Perspective sketches to denote the shape of the piece, 93.

Photo-engraving, drawings for, 266, 267.

Piece of work should, in mechanical drawing, be presented in as few views
as possible, 94.

Pillow block box, 294.

Pin, in a socket, in section, representation of, 87, 88.

Pinion teeth, to draw to the pitch of the inner and small end of, 206.

Pins and discs, discrimination of, in mechanical drawing, 96.

Pipe threading stock and die, drawing of, 85.

Pitch circle of the inner and small end of, to draw, 206.
to obtain a division of the lines that divide, 167.

Plan, 94.

Planing machine, a cutting tool for, 264-266.

Plotting mechanical motions, 223-263.
out the motion of a shaper link quick return, 250-253.

Point, a, 49.

Points of drawing instruments, 34.

Polished surfaces, to show by shading, 282.

Polygon of twelve equal sides, to draw, 129, 130.

Polygons, bolts and nuts, examples of, 112-151.
construction of, 61.
designation of the angles of, 62.
names of regular, 62, 63.
scales giving the lengths of the sides of, 135.

Preparation and use of the instruments, 34-47.

Produced line, 50.

Projecting one view from another, 106.

Projections, 178-192.

Protractors, 53.

Pulley, Medart, shading a, 280.

Pulleys, arrangement of idle, to guide bolts from one pulley to
another, 264.

Quadrangle, quadrilateral or tetragon, 59.

Quadrant of a circle, 50.

Quick return motion, Whitworth, plotting out, 253-256.

Radius across corners of a hexagon, 138.

Rankine's process for rectifying and subdividing circular arcs, 210.

Reducing scales, 175.

Rectangle, a, 59, 60.

Rectangular piece, a, to draw in two views, 98, 99.
requires two or three views, 96, 97.
representation of, 96.

Red ink, marking dimensions of mechanical drawings in, 91.

Rhomboid, a, 60.

Rhomb, rhombus or diamond, 54, 60.

Right line, a, 49.

Ring with a hexagon cross section, 98.

Rivet, side and end views of, 49.

Roller, example of a short arm having a, acting upon a larger roller, 225.

Rod, attached to an eccentric strap, to find the amount of motion imparted
in a straight line to a, 229-231.
end with a round stem, 148.

Round stem, a representation of, 96.
top and bottom thread, 156.

Rubber, 25.
form of, 26.
proper uses of, 25.
sponge, 26.
the use of, 25.
to be used on Bristol board, 26.
velvet, 26.

Rule, steel, 32.

Sapphire p