If the differences just shown be considered fatal to the relationship between the sailor’s song and the vessel noticed in the narrative, then Cherry’s very popular ballad belongs to the history of the sappers and miners. ----- In January and February, 1792, the Woolwich company was employed at the Tower of London, constructing an earthen battery for four guns in front of the gates, and a wooden battery for four guns, projecting from the coping of the wall of the fortress facing the Minories, to sweep the ditch and the hill. These defensive measures were undertaken by Captain Holloway of the engineers, sergeant John Watson being the overseer, and were intended to oppose any attack on the Tower which might be attempted by the turbulent Jacobins. ------------------------------------------------------------------------ [Illustration: Royal Military Artificers Plate V. UNIFORM 1792 Printed by M & N Hanhart. ] ------------------------------------------------------------------------ The Prussian system of tactics being lately introduced into the army, it was ordered that a union of corps should take place to ascertain its efficiency. An encampment for the purpose was formed on Bagshot Heath, early in July, under the Duke of Richmond, the Master-General of the Ordnance. The regiments present were the 2nd, 3rd, 14th, and 29th Foot; two regiments of light dragoons, two battalions of artillery, and one company of military artificers, made up of men from the Woolwich, Chatham, Portsmouth, and Gosport, companies, under Lieutenant-Colonel Moncrief, royal engineers. The sergeant-majors of these four companies were present. A large quantity of intrenching implements and tradesmen’s tools accompanied the party. The encampment lasted for about a month, the troops marching from one position to another, and manœuvring in a body, as if in actual warfare. During this time there were three grand field-days and two _sham_ battles; at the whole of which his Majesty was present, as also, on some occasions, were the Prince of Wales and the Dukes of York and Gloucester. The company of artificers manœuvred with the troops when not otherwise required; but more generally they were employed in making bridges over small rivulets for the passage of the troops, throwing up occasional earthworks, as well as mining and constructing wooden redoubts. One of the mines was sprung on the 4th August, and created quite a spectacle. It raised the earth in a solid mass about thirty feet in diameter, throwing its contents to a considerable distance. Another mine was exploded on the 7th August, under one of the advanced redoubts, with equal success; but the third and last mine was the largest, and almost amazing in its effects. Of this mine some particulars have been preserved. Upon a round hill was erected one of Colonel Moncrief’s square wooden redoubts, that the