TEACHING SCIENCE IN SECONDARY SCHOOLS


 For chemistry, in addition to the above, simple ratio and
proportion should be reviewed. The metric system will be in-
troduced for the first time for practical use. We do not recom-
mend that any great amount of time be spent on conversion to
English systems of measurement; for this is seldom necessary.
In science courses only one system need be used-the metric
system. It is important, however, that all the relationships be-
tween metric measurements be thoroughly understood.
 In physics, besides the mastery of the use of the metric sys-
tem, a review will be needed in common and decimal fractions,
in ratio and proportion, in percentage, in finding area and
volume, and in square root. The very simplest principles of
geometry, such as diagonals and angles, may be presented with-
out previous courses in plane geometry.
 Problems will have meaning only as pupils are able to visual-
ize materials used. This can be done by showing models and by
having students measure objects by the units to be used. Science
teachers should secure the help of the teachers of mathematics
in having students actually use the metric system. Students
should be led to see a need for solving scientific problems, and
as far as possible problems should be practical and within the
realm of their interests.

 SECTION 4. TEACHING THE HISTORY OF SCIENCE
 Someone has said, "History is biography, and the stories of
science are the stories of scientists." One of the best ways to
arouse interest at almost any point in a science course is by lead-
ing the students to find-for themselves and for each other-
the historical facts behind the phase of science at hand. Stories
of early investigators and inventors and the processes or devices
that they used, of explorers and research workers along many
lines, and of authors who have preserved the records for us, add
life and human interest to the course.
 As we study biographies of scientists, we are impressed with
the insight of early workers and investigators, their persistence,
the hardships they endured, and the real results obtained in spite
of difficulties. We are also impressed with the facts that scien-