Engineering Wonders of the World
Volume III

GREAT UNDERPINNING ACHIEVEMENTS. 315 up, and tightly pinned to the under-side of the masonry constituting the original founda- tions of the cathedral. Examination proved that nearly every wall of the building rested upon the peat men- tioned. The south transept was more than four feet out of the perpendicular. The most serious fact was that the cathedral was sink- ing, due to the further compression of the peat in those places where it had not been removed. Fillets of cement, known as “ tell- tales,” were placed across the cracks that could be noticed, so that immediate warning might be given of any further movement. Except in the parts already underpinned, these fillets were in many instances broken within three or four weeks. In fact, the cathedral was doomed unless it were underpinned, and that without delay. At the invitation of the Royal Institute of British Architects, in February 1908, an ex- tremely interesting account was given of this and kindred underpinning work which has been accomplished, and polished sections cut from one of the beech trees, labelled “ Win- chester Cathedral foundation, a.d. 1202,” were exhibited. There are several other specimens from wooden foundations dated 1079, as well as one that goes back as far as a.d. 888. This last curious relic came from under the Campanile at Venice, and was presented to its present owner by Count Grimani, the sindico, or mayor, of the ancient city. All these specimens have been under water for centuries, and yet are as sound to-day as when they were laid by the early builders. Another striking example of underpinning is associated with the magnificent Church of Holy Trinity at Hull. One of the three largest churches in England, it con- Holy Trinity gjs|g an unuSuaßy fine nave Church, Hull. . . , , , ., of eight arenes on each side, with side aisles, choir of five arches and side aisles, transept, and a handsome tower in the middle, resting on four massive piers, each cruciform in plan. The total weight of the tower is 2,800 tons, so that each pier is called upon to support 700 tons. A period of more than two hundred years elapsed before the structure was completed. The foundations of the tower were laid soon after 1300, the choir was finished in 1361, the nave in 1418, and the upper portion of the tower in 1520. A few years ago it became evident that the edifice was falling. Settlements had been detected in the arches and piers surrounding the tower. Considerable cracks resulted, and from time to time portions of masonry dropped. Matters became still more alarming when a large corbel supporting the ridge of the choir roof on the eastern face of the tower collapsed. Mr. F. S. Brodrick, the York diocesan surveyor, then consulted Mr. Fox, in connection with the difficult and delicate work of underpinning. Each of the slender piers of the nave had imposed upon it a dead weight of 75 tons, and all were exhibiting serious deviation from the perpendicular, being as much as 6 or 7 inches out of plumb. It was, indeed, evident that the tower was sinking slowly. A tradi- tion existed locally that it rested on a timber raft, and careful examination proved the truth of the story. The first step to save the church from the complete demolition of which it was in immi- nent peril was to strut and cross-brace the arches and columns, so as to prevent the possibility of a ^*acksS downfall during the process of restoration. In the next place the brickwork in the spandrels of the arches adjacent to the tower was minutely inspected, and when the plaster covering was taken away large cracks indicated that the brickwork was being dragged down by the pier. A hole was made in the floor of the church, and the timber raft was discovered. It rested upon clay overlying a deep bed of silt, and consisted of horizontal oak baulks, crossing each other at right angles.