THE NATURE OF MATTER AND ELECTRICITY

AN OUTLINE OF MODERN VIEWS

By DANIEL F. COMSTOCK, S.B., Ph.D.

Engineer and Associate Professor of Theoretical Physics In the Massachusetts Institute of Technology, and

LEONARD T. TROLAND, S.B., A.M., Ph.D.

Instructor In Harvard University

225 Pages 5½ × 8 Cloth 22 Illustrations 11 Plates Postpaid $2.50

THE MYSTERY OF MATTER AND ENERGY

RECENT PROGRESS AS TO THE STRUCTURE OF MATTER

By A.C. CREHORE, Ph.D.

172 Pages 4½ × 6½ Cloth 8 Plates and Folding Charts Postpaid $1.00

THE ATOM

By A.C. CREHORE, Ph.D.

250 Pages 5 × 7½ 6 Illustrations $2.00