GLAZING-WAGGON, FOR FLAT ROOF.
"Whilst working, the men sat at one end of the platform (the ridge having been previously fixed in position by means of the extra-strong sash-bars), and they fixed the glass in front of them, pushing the stage backwards as they completed each pane. On coming to the strong sash-bars previously fixed, they temporarily removed them to allow the stage to pass. In this manner each stage travelled, uninterruptedly, from the transept to the east and west ends of the building, and the glaziers were enabled to follow up the previously-fixed work very closely. The average amount of glazing done by one man per day was fifty-eight squares, or about 200 superficial feet; and the largest amount done by any one man in a working-day was 108 squares, or 367 superficial feet."
The mode of fixing the squares of glass was this: a sash-bar having been nailed down between the ridge and the gutter, the workman inserted one long edge of a square of glass into the groove in the sash-bar, he then placed a loose bar against the other long edge of the glass and brought the whole down to bear upon the ridge and gutter, the second sash-bar fitting into the notches prepared for it; the glass was then pressed up a little, in order to insert its upper edge into the groove in the ridge, and the workman then filled in the grooves on the outside of the glass with putty, the lower edge of the glass having been also bedded on putty where it bears on the edge of the gutter. The ends of each sash-bar were fixed with a nail driven into the holes previously drilled.
S it might naturally be expected that out of the thousands of panes of glass employed, particularly in the flat roof of the building, many would be broken in the course of the works, subsequently to their being fixed, it was necessary that a ready means should be devised for repairing any such damage, as the glazing-waggons used for the first execution of the work would not be available for that purpose. A light stage was therefore constructed, travelling with wooden wheels upon the ridges instead of in the gutters; and from this the men were able to perform their work without walking along the narrow gutters, which would have been attended with much risk. This stage was also used for fixing the canvass on the outside of the roofing, where it is nailed along the ridges, and allowed to bag down slightly between them. The object of the canvass, which covers externally the whole of the roof except the transept, is twofold: it preserves the glass from damage, and also protects the objects exhibited from the direct rays of the sun, which would, of course, in many instances, be very prejudicial; for the latter purpose the upright sashes on the south side are also covered with canvass on the inside.
NE of the most interesting operations which attracted the attention of the numerous visitors to the works was the raising the ribs for the semicircular roof of the transept, the description of which we give from Mr. Wyatt's paper:—
"The operation about which most anxiety had been felt was the hoisting of the arched ribs of the transept. These ribs were constructed on the ground horizontally, and when completed with all their bolts, two of them were reared on end, and maintained in a vertical position, at a distance of twenty-four feet from each other, by guy-ropes. As the ribs singly possessed little lateral stiffness, they were framed together in pairs with the purlins, intermediate small ribs and diagonal tie-rods, forming a complete bay of the roof twenty-four feet long; two complete sets of temporary ties were also introduced to provide for the strains incident to the variations in position of the ribs during the hoisting. The feet of the ribs were bolted on to a stout piece of timber, and the lower purlins strutted up from the same." In this state the framework is shown in the engraving.