 Complete the following phrase:  Derby Cathedrals clock has two dials, one facing West along St Marys Gate, and one facing South down Irongate. Both are of stone and are 8 feet in diameter. They were restored and gilded in 1964, then again in the early 21st century. The 1964 restoration proved beyond doubt that the long metal tubes driven through the tower walls to operate the clock mechanism were actually gun barrels cavalry carbines dating from the 