Each Volume Crown 8vo, Uniformly Bound and Illustrated.

MANUAL OF ASSAYING GOLD, SILVER, COPPER, AND LEAD ORES. By Walter Lee Brown, B.Sc. Revised, Corrected, and considerably Enlarged, with a chapter on the Assaying of Fuel, &c. By A. B. Griffiths, Ph.D., F.R.S. (Edin.), F.C.S. 7s. 6d.

Financial World.—"The most complete and practical manual on everything which concerns assaying of all which have come before us."

GEODESY. By J. Howard Gore. 5s.

Science Gossip.—"It is the best we could recommend to all geodetic students. It is full and clear, thoroughly accurate, and up to date in all matters of earth-measurements."

THE PHYSICAL PROPERTIES OF GASES. By Arthur L. Kimball. 5s.

Chemical News.—"The man of culture who wishes for a general and accurate acquaintance with the physical properties of gases, will find in Mr. Kimball's work just what he requires."

HEAT AS A FORM OF ENERGY. By R. H. Thurston. 5s.

Journal of Microscopy and Natural Science.—"The author presents in popular language an outline of the growth of our modern philosophy of the form of energy known as heat."

A MANUAL OF BACTERIOLOGY. By A. B. Griffiths, Ph.D., F.R.S. (Edin.), F.C.S. [In the Press.

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