hout aims to have a human interest and a practical value, and to
provide the simplest and most easily comprehended method of
demonstration. At the end of each chapter are lists of references to
both elementary and advanced books for collateral reading.

* * * * *

SHARPE'S LABORATORY MANUAL IN BIOLOGY

$0.75

In this Manual the 56 important problems of Hunter's Essentials of
Biology are solved; that is, the principles of biology are developed
from the laboratory standpoint. It is a teacher's detailed directions
put into print. It states the problems, and then tells what materials
and apparatus are necessary and how they are to be used, how to avoid
mistakes, and how to get at the facts when they are found. Following
each problem and its solution is a full list of references to other
books.

AMERICAN BOOK COMPANY

ESSENTIALS OF PHYSICS

By GEORGE A. HOADLEY, C.E., Sc. D., Professor of Physics, Swarthmore
College.

$1.25

This is the author's popular and successful Elements of Physics
enriched and brought up to date. Despite the many changes and
modifications made in this new edition, it retains the qualities which
have secured so great a success for the previous book.

It tells only what everyone should know, and it does this in a
straightforward, concise, and interesting manner. It takes into
consideration the character of high school needs and conditions, and,
throughout, lays particular emphasis upon the intimate relation
between physics and everyday life.

While the subject matter, as a whole, is unchanged, the order of
topics in many cases has been altered to adapt the development of the
subject to the habits of thought of high school pupils. Instead of
beginning the treatment of a subject with the definition and
proceeding to a discussion of the sub-topics, the author starts with a
discussion of well-known phenomena and leads up to the definition of
the subject discussed. The text, wherever possible, has been
simplified, more than fifty topics having been amplified, expanded, or
reworded. More familiar illustrations of the topics treated are given,
and the demonstrations of many of the experiments are simplified by
the use of materials that are readily obtainable in the classroom.

There have been added a number of new topics, mostly in connection
with the recent advances in applied science. The number both of
questions and problems has been greatly in