1836.] St. Peter's Church in Fort William. 215 



work people were enabled by means of crow-bars and pick-axes to 

 commence the demolition of the side roofs without any apprehension 

 of danger. These frames being made movable, the expence of centre- 

 ing up the entire side vaults was avoided. The vaulted roofs of the 

 aisles were thus safely removed, without the slightest injury arising 

 to the centre roof of the nave, thereby confirming the correctness of 

 the opinion formerly advanced that no danger would arise to it. Ac- 

 cordingly measures were now taken for the removal of the main vault, 

 together with the flying buttresses and cleristory walls. The erec- 

 tion of any external shores was still considered wholly unnecessary, 

 but from the great height of the nave (46 feet), it became indis- 

 pensable to secure the work people from all probability of danger, 

 during the progress of demolition, by any portion of the vault falling 

 inwardly, when the vertex or keying should be cut away ; but as the 

 construction of a frame-work of sufficient strength underneath the 

 vault could not have been executed without incurring considerable 

 expence, the following plan was devised and put into execution. 



Mode of removing the great vault of the nave. — The upper pinnacles 

 and battlements of the north and south cleristory walls were removed, 

 and a planking laid upon the top of the walls, which admitted of a plat- 

 form (k), fig. 3, placed across the roof being easily slid along its whole 

 length. This platform, in order to give perfect security to the work 

 people, in the event of any part underneath giving way, was suspend- 

 ed by ropes from the four towers, as shewn in the section ; and upon 

 this the work people were enabled to commence the demolition of the 

 roof with perfect confidence ; but so firm was the masonry found to be, 

 that they soon got off on to the roof itself, although entirely unsup- 

 ported from below, and the continuity of the arch was destroyed by 

 cutting from the vertex downwards, thus giving the most unequivocal 

 proof of its exceeding firmness and stability. In this manner the 

 entire roof was destroyed ; after which the flying buttresses being cut 

 at their two extremities, were allowed to fall inwardly ; and finally 

 the cleristory walls were brought down to a level with the shattered 

 parts of the columns. Having thus briefly shewn the state in which 

 the foundations, roofs, and pillars were found, after a most careful 

 examination, and the plan pursued in the removal of the roofs, abund- 

 ant evidence has been furnished of the ultimate cause which destroyed 

 the safety of the building, and it can only be a matter of surprise, that 

 an edifice, constructed of brick upon the principles of Gothic architec- 

 ture, should (after the main supports of the side aisles had been cut 

 away, and the pillars reduced to half their original strength), have so 

 long resisted the fatal injury committed ; the punkah beams having 

 been put up in 1827." G. Hutchinson, Major, Engineers. 



