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present stage of mechanical engineering, advanced as it may be considered to be, hardly warrants the belief that a surface war fleet, with all which that implies, can be completely replaced now by aircraft or submarines or a combination of both. The art of war is constantly changing, but by a gradual progress, and many of the old views with modifications will be found to be sound in the future as in the past. Amongst these it is contended that the basic principles underlying British schemes of coast defence before the war will be found to have been of this sound nature, and only require modification in detail.

In order to understand these general principles it is necessary to consider the whole question of the contest between the ship and the shore defences, the main element of which is artillery. These two contestants have never been on an equality, and that for various reasons which may be briefly recapitulated:

(1) Gun Platform. The shore gun is on an immovable plat- form while the naval gun is not. It may be taken that a shore gun presents a vertical target of about nine feet. This subtends an angle of slightly over 30 sec. at a range of 20,000 yards. Assuming a naval gun correctly aimed at the centre of this target a movement of the gun of 15 sec. in the vertical plane containing the trajectory of the shell at the moment of firing would be sufficient to throw the gun off the target. Such a movement is almost imperceptible on a ship.

(2) Control of Fire. On a ship the means of range-finding are necessarily restricted within the dimensions of the ship and its masts, while the shore gun has the whole coast within the limits of vision to use for purposes of bases for range-finding. It is true that in these days aircraft can be used for correcting fire, but the results of this are not so accurate as those from terrestrial instru- ments, and in any case aircraft can be used by both sides.

(3) Ammunition. The supply of ammunition of the shore gun is naturally kept up more readily than that of the gun afloat.

(4) Visibility of Target. So long as a ship is within the horizon it cannot conceal itself except by means of a smoke screen. This latter has disadvantages from the point of view of offensive action from the ship. A shore gun on the contrary can be rendered very inconspicuous, and in many cases may be invisible from the sea behind a fold of the ground, using indirect fire.

(5) Target. Apart Irom the visibility of the respective targets their vulnerability differs. It is not difficult to design a shore bat- tery so that only a direct hit on the gun itself will put it out of action, all other parts of the battery being fully protected. At Tsingtao on Oct. 29 1914 ten large shell from H.M.S. " Triumph " were observed to burst just inside Fort Iltis, but none of the guns of the fort were damaged. With the ship, on the contrary, there are many parts, other than the guns, damage to which would mate- rially affect its fighting efficiency. Examples of this occurred on March 18 1915 in the Dardanelles.

To a certain extent these unequal conditions have always existed, but when they are examined it will be seen that the increase of power of artillery and improved methods of range- finding tend to put the ship's guns more and more at a dis- advantage. When the effective range of artillery was about 1,000 yd. it was very difficult to make anything inconspicuous on shore, and range-finding instruments did not exist at that time. In these days of ranges of 30,000 yd. and more, shore guns become practically invisible from a ship even if they are in direct view from the sea, and range-finders may be situated several miles away from the guns they serve and give no indi- cation of their presence. It is true that with modern ranges it cannot be expected that shooting can be very constant; there are too many factors to prevent it. But this fact is at least as disadvantageous to the naval gun as to its rival on shore. Guns are not mathematical instruments. Their shooting powers are affected by very slight variations of propellant charge in quality and in quantity, of weight of projectile, of the amount by which the latter is rammed home in the bore, and by the wear of the gun itself, not to speak of change of atmospheric conditions and wind. The Battle of Jutland brought out the fact that a large number of shell are required even to hit a ship, and still more would be needed to hit such a target as a shore gun.

In one other point also modern ships are at a greater dis- advantage than their predecessors in a contest against shore batteries in the fact that they possess a smaller number of guns. If it be granted that a direct hit is necessary to put a shore gun out of action then the more guns which are available to fire at it the greater the chance of hitting. During the World War a number of British monitors were built and used for bombarding

the German batteries on the Belgian coast. While they possessed many advantages in their design which tended to render them less vulnerable, they had the grave disadvantage of an arma ment small in number.

