SILVER MEDAL PRIZE ESSAY, 1893 . 
371 
Referring to the battle of Algiers, Captain Jackson writes : l 2 “ Here 
we have the old story which cannot too often be repeated :—Closely 
packed guns on low sites silenced by the fire of ships ; dispersed guns 
on high sites holding out.” And again, in connection with the naval 
attack on Sebastopol, 17th October, 1854, “ Two little open batteries 
on a high site drove six ships out of action; while an open barbette 
battery on a low site was silenced, and the fire of a casemated battery 
much reduced, by three ships, assisted by others at long range.” The 
two little batteries were the “Wasp” and “Telegraph,” at heights of 
130 feet and 100 feet, each only having five medium guns bearing on 
the ships. 
Commander Mahan, U.S.N., remarks when commenting 3 on the 
attack of the river flotilla, on the Confederate position at Grand Gulf, 
on 29th April, 1863 : “ The limitation of the power of the vessels was 
very clearly shown here, as at Fort Donelson; the advantage given by 
commanding height could not be overcome. On a level, as at Fort 
Henry, or with slight advantage of command against them, as at 
Arkansas Post, the chances were, that they would, at close quarters, 
win by disabling or silencing the guns ; but when it came to a question 
of elevation, the guns on shore were too much sheltered.” 
The same lesson was again repeated at Lissa. 3 
Colonel Clarke has well shown the difficulty of the task of the seaman- 
gunner. 4 “ Thus with the service 10-inch R.M.L. gun, using the 70 lb. 
charge, a ship must be at 1750 yards distance to obtain a horizontal 
trajectory at the crest of a battery 300 feet high, while to obtain an 
angle of descent of 6 degrees she must move to 3350 yards. If the 
crest of the battery is 100 feet high the corresponding ranges are 1050 
yards and 2950 yards. A common shell arriving at an emplacement 
with a horizontal trajectory can do little injury to the revetment wall. 
Striking only a few feet short of the crest, it will be deflected up, 
unless the burst is instantaneous, in which case (as proved at East¬ 
bourne) the splinters all clear the emplacement. Practically therefore, 
to be really dangerous, the shell must burst exactly at the crest, which 
means hitting a target a few inches high, as well as securing an instan¬ 
taneous burst.” 
Vertical fire, of which the Zalinski gun is a powerful development, 
especially at short ranges, is all in favour of the Defence. 
Ships present a large horizontal target on which, except in a few 
cases, the whole “ effective target ” is exposed. Gun emplacements on 
land are very small targets, and in the worst placed and designed 
batteries can be given an impenetrable concrete roof. On land, the 
laying is done on a perfect platform, with the aid of range instruments, 
and with facilities for observation of fire. On the ships, the platform 
is unsteady, the obtaining of the range much more difficult, and obser¬ 
vation must be of a most imperfect description. 
Colonel Clarke says : 5 “ For several reasons the result of the practice 
1 Ships versus Ports; Jackson. R.E. Occasional Papers, 1889. 
2 The Navy in the Civil War. 3 vols. Soley, Ammen, Mahan. 
3 Attack on Lissa, 1866 ; Lewis. R.E, Occasional Papers. Vol. IX, 
4 Fortification ; Clarke. 1890. 
5 Fortification; Clarke. 1890, 
