INTRODUCTION 



The interest of the Smithsonian Institution in aeronautics dates 

 almost from the beginning of its work. Its early investigations in meteor- 

 ology and later researches in the nature of the atmosphere under the 

 Hodgkins Fund are fully treated in its publications. 



As early as 1861 the Institution was asked for assistance in carrying 

 out experiments to cross the Atlantic by means of a balloon, and in 1863 

 published two papers on the general subject of aeronautics, one being a 

 translation from the works of Francis Arago, entitled "' Aeronautical 

 Voyages Performed with a View to the Advancement of Science," and 

 the other an account of balloon ascensions by James Glaisher. Since the 

 latter date it has issued some thirty-five publications on various phases of 

 the subject. 



The greatest era in the development of aeronautical science in connec- 

 tion with the Institution began, however, when, in 1887, Dr. Samuel 

 Pierpont Langley became Secretary. His publication entitled " Experi- 

 ments in Aerodynamics," in which the laws of flight as deduced by him 

 were for the first time stated, appeared in 1891. Later he added to this 

 another important technical publication, " The Internal Work of the 

 Wind." He was the first to construct a successful model of a heavier- 

 than-air machine that would sustain itself in flight under its own power. 

 This model was built mainly of steel and was driven by a steam engine. 

 On May 6, 1896, it made two flights, each over half a mile in length, and 

 a third flight of nearly a mile was made in November of the same year 

 by a similar mechanism of Mr. Langley's construction. On the eighth of 

 August, 1903, a quarter-size counterpart of his man-carrying machine 

 propelled by a gasoline engine was successfully tested, and it is conceded 

 by experts that, but for an accident in the launching, his large machine, 

 with Mr. Charles M. Manly as operator, would have flown in 1903. Dr. 

 Langley's latest experiments in mechanical flight, recorded by him in 

 copious and painstaking notes, are now in course of preparation for publi- 

 cation by the Institution. 



Secretary'Langley brought with liim to the Institution the nucleus of a 

 library of aeronautical literature, to which additions have since been 



(v) 



