February lo, 1916. 
LAND AND WATER 
BRITAIN'S AEROPLANE POLICY. 
By F. W. Lanchester. 
[The pnhlic have been dazzled from time to time bv 
accounts of monster aeroplanes capable of carrying 
a numerically large crew and many guns of 
various calibre. Sections of the British Press 
have asked it'hy we are behindhand in the 
development of the big aeroplane. In the present 
articles, Mr. Lanchester points outthe limitations 
of the big machine and some of the advantages 
to be derived from concentrating our national 
resources on numbers rather than on individual 
size or power.] 
THERE is a degree of attractiveness, and to the 
more adventurous an almost fatal fascination, 
in any extreme, no matter in wfiat direction it 
may be, which is not possessed or excited by 
anything moderate or ordinary ; the ordinary thing by 
contrast frequently wears the aspect of the humdrum. 
This attractiveness or fascination is commonly greater 
when bigness rather than smallness is in question. A 
proposal to do something or anything on a scale larger 
than has ever been done before is rarely found to lack 
advocates. It is to this that many of the "white elephants" 
of history have owed their existence ; thus for example, 
the anticipation of the mammoth liner of to-day in the 
building of the Great Eastern — incidentally a strik- 
ing monument to the genius of Brunei — was, broadly 
speaking, a fruitless enterprise ; it was premature. Again 
the attempts made by engineers (mainly on the Continent), 
to build gas-engines of large individual units, i.e., cyHn- 
ders of 30 inches bore or even greater, were foredoomed 
to failure — failure which might have been predicted by 
any scientific engineer of the period, and probably would 
have been so predicted had not those concerned been 
hypnotised or dazzled by the hopes of big achievement— 
by the very idea of bigness. 
Fearlessness of Pioneers. 
On the other hand one cannot be other than filled with 
admiration for the fearlessness of the pioneers of the steam 
engine when confronted with some of their handiwork. Take 
for example a large Cornish pumping engine, or the engines 
of the Great Eastern itself, cylinders of colossal size almost 
unknown in modern practice, and this at a time when 
available resources in material and knowledge were not 
a tithe of what they are to-day. And, let it be said, this 
early work has stood the test of time to a degree and in 
a manner that even its authors can scarcely have antici- 
pated ; examples have survived as much as a century's 
continuous usage. 
To a certain extent therefore we must regard the 
craving for bigness as one of the factors in history which 
has contributed materially to progress, in fact it is prob- 
able that there is scarcely a man who has made a mark 
in the world, who has not at one time or another derived 
inspiration from the mere thought or conception of 
something bigger or finer than anything of which he has 
experience. 
When it comes to execution or realisation in any 
problem it is necessary to strike a balance ; on the one 
hand we must not be carried away by an access of mild 
megalomania, neither on the other hand must we be 
incapable of imagining a courageous thing and of 
carrying it into execution when the circumstances 
warrant. We must be ever prepared to adopt a bold 
and fearless policy when once after due consideration 
we have decided that it. is right ; it is in the niatter of 
reaching the correct decision that the scientific training 
of the modern engineer should if anywhere justify itself. 
There is a popular tendency which frequently mani- 
fests itself to jump to conclusions by founding a too hasty 
judgment on analogy. To postulate an analogy ,is 
dangerous ; it is dangerous in any case, but it is often the 
more dangerous by its very plausibility, at the best it 
is a mere imitation of true reasoning. We may grayt 
that experience has demonstrated the commanding im- 
portance of the bitr warship, whether battleship or cruiser ; 
also experience has demonstrated the value of big guns 
both in warfare by land and by sea ; big ship must be 
met by big ship, big gun must be answered by big gun. 
But it does not follow from this in the least degree that 
tlie big aeroplane will require to be met or answered by 
big aeroplane, or indeed that an extension in the direc- 
tion of bigness will in the aeroplane be of any advantage 
whatever. This is a matter which must be settled by 
the properties or characteristics of the aeroplane as an 
instrument of war, and in this connection the aeroplane, 
and more generally the Aeronautical Arm, must be 
studied as a thing sui i^encris. 
Cheap Analogies. 
The foregoing might be deemed as bordering on the 
obvious, but, that it is not so, witness the enormous 
number of " cheap " analogies which are made the basis 
of so-called inventions, and dished up for the delectation 
of the various inventions committees and sub-committees 
• — much to their pain and sorrow. 
As a prelude to entering on the main subject of dis- 
cussion it may be pointed out that the most appropriate 
size of aeroplane, and number required, for the perform- 
ance of any stated duty will in any case depend upon a 
balance of advantages and disadvantages. There are 
some factors which in any case are without material or 
serious influence, and which in the language of the 
mathematician may be regarded as constants ; at the out- 
set it is necessary to form some true appreciation of the 
relative importance of those other factors and considera- 
tions on which the issue may be definitely said to depend. 
Firstly it may be laid down that the basis, on the 
material or economic side, must be that of cost. It may 
be asked, wlien so many hundreds of millions are being 
spent annually and when so relatively small a part of 
this mighty total is being spent upon aircraft, why worry 
as to cost. If big machines are better than small why 
not order big machines in the same numerical quantity ? 
The reason is that just as cost qua cost ceases to be im- 
portant, it follows that the manufacturing resources 
of the country, and we may say the world, will be occupied 
to the full, and so cost as a measure of the facility of 
manufacture becomes again paramount, or, we may say, 
remains paramount. 
Cost and Size. 
Now as to the relation between cost and size of 
machine. There is no invariable rule relating the cost 
to the size (or weight in the present case) of any manu- 
factured article. Expressing the cost at per lb. or per 
ton there are cases, as in yacht or ship building for 
example, where for a certain class or quality of article 
the cost per unit weight is little affected by size. It so 
happens that the military aeroplane comes roughly 
speaking within this category ; it can be manufactured 
and sold at the present time complete with engine, at a 
figure round about 15s. per lb. whether it be large or small. 
This figure is no actual guide to the future ; eventually it 
may become lower, but for some time it may rise, since 
the tendency is for the power installation to increase, 
and this is the most expensive portion of the whole. 
Beyond this the greater part of the cost is involved in 
removing or cutting away superfluous material, and so 
far as improvement is effected in this direction the 
weight is reduced and the cost increased so that the 
price per lb. goes up on two counts. 
The point of importance here is not so much the 
actual present day or future cost figure or selling value, 
it is the fact that cost and weight go together, and that 
consequently the military problem, as concerning con- 
structive policy, is to determine, for any given duty, 
whether a certain limited aggregate weight of tonnage 
of machines is best disposed by the provision of a certain 
number of large machines, or by a greater number of 
smaller ones. Put tersely the problem is, given a certain 
total tonnage to what extent it is desirable that it should 
be subdivided in order to obtain the highest military 
\^aJue There may arise special reasons why a machine for 
