AN ELEMENTARY COURSE OF CIVIL ENGINEERING, FOR THE USE OF CADETS OF THE UNITED STATES' MILITARY ACADEMY BY D. H. MAHAN, M. A., PROFESSOR OF MILITARY AND CIVIL ENGINEERING IN THE U. 8. MILITARY ACADEMY. NEW EDITION, WITH NEW APPENDIX-CUTS, &C. NEW YORK: JOHN WILEY & SON, 2 CLINTON HALL, ASTOR PLACE. 1872. Entered according to Act of Congress, in the year 1868, by JOHN WILEY, In the Clerk's Office of the District Court of the United States for the Southern District of New York. ENGIN. M29 1872 PREFACE. THE present Edition of this Work, like the two preceding, has been compiled for the use of the cadets of the U. S. Military Academy, and comprises that part of the Course of Civil Engineering taught them which the Author deemed would prove the most useful to pupils in other seminaries, studying for the profession of the civil engineer. In preparing this Edition, the Author has found it necessary to recast and rewrite the greater portion of the work; owing to the considerable additions made to it, and called for by the vast accumulation of important facts since the publication of the former editions. A new form has also been given to the work, in the substitution of wood-cuts in the body of it for the plates, in the former editions, as better adapted to its main object as a text-book. From these additions and changes, the Author trusts that the work will be found to contain all of the essential 4861 The University of Iowa |