Fig. 174.
Fig. 173.—Ground Plan of Octagonal Summer house.
Fig. 174.—Section of Octagonal Summer-house at Y Z ([Fig. 173]), showing Framework.
Its framework and the main part of it are of larch poles; other woods are, however, used for minor purposes. The roof is of thatch. In the arrangement of this building there is a certain resemblance to a tent. It has a central pillar, A, not unlike a tent pole, which sustains much of the weight of the roof. Being of first importance, this pillar is somewhat larger than any of the other timbers—say 6 in. in diameter near its bottom, and tapering as little as may be. A rod of iron or wood rises from its top to form the centre of the straw pinnacle seen crowning the roof in [Fig. 172]. This pillar shows a height of 11 ft. 2 in. above ground, and it should be let 3 ft. or more into the soil; for it will need to be firmly fixed, or it may be forced out of the perpendicular during the erection of the roof; when the roof timbers are once fixed in place, it will have little further chance of moving. The diagram [Fig. 173] is a ground plan, and [Fig. 174] is a section showing the timbers from the interior; both are drawn on a scale of ¼ in. to the foot.
The eight collar-posts (B, [Figs. 173] and [174]) at the corners of the octagon are of somewhat smaller stuff—say 4 in. They show 6 ft. above ground, and should have 2 ft. below. It will be well to gas-tar all the underground work.
The ground plan of a building in this shape is readily laid out. The space being levelled, a string is taken which has a loop at each end, and is 5 ft. 2 in. long. With a stake driven through the loop at one end as a centre, and with a stick passed through the loop at the other to serve as the travelling leg of the compasses, a circle is struck 10 ft. 4 in. in diameter, and into this pegs are driven at equal intervals (4 ft. apart) to mark the centres of the eight collar-posts. Whilst digging the holes for the posts, these points are kept by drawing two straight lines on the ground which intersect at the peg.
The cross-pieces which rest on the collar-posts, and which serve as wall-plates, are a trifle smaller stuff than the posts—say 3 in. [Fig. 175] shows how they are cut to fit the tops of the posts, and nailed there. In this building there are no mortise and tenon joints. On these ends above the posts rest the lower ends of the eight main rafters, D, the upper ends of which rest against and are nailed to the central pillar. The eight intermediate rafters, E, rest at the bottom on the middles of the side plates, and at top are cut to fit upon and between the tops of the main rafters.
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Fig. 175.—Collar Posts and Ends of Wall Plates. |
Fig. 176.—Timbers over Entrance of Octagonal Summer-house. |
The laths used are in this case in no way particular—any sticks will do; they will not be seen, and under thatch there is no necessity that a level surface should be formed by them, as for slates or tiles. They are nailed 6 in. or 8 in. apart.
The gable over the entrance is arranged as in [Fig. 176]. The laths, when nailed on, will have to run over the little ridge formed by F, instead of keeping the level, as on the other sides. This will cause no special difficulties in the thatching.