Joint Author with D. A. Low or Machine.

SIMPSON BOLLAND

Practical Molder and Manager of Found-Author of The Iron-Founder, The Iron.

JOHN FULLER Author of the Art of Coppersmithing.

ROBERT GRIMSHAW, M. E.

Late. President. James Walt Association. No. 7. of New York. N. A. S. E.: Member. Fulton Council, No. 1. of New York, A-O-S. E.

Author or Steam-Engine Catechism. Boller catechism. Locmotive Catechism, Engine Hunners' Catechism. Shop Kinks.

GARDNER D. HISC0X. M. EL Author of Mechanical Movements, Power Devleesices and Appllances Gas, Gasoiline and- .Oil Oil Vapor Engines.

WILLIAM KENT, M. E.

Consulting Engineer; Membet. American institute Mining; Engineers; American So-. Cilty,Mechanical Engineers.

Author of strength of Materials, Strength of Wrought Iron and Chain Cattles. The Mechanical Engineers'Pocket Hook. Steam Boiler Economy.

GAETANO LANZA, S.B., C.E., M.E.

Professor, Theoretical and Applied Mechanics. Massach.-setts Institute of Technology; Member. British Association Advancement science, American Society Me-thanlial Engineers, etc.,etc.

Author of Applied Mechanics and Many Papers Presented to Various sclentitic Societies and Published.

DAVID ALLAN LOW (Whitworth Scholar) M. I. Mech. E.; Professor of Engineering. East London Technical Oil lege, London.

Author of Textbook on Practical. Solid and Descriptive Geometry, An Elementary Textbook on Applied Mechanics. Joint author with A. W. Bevis of Machine.

W. H. FORD, M. E. Author of Boiler-Making for Boller-Makers.

C. W. MacCORD, A. M. Professor of Mechanical Drawing, Stevens Institute or Technology. Author of Movement. 0f Slide Valve by Eccentries.

WILLIAM JOHN MACQUORN RANKINE, LL. D., F. R. S. S.

Civil Engineer: Late Regiua Professorof Civil Engineering and Mechanics in Uni-versity of Glasgow. etc.,etc.

Author of Applied Mechanics. The Steam Engine. Civil Engineering. Useful Rules and Tables. Machinery and Mill Work. A

Mechanical Textnuon.

EDWARD R. MARKHAM Formerly Superintendent Wall ham American Steel Worker.

MANSFIELD MEGRIM AN, Ph. D.

Professor of Civil Engineering, Lehigh University; Member, American Society Civil Engineers, etc, etc.

Author Method of Least Squares, Mechanics. of Material-, Treatise on Hydraulics. Roofs and Bridges. Strength of Mater lals. Elements of Sanitary Engineering, Precise Surveying and Geodesy.

WILLIAM METCALF

Engineer and Steel Manufacturer; Member and Late President, American Society Civil Engineers and American Institute Mining Engineers Member, American Society Mechanical Engineers, etc., etc.

Author of Steel; A Manual for Steel Users.

CECIL HOBART PEABODY, S. B. and EDWARD F. MILLER Assistant Professor of Steam Engineering at the Massachusetts Institute of Technology.

Joint Authors of Steam Boilers.

WILLIAM RIPPER

Professor of Mechanical Engineering in tte Shemeld Technical School: Member the Institute of Mechanical Engineers.

Author of Machine Drawing and Design, Practical Chemistry. Steam, etc.

JOSHUA ROSE, M. E.

Author of Mechanical Drawing. Self Taught. Modern Steam Engineering.Steam Boilers. The Slide Valve, Pattern Makers' Aasistant.The Completc Mschinist, etc.

PETER SCHWAMB, S. B.

Professor of Machine Design, Director of Mecanical Laboratories, Massachusetts Institute.

BALFOUR STFWART, M.A., LL.D., F.R.S. Late Professor of Physics. Victoria Uni-versity, The Owens College, Manchester.

Author .of Primer of Physles Lessons in Elementary Physics.

BALFOUR STEWART and W. W. HALDANE GEE, B. Be.

Joint Authors of Lessons In Elementary Practical Physics.

ROBERT HENRY THURSTON, C. E., Ph. B., A. M., LL. D.

Director. Sibley College. Cornell Univerversity, etc. etc.

Author of Friction and Lubrication. Maneering.Manual.of the Steam Engine, History of the. Steam Engine. Man-ual of Steam Boliers Professional and Scientific Pappers. Editor of "Silence." and of Johnston's cyclopedia.

WILLIAM CAWTHORNE UNWTN, F. R. S., M. Inst. C. E.

Professor of Civil and Mechanical Engineering. Central Technical College, City and Guilds of London Institute, etc.. etc.

Author of Wrought Iron Bridges and And Roofs. Machine. Design, The Testing of Materials of Construction. The Develop. ment and Transmission of Power from Central stations. Cantor Lectures .on Machines for Testing Materials, etc.

WILLIAM H. VAN DERVOORT, M. E. Author of Modern Machine shop Tools.

