of the stairway has also much to do with its appearance; in a private house, it should never be less than 2 feet 8 inches wide, and in public buildings never less than 4 feet 6 inches. The staircase wherein the stairway is enclosed should be given special attention, and the correct length and width should be carefully considered. It is not conducive to sound construction to be obliged to cut out trimmer beams; neither is it good practice to have to piece out a few inches when the staircase has been framed too large.
The importance of proper arrangement of stairways is evident, when it is considered that they are seen by every one, their convenience and beauty being readily appreciated, and their faults and defects instantly detected.
2. The materials most commonly used in the construction of stairways are stone, iron, and wood; the selection of material should be based on the location and the use to be made of the stairway. If placed outside of a building, stone, owing to its natural capability of resisting atmospheric influences, should be used; while, if placed inside a building designed to be fireproof, iron is generally selected, as it possesses great resistance to heat. Both iron and stone are preferable to wood when used in public buildings, where the amount of travel requires extra strength; wood, however, is the material most commonly used, especially in private buildings, where no heavy travel is to be expected.
3, In stair building\", a riser and tread together are termed a step, the riser being the upright portion which supports the tread, or horizontal part, upon which the foot is placed. The nosing is the projection of the tread beyond the face of the riser.