530 SAMUEL PIERPONT LANGLEY. 



aeroplane or other form of machine heavier than the air will be 

 based upon the models Avhich he made and which actually flew. 



The tributes in recognition of his work are almost too numerous 

 to recite. He received the degree of D. C. L. from Oxford, D. Sc. 

 from Cambridge, and, among numerous others, the degree of LL. D. 

 from the universities of Harvard, Princeton, Michigan, and Wiscon- 

 sin. He was awarded the Henry Draper medal by the National 

 Academy of Sciences, the Enmford medal by the Royal Society of 

 London, and the Rumforcl medal by the American Academy of Arts 

 and Sciences, as well as the Janssen medal from the Institute of, 

 France, and the medal of the Astronomical Society of France. He 

 was a foreign member of the Royal Society of London, a correspond- 

 ent of the Institute of France, a fellow of the Royal Astronomical 

 Society of London, member of the Royal Institution of London, 

 member of the Academia dei Lincei, of Rome, of the National Acad- 

 emy of Sciences, and of many others. 



Mr. Langle}^, although a member of very many scientific and other 

 societies, was not a regular attendant at any of them. He systemat- 

 ically avoided holding any office in any society, the only exceptions 

 that I know of being his presidency of the American Association for 

 the Advancement of Science, his acceptance of the vice-presidency for 

 a brief time of the American Philosophical Society, and membership 

 in the council of the National Academy of Sciences. It w^as not that 

 he failed to recognize the importance of scientific societies, but rather 

 that he felt confident that others could attend to their management, 

 and that his time must be guarded for his official duties and for his 

 scientific work. 



Among tlie many societies to which he belonged he had an especial 

 affection for this philosophical society. He Avas elected to member- 

 ship in it in 1887, the 3'ear in which he came to Washington, and 

 with hardly any exception read before it the scientific papers that he 

 presented in this city. Many of you will probably remember his 

 various papers on the infra-red spectrum and that on mechanical 

 flight, and I may be permitted to say in passing that no novice ever 

 prepared a paper or lecture more carefully than he did, for while he 

 always spoke with great directness and simplicity and clearness, ap- 

 parently without effort and usually without notes, his communica- 

 tions were always written caref idly in advance, every slide gone over, 

 and an actual rehearsal made, and this method was one that he car- 

 ried into his scientific work as w^ell. I remember that before going 

 on the eclipse expedition to Wadesboro there was a rehearsal almost 

 daily for a period of nearly three months on both his own part and 

 that of every other person in the party as to the duties which each 

 one would be expected to perform during the very few moments wdien 

 the phenomenon was observable. 



