This survey of the White Tower is undated, but the type of paper and the style of the drawing suggest it was made in the 18th century. The back (or verso) of the drawing is marked with the distinctive 'broad arrow' of the Board of Ordnance. The Board of Ordnance, which was responsible for fortifications, arms, armour and military equipment, had its headquarters at the Tower of London until it was disbanded in 1855.
The drawing appears to show the upper floor of the White Tower fitted out for storage. The annexe to the east of the Norman Keep was probably built by Edward III (1327-77), but was demolished in 1879 during the Victorian 'restoration' of the Tower.