SAMUEL EDWARD WARBEN

Late Professor Descripitive.Geometryand and. Massachusetts Institute Of Technology etc. etc. Author of general Problems in Descrlp-tive Geometry, Elementary Projection Drawing, Elementary Linear Perspective, lira Drawing Instruments and Operations. Plane Problems in Elementary Geometry, General Problems in Shades and Shadows. Higher General Problems with Linear Perspective of Form. Shadow and Reflection, Elements of Machine Constrution and Drawing (two volumes). Elementary Freehand Geometric Drawing, Problems in Stone. Cutting. Elements of Deserlpitive Geometry. Shadows and Perspective, A Primary Geometry.

THOMAS D. WEST

Practical Moulder and Foundry Manager, Member of American Society Mechanical Engineers, etc., etc.

Author of American Foundry Practice. Moulder's Textbook, etc.

ROBERT WILSON Associate Institute Civil Engineers.

Author of Treatise on Steam Boilers, Common. Sense for Gas Users, Boiler and Factory Chimneys etc. etc.

FRANCIS BACON CROCKER, M. E., Ph. D.

Professor of Electrical Engineering, Columbia College, New York; Vice-President, Crocker-Wheeler Electric Company; and SCHUYLER S. WHEELER, D. Sc, Electrical Expert of the Board of Electrical Control. New York City; Member, American Society of Civil and Mechanical Engineers.

Joint Authors of Practical Management of Dynamos and Motors, Electric Lighting.

WILLIAM FRED. DURAND, Ph. D.

Professor of Marine Engineering, Cornell University: Fellow, American Academy Arts and Sciences, etc., etc.

Author of Resistance and Propulsion of Ships, Practical Marine Engineering.

J. A. FLEMING, M. A., D. Sc. (Lond.), F. R. S.

Professor of Electrical Engineering in University College, London; Late Fellow and Scholar of St. John's College, Cambridge; Fellow of University College, London ; Member of the Institution of Electrical Engineers; Member of the Physical Society of London; Member of the Royal Institution of Great Britain, etc., etc.

Author of The Alternate Current Transformer, etc.

HORATIO A. FOSTER, Member of American Institute of Electrical "Engineers: Member of American Society of Mechanical Engineers; Consulting Engineer.

Author of Electrical Engineer's Pocket-Book.

J. FISHER-HINNEN.

Late Chief of the Drawing Department at the Oerlikon Works. Author of Continuous Current Dynamos.

GEORGE C. V. HOLMES.

Whltworth Scholar; Secretary of the Institute of Naval Architects, etc., etc.; Knight of the Order of Francis Joseph of Austria.

Author of The Steam-Engine.

WILLIAM L. HOOPER, Ph. D.

Professor of Electrical Engineering, Tufts College, Mass. Joint Author with:

ROY T. WELLS, M. S.

Senior Fellow in Physics. Clark University, Worcester, Mass., of Electrical Problems for Engineering Students.

KEMPSTER B. MILLER, M. E., Author of American Telephone Practice.

EDWIN JAMES HOUSTON, Ph. D.

Professor of Physics, Franklin Institute, Pennsylvania; Joint Inventor of Thompson-Houston System of Arc Lighting; Electrical Expert and Consulting Engineer; and:

ARTHUR E. KENNELLY, D. Sc.

Joint Authors of Algebra Made Easy, Alternating Currents, Arc Lighting, Electric Heating, Electricity Made Easy, Electric Motors, Electric Railways, Electrical Engineering Leaflets. Electro-Dynamic Machinery, Electro-Therapeutics, Incandescent Lighting, Interpretation of Mathematical Formulae, Magnetism, Recent Types of Dynamo-Electric Machinery, Telephony.

DUGALD C. JACKSON, C. E.

Professor of Electrical Engineering in the University of Wisconsin; Member of the American Society of Mechanical Engineers, American Institute of Electrical Engineers, etc. Joint Author with:

JOHN PRICE JACKSON, M. E.

Of Text-Book on Electro-Magnetism and the Construction of Dynamos, and Alternating Currents and Alternating Current Machinery.

LAMAR LYNDON, B. E., M. E.

Consulting Electrical Engineer; Associate Member American Institute of Electrical Engineers; Member American Electro-Chemical Society.

Author of Storage Battery Engineering.

MAURICE A. OUDIN, M. S.

Member of American Institute of Electrical Engineers.

Author of Standard Polyphase Apparatus and Systems.

JOHN PERRY, M. E., D. Sc, F. R. S.

Professor of Mechanics and Mathematics, Royal College of Science, South Kensington.

Author of The Steam Engine. Practical Mechanics, and about 100 Scientific Papers.

HENRY WILSON SPANGLER.

Professor of Mechanical Engineering, University of Pennsylvania; Member, Franklin Institute, etc., etc.

Author of Valve Gears.

SYLVANUS P. THOMPSON, D. Sc, B. A., F. R. S., F. R. A. S.

Principal and Professor of Physics in the City and Guilds of London Technical College, etc., etc.

Author of Electricity and Magnetism, Dvnamo-Electric Machinery. Polyphase Eiectric Currents, Electromagnet, etc.