he brush are given as
follows:

Figure 300 represents a Medart pulley, constructed by the Hartford Steam
Engineering Company; the arms and hub are cast in one piece, and the rim
is a wrought iron band riveted to the arms, whose ends are turned or
ground true with the hub bore. The figure is obviously a wood engraving,
but it presents the varying degrees of shade or shadow with sufficient
accuracy to form a good example to copy and brush shade with India ink.
Figure 301 represents a similar pulley with a double set of arms,
forming an excellent example in perspective drawing, as well as for
brush-shading.

[Illustration: Fig. 300.]

In brush-shading as with line-shading, the difficulties increase with an
increase in the size of the piece, and the learner will find that after
he has succeeded tolerably well in shading these small pulleys, it will
be quite difficult, but excellent practice to shade the large pulley in
Figure 302.

One of the principal considerations is to not let the color dry at the
edges in one part while continuing the shading in another part of the
same surface, hence it is best to begin at the edge or outline of the
drawing and carry the work forward as quickly as possible, occasionally
slightly wetting with water edges that require to be left while the
shading is proceeding in another direction.

[Illustration: Fig. 301.]

When it is required to show by the shading that the surfaces are highly
polished, the lighter parts of the shading are made to contain what may
be termed splashes of lighter and darker shadow, as in Figure 303, which
represents an oil cup, having a brass casing enclosing a glass cylinder,
which appears through the openings in the brass shell.

Figure 304 represents an iron planing machine whose line-shading is so
evenly effected that it affords an excellent example of shading. Its
parts are similar to those shown in the iron planer in Figure 297, save
that it carries two sliding heads, so as to enable the use,
simultaneously, of two cutting tools.

[Illustration: Fig. 304. (Page 282.)]

[Illustration: Fig. 302.]

A superior example in shading is shown in Figures 305 and 306, which
represent a plan and a sectional view of the steam-cylinder of a Blake's
patent direct-acting steam-pump. The construction of the parts is as
follows: A is the steam-piston, H 1 and H are the cylinder
steam-passages; M is the cylinder exhaust port.

[Illustration: Fig. 303.]

[Illustratio