Ashlar (also known as achelor or ashler) is hewn or squared stone, as distinguished from that which is rough, as when it came from the quarry. The term also extends to masonry made of squared or hewn stone and masonry consisting of stones squared and smoothed in front and built in regular courses. Research Ashlar
In architecture, bonders, also known as bond-stones and binding-stones, are stones which reach a considerable distance into, or entirely through a wall for the purpose of binding it together. Bonders are principally used when the work is faced with ashlar, and are inserted at intervals to tie it more securely to the rough walling or backing. Research Bonder
Emplection is a kind of masonry in which the outer faces of the wall are ashlar, the space between being filled with broken stone and mortar. Cross layers of stone are interlaid as binders. Research Emplecton
In masonry herringbone work is one in which the stones are laid aslant instead of being bedded flat. It is very commonly found in rough walling, and occasionally, in the Norman style, in ashlar work. It is more frequent in the Norman than any other style, but it is not to be relied upon as evidence of the date of a building. It is sometimes found introduced in the walls in bands, apparently for ornament, but it has often been manifestly adopted for convenience, in order to enable the workmen to level off the work at each course, which could not well be done in any other way with stones of
irregular shapes and sizes. In herringbone work, by varying the inclination of the stones, it is easy to preserve a level. The interior, or backing, of Roman walls, is often of irregular herringbone work, formed in this way. Research Herringbone
In architecture, a perpent-stone is a large stone reaching through a wall so as to appear on both sides of it, the same as what is now usually called a bonder, bond-stone, or through, except that these are often used in rough-walling, while the term perpent-stone appears to have been applied to squared stones, or ashlar. Bonders also do not always reach through a wall. The term is still used in some districts; in Gloucestershire, ashlar thick enough to reach entirely through a wall, and show a fair face on both sides, is called Parping ashlar. This name may perhaps also have been sometimes given to a corbel. Research Perpent-Stone
Abbreviations
Research Ashlar
