e term "building stone" includes all stones for ordinary masonry construction, as well as for ornamentation, roofing, and flagging. A very wide variety of stones is used for this purpose, including practically all varieties of igneous, sedimentary and metamorphic rocks. There are a few, however, which are more commonly used than others, because of their widespread occurrence and durability. The color of a building stone quite often gives it a popularity which determines, to a large degree, the extent of its use. New England brownstone is probably the best example of this. The growth of the brick industry and also of the cement industry has opened a severe competition with building stones. Brick and concrete blocks being cheaper, are widely used in many sections of the country. Solid concrete, in many cases, has replaced stone for not only super-structures but sub-structures as well. However, there is still a very great demand for high class building stones and probably always will be. 11 p.