Carrying siege-guns.This giant sling-cart was built by the Confederates for the purpose of handling the two 12-inch guns that were cast at the Tredegar Iron Works, in Richmond, just before the evacuation. These guns weighed nearly fifty thousand pounds each. The size of the cart can be estimated by comparing it with the man visible through its spokes in the upper photograph. The wheels are more than eleven feet high. The cart required twelve mules and one hundred and fifty men with drag ropes to move it, when carrying only an 8-inch rifle or a heavy Columbiad over bad roads. The big guns were slung underneath the cart by ropes so as to clear the ground by a few inches. It was captured by the Federals, and used in the removal of the ordnance from Drewry's and Chaffin's bluffs.