offices, from the Superintendent U. S Coast and Geodetic Survey, the Director U. S. Geological Survey, and the Commissioner of the General Land Office; also the Chief of Engineers, U. S. Army, for the excellent contoured maps of the battle-field of Gettysburg. To Messrs. W. & L. E. Gurley, Troy, N. Y., manufacturers of drawing and surveying instruments, I desire to express my obligations and thanks for their kindness in furnishing me with their electroplates of instruments with which to so completely illustrate the text. To Captain Wm. D. Beach, 3rd Cavalry, Instructor, and 1st Lieutenant Thomas H. Slavens, 6th Cavalry, Assistant Instructor, Department of Engineering, I wish to acknowledge my thanks for assistance and encouragement during the preparation of this work. U.S. INFANTRY AND CAVALRY SCHOOL, EDWIN A. ROOT, 1st Lieutenant 19th Infantry, PREFACE TO SECOND EDITION. Another edition of "Military Topography and Sketching" having become necessary, it has been deemed wise by the author (who has been transferred to another station) to request the Department of Engineering of the Infantry and Cavalry School to undertake the task. The first edition has undergone a year's criticism while it has been in use at this school, as severe and uncompromising a criterion as any to which a text-book can be subjected. The result is set forth in this edition. The methods laid down have been given a very thorough and practical field test by successive classes in this institution, where a large amount of time is devoted to the more rapid methods of reconnaissance sketching, with considerable resuiting skill, as witnessed by the ability of its graduates to map, in a single day, twenty miles of road with which they are totally unfamiliar. It is the desire of the author, Lieutenant E. A. Root, 19th Infantry, that the book be given the benefit of criticism and experience incident to its use here, and that, in succeeding editions, it be kept up to date by this department of instruction. Fort Leavenworth, Kansas, W. D. B. good old U.S.Q.! LIST OF BOOKS CONSULTED IN THE PREPARATION OF THIS WORK. Appendices, U. S. Coast and Geodetic Survey Reports. World's Fair Pamphlets, U. S. Coast and Geodetic SurT. M. Mendenhall, Supt. vey.... Manual of Topographic Methods, U. S. Geological Survey Monograph XXII... .. Gannett. U. S. General Land Office Surveying Instructions, 1894. U. S. Engineers' Topographic Field Note Book. Gillespie's Land Surveying. Davies' Surveying.. ..J. B. Johnson. Cady Staley. ..... Van Amring. The Topographer, His Instruments and Methods. L.M.Haupt. Manual of Surveying Instruments...... W. & L. E. Gurley. Military Surveying ....... Capt. G. H. Mendall, U. S. Army. Notes on Military Surveying and Reconnaissance, Lt.-Col. Wm. Paterson. Text-Book of Military Topography.... Col. W. H. Richards. Elementary Military Topography.... ...... Capt. J. Demagel. Rapid Sketching and Reconnaissance...... Capt. W. Verner. Military Topography .. Capt. W. Verner. .Hutcheson & McGregor. Military Sketching.. ... Capt. J. G. D. Knight, U. S. Army. PART I.-TOPOGRAPHIC SURVEYING. Location of Points and Lines, how fixed.. ing.... Scales of Equal Parts. CHAPTER III. SCALES OF MAPS.-The Scale, Principles govern- |