Except in special cases ships are built to fight other ships and not to fight coast batteries, and it would seem to be admitted now that naval fire can never be effective against such small targets, and that it is better to reserve it, in action against the shore, for firing upon areas such as docks or dockyards.

If a fleet was determined, regardless of loss, to come to really close quarters with coast defences, some of the advantages of the shore gun would undoubtedly be minimized. But the superiority of the land range-finder would render such an operation in day-time extremely hazardous to the fleet, apart from any action by submarines-on the part of the defender, while at night it is difficult to see what object could be attained, apart from such a special attack as was carried out at Zeebrugge.

Very many actions have been fought between ships and batter- ies, and a lew of the most instructive may be mentioned here.

At Eckernforde in April 1849 a Danish fleet consisting of one battleship, three lighter vessels and two steam gunboats attacked the Prussfan defences, which comprised two batteries containing two 8-in. guns, two 24-prs. and six l8-prs., assisted by one field battery and three battalions of infantry. The batteries were near the water's edge on low sites. After a long action at short ranges, the battleship and one frigate surrendered and the remaining ships retired, all having suffered severely. The casualties in the batteries were one gun temporarily disabled and ten men.

One of the most instructive instances in the past was the naval attack on Sevastopol in 1854. There the British in-shore squadron of five large ships engaged three works Fort Constantine, a large masonry-casemated fort with barbette guns on the top, which rose from the sea at the mouth of the harbour; a small brick fort called the Wasp battery, on a cliff 1 10 ft. high ; and the Telegraph battery, an earthen one on the same cliff, the two latter works having five guns each on the sea front.

From a range of 800 yd. 22 out of the 27 barbette guns of Fort Constantine were silenced in a very short time by the fire of three ships, the splinters from the stone walls causing a great deal of damage. But the other two batteries caused the retirement of the whole squadron with considerable loss, while they themselves suffered very little, the Wasp battery having one gun upset and 22 men wounded while the Telegraph sustained no loss at all.

In the action at Alexandria in 1882 the conditions were almost wholly in favour of the ships, namely, smooth water, works not only on very low sites close to the water but badly designed, a poor armament and inexpert gunners; yet the shooting of the ships had little real effect, and against better troops the fleet would hardly have gained its object. This was due, no doubt, principally to the nature of the naval armament, which consisted to a very large extent of slow-shooting heavy guns, few in number, while the shore guns were well dispersed.

When the World War began it was sometimes argued, as it had been argued in past periods, that present-day naval artillery is so powerful that it would reverse the lessons of the past. But the experiences of the war have only emphasized those of its predecessors.

A long series of engagements took place between British ships and the batteries erected by the Germans on the Belgian coast. The number of these actions was at least 40, and yet no gun, mount- ing or magazine of the'se numerous batteries was ever hit.

In the naval operations in the Dardanelles, on March 18 1915, a deliberate attack was made on the main batteries of the defence near the Narrows by 1 6 battleships, at the comparatively short ranges of from 10,000 to 14,000 yards. The Turkish batteries and guns were old, the works were badly sited, as a rule close to the water, and their high traverses rendered them very conspicuous. At the end of the day three battleships had been sunk by mines and three others so badly damaged by shell-fire as to necessitate immediate withdrawal to a dockyard.

The damage to the batteries was very small. For instance, the old Hamidie I. battery near Chanak, which contained three 14-in. and six g-2-in. guns, had one of the latter put out of action and suffered some losses in its garrison. A war-time battery of five 6-in. guns at Dardanos, near the top of a conspicuous hill some 150 ft. high, received a large amount of attention, but the only result was that three gun-shields were dented by splinters.

A general summary having been given of the conditions of the combat between ships and shore batteries in the past, the point next to be considered is what are the objects to be attained by coast defences to-day.

In order that the navy shall be free to carry out its true func- tion of attacking the enemy's naval forces and keeping clear the ocean lines of communication of the country, it must not be