12 Scientific Works published by Longmans, Green, 6 Co. GEOMETRY AND EUCLID- Continued.

LOW. TEXT-BOOK ON PRACTICAL, SOLID, AND DESCRIP- TIVE GEOMETRY. By DAVID ALLAN Low, Professor of Engineering, East London Technical College. Crown 8vo. Part I. With 114 Figures, 2s. Part II. With 64 Figures, $s. THE DIAGRAM MEASURER. An Instrument for measuring the - Areas of Irregular Figures and specially useful for determining the Mean Effective Pressure from Indicator Diagrams from Steam, Gas and other Engines. Designed by D. A. Low. With Full Instructions for Use. is. net. MORRIS AND HUSBAND. PRACTICAL PLANE AND SOLID GEOMETRY. By I. HAMMOND MORRIS and JOSEPH HUSBAND. Fully Illustrated with Drawings. Crown 8vo., 2s. 6d. MORRIS. GEOMETRICAL DRAWING FOR ART STUDENTS. Embracing Plane Geometry and its Applications, the Use of Scales, and the Plans and Elevations of Solids as required in Section I. of Science Subjects. By I. HAMMOND MORRIS. Crown 8vo. , zs. SMITH. ELEMENTS OF GEOMETRY. By J. HAMBLIN SMITH, M.A. Containing Books i to 6, and portions of Books n and 12, of Euclid, with Exercises and Notes. Cr. 8vo., y. 6d. KEY, crown 8vo., 8s. 6d. Books i and 2, limp cloth, is. 6d., may be had separately. SPOONER. THE ELEMENTS OF GEOMETRICAL DRAWING : an Elementary Text-book on Practical Plane Geometry, including an Introduction to Solid Geometry. Written to include the requirements of the Syllabus of the Board of Education in Geometrical Drawing and for the use of Students preparing for the Military Entrance Examinations. By HENRY J. SPOONER, C.E., M.Inst.M.E. Cr. 8vo., y. 6d. WILSON. GEOMETRICAL DRAWING. For the use of Candidates for Army Examinations, and as an Introduction to Mechanical Drawing. By W. N. WILSON, M.A. Parts I. and II. Crown 8vo., 45. 6d. each. WINTER. ELEMENTARY GEOMETRICAL DRAWING. By S. H. WINTER. Part 1. Including Practical Plane Geometry, the Construction of Scales, the Use of the Sector, the Marquois Scales, and the Protractor. With 3 Plates and loco Exercises and Examination Papers. Post 8vo., 55. OPTICS, PHOTOGRAPHY, ETC. ABNEY.& TREATISE ON PHOTOGRAPHY. By Sir WILLIAM DK WIVELESLIE ABNEY, K.C.B., F.R.S., Principal Assistant Secretary of the Secondary Department of the Board of Education. With 134 Illustrations. Fcp. 8vo., 55. DRUDE. THE THEORY .OF OPTICS. By PAUL DRUDE, Professor of Physics at the University of Giessen. Translated from the German by C. RIBORG MANN and ROBERT A. MILLIKAN, Assistant Professors of Physics at the University of Chicago. With no Diagrams. 8vo., 155. net. GLAZEBROOK. PHYSICAL OPTICS. By R. T. GLAZEBROOK, M.A., F.R.S., Principal of University College, Liverpool. With 183 Woodcuts of Apparatus, etc. Fcp. 8vo., 6s. VANDERPOEL. COLOR PROBLEMS : a Practical Manual for the Lay Student of Color. By EMILY NOYES VANDERPOEL. With 117 Plates in Color. Square 8vo. , 2is. net. WRIGHT. OPTICAL PROJECTION : a Treatise on the Use of the Lantern in Exhibition and Scientific Demonstration. By LEWIS WRIGHT, Author of 1 Light : a Course of Experimental Optics'. With 232 Illustrations. Crown 8vo., 6j.