s and shrinks, middle grounds obstruct it, and shelving
foreshores persistently deny it that easy access to the land that
alone can create great seaboard cities. All the ports of the Ems are
tidal; the harbour of Delfzyl, on the Dutch side, dries at low water,
and Emden, the principal German port, can only be reached by a lock
and a mile of canal.

But this depreciation is only relative. Judged on its merits, and not
by the standard of the Elbe, it is a very important river. Emden is a
flourishing and growing port. For shallow craft the stream is
navigable far into the interior, where, aided by tributaries and
allied canals (notably the connection with the Rhine at Dortmund,
then approaching completion), it taps the resources of a great area.
Strategically there was still less reason for underrating it. It is
one of the great maritime gates of Germany; and it is the westernmost
gate, the nearest to Great Britain and France, contiguous to Holland.
Its great forked delta presents two yawning breaches in that singular
rampart of islets and shoals which masks the German seaboard--a
seaboard itself so short in proportion to the empire's bulk, that, as
Davies used to say, every inch of it must be important'. Warships
could force these breaches, and so threaten the mainland at one of
its few vulnerable points. Quay accommodation is no object to such
visitors; intricate navigation no deterrent. Even the heaviest
battleships could approach within striking distance of the land,
while cruisers and military transports could penetrate to the level
of Emden itself. Emden, as Davies had often pointed out, is connected
by canal with Wilhelmshaven on the Jade, a strategic canal, designed
to carry gunboats as well as merchandise.

Now Memmert was part of the outer rampart; its tapering sickle of sand
directly commanded the eastern breach; it _must_ be connected with the
defence of this breach. No more admirable base could be imagined;
self-contained and isolated, yet sheltered, accessible--better than
Juist and Borkum. And supposing it were desired to shroud the nature of
the work in absolute secrecy, what a pretext lay to hand in the wreck
and its buried bullion, which lay in the offing opposite the fairway!

On Memmert was the depot for the salvage operations. Salvage work,
with its dredging and diving, offered precisely the disguise that was
needed. It was submarine, and so are some of the most important
defences of ports, mines, a