mple explanation of, 48.

Geometry, advantage of to the draughtsman, 48.

Governor of an engine, 292, 293.

Guide bolts from one pulley to another, arrangement of idle pulleys
to, 264.

Heart cam, to draw, 75, 76.

Hexagon, a, 62, 63.
head, representation of a piece with, 96.
head, to draw the end view of, 125, 126, 127.
headed screw, to draw, 113, 114.
radius across corners, 138.

Hexagonal form, representation of, 98.
or hexagon heads of bolts, 118, 119.

Hole, representation of by shade or shadow line, 83.

Hollows in connection with round pieces, representations of, 87-89.

Hypocycloides for the flanks of teeth, to trace, 200.

Independent condenser, 288.

India ink, advantages of in drawing, 30.
difference between good and inferior, 31.
good, characteristics of, 31.

India ink, Higgins', 30.
mixing, 25.
testing, 31, 32.
the two forms of, 30.
to be used thick, 32.
use of, 30.
use of on parchment, 32.

Ink, applying, to the bow pen, 46.
for drawing, 30-33.

Instruments, preparation and use of, 34-47.

Iron planing machine, representation of, 282.

Iron, wrought and cast, representation of by cross-hatching, 82.

Journal, 294.

Journals of shafts, 277.

Key, a, drawn in perspective, 92, 93.
drawing of a, 91.
marking the dimensions of on a drawing, 92.
representation of with a shade line, 84.

Knuckle-joint, pencil eye for, 146.
with an offset, 147.

Large bow or circle pen, joints of, 23.

Lathe centre, representation of, 86.

Lathe feed motion, drawing of a part of a, 208.

Lead pencils for drawing, 23.

Lead, representation of by cross-hatching, 82.

Left-hand thread, 156.

Lever, a, actuating a plunger in a vertical line, to find how much a given
amount of motion of the long arm will actuate the plunger, 226.
and shaft, drawing, 103, 104, 105.
arm and cam, in one piece on a shaft, a shoe sliding on the line, and
held against the cam face by the rod, to find the position of the face
of the shoe against the cam, 228.
example of the end of a, acting directly on a shoe, 225.
to find how much a given amount of motion of a long arm will move the
short arm of a lever, 224.

Levers, two, upon their axles or shafts, the arms connected by a link, and
one arm connected to a rod, 227.

Light in shading, 280.
management of, in mechanical drawing, 82, 83.

Line-shaded engravings, drawing for, 264-276.