After the seats for the timbers had been dressed in this manner, the carpenters were employed cutting the beams to their respective lengths, the piece to be cut off being measured, as already stated, by the length through which the sliding-board _f f_ (No. 4, p. 85) had been raised above its position on the level platform on which the pyramid had been erected in the workyard at Greenock. At the same time, the stancheons (_k k_) in the figure (No. 8, p. 88), and the glands or collars _e_ _e_ (in figure No. 8), were let into grooves in the beam, and the holes admitting the screwed bolts _a_ _a_, to pass through the two stancheons and the beam between them, were bored with an auger, and widened with a red hot iron. The tops of the beams _b_ _b_ (see fig. No. 9), having been already fitted in the workyard at Greenock, so as to meet a hexagonal quoin of hardwood _e_, round which they were assembled as shewn in the figure (No. 9), straps of iron _d d_, were made to pass over the top of the whole, and were secured to the beams with bolts, and a spike at _a_ was driven into the centre to wedge the timbers tightly up, so as to fill a ring which embraced the exterior of the whole. It was obvious, that if the sliding-board (described on p. 85) had indicated the true inclination of the seat on the Rock for the end of the beam to rest on, as well as its radial distance from the centre of the pyramid and the corresponding length of the beams, the top of each beam must necessarily meet in its exact place around the central hexagonal quoin. The operation of determining the positions and lengths of such beams on a rugged rock, and placing them with the accuracy requisite, to insure their _mitering_ truly at the top, was attended with a good deal of trouble; and I have judged it advisable to give these details, as they may prove useful to others who may have a similar work in hand. [Illustration: No. 9.]