Plane Problems in Elementary Geometry 12mo, 1 25 Warren’s Primary Geometry 12mo, 75 Elements of Descriptive Geometry, Shadows, and Perspective 8vo, 3 50 General Problems of Shades and Shadows 8vo, 3 00 Elements of Machine Construction and Drawing 8vo, 7 50 Problems, Theorems, and Examples in Descriptive Geometry 8vo, 2 50 Weisbach’s Kinematics and Power of Transmission. (Hermann and Klein.) 8vo, 5 00 Whelpley’s Practical Instruction in the Art of Letter Engraving 12mo, 2 00 Wilson’s (H. M.) Topographic Surveying 8vo, 3 50 Wilson’s (V. T.) Free-hand Perspective 8vo, 2 50 Wilson’s (V. T.) Free-hand Lettering 8vo, 1 00 Woolf’s Elementary Course in Descriptive Geometry Large 8vo, 3 00 ELECTRICITY AND PHYSICS. Anthony and Brackett’s Text-book of Physics. (Magie.) Small 8vo, 3 00 Anthony’s Lecture-notes on the Theory of Electrical Measurements 12mo, 1 00 Benjamin’s History of Electricity 8vo, 3 00 Voltaic Cell 8vo, 3 00 Classen’s Quantitative Chemical Analysis by Electrolysis. (Boltwood.) 8vo, 3 00 Crehore and Squier’s Polarizing Photo-chronograph 8vo, 3 00 Dawson’s “Engineering” and Electric Traction Pocket-book 16mo, morocco, 5 00 Dolezalek’s Theory of the Lead Accumulator (Storage Battery). (Von Ende.) 12mo, 2 50 Duhem’s Thermodynamics and Chemistry. (Burgess.) 8vo, 4 00 Flather’s Dynamometers, and the Measurement of Power 12mo, 3 00 Gilbert’s De Magnete. (Mottelay.) 8vo, 2 50 Hanchett’s Alternating Currents Explained 12mo, 1 00 Hering’s Ready Reference Tables (Conversion Factors) 16mo, morocco, 2 50 Holman’s Precision of Measurements 8vo, 2 00 Telescopic Mirror-scale Method, Adjustments, and Tests Large 8vo, 75 Kinzbrunner’s Testing of Continuous-current Machines 8vo, 2 00 Landauer’s Spectrum Analysis. (Tingle.) 8vo, 3 00 Le Chatelier’s High-temperature Measurements. (Boudouard—Burgess.) 12mo, 3 00 Löb’s Electrochemistry of Organic Compounds. (Lorenz.) 8vo, 3 00 * Lyon’s Treatise on Electromagnetic Phenomena. Vols. I. and II. 8vo, each, 6 00 * Michie’s Elements of Wave Motion Relating to Sound and Light 8vo, 4 00 Niaudet’s Elementary Treatise on Electric Batteries.