PREFACE 



The present volume on Mechanical Flight consists, as the title page indi- 

 cates, of two parts. The first, dealing with the long and notable scries of early 

 experiments with small models, was written almost entirely by Secretary Lang- 

 ley with the assistance of Mr. E. C. HulTaker and Mr. G. L. Fowler in 1897. Such 

 chapters as were not complete have been finished by the writer and are easily 

 noted as they are written in the third person. It has been subjected only to such 

 revision as it would have received had Mr. Langley lived to supervise this pub- 

 lication, and has therefore the highest value as an historical record. The com- 

 position of the second part, dealing with the later experiments with the original 

 and also new models and the construction of the larger aerodrome, has neces- 

 sarily devolved upon me. This is in entire accordance with the plan formed by 

 Mr. Langley when I began to work with him in 1898, hut it is to me a matter of 

 sincere regret that the manuscript in its final form has not had the advantage of 

 his criticism and suggestions. If the reader should feel that any of the descrip- 

 tions or statements in this part of the volume leave something to be desired in 

 fullness of detail, it is hoped that some allowance may he made for the fact that 

 it has been written in the scanty and scattered moments that could be snatched 

 from work in other lines which made heavy demands upon the writer's time and 

 strength. It is believed, however, that sufficient data are given to enable any 

 competent engineer to understand thoroughly even the most complicated phases 

 of the work. 



Persons who care only for the accomplished fact may be inclined to under- 

 rate the interest and value of this record. But even they may be reminded that 

 but for such patient and unremitting devotion as is here enregistered, the now 

 accomplished fact of mechanical flight would still remain the wild unrealized 

 dream which it was for so many centuries. 



To such men as Mr. Langley an unsuccessful experiment is not a failure but 

 a means of instruction, a necessary and often an invaluable stepping-stone to the 

 desired end. The trials of the large aerodrome in the autumn of 1903, to which 

 the curiosity of the public and the sensationalism of the newspapers gave a char- 

 acter of finality never desired by Mr. Langley, were to him merely members of 

 a long series of experiments, as much so as any trial of one of the small aero- 

 dromes or even of one of the earliest rubber-driven models. Had his health and 

 strength been spared, he would have gone on with his experiments undiscouraged 

 by these accidents in launching and undeterred l.y criticism and misunder- 

 standing. 



