square, improved, with pivoted blade, 19.

Steps, to draw a piece containing, 99-101.

Stock and die, pipe-threading, drawing of, 85.

Straight line in geometry termed a right line, 49.
or lining pen, use of with a T square, 45, 47.

Stud, to draw a, 142.

Stuffing-box and gland, 169.

Surface of the paper, condensing after rubbing out, 25.

Surfaces, highly polished, to show by shading, 282.

Tacks for drawing paper, 27, 28.

Tangent, 51.

Taper or conical hole, to denote in drawing, 102.
sides in a drawing, 102, 103.

Tees, 180.

Teeth of wheels, rules for drawing, 203.
pinion, to draw the pitch of the inner and small end of, 206.
spur wheel, how to draw, 194.
to trace hypocycloides for the flanks of, 200.

Template for drawing the curves of thread, 165.

Templates called curves, 21.

T square, 18, 19.

T squares, different kinds of, 19.

Tetragon, a, 59, 62, 63.

Thread, a double, 156.
a round top and bottom, 156.
depth in the top or end view of a nut, to show, 166.
left hand, 156.
square, to draw a, 162-164.
Whitworth, 156.

Threads of a large diameter, 156.

Thumb tacks for drawing paper, 27.

Tint, to graduate the depth of, for a cylindrical surface, 279.

Tooth face, how to find the curve for, 198.
proportions, Willis' scale of, 195.

Tracing cloth, 29.
paper, 29.

Trammel, use of in drawing an ellipse, 72.

Trapezium, 60.

Trapezoid, a, 60.

Triangle, equilateral, 58, 59.
isosceles, 58, 59.
obtuse, 58.
right angle, 58.
scalene, 59.
use of in dividing circles, 129.
use of in drawing polygons, 129, 130.
use of to draw slots radiating from a centre, 131.

Triangles, 19-21, 58-60.
requirements in use of, 20, 21.
to draw, 133.
using with the square, 20.

Triangular scale, 33.

Trigon, a, 62, 63.

True ellipse, a near approach to the form of, 69-72.

United States standard bolts and nuts, 114-118.
standard thread, to draw, 159, 160.

Valve of an engine, 290-292.

Valves, 301.

Vertex, the, 59.

Views, different arrangement of, 94-111.
of a piece of work, designations of, 103, 104.
of a piece, two systems of placing, 106-111.

Washer, a, representation of the shadow side of, 83.

Wax process, drawings for engravings by, 268, 269.
engraving from a print from a wood engraving, 269.

Wedge-shaped piece, representation of a, 97.

Wheel, edge view of a, to draw, 203.
sectional view of a section