This photograph is from the Victorian era and shows men polishing cannonballs for distribution as ordinance to warships of the Royal Navy.
This part of the Royal Dockyard was run quite separately from the Admiralty who had control of the South Yard. In fact it was run by the Ordnance Department and was called the Gun Wharf. Its purpose was to enable ships' guns tested by the Army's Board of Ordnance to be fitted to warships built or maintained within the Royal Dockyard and to supply those ships with munitions and equipment.
A small gun wharf and storehouse had been established at Mount Wise shortly after the Dockyard came into existence. By 1717 it was inadequate. When the Navy Board heard about plans for a new gun wharf they asked for it to be nearer the Dockyard. Land was leased from Sir Nicholas Morice in 1719 and the new yard was named after him.
The estimated cost of the work in November 1718 was £16,745 7s 3d. In the autumn of 1720 the construction contract was awarded to Mr William Cowley, stonemason, of London. He was later joined by Mr Abraham Curtis in respect of the carpentry and joinery. Although it is thought that Colonel Christian Lilly's plans of the yard may have been shown to Sir John Vanbrugh, Comptroller of the King's Works, there is no evidence of Vanbrugh's actual involvement so the styling of the buildings may be just an attempt by Lilly or his draughtsman, Schutze, to copy Vanbrugh's style.
In January 1720 Mr Andrew Jelfe was appointed Clerk of Works. He appears to have designed the labourers' houses (later guard houses). Work started on site in 1720. A small powder magazine was included. In 1723 a Mr Jonathan Devall replaced Cowley as the stonemason.
The gun wharf was partially operational by 1724. The powder magazine became too small and by 1730 the ships' powder was being kept in the Citadel and manhandled through the streets to the gun wharf, a highly dangerous practice. In 1743 the Board of Ordnance obtained permission for a new magazine, rubble-built with double skin walls and a barrel vault and bearing the arms of the Duke of Montagu, Master General of the Ordnance 1739-49. In the 1770s two new powder magazines and a shifting house were built at Keyham, closer to the powder mills at St Budeaux.
A gas service was first installed to light the Gun Wharf in November 1846. The gas was supplied by the Devonport Gas and Coke Company from their gasworks just across the main road from the Keyham Steam Yard. 
In 1855 the Board of Ordnance was disbanded and its functions handed over to the War Office.
All the buildings inside this Yard, including the gateways in Queen Street and Morice Town, are scheduled ancient monuments. The armoury used to hold large chests containing an immense collection of muskets, pistols, cutlasses and other instruments of destruction, with some of them arranged about the walls in star, circle, fan and crescent formations. On the wharves were cannons of all calibres from the ships moored in the Hamoaze.
When wars were fought only in lands far away, i.e. before the Great War, it used to be simple to gain access to the Gun Wharf by just asking the police at the gate.
The Gun Wharf was transferred to the Admiralty in 1937 and but did not become a part of the Royal Dockyard until 1941.
Empire in Your Backyard: Plymouth Article