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Ordnance Survey

Control over mapping Britain was important to the king and government for protecting the country against rebellions and invasions. The Ordnance Survey was developed from the Ordnance Drawing Room at the Tower of London in the early 18th century. It was a natural progression from surveying and plan-drawing to map-making.

Ordnance engineers had a long tradition of surveying the landscape and designing fortifications. In 1716 a Drawing Room on the east side of the White Tower was fitted out to allow plans and maps to be drawn. In 1791 the Ordnance Survey became a distinct branch of the Board of Ordnance under the direction of the Master-General of the Ordnance.

Drawing Room staff, supervised by Superintendents of the Survey William Mudge and later Thomas Colby, began to map England and Wales. After the Grand Storehouse fire in 1841 the Ordnance Survey became a separate government department and moved to Southampton.

Ordnance Survey – Mapping Britain

Where is it now?
Ordnance Survey is still at Southampton

1841 Act of Parliament established Ordnance Survey as a separate government department

1798 William Mudge appointed Superintendent of Ordnance Survey under authority of Master General of Ordnance

1765 William Roy appointed as surveyor general of the coasts and engineer for making and directing military surveys in Great Britain. Advocated national mapping survey

1716 Board of Ordnance established a Drawing Office at Tower of London

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  • The Tower of London served as a military depot from the 13th century. The Privy Wardrobe and later the Board of Ordnance made, stored and issued arms, armour and artillery to the navy, armies and garrisons when they were needed.

  • A list of people connected with the Tower of London over its long history.

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Is newer better?

The last cast-iron British smoothbore cannon, the 68 pounder, was 8 inches (203 mm), the same calibre as the heaviest guns of King Henry VIII three hundred years earlier. Their performance was probably not very different either!