of
view, he tells us, some analogy to his almost hopelessly complex
problems of life and heredity. Even those medical men whose interest
is entirely commercial appreciate the convenience of the X-ray and the
importance of correctly interpreting the pathological effects of the
rays of radio-activity and ultra-violet light. One finds a great
geologist in collaboration with his distinguished colleague in
physics, and from the latter comes a contribution on the rigidity of
the earth. Astronomy answers nowadays to the name of astrophysics, and
progressive observatories recognize in the laboratory a tool as
essential as the telescope. In a word, the professional student of
science not only finds that the subject matter of physics has many
fundamental points of contact with his own chosen field, but also
recognizes that the less complex nature of its material allows the
method of study to stand out in bolder relief. Training in the method
and a passion for the method are vital to a successful and an ardent
career.

=Should the teaching of college physics change its aim for different
classes of students?=

In the teaching of physics, then, the aim might at first sight appear
to be quite varied, differing with different classes of students. A
careful analysis of the situation, however, will show, we think, that
this conclusion can with difficulty be justified: that it is necessary
to conduct college instruction in a fashion dictated almost not at all
by the subsequent aims of the students concerned. In the more
elementary work, certainly, adherence to this idea is of great
importance. The character, design, and purpose of an edifice do not
appear in the foundations except that they are massive if the
structure is to be great.

Not infrequently this seems an unnecessary hardship to a professional
student anxious to get into the work of his chosen field. If such is
the case, let him question perhaps whether any study of physics should
be attempted, as this query may have different answers for different
individuals. But if he is to study it at all, there is but one place
where the analysis of physical phenomena can begin, and that is with
fundamentals--space, time, motion, and inertia. How can one who is
ignorant of the existence and characteristics of rotational inertia
understand a galvanometer? How can waves be discussed unless in terms
of period, amplitude, frequency, and the like, that find definition in
simple harmonic