Wooden cornices are often used in the principal rooms of dwellings, and if without carving they cost about the same as plaster cornices. They should be put up after the plastering is thoroughly dry, and in the best class of work they are glued together in long sections before putting up, being stiffened where necessary by pine blocks glued to the back of the cornice. To make a good job grounds should be put on the walls and ceiling before plastering at the proper place for nailing the upper and lower members.
When the cornice is glued together before putting up the moulding next the ceiling should be left loose, to be nailed on after the cornice is set in place.
Figs. 281 and 282 show two different styles of cornices. In the former the picture moulding is placed close under the cornice, of which it apparently forms a part. Attention is called to the way in which the dentils are made in Fig. 282. Instead of each dentil being fig. 280.
a separate piece they all form a part of the piece marked a, the spaces between the dentils being cut out. This insures against the dentils dropping off.
Beams. - The beams seen on the ceilings of dwellings are not usually solid, as they appear, but are a mere shell of thin stuff tongued and grooved together. Around the room is usually placed a half beam or cornice into which the principal beams are framed, and the smaller beams are in turn framed into the principals, as shown in Fig. 283, the side member of the small beams being usually, although not always, continued on the side of the larger beams. When made by cabinet makers the entire ceiling is often put together on the floor and raised in position against the plaster ceiling, where it is fastened.
When put up by joiners most of the work is built in place, the beams themselves being usually glued together in lengths at the shop and put up separately. Whichever way they are put up the architect should require that grounds be put on the ceiling for securing the beams, as shown in Fig. 283, and for nailing the panel mould.
As the beams are hollow some method of strengthening them at .the intersections is needed. Cabinet makers usually set in a pine block the full depth of the beam inside and sufficiently long to have strength when mortised out to receive the end of the beam tenoned into it. The end of this latter beam is also strengthened by a similar block on which the tenon is cut.
The outside or show wood should be mitred where the joint is made. In addition to the blocks placed at the points of intersection, others should be placed at intervals of about every 2 feet to give stiffness to the whole structure. The moulding surrounding the panels between the beams should be left loose and set after the beams are in place, as also the moulding below the wall beams. The panels may be of plaster or wood ; if of the latter they should be put together and finished in the shop and raised in position after the beams are up, and the loose moulding then nailed in place.
When the bottom of the beams are paneled, as in Fig. 283, pieces should be put in at the ends and intersections of the beams to form the end of the panels, as shown in Fig. 284, which represents a plan of the intersection of the smaller beams.
Sometimes the finished beams enclose solid beams which form a part of the floor construction, in which case it is generally necessary to build the beams in place. It is always better to put ceiling beams together in the shop, however, as much as possible.
Fig. 285* shows how the column and entablature of one of the classic orders should be put together.
An octagonal post is first made by mitring and gluing the necessary number of planks together in such a manner that the centre of the post is hollow. If the finish wood is very expensive the planks are made thin and glued to a backing of pine or ash, which is not quite as well seasoned as the show wood, so that the shrinkage of the
• This cut i. liken by permission from an article by A. C. Nye. on " Interior Woodwork," backing tends to close the joints in the show wood more tightly. The angles of the backing, or of the solid planks if no backing is used, should be splined together, as shown in section B. After the shell is glued up it is turned and fluted as if a solid timber.
In fluting the shaft, the flutes should be arranged so that the glue joint will come a little to one side of the centre of the flutes and not on the arris. "Practice has shown that when the joint is on the arris the thin edges necessarily resulting are likely to warp and the joint open. With the joint as shown there is no feather edge and a firm butt-joint can be made with little possibility of its opening."
The base is made of octagonal rings glued one on top of the other until the correct size is obtained, when it is turned into shape. The capital is so deeply carved in the example shown that thick pieces of wood are required at the outset, but the hollow space in the centre is retained. The shaft of the column should be rebated into cap and base.
In the construction of the entablature a joint is made wherever possible, to diminish the liability to shrink. The frieze, being wide, is veneered, and the conge at A is made of a separate piece, which effects a considerable saving in material. The dentils are cut from one long strip of wood, and together with the blocks between them form a continuous length, which is fastened in place like any other moulding. The cyma at the top of the cornice is cut from a thick piece of wood, moulded on the flat and stiffened at intervals of about every 2 feet by blocks glued to the back.