SPIRE ON A NEW C05STRUCTI0N. 245 



linearly semicircular, and about four inches in diameter, was Mode of fas- 

 -. placed so as to cover the joints of the slates, where they met tuning the 

 1. •■!••, ,-. ■ ^ slaies. 



the bars, sinking into the grooves which were just suffi- 

 ciently wide to receive the copper. The copper by its 

 i^hape and elasticity caught in the grooves, so as to form, 

 when painted, a covering perfectly ijnpervious to rain and 

 snow, 

 '^:.: To fasten these copper caps and the slates to the skeleton 

 ■)<lif the spire, a contrivance was adopted, which requires 

 iome detail to become intelligible. The general idea was 

 to fasten the capping and the slates J'rom ivithiny so as to 

 leave no holes to be stopped on tiie outside by putty or 

 paint. Fig. 7 isasectionof theslateson alargerscale thanthat 

 irf" the spire, where they join on the rib ; of the copper cap- 

 ping; and of a collar, or band, by which they are connected 

 with an iron cramp, that passes round the inside of the rib, 

 and, hooking into the collar or band, is wedged withip, 

 against the inside of the rib. In looking at this section, 

 care must be taken to distinguish the circular edge of. the 

 copper capping from the edge of the band or collar. The 

 band, as may be seen in the drawing, is twice as thick as the 

 capping. In this section of all these parts, as connected 

 together, C is the copper capping; S S, the band or collar; 

 i;H ,H, the cramp, or holdfast; and W, the wedge. 



The whole of this apparatus for fastening the slates suc^ 

 ceeded to my wishes: it was easily executed by common 

 workmen; the parts were easily put together; and, when . . 



adapted to their several places, ihey held the slates and their 

 ,-<japping firmly upon the bars, at the same time producing a 

 very good effect by raising a bold and ornamental moulding, 

 or torus, fig. 7> on every angle of the spire. It is scarcely 

 necessary to add, that pari of the lower corner of each slate 

 : was cut away at A to permit the cramps to pass through, 

 , and to embrace the iron rib; and that the ends of the dia- 

 -phragnis were permitted to extend beyond the outward sur- 

 face of the ribs, to support the perpendicular pressure of 

 the slates. Such slates as were not thus supported rested 

 upon the rabbets of those that were beneath them. 



The machinery, by which the spire, when it was thus 6- Description of 



j^ished, was drawn up, must npw be described. the machinery 



_,, for raising the 

 The gpire. 



