This series of scientific books for boys, girls, and students of every age, was designed by Prof. Alfred M. Mayer, Ph. D., at the Stevens Institute of Technology, Hoboken, New Jersey. Every book is addressed directly to the young student, and he is taught to construct his own apparatus out of the cheapest and most common materials to be found. Should the reader make all the apparatus described in the first book of this series, he will spend only $12.40.

NOW READY:

I.—LIGHT.

A Series of Simple, Entertaining, and Inexpensive Experiments in the Phenomena of Light, for Students of every Age.

By ALFRED M. MAYER and CHARLES BARNARD.

II.—SOUND.

A Series of Simple, Entertaining, and Inexpensive Experiments in the Phenomena of Sound, for the Use of Students of every Age.

By ALFRED MARSHALL MAYER,

Professor of Physics in the Stevens Institute of Technology; Member of the National Academy of Sciences; of the American Philosophical Society, Philadelphia; of the American Academy of Arts and Sciences, Boston; of the New York Academy of Sciences; of the German Astronomical Society; of the American Otological Society; and Honorary Member of the New York Ophthalmological Society.

In Active Preparation:

LIGHT:

A Series of Simple, Entertaining, and Inexpensive Experiments in the Phenomena of Light, for the Use of Students of Every Age.

BY ALFRED M. MAYER and CHARLES BARNARD.

"Professor Mayer has invented a series of experiments in Light which are described by Mr. Barnard. Nothing is more necessary for sound-teaching than experiments made by the pupil, and this book, by considering the difficulty of costly apparatus, has rendered an important service to teacher and student alike. It deals with the sources of light, reflection, refraction, and decomposition of light. The experiments are extremely simple and well suited to young people."—Westminster Review.

"This work describes, in simple language, a number of experiments illustrating the principal properties of light, by means of a beam of sunlight admitted into a dark room, and various contrivances. The experiments are highly ingenious, and the young student can not fail to learn a great deal from the book. As an example of the effective experimental method employed, we may specially mention the device for illustrating the refraction of light. This book is specially designed 'to give to every teacher and scholar the knowledge of the art of experimenting.'"—The Quarterly Journal of Science (London).

"A singularly excellent little hand-book for the use of teachers, parents, and children. The book is admirable both in design and execution. The experiments for which it provides are so simple that an intelligent boy or girl can easily make them, and so beautiful and interesting that even the youngest children must enjoy the exhibition. The experiments here described are abundantly worth all that they cost in money and time in any family where there are boys and girls to be entertained."—New York Evening Post.

"The experiments are capitally selected, and equally as well described. The book is conspicuously free from the multiplicity of confusing directions with which works of the kind too often abound. There is an abundance of excellent illustrations."—New York Scientific American.

"The experiments are for the most part new, and have the merit of combining precision in the methods with extreme simplicity and elegance of design. The value of the book is further enhanced by the numerous carefully-drawn cuts, which add greatly to its beauty."—American Journal of Science and Arts.

SOUND:

A Series of Simple, Entertaining, and Inexpensive Experiments in the Phenomena of Sound, for the Use of Students of Every Age.

By ALFRED MARSHALL MAYER,

Uniform with "LIGHT," first volume of the Series.

"It would be difficult to find a better example of a series which is excellent throughout. This little work is accurate in detail, popular in style, and lucid in arrangement. Every statement is accompanied with ample illustrations. We can heartily recommend it, either as an introduction to the subject or as a satisfactory manual for those who have no time for perusing a larger work. It contains an excellent description, with diagrams, of Faber's Talking Machine and of Edison's Talking Phonograph, which can not fail to be interesting to any reader who takes an interest in the marvelous progress of natural science."—British Quarterly.

"The style of the book is very clear, and the experiments interesting. It can not fail to have an important educational influence."—Westminster Review.

"It would really be difficult to exaggerate the merit, in the sense of consummate adaptation to its modest end, of this little treatise on 'Sound.' It teaches the youthful student how to make experiments for himself, without the help of a trained operator, and at very little expense. These hand-books of Professor Mayer should be in the hands of every teacher of the young."—New York Sun.

"An admirably clear and interesting collection of experiments, described with just the right amount of abstract information and no more, and placed in progressive order. The recent inventions of the phonograph and microphone lend an extraordinary interest to this whole field of experiment, which makes Professor Mayer's manual especially opportune."—Boston Courier.