io WORKS published by LONGMANS CO.

NATURAL HISTORY and PHYSICALSCIENCE.

Professor Helmholtz’

Popular Lectures on Scientific Sub-jects. Translated by E. Atkinson,F. C. S. With numerous Wood Engrav-ings. 8vo. I2r. 6 d.

Professor Helmholtz on

the Sensations of Tone, as a Physio-logical Basis for the Theory of Music.Translated by A. J. Ellis, F.R.S.8vo. 36^

Ganot’s Natural Philo-sophy for General Readers andYoung- Persons ; a Course of Physicsdivested of Mathematical Formulae andexpressed in the language of daily life.Translated by E. Atkinson, F. C. S.Third Edition. Plates and Woodcuts.Crown 8vo. 7 s. 6d.

Ganot’s Elementary

Treatise on Physics, Experimentaland Applied, for the use of Collegesand Schools. Translated and editedby E. Atkinson, F.C.S. EighthEdition. Plates and Woodcuts. Post8vo. 151-.

Arnott’s Elements of Phy-sics or Natural Philosophy. SeventhEdition, edited by A. BAIN, LL. D.and A. S. Taylor, M.D. F.R.S.Crown 8vo. Woodcuts, 12 s. 6d.

The Correlation of Phy-sical Forces. By the Hon. Sir W.R. Grove, F.R.S. &c. Sixth Edition,revised and augmented. 8vo. 15-r.

Weinhold’s Introduction

to Experimental Physics; includingDirections for Constructing PhysicalApparatus and for Making Experiments.Translated by B. Loewy, F.R.A.S.WithaPrefaceby G. C. Foster, F.R.S.8vo. Plates & Woodcuts 311-. 6d.

A Treatise on Magnet-ism, General and Terrestrial. By H.Lloyd, D.D. D.C.L. 8vo. ior. 6 d.

Elementary Treatise on

the Wave-Theory of Light. ByII. Lloyd, D.D. D.C.L. 8vo. lor. 6 d.

Fragments of Science,

By John Tyndall, F.R.S. LatestEdition. Crown 8vo. 10 s. 6d.

Heat a Mode of Motion.

By John Tyndall, F.R.S. FifthEdition nearly ready.

Sound. By John Tyndall,

F.R.S. Third Edition, includingRecent Researches on Fog-Signalling.Crown 8vo. price I or. 6 d.

Researches on Diamag-netism and Magne-CrystallicAction;including Diamagnetic Polarity. ByJohn Tyndall, F.R.S. With 6Plates and many Woodcuts. 8vo. 14L

Contributions to Mole-cular Physics in the domain of Ra-diant Heat. By John Tyndall,F.R.S. Plates and Woodcuts. 8vo. i6r.

Six Lectures on Light,

delivered in America in 1872 and 1873.By John Tyndall, F.R.S. SecondEdition. Portrait, Plate, and Diagrams.Crown 8vo. 7 s. 6 d.

Lessons in Electricity at

the Royal Institution, 1875-6- ByJohn Tyndall, F.R.S. With 58Woodcuts. Crown 8vo. 2 s. 6d.

Notes of a Course of

Seven Lectures on Electrical Phe-nomena and Theories, delivered atthe Royal Institution. By John Tyn-dall, F.R.S. Crown 8vo. is. sewed,or ir. 6 d. cloth.

Notes of a Course of Nine

Lectures on Light, delivered at theRoyal Institution. By John Tyndall,F.R.S. Crown 8vo. is. sewed, oris. 6d. cloth.

Principles of Animal Me-chanics. By the Rev. S. Haughton,F.R.S. Second Edition. 8vo. 21s.