MASONRY. The art of construction in stone. The earliest existing examples are among the most magnificent specimens of the art. No nation has excelled the ancient Egyptians in stonework, whether we consider the size of the materials, or the unequaled exactness with which they are fitted together. The Egyptians did not use mortar in their important structures, such as the Pyramids, the joints being all carefully polished and fitted. Cyclopean o• polygonal ma sonry. of which remains exist, in many parts of Greece and Italy. as we]] as Asia Minor, also ex hibits stones of great size and with carefully ad justed joints. The walls of Mycena: are among the earliest examples. These are built with huge irregular blocks, the spaces between being filled up with smaller stones. The Italian specimens are usually more carefully executed; the stones are not squared. but they are all carefully fitted together. In some cases, the beds or horizontal joints are made level, and the upright joints left unsquared. No mortar is used in eyclopean ma sonry.
The masonry of the Greeks and Romans very closely resembled that of the present day: Rubide-work (opus inecrt cm), in which the stones are not regularly coursed; coursed work, whe•e the joints are all level, and the stones of equal height: ashlar, resembling the latter, but built with larger stones all carefully dressed on the joints. Many of the' Roman buildings in the East were constructed with blocks of enormous size, as at Baalbek (q.v.), where some of the stones are fS0 feet in length.
Modern stone masonry is classified according to (1) the degree of finish of the face of the stones. into quarry faced, pitch faced, and dressed; according to (2) whether the horizontal courses o• layers are of the same thickness at similar heights, into range. broken range, and random masonry; according to (3) the care exer cised in dressing the beds. into ashlar, squared stone, and rubble masonry. (1) Quarry faeod masonry is that in which the faces of the stones are left as they conic from the quarry; it is used chiefly for massive structures such as bridge piers, retaining walls; dams, and arch bridges. Pitch faced masonry is that in which the face of the stones is roughly dressed so as to make the front of the horizontal joint a straight line; it is used for work where a rugged appearance is desired without the extreme roughness of quarry faced masonry. Dressed masonry, as the name indicates, is that in which the face of the stones is dressed to a more or less smooth plane surface; it is employed chiefly in building construction and for the finishing courses of engineering works. Range imisoury is that in which the hori
zontal joints are continuous throughout, or, stated in other words, in which each course is of the same thickness throughout. Broken range masonry is that in which the horizontal joints are not continuous throughout, but in which the masonry is not laid in courses at all. masonry is cut stone masonry in which the joint faces are so truly cut that the distance between the general planes of the contiguous surface of the stones is inch or less. Ashlar masonry may be subdivided into range ashlar. broken range ashlar, random ashlar, quarry faced ashlar, pitch faced ashlar or dressed ashlar, and also into combinations of these sub-classes, as, for ex ample, quarry faced range ashlar. ,Squsn•ed stone masonry is that in which the stones are roughly dressed and roughly squared on their joint faces; when the distance between the general planes of the contiguous surfaces of the stones is inch or more, the masonry belongs to this class. In practice the distinction between ashlar masonry and squared stone masonry is not well defined. Rubble masonry is that composed of unsquared stone, and may be laid with or without an at tempt to approximate regular courses. Several of the above types are illustrated in the article ButtniNG.
Sonic: of the other current definitions of stone masonry work are as follows: Face, the front surface of a wall ; bark, the inside surface; facing, the stones which form the face of a wall; barking, the stones which form the back of a wall; batter, the slope of the surface of a wall; course, a horizontal layer of stone in a wall ; joints, the mortar lying between the stones (usn ally the horizontal joints are called beds or bed joints, while the vertical joints are called bands or simply joints) ; roping, a course of stone on the top of the wall to protect it: pointing, a better quality of mortar put in the face of the joints to help them to resist weathering; bond, the arrangement of stone in adjacent courses; stretcher, a stone whose greatest dimension lies parallel to the wall: header, a stone whose great est dimension lies perpendicular to the wall; quoin, a corner stone: doweis, straight bars of iron which enter a hole in the upper side of one stone and also a hole in the lower side of the stone above; cramps, bars of iron having the ends bent to right angles with the body, the bent ends 4it which enter holes in the upper surfaces of adjacent stones.