Tracy and North’s Descriptive Geometry. (In Press.) Warren’s Elements of Descriptive Geometry, Shadows, 8vo, 3 50 and Perspective Elements of Machine Construction and Drawing 8vo, 7 50 Elements of Plane and Solid Free-hand 12mo, 1 00 Geometrical Drawing General Problems of Shades and Shadows 8vo, 3 00 Manual of Elementary Problems in the Linear 12mo, 1 00 Perspective of Forms and Shadow Manual of Elementary Projection Drawing 12mo, 1 50 Plane Problems in Elementary Geometry 12mo, 1 25 Weisbach’s Kinematics and Power of Transmission. 8vo, 5 00 (Hermann and Klein.) Wilson’s (H. M.) Topographic Surveying 8vo, 3 50 * Wilson’s (V. T.) Descriptive Geometry 8vo, 1 50 Free-hand Lettering 8vo, 1 00 Free-hand Perspective 8vo, 2 50 Woolf’s Elementary Course in Descriptive Geometry Large 8vo, 3 00 ELECTRICITY AND PHYSICS. * Abegg’s Theory of Electrolytic Dissociation, (von 12mo, 1 25 Ende.) Andrews’s Hand-book for Street Railway Engineers 3 × 5 1 25 inches mor. Anthony and Ball’s Lecture-notes on the Theory of 12mo, 1 00 Electrical Measurements Anthony and Brackett’s Text-book of Physics. (Magie.) Large 12mo, 3 00 Benjamin’s History of Electricity 8vo, 3 00 Betts’s Lead Refining and Electrolysis 8vo, 4 00 * Burgess and Le Chatelier’s Measurement of High 8vo, 4 00 Temperatures. Third Edition Classen’s Quantitative Chemical Analysis by 8vo, 3 00 Electrolysis. (Boltwood.) * Collins’s Manual of Wireless Telegraphy and 12mo, 1 50 Telephony Crehore and Squier’s Polarizing Photo-chronograph 8vo, 3 00 * Danneel’s Electrochemistry. (Merriam.) 12mo, 1 25 Dawson’s “Engineering” and Electric Traction Pocket 16mo, mor. 5 00 book Dolezalek’s Theory of the Lead Accumulator (Storage 12mo, 2 50 Battery). (von Ende.) Duhem’s Thermodynamics and Chemistry. (Burgess.) 8vo, 4 00 Flather’s Dynamometers, and the Measurement of Power 12mo, 3 00 * Getman’s Introduction to Physical Science 12mo, 1 50 Gilbert’s De Magnete. (Mottelay) 8vo, 2 50 * Hanchett’s Alternating Currents 12mo, 1 00 Hering’s Ready Reference Tables (Conversion Factors) 16mo, mor. 2 50 * Hobart and Ellis’s High-speed Dynamo Electric 8vo, 6 00 Machinery Holman’s Precision of Measurements 8vo, 2 00