Samuel Pierpont Langley, Secretary of the Smithsonian Institution, 1887-1906. Memorial Meeting, December 3, 1906
Langley Memoir on Mechanical Flight - Pt.1 1887 to 1896 by Samuel Pierpont Langley - Pt.2 1897 to 1903. (V.27 No.3).
The following is the speech delivered by the Public Orator in presenting Mr. Samuel Pierpont Langley for the degree of Doctor in Science, honoris causa