MEMOIRS OF THE AMERICAN ACADEMY OF ARTS AND SCIENCES. NEW SERIES. VOL. VI.-PART I. CAMBRIDGE AND BOSTON : PRINTERS TO THE UNIVERSITY. 1857. CONTENTS OF PART I. PAGE I. On the Practicability of Constructing Cannon of Great Caliber, capable of endur- ing long-continued Use under full Charges. BY DANIEL TREAdwell. IV. Magnetic Observations on the Boundary Line between the United States and Mex- ico, made in 1855, under the Direction of MAJOR W. H. EMORY, United States Commissioner under the Treaty of 1853; and General Discussion of the Magnetic Observations made in Connection with the Mexican Boundary Surveys. Recom- |