MA'SONRY, 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 ccasider 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 masonry, of which remains exist in many parts of dreece and Italy, also exhibits stones of great size and with carefully-adjusted joints. The walls of Mycenw are among the earliest examples. These are built with huge irregular blocks, ,the spaces between being filled up with smaller stones. The Etruscan specimens are 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 cyclopean masonry.
The masonry of the Greeks and Romans very closely resembled that of the present day: Rubble-work (opus ineertum), in which the stones are not reg,ularly coursed; coursed work, where 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 eastern empire were constructed with blocks of enormous size, as at Baalbec, where some of the stones are 60 ft. in length. Ashlar-work is frequently used for the exterior surface of walls, the inside beiftg ' backed up" with rubble-work. This kind of work is sufficient for ordinary purposes; but where great strength is required, the whole thickness must be built with solid blocks. Ashlar-work is generally bedded in fine mortar, with one inch of oil-putty on the outer edge.
The early medimval masonry was of very' bad construction, being, in fact, little better than common rubble, with an occasional use of herring-bone work. The Normans improved upon this kind of work, but their masonry was also so bad that most of the towers built by them either fell or had to be taken down. The fall of the tower of Chichester cathedral, a few years ago, was occasioned by defective Norman masonry. The art gradually improved with the advance of Gothic architecture, and ashlar was reintroduced for all important works. The ashlar-m ork so constantly used in renais sance buildings, has lately given place to a more picturesque style of masonary called .haramer-dressed and squared work--the money saved upon this cheeper work being applied with good effect in improving the appearance of the doors, windows, and other prominent features of the buildings.
There is one very simple rule, too little attended to in modern masom7—viz., that all stones, at least when stratified, should be laid on their natural bed, for if set on edge, they are sure to scale off and decay tinder the influence of the weather.
Special materials sometimes produce special kinds of work; thus, in Norfolk and: Suffolk, where large flints abound, the walls am often faced with these_ split so as to form a clean face and good joints, and arranged in bands or panels between stonework or brickwork. In Aberdeenshire, where granite is the usual building material, ashlar work is almost universal, large blocks being more easily obtained and dressed than. smaller ones. Again, where rag-stone only can be got, it is frequently neatly used in a. similar manner to the flint above described.