a poor state of repair and is a high priority for both English Heritage and the Ministry of Defence. As of 2006 a project is under way to ensure the building and contents are preserved, if not restored. See also Grade I listed buildings in Hampshire Notes References The English Heritage reports and other documentation may be consulted as they become available in the National Monuments Record at Swindon, Wiltshire. Cooper, C. C. 'The Production Line at Portsmouth Block Mill', in Industrial Archaeology Review VI, 1982, 28–44 Cooper, C. C. 'The Portsmouth System of Manufacture', Technology and Culture, 25, 1984, 182–225 Coad, Jonathan, The Royal Dockyards 1690-1850, Aldershot, 1989 Coad, Jonathan, The Portsmouth Block Mills : Bentham, Brunel and the start of the Royal Navy's Industrial Revolution, 2005, Wilkin, Susan, The application of emerging new technologies by Portsmouth Dockyard, 1790–1815, The Open University PhD Thesis, 1999. (Copies available from the British Thesis service of the British Library) Cantrell, J. and Cookson, G. eds. Henry Maudslay and the Pioneers of the Machine Age, Stroud, 2002 External links National Museum of Science and Industry, London - Making of the Modern World Photographs of block making machines in The National Museum of Science & Industry Royal Navy Grade I listed buildings in Hampshire Scheduled monuments in