In Fig. 23 is shown a stairway winding one-quarter turn at the top and bottom, with an 8-inch cylinder, for a continued hand rail. In planning winding stairways, it is important to make the treads as nearly as possible of the same width on the line of travel. This line should be about 14 inches from the face of the stringer, as shown on the plan (a). The width between finished walls for this stairway should be at least 6 feet 4 inches, as follows:

Width of stairway from finished wall............

2

feet

10

inches.

Diameter of cylinder.........................

8

inches.

Hall passage................................

2

feet

10

inches.

6

feet

4

inches.

The distance from the finished wall to the cylinder is made 3 feet 1 inch, so as to allow room for moving furniture. Where the stairway is continuous, the first and last risers of each flight should be placed 2 inches beyond the landing facia line, in order to make a proper finish with the facia.

In commencing the drawing, the starting and landing risers are marked on the plan, and the line of travel divided equally, as before mentioned. Then the space along the cylinder is divided; and lastly, the risers along the straight stringer are drawn in position. Lines are drawn through the points found along the line of travel and passing through the points located along the front stringer, thus completing the plan of the stairway. The elevation (b) of the stairway is drawn by projecting the lines of the risers down from the plan, and by drawing the lines of the treads horizontally from the story rod, as shown at tread 10. For the development of the wall stringer, follow the method given in Fig. 22. The headroom, as shown, is 7 feet 6 inches from the top of the third step to the ceiling.