elow the drawing
surface. To obviate such difficulties, some instructors demonstrate
principles by first angle constructions. Others invert surfaces which
in the first angle have their bases in the horizontal plane. This
undesirable device may be overcome by using a second horizontal plane
in the third angle. Such means of demonstration may be avoided
altogether by considering the space relations of magnitude to one
another instead of relating them to the planes of projection. This
method centers the attention of the student on the relation of
magnitudes represented and develops visualization. It has been found
to give excellent results in both elementary drawing and descriptive
geometry.

To bring the teaching of descriptive geometry into closer harmony with
its application in practice, auxiliary views are frequently used
instead of the method of rotations.

Briefly, then, it appears that the modern course in descriptive
geometry should contain enough applications to hold the interest of
the student and to test his power of visualization; that the third
angle should be emphasized, and some use should be made of auxiliary
views. Above all, the development of visualizing ability should be
considered one of the chief aims of the course.

=Methods of instruction in general courses=

In teaching drawing and descriptive geometry, lectures,
demonstrations, and individual instruction each have a place.
Principles can best be presented in the form of lectures. The manual
part of the work can be presented most effectively by means of
demonstrations. The instructor should illustrate the proper use of
instruments and materials by actually going through the process
himself, calling attention to important points and explaining each
step as he proceeds. Individual instruction given at the student's
desk is a vital factor in teaching drawing, as it offers the best
means of clearing up erroneous impressions and ministering to the
needs of the individual student.

Frequent recitations and quizzes serve the purpose of keeping the
instructor informed as to the effectiveness of his instruction and as
a means by which the student can measure his own progress and grasp
upon the subject.

=Methods of instruction in technical drawing courses=

Those drawing courses which have for their primary object the teaching
of technical subject matter make use of the drawings as an instrument
to record facts and to test the student's knowledge