452 



NATURE 



[February i, 191 2 



ment<il achievement, and have an idea of the 

 endless chain of Jinked difficulties that runs through 

 the whole problem of mechanical flight, cannot fail to 

 recognise that no better man could have harnessed 

 himself to its solution, and will open the book with 

 a feeling of expectation which, it is needless to say, 

 does not end in disappointment. The gradual evolu- 

 tion of a full-size gasoline-propelled flying machine 

 from a shellaced paper model propelled by twisted 

 india-rubber is presented with a faithfulness and a 

 precision of details that render the story most fascinat- 

 ing. 



Two things, in our opinion, concur in makmg the 

 tale unfolded before us specially captivating. The 

 first is the impartiality with which both successes and 

 failures are recorded, the latter being rightly judged 

 as important and as worthy of being fully reported 

 as the former; to quote Mr. Manly: "To such men 



The aim of the research is staled simply to 1 

 "putting a trial aerodrome — to us«! the name adopt, 

 by the investigator — successfully in flight, and the 

 giving an early demonstration . . . that mechanic 

 llighl is possible, by actual flying." We shall leav 

 the reader to judge if such a modest statemei 

 adequately describes the strenuous endeavour to ov< ; 

 come the manilold difllculties, by fathering highl 

 specialised knowledge in widely different fields < 

 technical attainment until a new science was foun 

 to have sprung from the harvest of accumulated dai 

 and the acquired experience. 



The work is divided in two parts. Part i,, written 

 by Dr. Langley himself, deals in chronological 

 order with the flight of models, in ten chapters r. 

 tracing the successive attempts, beginning with indi. 

 rubber models similar to those previously construct. <. 

 by Penaud. This portion of the book (chapter ii.) i-- 



I Fig. 2. — Front end of track iust preparatory to launching aerodrome. 



as Mr. Langley, an unsuccessful experiment is not a 

 failure, but a means of instruction, a necessary and 

 often invaluable stepping-stone to the desired end." 

 The second and chief cause of sustained interest is 

 undoubtedly the special circumstances in which the 

 work was undertaken, for, although small toys had 

 been made to fly a few yards, yet, at that time, 

 "hardly anv scientific men of position had made even 

 preliminary investigations, and almost every experiment 

 to be made was made for the first time." The book 

 is therefore, we believe, perhaps unique in its kind, 

 being a complete record of the production of a highlv 

 complex and novel machine from an initial sta^e 

 where very little help was available, not even an idea 

 of the proportion of sustaining surface area to weight, 

 \vhich had to be gathered from measurements on 

 birds, nature supplying the first— and misleading- 

 data in an almost virgin field of knowledge. 

 NO. 2205, VOL. 88] 



by no means the least interesting, owing to the fm 

 that practically every difficulty experienced later w;i- 

 met at the outset, the structure being too heavy if 

 able to bear the strain, or too fragile if sufficientiv 

 light, while even the difficulty of launching, that w.; 

 to require so much skill and ingenuity later, was f* ; 

 at this early stage. A short discussion of the avail- 

 able propelling agents and the history of the special 

 type of steam engine finally found to answer the con- 

 tradictory requirements as to power and weight i> 

 the subject of the next two chapters, and goes far 

 to show that the key to success was the determination 

 with which the word "disheartening" was cancelled 

 from the dictionary of the experimenter and of his 

 able assistant. 



Sustaining surfaces and "balancing" are then 

 shortly dealt with. The relative importance of skin 

 friction is not touched upon. The important subject 



