ON AERONAUTICAL PROBLEMS. 401 
Aeronautical Terms ; but the helicopter may also be defined as ‘ a form of 
aircraft by which all Governments are attracted, and which they endeavour 
to develop by means of prize competitions’. What is the origin of the 
attraction | am unable to say. We are told (my source of information is 
the daily Press) that ‘it is considered to offer great military advantages ’. 
I personally suspect that what really happens is something like this :-— 
Members of the Air Council of Ruritania, meeting representatives of the 
War Office at the Ruritanian Committee of Imperial Defence, say to them, 
“We quite appreciate the reasons why you find it difficult to enthuse 
about our hydrogen-filled kite balloons: no one, to say the least, could 
call them pretty ; they are awkward things to haul in to the winch; and 
they are almost defenceless against hostile aircraft, by reason of the ease 
with which they can be set on fire. Now, how would you like to possess a 
machine which can hover, yet needs no mooring cable or winch; and 
which can’t be shot down ?”’ What, confronted by this question, could any 
general reply, except that such a form of aircraft would ‘ offer great military 
advantages’? But his position is really that of a man who reads an 
advertisement which says :—‘ What would you say to a shaving-stick 
which costs only sixpence, lasts practically for ever, and in two seconds 
gives a creamy lather which can’t rust the razor and doesn’t dry on the 
face’ ? Of course he wants it ; he has been wanting it for years: but that 
is not to say that such a thing exists, or will ever exist. 
The Question of its Military Value. 
9. I hope that I shall not be thought to minimize the importance of 
military aspects: the dullest imagination must see that war, under any 
conditions which our experience enables us to contemplate, will come more 
and more beneath the domination of the air. Personally, I do not believe 
that the helicopter is a form of aircraft which will prove to have great 
military value. It will not be so easily set on fire as the kite balloon, no 
doubt; but I think that its restricted field of fire, together with its un- 
wieldiness and its inability to manceuvre rapidly, will always make it an 
easy prey to the fighting aeroplane. 
Its Technical Problems. 
If I am wrong, as I very probably am, I quite appreciate the necessity 
for its development ; and if any Government really wants to develop a 
helicopter, I see no reason why it should not have its desire, provided only 
that it adopts a reasonable plan for obtaining it, which isnot that of the prize 
competition. The essence of the helicopter is its lifting screw, and it happens 
‘that we know a considerable amount about airscrews; so a properly 
constituted technical committee could estimate fairly well the performance 
which is to be expected from a craft of specified size. Again, with assistance 
from a committee of this kind, any of the well-known designers could, I 
believe, produce a helicopter which would give something like the esti- 
mated performance. But the crucial problem of the helicopter, as in 
climbing trees, is not so much how to get up as how to get down! Engines, 
regrettable as it is from the disciplinary standpoint, do sometimes fail in 
the air. 
DD 
