At first the idea was entertained of restoring the ruins, but this was finally abandoned by royal warrant to the Commissioners in 1668, and clearing and excavations began. The workmen with pickaxes stood on the top of the walls some eighty feet high, and others below cleared away the dislodged stones--a dangerous task in which lives were lost. Of the Central Tower some two hundred feet remained, and a more expeditious plan was adopted. A deal box, containing eighteen pounds of gunpowder, was exploded level with the foundations at the centre of the north-west pillar, and the adjacent arches were lifted some nine inches, while these ruins "suddenly jumping down, made a great Heap of Ruin in the Place without scattering." Wren estimated the whole weight lifted at three thousand tons, and the labour saved equal to that of a battalion of a thousand men. When the alarmed inhabitants of the neighbourhood heard and felt the concussion, they naturally took it for an earthquake. In the surveyor's absence a subordinate used too much powder in attempting a second mine, and neither burying it low enough nor building up the mouth, a stone was projected through an open window into a room where some women were sitting at work. Although no one was hit, the neighbours took alarm, and successfully agitated against all further blasting. Delay was caused, and finally a battering-ram some forty feet in length, worked by thirty men, completed the demolition. The stones and rubbish were cleared away, and used in different buildings and in repairing the streets. Afterwards some houses on the north side which encroached on the building, and may have been those that assisted the passage of the Fire, were levelled, and their site included in the churchyard.