First in consideration of the superintendence of stonework is the preparation of the material. In former times, for a work of importance, the stone was often brought to the building site in the rough, as it came from the quarry, and all stone cutting was done upon the spot, but in modern practice the stone will be prepared at a stone yard, often by machinery, and will be ready to be set when received. The stone should be carefully examined when delivered and not be allowed to accumulate in great quantities without inspection, as a thorough examination is then more difficult. According to the nature of the work, the stone will have received more or less of preparation by being worked into the various shapes and finishes suited for its purpose.


The principal building stones in use in this country are granite, limestone, marble and sandstone, and these will be selected for a given building with reference to color, durability and strength. Probably the question of color will enter more strongly into the selection than any other consideration, but this should not wholly overshadow the consideration of strength and durability. Cheapness and accessibility are factors which enter largely into the question of stone for a building, and in cities, the resistance to atmospheric action and especially to fire, may well be considered. While no building stone will resist the action of fire for any length of time, of the different kinds of stone mentioned, fine-grained sandstone will probably stand the best, granite next, and marble and limestone the least.

Testing Of Stone

Although it is possible in most cases to obtain stone for a building from some well-known quarry, the qualities of which have been sufficiently proved, occasion may arise when some simple tests of a certain stone may be desirable. These tests should be made for compactness, absorption, strength and fracture. The compactness of a stone can be best determined by comparison with some known stone of similar constituents, when the least porous in appearance will usually prove the most durable. The porosity may be determined by the power of absorption which it exerts. This may be found by immersing the thoroughly dried stone in water, and noting the difference in weight between the dry and the wet stone. The absorption of ten per cent of the weight of the stone denotes a degree of porosity which is liable to become, after a while, grimy in appearance, while a hard non-absorbent stone suffers little from age.

In situations where the atmosphere is charged with acids, as in large cities or manufacturing towns, there will be danger from the solubility of the stone, especially in damp climates. Too great a tendency may be discovered by soaking the stone in a dilute solution of acid, or by dropping acid upon the surface, when presence of soluble carbonates will be denoted by an effervescence. The presence of substances easy of solution in water, may be detected by placing some of the powdered stone in a glass with water and allowing the particles to settle. If the water is later disturbed, the presence of soluble matter will cause the water to turn muddy, but if the water remains clear it will denote the presence of only insoluble crystals.