health and disease must always lie in a certain vitality of mind with
which it must be approached and practised. It is only in the history
of tactics, under all conditions of weapons, movement and material,
that the conditions of that vitality can be studied.

For a civilian to approach the elucidation of such points without
professional assistance would be the height of temerity, and my thanks
therefore are particularly due for advice and encouragement to Admiral
Sir Cyprian Bridge, Vice-Admiral Sir Reginald Custance, Rear-Admiral
H.S.H. Prince Louis of Battenberg, and to Captain Slade, Captain of
the Royal Naval College. To Sir Reginald Custance and Professor
Laughton I am under a special obligation, for not only have they been
kind enough to read the proofs of the work, but they have been
indefatigable in offering suggestions, the one from his high
professional knowledge and the other from his unrivalled learning in
naval history. Any value indeed the work may be found to possess must
in a large measure be attributed to them. Nor can I omit to mention
the valuable assistance which I have received from Mr. Ferdinand Brand
and Captain Garbett, R.N., in unearthing forgotten material in the
Libraries of the Admiralty and the United Service Institution.

I have also the pleasure of expressing my obligations to the Earl of
Dartmouth, the Earl of St. Germans, and Vice-Admiral Sir Charles
Knowles, Bart., for the use of the documents in their possession, as
well as to many others whose benefits to the Society will be found
duly noted in the body of the work.