A glance at Chart F [Transcriber’s note:  Not preserved in book.] will show how widely separated are these objectives and how impossible it was for the small Dover force to defend them all simultaneously, especially during the hours of darkness.  Any such attempt would have led to a dispersion of force which would have been criminal.  The distance from Dunkirk along the French coast to Calais, thence to Dover and along the English coast to the North Foreland is 60 miles.  The distance at which an enemy destroyer can be seen at night is about a quarter of a mile, and the enemy could select any point of the 60 miles for attack, or could vary the scene of operations by bombarding Lowestoft or towns in the vicinity, which were only 80 miles from Zeebrugge and equally vulnerable to attack, since the enemy’s destroyers could leave their base before dark, carry out their hurried bombardment, and return before daylight.  In whatever quarter he attacked he could be certain of great local superiority of force, although, of course, he knew full well that the first sign of an attack would be a signal to our forces to try to cut him off from his bases.  Therein lay the reason for the tip-and-run nature of the raids, which lasted for a few minutes only.  The enemy realized that we should endeavour to intercept his force as soon as it had disclosed its presence.  The Germans had naturally to take the risk of encountering our vessels on the way to his objectives, but at night this risk was but slight.

As it was obviously impossible to prevent bombardments by stationing destroyers in adequate force for the protection of each town, the only possible alternative, unless such bombardments were ignored, was to give the most vulnerable points protection by artillery mounted on shore.  This was a War Office, not an Admiralty, responsibility; but as the War Office had not the means available, the Admiralty decided to take the matter in hand, and in the spring of 1917 some 6-inch naval guns taken from our reserves were mounted in the vicinity of the North Foreland.  Further, an old monitor, which was of no use for other work owing to her machinery being unfit, was moored to the southward of Ramsgate, and her guns commanded the Downs.  Searchlights were also mounted on shore, but more reliance was placed on the use of star shells, of which the earliest supplies were sent to these guns.  The result was immediately apparent.  German destroyers appeared one night later on off the North Foreland and opened fire, which was returned by the monitor and the shore guns.  The enemy immediately withdrew, and never appeared again in 1917 in this neighbourhood.