EARL.—THE ELEMENTS OF LABORATORY WORK: a Course of Natural Science. By A. G. Earl, M.A., F.C.S., late Scholar of Christ's College, Cambridge. With 57 Diagrams and numerous Exercises and Questions. Crown 8vo., 4s. 6d.

GANOT.—Works by PROFESSOR GANOT. Translated and Edited by E. ATKINSON, Ph.D., F.C.S.

ELEMENTARY TREATISE ON PHYSICS, Experimental and Applied. With 9 Coloured Plates and Maps, and 1028 Woodcuts, and Appendix of Problems and Examples with Answers. Crown 8vo., 15s.

NATURAL PHILOSOPHY FOR GENERAL READERS AND YOUNG PERSONS; With 7 Plates, 624 Woodcuts, and an Appendix of Questions. Crown 8vo., 7s. 6d.

GLAZEBROOK AND SHAW.—PRACTICAL PHYSICS. By R. T. Glazebrook, M.A., F.R.S., and W. N. Shaw, M.A. With 134 Woodcuts. Fcp. 8vo., 7s. 6d.

GUTHRIE.—MOLECULAR PHYSICS AND SOUND. By F. Guthrie, Ph.D. With 91 Diagrams. Fcp. 8vo., 1s. 6d.

HENDERSON.—ELEMENTARY PHYSICS. By John Henderson, B.Sc. (Edin.), A.I.E.E., Lecturer in Physics, Manchester Municipal Technical School. Crown 8vo., 2s. 6d.

HELMHOLTZ.—POPULAR LECTURES ON SCIENTIFIC SUBJECTS. By Hermann von Helmholtz. Translated by E. Atkinson, Ph.D., F.C.S., formerly Professor of Experimental Science, Staff College. With 68 Illustrations. 2 vols., crown 8vo., 3s. 6d. each.

Contents.—Vol. I.—The Relation of Natural Science to Science in General—Goethe's Scientific Researches—The Physiological Causes of Harmony in Music—Ice and Glaciers—The Interaction of the Natural Forces—The Recent Progress of the Theory of Vision—The Conservation of Force—The Aim and Progress of Physical Science.

Contents.—Vol. II.—Gustav Magnus. In Memoriam—The Origin and Significance of Geometrical Axioms—The Relation of Optics to Painting—The Origin of the Planetary System—Thought in Medicine—Academic Freedom in German Universities—Hermann Von Helmholtz—An Autobiographical Sketch.