BUILDING A HOUSE - In spite of the news of the war, which was daily assuming a more threatening character, M. de Gandelau insisted on the works not being interrupted; and the inhabitants of the cluiteau found in the execution of the plans prepared by Eugene and Paul a beneficial distraction from the sad fore bodings which oppressed them.
In the evening, after reading the paper, which recorded, alas ! only a succession of disasters, everyone remained silent, with eyes fixed on the hearth; but soon, with a determined effort, M. de Gandelau started the inquiry how the house was getting on. It was for Paul, as Clerk of the Works, to give an account of the operations of the day, and he began to perform his task with a fair amount of exactness and clearness. He showed his memorandum books, which, thanks to Eugene's corrections, were not very badly drawn up, and which, by the help of a daily summary of accounts, indicated the expenses that had been incurred.
The excavations had hitherto furnished enough materials to obviate the necessity of sending for any from the neigh bouring quarries. About the 15th of the cellar walls were already beginning to make their plan visible, and it was time to think of the exterior plinths in elevation, and of the cellar vaultings, for whose construction wooden centres were required. The carpenter was therefore com missioned to send for timber-sawyers, to convert some trunks of poplars, which having been cut some time before, were put by for the purpose. The best part of the wood was sawn into thin boards for battens, to be employed when required; and the slabs - that is, the part near the bark - were cut up for centring for the cellars. As the plans gave only two barrel-vaults whose arches were dif ferent, the curves were soon struck out, and the carpenter prepared the centres, which were fixed, up as soon as the cellar walls reached the level of the spring of the vaults These centres were formed in the manner shown in Fig. 25- –that is, consisted each of a tie-piece, A, a king post, B, two blades, c, and clips, D, which held fast the curves formed of slabs of poplar nailed together, as shown at E, and fixed at G and H on to the king-post by means of a notch, F, and to the tie-piece by an iron staple. On these centres, supported by props K, and set five feet apart, they laid a covering composed of planks, L, 3 inches thick, to receive the vaults, which were made of blocks of tufa extracted from the banks of the rivulet, 8 inches in thickness, with a good layer of mortar over all. The openings for the air-holes had to be contrived in the haunches of the vault, a piece of work which gave Paul considerable trouble - or rather, he had some difficulty in understanding it and sketching it in his notebook; for, as to Branchu, he did not seem to find any particular difficulty in it.
Eugene had given the sketch for the air-holes at the same time as the section of the plinth, 5 feet in height above the ground level.
This drawing presented, in section at A, and in plan at B, the figure 26. Eugene had to explain this sketch to his clerk-of-works, who did not understand it at the first glance."As the light comes from the sky, at the mean angle of 45°, the cellars must be lighted accordingly,"said Eugene."The plinth consists of a course, D, half sunk in the ground, two clear courses, E F, and a course bearing the set-off. We give the cellar wall bearing the spring of the vaults, 3 feet. The wall above the floor-level being 2 feet, this wall gives one foot on each side of the fixed centre-line, but as the plinth has 4 inches of projection outside, there will be 16 inches from the centre to the exterior face of this plinth. Within, the wall descends plumb as far as the skew-back which carries the vaults. A width of 8 inches is needed to receive the latter. Thus, from the centre-line below the spring of the vaults there will be 20 inches in the interior, and 16 inches on the exterior : total, 3 feet. The lower course rising above the surface 6 inches, and the height of the plinth being 5 feet, there remains above these 6 inches, 4 feet 6 inches, which divided by three gives for each course 18 inches. I take the opening of the air-hole in the second course; out of the third, I take a chamfer of 4 inches, to admit the light, as the exterior, M, and the section indicate. I cut the first course to a slope of 45°, as shown at I, leaving a flat, a, of 12 inches, as you see • in the plan. Then, behind this sill, I place a lintel, with a chamfer in the same way, as drawn at 0, and take care to leave at b, two rebates of 2 inches, for casements or gratings, at discretion. At the back of these rebates, I splay the air-hole, which has only 2 feet 8 inches of exterior opening, to 3 feet 4 inches. I draw in section an inclined line, ni n, 8 inches above the lintel 0, which 8 inches will be the rise of the arched open ing that will penetrate into the barrel-vault, and whose curve in horizontal projection will give the outline x. Thus this arch, x, will receive the thrust of the courses of the barrel-vault, and will throw it on the two cheeks, P. Branchu will only have to mark the curve x on the covering of the centres to form his arched opening." FIG. 27.