point a, the intersection of the center lines of the rail, the wreath piece will conform to the common pitch of the flights. If the front stringer is a close one, and the risers are placed as shown, the effect will be more agreeable than it would be if the risers were placed either nearer to, or farther from, the point a. This arrangement of the risers will allow of a graceful curve in the development of the front stringer and the hand rail, while if placed in any other position, the result would be an unsightly crippled rail and stringer.
45. Quarter-Turn Winding. — The plan of a quarter-
turn winding stairway, with a quarter cylinder for a
continued hand rail, and with regular treads above aAd
below, is shown in Fig. 41. It will be noticed that the
treads adjoining the cylinder in both flights are reduced.
The benefit derived from the reduction will appear in the
curve of the rail and stringer, as it modifies the angle of
intersection between the pitch of one straight rail and that
over the winders, the stringer, of course, being affected in
the same manner.
46. Platform and Curved Risers. — In Fig. 42 is
shown a plan of a stairway which includes two platforms
with a step and two curved risers in the 10-inch cylinder
between the platforms, making a half turn. The wreathed rail