Samuel Langley

Samuel Langley Samuel Pierpont Langley (August 22, 1834 – February 27, 1906) was an American aviation pioneer, astronomer, physicist, inventor of the bolometer, founder of the Smithsonian Astrophysical Observatory, and secretary of the Smithsonian Institution from 1887 to 1906. He was elected in 1875 to the American Philosophical Society and in 1876 to the U.S. National Academy of Sciences. Langley was awarded in 1886 both the Rumford Medal and the Henry Draper Medal and in 1893 the Janssen Medal (French Academy of Sciences) Janssen Medal. Quotes ... With rare exceptions, the backward steps—that is, the errors and mistakes, which count in reality for nearly half, and sometimes for more than half, the whole—are left out of scientific history; and the reader, while he knows that mistakes have been made, has no just idea how intimately error and truth are mingled in a sort of chemical union, even in the work of the great discoverers, and how it is the test of time chiefly,—which enables us to say which is progress, when the man himself could not. If this be a truism, it is one which is often forgotten, and which we shall do well to here keep before us. 1888 Address of S.P. Langley: President of the American Association for the Advancement of Science, delivered at the Cleveland meeting, August 1888 Salem Press https://books.google.com/books?id=D9gEAAAAYAAJ&pg=PA2 2–3 (23 pages, address delivered as retiring president) I have now been engaged since the beginning of the year 1887 in experiments on an extended scale for determining the possibility of, and the conditions for, transporting in the air a body whose Relative density specific gravity is greater than the air, and I desire to repost my conviction that the obstacles in its way are not such as have been thought; that they lie more in such apparently difficulties as those Guidance, navigation and control guiding the body so that it may move in the direction desired, and Takeoff and landing ascend or descend with safety, than in what may appear to be the primary difficulties due to the nature of the air itself, and that in my opinion the evidence for this is now sufficiently complete to engage the serious attention of engineers to the practical solution of these secondary difficulties, and to the development of an art of mechanical flight which will bring with it a change in many of the conditions of individual and national existence whose importance can hardly be estimated. Experiments in aerodynamics Vol. 801, Smithsonian Contributions to Knowledge Smithsonian institution 1st 1891 https://books.google.com/books/about/Experiments_in_Aerodynamics.html?id=vxtRAAAAYAAJ&pg=PA4 4 (115 pages) Physical astronomers, armed with new methods and perfected appliances, are helping us to a view of the progress of creation, from its beginning in the nebula, which must interest every student of nature. But however much our attention is aroused by the purely scientific aspect of such general studies, we must, it seems to me, consider, in the case I have now to present, utility, even before abstract interest. I refer to the study of the Sun, for though the most unformed nebula may hold the germs of future worlds, yet for us these possibilities are but interesting conjectures. For, as I have said elsewhere, I recognize that every nebula might be wiped out of the sky tonight without affecting the price of a laborer's dinner, while a small change in the solar radiation may conceivably cause the deaths of numberless men in an Indian famine. The "Solar Constant" and Related Problems 17 2 March 1903 The Astrophysical Journal https://books.google.com/books?id=7oQRAAAAYAAJ&pg=PA89 89–99 (quote from p. 89) Quotes about Samuel Pierpont Langley In 1869, 1870, 1878 and 1900 he observed the total Solar eclipse eclipse of the sun, and his account of the Solar eclipse of July 29, 1878 eclipse of 1878 from Pikes Peak is particularly notable.... From 1878 to 1880 he was engaged in various attempts to devise a more perfect instrument for measuring Thermal radiation radiation, and he succeeded at length in the invention of the bolometer, an instrument in world-wide use. With this instrument, essentially an electrical thermometer on the Wheatstone bridge Wheatstone's bridge principle, changes of temperature of less than the hundred-thousandth of a degree Centigrade are measured; and by special installation, differences in temperature amounting to one-billionth of a degree may be detected. Charles Doolittle Walcott, Biographical Memoir of Samuel Pierpont Langley, 1834-1906 Vol. 7, Biographical Memoirs of the National Academy of Sciences (NAS) U.S. National Academy of Sciences 1912 https://books.google.com/books?&id=nbAaAAAAYAAJ&pg=PA249 245–268 (quote from p. 249; memoir presented to the autumn 1911 meeting of the NAS) External links Category:1834 births Category:1906 deaths Category:Academics from the United States Category:Aerospace engineers from the United States Category:Astronomers from the United States Category:Inventors Category:Members of the American Philosophical Society Category:Members of the United States National Academy of Sciences Category:Physicists from the United States Category:Scientists from Boston Category:Scientists from Pittsburgh