MORTON. - The System of Calculating Diameter, Circumference, Area, and Squaring the Circle:

Together with Interest and Miscellaneous Tables, and other information. By James Morton. Second Edition, enlarged, with the Metric System. 12mo. $1.00

NAPIER. - Manual of Electro-Metallurgy:

Including the Application of the Art to Manufacturing Processes. By James Napier. Fourth American, from the Fourth London edition, revised and enlarged. Illustrated by engravings. 8vo. $1.50

NAPIER. - A System of Chemistry Applied to Dyeing.

By James Napier, F.C.S. A New and Thoroughly Revised Edition. Completely brought up to the present state of the Science, including the Chemistry of Coal Tar Colors, by A.A. Fesquet, Chemist and Engineer. With an Appendix on Dyeing and Calico Printing, as shown at the Universal Exposition, Paris, 1867. Illustrated. 8vo. 422 pages $5.00

NEVILLE. - Hydraulic Tables, Coefficients, and Formulæ, for finding the Discharge of Water from Orifices, Notches, Weirs, Pipes, and Rivers:

Third Edition, with Additions, consisting of New Formulæ for the Discharge from Tidal and Flood Sluices and Siphons; general information on Rainfall, Catchment-Basins, Drainage, Sewerage, Water Supply for Towns and Mill Power. By John Neville, C.E.M.R. I.A.; Fellow of the Royal Geological Society of Ireland. Thick 12mo. $3.50

NEWBERY. - Gleanings from Ornamental Art of every style:

Drawn from Examples in the British, South Kensington, Indian, Crystal Palace, and other Museums, the Exhibitions of 1851 and 1862, and the best English and Foreign works. In a series of 100 exquisitely drawn Plates, containing many hundred examples. By Robert Newbery. 4to. $12.50

NICHOLLS. - The Theoretical and Practical Boiler-Maker and Engineer's Reference Book:

Containing a variety of Useful Information for Employers of Labor, Foremen and Working Boiler-Makers, Iron, Copper, and Tinsmiths,

Draughtsmen, Engineers, the General Steam-using Public, and for the Use of Science Schools and Classes. By Samuel Nicholls. Illustrated by sixteen plates, 12mo. $2.50

NICHOLSON. - A Manual of the Art of Bookbinding:

Containing full instructions in the different Branches of Forwarding, Gilding, and Finishing. Also, the Art of Marbling Book-edges and Paper. By James B. Nicholson. Illustrated. 12mo., cloth $2.25

NICOLLS. - The Railway Builder:

A Hand-Book for Estimating the Probable Cost of American Railway Construction and Equipment. By William J. Nicolls, Civil Engineer. Illustrated, full bound, pocket-book form. $2.00

NORMANDY. - The Commercial Handbook of Chemical Analysis:

Or Practical Instructions for the Determination of the Intrinsic or Commercial Value of Substances used in Manufactures, in Trades, and in the Arts. By A. Normandy. New Edition, Enlarged, and to a great extent rewritten. By Henry M. Noad, Ph.D., F.R.S., thick 12mo. $5.00

NORRIS. - A Handbook for Locomotive Engineers and Machinists:

Comprising the Proportions and Calculations for Constructing Locomotives; Manner of Setting Valves; Tables of Squares, Cubes, Areas, etc., etc. By Septimus Norris, M.E. New edition. Illustrated, 12mo. $1.50

NORTH. - The Practical Assayer:

Containing Easy Methods for the Assay of the Principal Metals and Alloys. Principally designed for explorers and those interested in Mines. By Oliver North. Illustrated. 12mo.

NYSTROM. - A New Treatise on Elements of Mechanics:

Establishing Strict Precision in the Meaning of Dynamical Terms: accompanied with an Appendix on Duodenal Arithmetic and Metrology. By John W. Nystrom, C.E. Illustrated. 8vo. $2.00

NYSTROM. - On Technological Education and the Construction of Ships and Screw Propellers:

For Naval and Marine Engineers. By John W. Nystrom, late Acting Chief Engineer, U.S.N. Second edition, revised, with additional matter. Illustrated by seven engravings. 12mo. $1.50

O'NEILL. - A Dictionary of Dyeing and Calico Printing:

Containing a brief account of all the Substances and Processes in use in the Art of Dyeing and Printing Textile Fabrics; with Practical Receipts and Scientific Information. By Charles O'Neill, Analytical Chemist. To which is added an Essay on Coal Tar Colors and their application to Dyeing and Calico Printing. By A.A. Fesquet, Chemist and Engineer. With an appendix on Dyeing and Calico Printing, as shown at the Universal Exposition, Paris, 1867. 8vo., 491 pages. $5.00

ORTON. - Underground Treasures:

How and Where to Find Them. A Key for the Ready Determination of all the Useful Minerals within the United States. By James

Orton, A.M., Late Professor of Natural History in Vassar College, N.Y.; Cor. Mem. of the Academy of Natural Sciences, Philadelphia, and of the Lyceum of Natural History, New York; author of the "Andes and the Amazon," etc. A New Edition, with Additions. Illustrated. $1.50

OSBORN. - The Metallurgy of Iron and Steel:

Theoretical and Practical in all its Branches; with special reference to American Materials and Processes. By H.S. Osborn, LL. D., Professor of Mining and Metallurgy in Lafayette College, Easton, Pennsylvania. Illustrated by numerous large folding plates and wood-engravings. 8vo. $25.00

OVERMAN. - The Manufacture of Steel:

Containing the Practice and Principles of Working and Making Steel. A Handbook for Blacksmiths and Workers in Steel and Iron, Wagon Makers, Die Sinkers, Cutlers, and Manufacturers of Files and Hardware, of Steel and Iron, and for Men of Science and Art. By Frederick Overman, Mining Engineer, Author of the "Manufacture of Iron," etc. A new, enlarged, and revised Edition. By A.A. Fesquet, Chemist and Engineer. 12mo. $1.50

OVERMAN. - The Moulder's and Founder's Pocket Guide:

A Treatise on Moulding and Founding in Green-sand, Dry-sand, Loam, and Cement; the Moulding of Machine Frames, Mill-gear, Hollow-ware, Ornaments, Trinkets, Bells, and Statues; Description of Moulds for Iron, Bronze, Brass, and other Metals; Plaster of Paris, Sulphur, Wax, etc.; the Construction of Melting Furnaces, the Melting and Founding of Metals; the Composition of Alloys and their Nature, etc., etc. By Frederick Overman, M.E. A new Edition, to which is added a Supplement on Statuary and Ornamental Moulding, Ordnance, Malleable Iron Castings, etc. By A.A. Fesquet, Chemist and Engineer. Illustrated by 44 engravings. 12mo. $2.00