LANGLEY
LANGLEY
at Harvard college in ISGo; was assistant profes-
sor of mathematics at the U.S. Naval academy at
Annapolis, 1865-07, and while there he engaged
in vemoiinting the astronomical instruments in
the observatory built by Professor Chauvenet.
Dr. Langley was di- rector of the Alle- glieny observatory and professor of as- tronomy and physics at the Western Uni- versity of Pennsylva- nia, 1867-87; assistant secretary of the Smithsonian Insti- tution, 1887, and up- on the death of Pro- fessor Baird, Aug. 19, 1887, he succeeded C/^/C? 6/^ /^ the latter as secre- Cy. (/. ^X^^*^'*^^ tary. While at the
- ^ "^ Allegheny observa-
tory he established first in this country a complete time service and arranged to supply automatic time signals to the railroads centering in Pitts- burg, and to the city of Pittsburg, and from the income derived from the sale of these signals he fitted out and supported the observatory. He was a member of the party sent out by the U.S. government to observe the total eclipse of the sun at Oakland, Ky. , in 1869, and at Xeres, Spain, in 18 ro. He observed the eclipses of 1878 from Pike's Peak. Colorado, and in 1870 he began a series of researches on the sun, and published papers on the structure of the photosphere and on the heat of the solar surface. To further his investigations, he invented the bolometer. In the winter of 1878 he made observations on Mount ^tna, Sicily, and in 1881, under the auspices of the U.S. signal service, he organized an expedi- tion to the summit of Mount Whitney, California, for the purpose of making observations on the sun's rays before they reached the lower strata of the atmosphere. The expenses of this expedi- tion were defraj-ed by William Thaw, of Pitts- burg. In 1881 Dr. Langley began in his leis- ure hours a series of experiments on atrial navigation, and through the assistance of Mr. Thaw, he fitted out a laboratory for the prosecu- tion of his work. He labored for ten years in preliminary researches whose results were pub- lished in 1891, in " Experiments in Aerodynam- ics," and " The Internal Work of the Wind," in 1893. In 1896 he produced the first successful aerodrome, or flying machine, that succeeded in a flight, without gas of any kind, by pui-ely mechan- ical means. The first of these successful flights was made in May, 1896, and another took place in December, 1896. The airship was constructed
almost entirely of steel, was driven by a steam
engine and propeller, and held in the air by two
pairs of rectangular wings, i.e., motionless sus-
taining surfaces. The weight of the machine was
about tliirty pounds. In 1898 the board of ord-
nance and for-
tification de- ijij J
cided to inves-
tigate the pos-
sibilities of fly-
ing machines
for use as en-
gines of de- S^lTHSO^IAA^ INSTITUTION.
struction in time of war, and placed the pros- ecution of these investigations unreservedly in charge of Dr. Langley. He was elected a mem- ber of the Royal Institution of Great Britain, for- eign member of the Royal Society of London, cor- respondent of the Academy of Sciences of the In- stitute of France, associate member of the Royal Astronomical society, honorary member of the Society of Physics and of History of Geneva, and of the Manchester Literary and Philosophical society, member of the National Academy of Sciences, member of the American Association for the Advancement of Science, of which he was vice-president in 1878, and president in 1886, fel- low of the American Academy of Arts and Sciences, member of the American Philosophical society, honorary member of the New York Academy of Sciences and of the California Acad- emy of Sciences. He received the honorary de- gree of D.C.L, from Oxford in 189-4; that of D.Sc. from Cambridge, Oct. 12, 1900; and that of LL.D. from Stevens Institute of Technology in 1882, from the University of Wisconsin in 1882, from the University of Michigan in 1883, from Harvard in 1886, and from Princeton in 1896. The first Henry Draper medal awarded by the National Academy of Sciences was conferred on him in
1886 for his work on astronomical physics, and in
1887 he received the Rumford Medal from the Royal Society of London, and also the Rumford Medal from the American Academy of Arts and Sciences. He also received the Janssen ^ledal from the Institute of France, and the Medal of the Astronomical Societj' of France. He published numerous articles on scientific topics in the lead- ing technical journals, including a series of popular articles called "The New Astronomy," which he contributed to the Century Magazine, 1884-86; and he delivered lectures before the Lowell Institute, Boston, and the Peabody Insti- tute, Baltimore, Maryland, and before the British Association for the Advancement of Science at Southampton, England, in 1882. Dr. Langley's administrative duties as secretary of the Smith- sonian Institution occupied most of his time, and a portion of these duties included the founding
