given as upon the permanent interest stimulated and the initiative
aroused. The youthful mind, and indeed the average adult mind as
well, is singularly non-logical and incapable of continued
concentration, and loses interest under too consecutive thought and
sustained style. For this reason the author has sacrificed at times
detail to general effect, logical development to present-day interest
and facts, and has made use of a popular, light style of writing as
well as of the more formal and logical style common to books of
science.

No claim is made to originality in subject matter. The actual facts,
theories, and principles used are such as have been presented in
previous textbooks of science, but the manner and sequence of
presentation are new and, so far as I know, untried elsewhere. These
are such as in my experience have aroused the greatest interest and
initiative, and such as have at the same time given the maximum
benefit from the informational standpoint. In no case, however, is
mental training sacrificed to information; but mental development is
sought through the student's willing and interested participation in
the actual daily happenings of the home and the shop and the field,
rather than through formal recitations and laboratory experiments.

Practical laboratory work in connection with the study of this book is
provided for in my _Laboratory Manual in General Science_, which
contains directions for a series of experiments designed to make the
pupil familiar with the facts and theories discussed in the textbook.

I have sought and have gained help from many of the standard
textbooks, new and old. The following firms have kindly placed cuts
at my disposal, and have thus materially aided in the preparation of