This train of Artillery left the Tower in July, and remained in Byfleet until October, practising experiments in mining, and the usual exercises of Ordnance, under the immediate eye of the Master-General himself, the Duke of Marlborough, who marched at the head of the train, and encamped with it. An interesting allusion to a custom long extinct appears in the orders relative to the camp. We find certain artificers detailed for the flag-gun and the flag-waggon. The former was always one of the heaviest in the field; and the custom is mentioned in 1722, 1747, and in India in 1750. Colonel Miller, in alluding to this custom in his valuable pamphlet, expresses his opinion that the flag on the gun corresponded to the Queen's colour, and that on the waggon to the Regimental colour, the latter probably bearing the Ordnance Arms. The guns had been divided into Brigades, corresponding to the modern Batteries. Four 24-pounders, five 12-pounders, five 6-pounders, and six 3-pounders, respectively, constituted a Brigade. The howitzers were in Brigades of three. The discipline insisted upon was very strict. Lights were not allowed even in the sutler's tents after ten o'clock; no man was allowed to go more than a mile from camp without a pass; officers were not allowed to appear in plain clothes upon any occasion; strong guards were mounted in every direction, with most voluminous orders to obey,—orders which seem occasionally unreasonable. The Captain of the Guard had to see the evening gun fired, and was made "answerable for any accident that might happen"—a somewhat heavy responsibility, as accidents are not always within the sphere of control, where the executive officer's duties are placed. Whenever the weather was fine, all the powder was carefully aired, and all articles of equipment requiring repair were laid out for inspection. The powers of the commanding officers of companies in granting indulgences to their men were curtailed. No artificer was allowed to be employed at any time on any service but His Majesty's, without the leave of the Duke of Marlborough himself, or the commandant in the camp; and should any officer excuse a man from parade he was to be put in arrest for disobedience of orders.