This section is from the book "A Treatise On Architecture And Building Construction Vol3: Stair Building, Ornamental Ironwork, Roofing, Sheet-Metal Work, Electric-Light Wiring And Bellwork", by The Colliery Engineer Co.. Also available from Amazon: A Treatise On Architecture And Building Construction.
The length of newel posts is governed by the depth of the stringer, including the soffit molding. Fixing the height of the easement at G, Fig. 30, and the height of the level hand rail at j, the height of the hand rail up the flight is figured, and the rail is made parallel to the line of the stringer. There is nothing important in the position of G, except that it fixes the level of the knee at k.
To produce a good easement, i l must equal i m, and m n must be at right angles with m i. Let m o equal the thickness of the hand rail; from n as a center, describe the easement lines of and m l. For the ramp and knee, make q r from 1/2 to 1 1/2 inches; perpendicular to q s, draw r v; make t u equal to r t; from u draw u v at right angles to t u; make r w equal to the thickness of the rail, and draw w k parallel to q s. With v, the intersection of r v and u v, as a center, describe the arcs r u and w x. The ramp and knee at the upper landing are defined in the same way. The rail may be curved, as indicated by the arc c' e' forming a goose neck.