the pioneers; he was bold enough to publish the result of his investigations at a time when flying had only just been proved possible; and he has reason now to be well satisfied with the quality of his early work. In this new book he has discussed matters of wide interest and, at the present moment, of vital importance, and has considered in many bearings the relations between aeronautic science and military art. In this effort many difficulties have had to be faced, not the least of which is the lack of definite knowledge of the methods which have been employed and of the results which have been achieved by aircraft in the present war. And, further, there has been the necessity of exercising extreme discretion in the use of information which is within his knowledge. In the first respect I have some advantage over Mr. Lanchester; in the second he, in writing the book, and I in introducing it, suffer under the same disability.
During the past three years Mr. Lanchester and I have had several tussles in private on the questions debated in this book. Each can put up a pretty good defence on his own ground. Mr. Lanchester is well protected by his profound knowledge of physical science and his practical acquaintance with several branches of engineering. I am strongly entrenched behind a barricade of military prejudice, with some dim recollections of early scientific training as reserves for counter-attack. In my incursions into Mr. Lanchester's territory, I have now and then received a buffet which has made me more wary. And occasionally, I think, Mr. Lanchester has found himself hung up in my wire entanglements. I should like nothing better than to fight out, in public and with due formality, these points—not a few—on which he and I disagree; but at the present moment this is impossible,
