September 18, 1915. 
LAND AND WATER, 
THE ZEPPELIN PROBLEM. 
By A. H. POLLEN. 
In accordance with the requhement* of the Press Bureau, which does net object to the publication «t censored, and takes 
responsibility tor the correctness of tha statements. 
THE week has been altogether barren of any 
news of naval events. The American 
position has been complicated by the 
recall of the Austrian Ambassador, still 
more so by the German Note on the Arabic. It 
almost looks as if the " incredible blunder in states- 
manship," which I suggested last week might 
at any moment change the position, had actually 
occurred ; but the issue is still uncertain. As is not 
uncommon, there have been many rumours of im- 
pending naval events in Europe, but it will be 
time enough to attach importance to these when 
we have something definite to go on. Meanwhile 
Londoners have learned something about war in 
the air that they did not know before. 
War in the air has certain characteristics 
that it shares only with war at sea. Its instru- 
ments of aggression, airships and aeroplanes, can, 
like battleships and cruisers, appear off their 
enemy's positions entirely unheralded. Thus by 
air and by se^ there is a faculty for strategic sur- 
prise that hardly exists on land at all. The fact 
that such attacks can geaerally be anticipated 
does not rob the particidar attack of the element 
of the unexpected. Every town in the South and 
South-East of England within a certain radius of 
the German aerodromes may, when the weather is 
favourable, expect an attack from the sky. Any 
East Coast town is liable to be the victim of 
another fast cruiser raid. And the Germans, no 
less than ourselves, know that every town from 
Emden to the Danish border may some day be 
bombarded by the Allied Fleets and made a point 
of disembarkation for an invading army. And 
this is a piece of knowledge that may be the 
chief factor in deciding them not to risk their 
Dreadnought Fleet in the Baltic. For that matter, 
the Turks knew when they started on their Egyp- 
tian expedition that it was open to us to try to cut 
them off, either by an attack on the coast behind 
them or by an assault on the Dardanelles them- 
selves. The risk of such a counter-stroke was 
ignored, and in all probability because it was felt 
that a naval attack pure and simple would be 
harmless, and that it was unlikely Great Britain 
possessed the resources for inaugurating a 
military invasion on any useful and effective scale. 
The raid on London on Wednesday last was 
no exception to the general rule. No one expected 
a raid at that moment, and no one expected it to 
be any more effective than in fact it was. The 
capacity of an airship to inflict damage is un- 
doubtealy extraordinarily small compared to that 
of a warship. 
Handling guns to bring down aircraft is 
not quite so simple a problem as it seems, and 
we shall all have far greater confidence in the 
future from the knowledge that Sir Percy Scott 
is now to take over the air defence of London. So 
far as it rests with gunnery, it could hardly be in 
better hands. Sir Fercy is above all a great 
practical solver of difficulties. But he is faced by 
quite new problems, and it may prove interesting 
131 
to examine what they are when targets move 
freely through the air. 
FIRE CONTROL ON WATER AND 
IN AIR. 
In naval long-range gunnery two quite dis- 
tinct problems have to be solved. The nrst is to 
procure the right aiming of the guns, the second 
IS to make certain that the right range is on the 
gun when it is rightly aimed and fired. It is no 
use solving one problem unless the other problem 
is solved also. Good aiming with the sights at 
the wrong range is just as futile as bad aiming 
when the sights are right. It is to Sir Percy Scott 
more than to any single man that the Navy owes 
the fact that the first of these two problems is 
satisfactorily settled. He has always been a 
generous advocate of the inventions of others. 
Sketch I. will remind the reader what the 
elements of that problem are. A, a target ship, 
and B, a firing ship, are seen to be manoeuvring 
freely. They are travelling at different speeds 
and on different courses, and each changes course 
during the ten minutes that the sketch represents. 
Assuming B's aiming to be accurate, he can 
only keep A under fire if he ascertain A's 
movements exactly, ascertain his own move- 
ments exactly, and then integrate the two, 
60 that all factors arising from movement 
4_^ 
6 5 ^ i^>^ 
shall be eliminated. If the movement factors 
are gone, the problem of hitting A from 
B is obviously exactly the same as if both 
ships were stationary. It is a Question, not so 
much of good range finding, as of tne skilful obser- 
vation of fire. Such observations are possible at 
sea, because the shots that miss the target strike the 
surface of the water, send vast fountains into the 
air, and so, for an appreciable time, leave a defi- 
nite record, whose relation to the target can be 
judged, and the error in range ascertained. To 
mark the difference between the actual shot and 
the desired range, an observer is posted at the 
furthest possible point from the gun, which, m a 
