So rapid is the present development of aviation that it is
difficult to keep abreast with the times.  What is new to-day
becomes old to-morrow.  The Great War has given a tremendous
impetus to the strife between the warring nations for the mastery
of the air, and one can but give a rough and general impression
of the achievements of naval and military airmen on the various
fronts. 

Finally, I have tried to bring home the fact that the fascinating
progress of aviation should not be confined entirely to the
airman and constructor of air-craft; in short, this progress is
not a retord of events in which the mass of the nation have
little personal concern, but of a movement in which each one of
us may take an active and intelligent part. 

I have to thank various aviation firms, airmen, and others who
have kindly come to my assistance, either with the help of
valuable information or by the loan of photographs.  In
particular, my thanks are due to the Royal Flying Corps and Royal
Naval Air Service for permission to reproduce illustrations