PLATE XXXII.

SHOWING THE MOULDING OF RAILS, AND A METHOD OF PROPORTIONATELY

INCREASING OR DECREASING THE SIZE OF THEM.

Figs. 1 and 2 show pattern of rails full size, both of which look well

when finished, and nice to handle. The shaded parts at Fig. 1 show how

the rail should be worked out before it is moulded. It will be seen

that Fig. 1 has three dowels, while Fig. 2 has two.

At Fig. 2 is seen a method by which a rail may be proportionately

increased or decreased to any size. Let S be the given rail and R the

required one. Make A B equal the width of S, and A E the thickness of

R; from E draw square to A B, and make E F equal the thickness of S;

join A B. From A square out a line and make A D equal the width of the

required rail R. From B and D square out lines to meet in C; join A C.

From each member in S draw ordinates to cut A C and A F, and where

these meet again in R will be the same member in the required rail.

Fig. 3 shows a handrail screw, A being a round nut, a section of which

is seen at Fig. 4, and B a square one; W is a round washer. These

screws are let into about the centre of the section of rail at the

joints. A hole is cut in the under side of each piece for the nuts to

go in, and a small bent chisel, made for the purpose, is used to turn

the nut A.

Practical Stair Building and Handrailing By the square section and falling line system. · 第 76 / 78 题