THE ROYAL ARTILLERY INSTITUTION. 
107 
ON THE ADAPTATION OF THE CUPOLA OF CAPTAIN COLES 
TO 
MODERN FORTRESSES. 
By F. DUNCAN, M.A., Lieut. E.A. 
BELLOW OB THE GEOLOGICAL SOCIETY. 
That a change will of necessity occur in modem warfare, consequent 
upon the two great discoveries, which occupy public attention at present,— 
the advantage of iron-platings and the seeming absence of a limit to the 
increasing power of artillery, has become apparent to the most superficial 
observer. As yet the attention of scientific men has been devoted almost 
exclusively to naval changes; but there can be little doubt that an alteration 
in the modern system of fortification is more or less imminent. It is evident 
that fortresses derive a higher ratio of benefit from improvements in artillery, 
when these improvements involve heavier guns and larger charges, than either 
ships or armies in the field; for they have ampler magazine and other 
accommodation than any vessel, nor are they limited by considerations of 
tonnage or capabilities for sailing. And an army in the field cannot exceed 
a certain limit in the weight of its siege-train materiel, and in the reserves 
of ammunition which accompany it. These are circumstances which have 
occurred to many in the contest between artillery and ironsides; but it seems 
(as far as I am aware) to have escaped any writers on the subject, that the 
improvements in artillery w r ill not be more advantageous to forts than might 
the adaptation of the cupola ai$d other instruments become, which are con¬ 
sidered to belong exclusively to vessels. 
A few suggestions on the advantages which the introduction of this 
invention of Captain Coles into our fortifications would secure, may not be 
superfluous at the present crisis. These may be briefly enumerated as 
(1) Command given to the fort; 
(2) Immense lateral range; 
(3) The power of bringing every gun in the work to bear upon any 
single point, even if that point were in the work itself; thus enabling the 
defenders to subject the assailants to a murderous fire even after they might 
have entered the fort; 
(4) Economy of numbers at each gun; 
(5) The power of doing away with outworks, and the increased accom¬ 
modation for troops; 
(6) Economy in construction; 
(7) Durability and invulnerability. 
[vol. III.] 
15 
