Fig. 11. Shews the method of mitreing skirting, where tic wall of a staircase is continued before the first step, and after the landing.
Fig. 12. Shews another method, by taking away the an gles. Thus take two equal distances AB and AC. Draw BD perpendicular to AB, and CD perpendicular to AC. Then with D as a centre, describe the are BC, which is the curve required.
Fig. 13. Shews the method of finding the forms of the bars of a bow window. The principle is the same as de scribed in Fig. 9. No. 1. is a section of the given bar. No. 2. is a section of the raking bar in the mitre of an oblique angle. No. 3. section of the bar in a right angle.
Formation of Bodies in Parts by joining them with Glue.
Plate CCCXXXVI. Fig. 1. No. 1. Is a section of two boards glued up edge to edge. No. 2. face of the same.
Fig. 2. A section of two boards glued edge to edge, with a tongue inserted in a groove in each piece By these means, a board may be made to any breadth, though the pieces which compose it he ever so narrow.
Fig. 3. Two boards fixed at right angles, the edge of the one being glued upon the side of the other. They are strengthened by a block, which is fitted and glued to the interior sides.
Fig. 4. No. 1. A section of two boards at an oblique an gle, mitred and glued together, with a block in the angle. No. 2. shews the inner sides of the boards thus fixed. By this method columns are glued up.
Fig. 5. No. 1. Section of an architrave. As the mould ing is generally, if not always glued to the plate or board, the dotted line circumscribing the moulded part strews the section of the piece to be glued. No. 2. face of the archi trave. No. 3. a section of the architrave before it is mould ed. No. 4. a front of the same. No. 5. a section of the same to a reduced size, with the button and nail, shelving the manner in which the two parts are glued together. No. 6. shews the back of the architrave with the buttons. The black dots shew the heads of the nails. The buttons are used, in order to bring the two surfaces which are glued together in contact, after the pieces have been set and held together, and are afterwards knocked off when the glue becomes dry, and then the moulding is stuck, as shewn by the section, No. 1. and elevation, No. 2.
Fig. 6. Shews the method of glueing up a solid niche in wood. No. 1. is the elevation. Here the work is con structed in the same manner as if it were stone or brick, except that the joints are all parallel to the plane of the base ; for it is difficult to make a joint with curved surfaces, as would necessarily be the case if they all tendd to the centre of the sphere. No. 2. and No. 3. shew the two bot tom courses, where the vertical joints are made to break, and not to fall in the same planes. This is distinctly seen in the elevation, No. 1.
Fig. 7. Shews the manner of glueing veneers together, so as to form a cylindrical surface. This is done by nail ing brackets to a board, with their faces upwards, and their ends perpendicular, leaving a cavity sufficient for the ve neers and wedges between the ends. In No. 1. the thin part in the form of an arc shews the veneers in the state of being glued, and the wedges are shewn upon the convex side. No. 2. is a section of the board and bracket. The veneers ought to be heated before a large fire, and the glue laid on the surfaces that are to come in contact as hot as possible, to prevent the glue from setting, observing to glue only a small portion at a time, and then wedge it up. When the glue is dry, the wedges must be slackened, and the veneers, which will then form one solid, taken out.
Fig. 8. Shews a very strong method of forming a con cave surface, by laying the veneer upon a cylinder, and backing it with blocks in the form of bricks, which are glued to the convex side of the veneers, and to each other. The fibres of the blocks must be as nearly parallel as pos sible to the fibres of the veneers. Nn. t. chewy A section of the cylinder, veneer, and blocks. No. 2. shews the con vex side of the blocks.
Fig. 9. Shews another method of glueing veneers loge :her with cross pieces screwed to a cylinder, the veneers being placed between the cross pieces and the cylinder.