for free access to its valuable library of aeronautical
literature, and to Mr A. Vincent Clarke for permission to make
use of his notes on the development of the aero engine.

In this work is no claim to originality--it has been a matter
mainly of compilation, and some stories, notably those of the
Wright Brothers and of Santos Dumont, are better told in the
words of the men themselves than any third party could tell
them. The author claims, however, that this is the first
attempt at recording the facts of development and stating, as
fully as is possible in the compass of a single volume, how
flight and aerostation have evolved. The time for a critical
history of the subject is not yet.

In the matter of illustrations, it has been found very difficult
to secure suitable material. Even the official series of
photographs of aeroplanes in the war period is curiously
incomplete' and the methods of censorship during that period
prevented any complete series being privately collected.
Omissions in this respect will probably be remedied in future
editions of the work, as fresh material is constantly being
located.

E.C.V. October, 1920.

CONTENTS
Part I--THE EVOLUTION OF THE AEROPLANE
I. THE PERIOD OF LEGEND
II. EARLY EXPERIMENTS
III. SIR GEORGE CAYLEY--THOMAS WALKER