400 Scientific Intelligence. 



III. Miscellaneous Scientific Intelligence. 



1. Langley Memoir of Mechanical Flight. Part I, 1887 to 

 1806 ; by Samuel Piekuont Langley, edited by Charles M. 

 Manly. * Part II, 1897 to 1903 ; by Charles M. Manly. (Pub- 

 lication 194S.) Pp. x, 3-J0, with 101 plates. Washington, 1911. 

 Smithsonian Contributions to Knowledge, volume 27, number 

 3. — Now that practical aviation bas been developed so far and a 

 degree of success attained which even the most sanguine could 

 not have predicted ten or fifteen years ago, it is very interesting 

 to look back and follow the series of carefully conducted scien- 

 tific investigations, whose results were essential in the recent 

 development of the practical side of the subject. The experi- 

 ments by Professor Langley in mechanical flight are well known, 

 but as they stopped just short of the full success which would 

 probably have come to them had the author lived to carry them 

 further, especially with the aid of the perfected gasolene motor, 

 it may not be generally appreciated how thorough and exhaus- 

 tive his work was. Earlier publications on " Experiments in Aero- 

 dynamics" and "The Internal Work of the Wind" were printed 

 in 1891 and 1893, as parts of volume 27 of the Smithsonian Con- 

 tributions. The present memoir was in course of preparation at 

 the time of the author's death in 1906. At that time, part I (pp. 

 1-122, plates 1-31) had been practically completed by him. This 

 part describes experiments made between 1887 and 1896, and dis- 

 cusses the various forms of available motors, and the history of 

 the construction and use of various aerodromes, as the flying 

 machine was named by him in 1893. In the final preparation of 

 the manuscript for the press, Mr. Charles M. Manly, assistant in 

 charge of experiments, has acted as editor. 



The second part of the volume describes experiments made 

 betwen 1897 and 1903, and has been prepared by Mr. Manly. It 

 describes the later experiments with the original models as well as 

 with new models, and also the construction of the larger machine. 

 Although this last did not have full success, and the experiments 

 closed in December, 1903, it is to be noted that a machine of 

 essentially the same type was employed for a flight of nearly 500 

 feet by a French aviator in August, 1907. It is stated that the 

 third part of the present memoir will be published later, giving 

 technical data and tests of various types of curved surfaces, pro- 

 pellers, and other apparatus. The editor of this volume closes 

 his prefaces with the following paragraphs, which should be read 

 by all desirous of forming a correct estimate as to the importance 

 of Professor Langley's long-continued experiments : 



"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 



