Most individuals, observing the mouldings of the broken-arched cabinet cornice and longcase clock hood below could be forgiven for thinking “What handsome/hideous mouldings” without realising the technicalities involved with the mitring of the arches and flanking straight mouldings.
To even the keenest eye, the straight sections of moulding appear to be mitred at 45° where they meet the curved sections, however, it’s not that straightforward. The intersection of curved and straight fielding on the panel below clearly illustrates there is something else going on.
In A George III Mahogany Cabinet-on-Chest Redux, reader, Confur, commented (quite correctly) that to mitre a curved section of moulding with a commensurate straight section one must curve the mitre. This has since raised a few eyebrows, so I offer the following explanation.
With any juncture of mouldings, whether straight-to-straight, curved-to-identically-curved or curved-to-straight, all the mouldings’ elements must obviously intersect precisely for appearance’s sake. For straight-to-straight and curved-to-identically-curved mouldings, the mitres are, as one might expect, straight, however, with curved-to-non-identically-curved or curved-to-straight mitres, a ‘hunting’ mitre must be cut to ensure all the elements coincide.
The diagram below (click on it for an enlarged view) depicts a curved moulding and a straight moulding such as might be found in a cabinet cornice or longcase clock hood. The mouldings’ elements or ‘nodes’ can be seen to intersect each other.
To establish the cut line for the mitre, a solid line has been drawn from A to B such that it intersects each node. By comparison, a second, broken, straight line has been drawn from A to B which clearly does not intersect the nodes.
While, technically, a hunting mitre is required to accurately join a curved moulding with a commensurate straight one, narrow astragal mouldings such as employed on the doors of the George II Mahogany Cabinet on Chest are more often than not simply mitred at a nominal 45° as the human eye is incapable of picking up the irregularities on such a small scale.