Responsible for the supply of armaments and munitions to the army and the navy, based in the Tower of London and also used Verbruggen's House at the Woolwich Arsenal until 1939. Disbanded in 1855 due to poor performance in the Crimean War. The work was then carried out by a variety of departments until the creation of the (Royal) Army Ordnance Corps in 1918.
The Corps' Latin motto, Sua tela tonanti, is normally loosely translated as "To the Warrior his Arms".
Our image of the Board of Ordnance device comes, via Wikipedia, from the Tower of London. The equivalent for the Royal Army Ordnance Corps has a crown at the top instead of the turret and fist clutching lightening and thunderbolts.