Part 72

TESTIMONIALS OF PROMINENT EDUCATORS.

"I am delighted with Professor Mach's Science of Mechanics."--M. E. Cooley, Professor of Mechanical Engineering, Ann Arbor, Mich.

"You have done a good service to science in publishing Mach's Science of Mechanics in English. I shall take every opportunity to recommend it to young students as a source of much interesting information and inspiration."--M. I. Pupin, Professor of Mechanics, Columbia College, New York.

"Mach's Science of Mechanics is an admirable ... book."--Prof. E. A. Fuertes, Director of the College of Civil Engineering of Cornell University, Ithaca, N. Y.

"I congratulate you upon producing the work in such good style and in so good a translation. I bought a copy of it a year ago, very shortly after you issued it. The book itself is deserving of the highest admiration; and you are entitled to the thanks of all English-speaking physicists for the publication of this translation."--D. W. Hering, Professor of Physics, University of the City of New York, New York.

"I have read Mach's Science of Mechanics with great pleasure. The book is exceedingly interesting."--W. F. Magie, Professor of Physics, Princeton University, Princeton, N. J.

"The Science of Mechanics by Mach, translated by T. J. McCormack, I regard as a most valuable work, not only for acquainting the student with the history of the development of Mechanics, but as serving to present to him most favorably the fundamental ideas of Mechanics and their rational connexion with the highest mathematical developments. It is a most profitable book to read along with the study of a text-book of Mechanics, and I shall take pleasure in recommending its perusal by my students."--S. W. Robinson, Professor of Mechanical Engineering, Ohio State University, Columbus, Ohio.

"I am delighted with Mach's 'Mechanics.' I will call the attention to it of students and instructors who have the Mechanics or Physics to study or teach."--J. E. Davies, University of Wisconsin, Madison, Wis.

"There can be but one opinion as to the value of Mach's work in this translation. No instructor in physics should be without a copy of it."--Henry Crew, Professor of Physics in the Northwestern University, Evanston, Ill.

POPULAR SCIENTIFIC LECTURES.

A PORTRAYAL OF THE SPIRIT AND METHODS OF SCIENCE.

By DR. ERNST MACH.

PROFESSOR OF THE HISTORY AND THEORY OF INDUCTIVE SCIENCE IN THE UNIVERSITY OF VIENNA.

Translated by THOMAS J. McCORMACK.

Third Edition, Revised Throughout and Greatly Enlarged.

Cloth, Gilt Top. Exhaustively Indexed. Pages, 415. Cuts, 59. Price, $1.50.

TITLES OF THE LECTURES.

The Forms of Liquids.

The Fibres of Corti.

On the Causes of Harmony.

On the Velocity of Light.

Why Has Man Two Eyes?

On Symmetry.

On the Fundamental Concepts of Static Electricity.

On the Principle of the Conservation of Energy.

On the Economical Nature of Physical Inquiry.

On the Principle of Comparison in Physics.

On the Part Played by Accident in Invention and Discovery.