SCIENCE - LANGLEY Samuel (1834 - 1906) - Typed letter signed Typed letter signed, dated “May 12, 1899” by the American aviation pioneer, astronomer and physicist who invented the bolometer. He was the third secretary of the Smithsonian Institution and a professor of astronomy at the University of Pittsburgh, where he was the director of the Allegheny Observatory. Addressed to Mrs. Michaelis: “…I have Frank's letter and that of Professor Ames, and as I understand that it will be of service to Frank, I am willing to provide for his having the opportunity to attend to these examination papers on the stated days in June. My intervention, however, Mr. Ames will doubtless understand, will be chiefly formal…”. 1 p. ¼. In-8. With lithographic letterhead of the Smithsonian Institution. - This item is under temporary import. If the item is delivered within the United Kingdom, it will be subject to a 5% Value Added Tax (VAT) on the hammer price.