This section is from the book "A Practical Treatise On The Joints Made And Used By Builders", by Wyvill J. Christy. Also available from Amazon: Practical treatise on the joints made and used by builders.
This is formed by cutting a chase or mortise having elongated and diminishing cheeks, so that the tenon, on being inserted obliquely into it, can be
' slid or driven home sideways where there is not room to get it in endways.
Circular Joint occurs in framing where the abut ment of the butting timber is rounded off or circular. It is, however, rarely met with, and there are opposite notions as to its theoretical or practical value. It is otherwise termed Hounded Joint.
This is not so fine a joint as the joiner's of the same name. It occurs between gutter boards, in close boarding to roofs, boarded lining to wainscoting, sound boarding, etc. In heavier work it is found amongst a hundred other situations, in ordinary planking and strutting in sandy soils, between boards laid close to retain rubble filling, etc, and between planks that are intended to be caulked.
This will be found explained under Caulked Joint.
Cogged Joint is the most usual term for the third variety of caulked joint, as previously described in this section.
This is one of the alternative names of caulked joint.
Cottered Joint is fully described under the Smith's trade in Section VII., and is much used by the carpenter in trusses for tightening up the tie-beam, in cofferdams for adjusting the cross-bracing, etc. Fig. 32 affords an illustration of its application.
In planking foundations the planks are often laid in two thicknesses crossing each other and well spiked together, the bottom thickness being laid diagonally across the masonry courses. In this and similar situations the planks are said to be laid cross joint.
Double Notched Joint is made by cutting a notch on each of the pieces of timber passing over one another, as in Fig. 33, so that they may fit down upon each other. The notches, however, must not be of sufficient depth to constitute halving.
Dovetailing is shown in Fig. 40 and consists in a close-fitting union between a gradually expanding wedge-like pin or pins, or similar projections, cut out of one edge or end of a piece, and a similar number of corresponding holes, notches, sockets, or grooves in another. It is more efficacious in stone than wood, owing to the shrinkage of timber in the direction of breadth and thickness loosening the joint and allowing the pin to draw. Moreover, when the pin expands from moisture there is a chance of its acting with the power of the wedge and splitting off the sides of the notch. Wood joists embedded in, that is, jointed to concrete, are more likely to remain firm therein if cut to a dovetail section. Halved joints are sometimes dovetailed, and in heavy work a mortise and tenon joint is strengthened by being dovetailed on one side, the other being tightly wedged up with a detached wedge, which is driven in to keep the dovetail in its seat.