INTRODUCTORY. 5 



There is an excellent custom among scientific investigators, of prefacing tlie 

 account of each new research with an abstract of the work of those who have 

 already presumably advanced knowledge in the science in question ; but in this 

 case, where almost nothing is established, I have found hardly any test but that 

 of experiment to distinguish between those suggestions preoumably worth citation 

 and attention and those which are not. Since, then, it is usually only after 

 the experiments which are later to be described have been made, that we can 

 distinguish in retrospective examination what would have been useful to the 

 investigator if he could have appreciated its true character without this test, I 

 have deferred the task of giving a resume of the literature of the subject until it 

 could be done in the light of acquired knowledge. 



I have thus been led to give the time which I could dispose of, so exclusively 

 to experiment, that it may well be that I have missed the knowledge of some 

 recent researches of value ; and if this be so, I desii'e that the absence of mention 

 of them in the present publication, may be taken as the result, not of design, but 

 of an ignorance, which I shall hope, in such case, to repair in a later publication ; 

 while, among the few earlier memoirs that I am conscious of owing much useful 

 suggestion to, it is just that I should mention a remarkable one by Mr. Wenham, 

 which appeared in the first number of the London Aeronautical Society's report, 

 24 years ago, and some by Penaud in L'Aeronaute. 



The reader, especially if he be himself skilled in observation, may perhaps 

 be willing to agree that since there is here so little yet established, so great a 

 variety of tentative experiments must be made, that it is impossible to give each 

 of them at the outset all the degree of accuracy which is ultimately desirable, and 

 that he may yet find all trustworthy within the limits of their present application. 



I do not, then, offer here a treatise on aerodynamics, but an experimental 

 demonstration that we already possess in the steam-engine as now constructed, or 

 in other heat engines, more than the requisite power to urge a system of rigid 

 planes through the air at a great velocity, making them not only self-sustaining, 

 but capable of carrying other than their own weight. This is not asserting 

 that they can be steadily and securely guided through the air, or safely brought 

 to the gTound without shock, or even that the plane itself is the best form 

 of surface for support ; all these are practical considerations of quite another 

 order, belonging to the yet inchoate art of constructing suitable mechanisms 

 for guiding heavy bodies through the air on the principles indicated, and 

 which art (to refer to it by some title distinct from any associated with bal- 

 looning) I will provisionally call aerodromics:^ With respect to this inchoate 

 art, I desire to be understood as not here offering any direct evidence, or 



*From 'izfi'iopiitJ-luJ, to traverse the air; «^/""V"'/^"S', an air-runner. 



