These should always be built of some hard stone, preferably granite, and should have a solid bearing. Outside steps generally rest on a wall at each end, and if more than 6 feet long should have a support at the centre. Each step should rest on the back of the one below at least \\ inches. Steps to outside entrances should pitch outward about 1/8 inch. Steps are much more comfortable when cut with a nosing, but owing to the increased expense this is only done in costly buildings.
Stone stairs may be built with only one end supported. In European buildings, and many of our Government buildings, the stairs are constructed as shown in Fig. 113, either with or without nosings. One end of the steps is solidly built into the wall, and each step is supported by the one below, owing to the way in which they are cut. The bearing of one step on the other should not be less than that shown in the figure. The bottom step must obviously be well supported its full length, as it has to sustain nearly the full weight of the stairs. The steps are usually cut with a triangular cross section as shown, as it is less expensive and reduces the weight of the stairs, besides giving a pleasing appearance from below.
The railing is generally of iron, doweled into the ends of the steps.
The laying out and detailing of other stone trimmings will be governed by the principles above noted.