stem where each child does his own work at his natural rate of
progress. The children can carry on the work with almost no assistance
from the teacher, if provision is made for their doing the experiments
themselves and for their writing the answers to the inference
exercises. When the individual system is used, the children may write
the inference exercises, or they may use them as a basis for study
and recite only a few to the teacher by way of test. In the elementary
department of the San Francisco State Normal School, where the
individual system is used, the latter method is in operation. The
teacher has a card for each pupil, each card containing a mimeographed
list of the principles, with a blank after each. Whenever a pupil
correctly explains an example, a figure 1 is placed in the blank
following that principle; when he misapplies a principle, or fails to
apply it, an _x_ is placed after it. When there are four successive
1's after any principle, the teacher no longer includes that principle
in testing that child. In this way the number of inference exercises
on which she hears any one individual recite is greatly reduced.
This plan would probably have to be altered in order to adapt it to
particular conditions.

The Socratic method can be employed to great advantage in handling
difficult inferences. The children discuss in class the principle
under which an inference comes, and the teacher guides the discussion,
when necessary, by skillfully placed questions designed to bring the
essential problems into relief.[1]

[Footnote 1: At the California State Normal School in San Francisco,
this course in general science is usually preceded by one in
"introductory science."]

The chapters and sections in this book are not of even length. In
order to preserve the unity of subject matter, it was felt desirable
to divide the book according to subjects rather than according to
daily lessons. The varying lengths of recitation periods in different
schools, and the adaptation of the course to individual instruction
as well as to class work, also made a division into lessons
impracticable. Each teacher will soon discover about how much matter
her class, if she uses the class method, can take each day. Probably
the average section will require about 2 days to cover; the longest
sections, 5 days. The entire course should easily be covered in one
year with recitations of about 25 minutes daily. Two 50-minute periods
a week gi