W5 Entered according to Act of Congress, in the year 1860, by JULIUS BIEN, In the Clerk's Office of the District Court of the United States for the Southern District of New York. MRS. S. 3. MONTAGUE WM. M. FRANKLIN, PREFACE. MANY valuable accessions to our knowledge of the strength of materials have been made within a comparatively recent period; the records, however, have been scattered through different books, periodicals, &c., not always accessible or convenient for reference. We have, therefore, endeavored in this brief essay to bring together and arrange some of the more important elements, both old and new, so as to form an "aide memoire" for the Engineer and Architect, at the drawing office and elsewhere. The sources of information have been given as far as possible, in order that the results may be checked, and opportunities afforded for lengthened investigations, which are beyond the scope of these papers. Wherever it has been necessary to express the strength of any material in tons, we have modified the tables and formulas to admit the use of the American ton of 2,000 lbs. as promotive of simplicity. 117201 |