Before commencing this subject, let it be clearly understood that future
success will, in a great measure, depend upon the amount of care
bestowed upon it. The aim should be to obtain absolute accuracy, and for
this end the copies should be tested by the most careful measurements,
and corrected until they are true with the originals, but it should be
distinctly understood that these measurements are only to be made after
the eye and hand have done their best.
NOTE.--To some it may appear that too much time and care has been
bestowed on mere lines, but let it be understood that a good system of
line drawing is the basis of all education--the slightest outline by a
hand thus trained has a bold, free and masterly character; and with
regard to shading, which is simply an aggregation of good lines, it is
only by such a practiced hand its most charming effects can be
produced.
Fig. 66: Place the points _A_, _B_. Examine them to see that they are
the same distance apart as in the original, and that they are level;
place the point _C_ exactly under _A_, and make _A C_ equal in distance
to _A B_; now place the point _D_ opposite _C_ and under _B_; try the
distances between each point to see that they are the same; divide each
side by a point half way, and then draw the lines.
Fig. 67: Repeat the last figure and add the lines _A_ and _B_, taking
great care that the points for them are correctly placed.
Fig. 68: Commence with the square as before; then join the half-way
points.
Fig. 69: After the square is drawn, place the points _A_ and _B_ at the
right height above the half-way points, and _C_, _D_ at the proper
distance from the corners, then draw the figure.
Fig. 70: The greatest care should be taken with the squares for this and
the following figure, as the slightest error in them will destroy the
symmetry of the drawing within; when the square is completed, join the
opposite corners, and place on the crossed lines the points _B_, _C_,
_D_, _E_; examine these to see that they are each at the same distance
from the centre _A_, and that this distance is equal to the space from
_A_ to the sides of the square; when all are proved to be correct,
complete the figure.
[Illustration: Fig. 66.]
[Illustration: Fig. 67.]
[Illustration: Fig. 68.]
[Illustration: Fig. 69.]
[Illustration: Fig. 70.]
[Illustration: Fig. 71.]
Fig. 71: Repeat the last drawing with, if possible, greater exactness,
and outside the octagon place the points _A_, _B_, _C_, _D_, etc.;
examine each of these points to see that they are all at the same
distance from the centre, and then complete the figure.